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# Charles Elachi

Charles Elachi

### Former Director of the Jet Propulsion Lab

By David Zierler, Director of the Caltech Heritage Project

September 21, 30, and October 5, 7, 15, 22, 27, 2021

DAVID ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It is Tuesday, September 21st, 2021. I am delighted to be here with Professor Charles Elachi. Charles, thank you so much for joining me today.

CHARLES ELACHI: Sure. It's my pleasure—my pleasure.

ZIERLER: Charles, to start at the most basic level, your name. So, for a genealogist who might not know you personally, but understands these things, what does the name "Elachi" tell us about your family heritage, where they're from, the language and religion they have, and the cultural practices that they have?

ELACHI: Well, I was born in Lebanon, so the name "Elachi" is a Middle Eastern name, and in actuality, literally means "cook," like Captain Cook. So, I tell people usually—I mean, humorously—that I'm related to Captain Cook.

ZIERLER: [laugh]

ELACHI: But I was—I grew up in the Middle East.

ZIERLER: [laugh]

ELACHI: My family, is all from Lebanon, and from Syria. In fact, my mother is from Damascus, and my father is from Lebanon. My father's family is long traditional Lebanese because our ancestors come from a small village in the mountains of Lebanon. And in that village—not where I grew up but another village where my father came from—there are lots of Elachi families, cousins, faraway cousins. So, it really is a very traditional Lebanese family.

And being in Lebanon, I mean, I used to speak Arabic, but, also, Lebanon had a lot of French influence because between—not only between the two World Wars, when it was a Frenchsp protectorate. But for many centuries before that, the French were—had lots of influence in Lebanon because Lebanon was mostly a Christian country in a region which is mostly Muslim, and the French had a lot of missionaries in Lebanon. Most of the schools when I grew up were French schools, run by nuns and priests. So, French was also very common. Matter of fact, when we speak in Lebanon, it's a mixture of Lebanese and French, even in the regular—and almost everybody speaks French or knows, knows French.

And then English and German were also somewhat common because there were—particularly like the American University in Beirut was founded by American missionaries from Princeton University. And it has lots of connections still with Princeton and the state of New York. That was the main university of the Middle East, so there were also a lot of people who speak English, in that region.

ZIERLER: And what might we know about the name Elachi in terms of the religion affiliated with that name?

ELACHI: Yeah, as Lebanon is a mixture, about 50% Christian, 50%, Muslims. And in the Christian part, there are many sects, in the Middle East. So, my religion or my sect was what's called Maronite, and that's a sect which is kind of unique to the Middle East, but, also, it's part of the Catholic Church. So, the head of the Maronite church is also a cardinal, in Rome. And there are a number of Middle Eastern, Catholic or Middle Eastern Orthodox.

And then on the Muslim side, there are Sunnis and Shiites and then the rest. So, the aspect of it, the reason I'm explaining that a little bit, is, for us, it was very common to have people from different religion. And that was not an issue. I mean, we kind of knew different people who are from different religion. But some people, we didn't even know what religion, they were from.

Like, when I went to middle school and beginning of high school, I was in a boarding school which was run by priests, and we used to go to church every morning, because it was a boarding school, and it was priests. And there were a number of Muslims, in there because many Muslim families sent their family to schools run by priests because they were some of the best schools, in Lebanon. So, for us, religion was not an issue. We were familiar with that.

We were—that was not—I have many friends who are, who are Muslims. Even I had a friend early before there was a lot of immigration out of Lebanon who were Jewish. Matter of fact, they were some of the main traders in Beirut in the '50s and early '60s. So, one of the things which I kind of like about Lebanon is there was lots of tolerance, for religion. People from different religions worked together, and there was really no issue. Now, there was not very much intermarriage, but there were some, in that way.

ZIERLER: And, Charles, what about your first name? Was that your birth name, or did you take that on later?

ELACHI: No, that's my birth name, Charles. And it's interesting because most of the Christians, they have Christian names after saint names. And one thing which is interesting is when I was a kid, there is a tradition in Lebanon that everybody has a saint which is kind of their protector. And in our case, immediately next to our house there was a Church of Saint Anthony.

So, my protector, if you want, was Anthony. So, when I was a kid, they used to call me Anthony or Tony for that. Matter of fact, I didn't know that my name is Charles until I went to boarding school, and my parents had to register me. And I was looking, and say why did they put the name "Charles" in there?

ZIERLER: [laugh]

ELACHI: Because everybody was calling me Anthony, my nickname, named after the saint of the Maronite Church. So, that was kind of interesting. Even my younger brother, now who lives here in Pasadena, when we are talking, he called me Tony [laugh] instead of Charles because that's how we grew up, doing that.

ZIERLER: And in naming you Charles, would that be more of an Anglophone or a Francophone influence from your parents?

ELACHI: No, that was mostly because of the Francophone. And part of it is that my father used to be the director of the train station which was in our town, and the train company was a French company. So, all the interactions that my dad used to do, for his business was all in French. And at home, we used to talk always French and Arabic, and in school, we would study French. So, it's really a Francophone kind of thing.

ZIERLER: Charles, your background is a cornucopia of diversity of languages, of nationalities, of religions. Very broadly, in light of all of your scientific and engineering accomplishments, and your administrative leadership, what do you see as the value of having all of these influences even from the very beginning of your life?

ELACHI: Oh, that's a very good, question because I really believe the diversity of thought, background, religion, I think really enriches an organization. And that was something I used to emphasize when I was a director at JPL, that here in the United States, the reason the country is so great and so prosperous is because of the diversity of the immigrant who came here. They brought different ideas, different religion, different thought, even that we kept—many people kept the tradition of their country of origin.

And for the overall majority in the US—I cannot speak for everybody—people, enjoy that and value it. You go to Vietnamese restaurants, Chinese restaurants, Turkish restaurants, and you celebrate some of the traditions, but we're all Americans. And that, I think, enriches the United States, both intellectually and personally. And you look at here at Caltech, a very large percentage of the faculty and the students either were not born here or they—their parents immigrated, to Caltech. And that—a lot—there are a lot of relationships internationally.

in the early days, there was a lot of German, influence. And after that, there was a lot of French influence. the previous president of Caltech was French or was born, in France, and educated here. And many of my colleagues come from all around the world. And when we get together, we don't ask, "Where are you from?" [laugh]

Now, every once in a while, people, because of my accent, they say, "Oh, you have a funny accent, you know. Where are you from?" [laugh] Or they see my last name, and say, "Oh, are you Italian?" So, I tell them, "Well, not exactly. We are from the same base in the Mediterranean Basin, but not Italy."

ZIERLER: But you can say you're Tony. [laugh]

ELACHI: That's right. [laugh] But I tell them that 2,000 years ago, the Romans were all over the Mediterranean, so—

ZIERLER: Yes.

ELACHI: —I have maybe a little bit of Italian blood in me. [laugh]

ZIERLER: [laugh] Charles, I asked about your name. On a more official level, please tell me your title and institutional affiliation.

ELACHI: Well, at the present time, I'm faculty at Caltech, and I was faculty for many, many years. But during most of my career, I spent—split my time between Caltech and JPL, which is managed by Caltech. And JPL is a NASA facility, owned by NASA, but it's managed by Caltech, so all the employees are Caltech employees. And all the directors at JPL were Caltech, faculty.

So, I spent most of my career or almost all my career at JPL since I was a student, and then I was director of JPL from 2001 to 2016. And in 2016, I was getting a little bit kind of older, a little bit [laugh] or more mature, like I like to say. So, I decided it was time to have a younger person, or some new blood run JPL, so I came back to Caltech as a faculty. So, now, I do mostly research, at Caltech with many postdocs and graduate students.

ZIERLER: Now, the title professor of electrical engineering and planetary science, that suggests an affiliation with two divisions at Caltech. What is your home division?

ELACHI: Well, I got my degree in electrical engineering, so when I came as a student to Caltech in the late '60s, early '70s, I did my PhD in electrical engineering and applied physics. So, that was my original home. But then, as I did more work at JPL, I became very closely working with planetary scientists and geologists. So, when I retired from JPL, both departments, the geology and planetary science department, and the electrical engineering department, they both wanted me to be associated with their divisions.

So, to tell you the story, I said, whoever gives me a better office, that's where I will go. Well, then, both of them gave me very nice office, so I decided to be both places. [laugh] So, sometimes, there are a practical reason, between the two. But I have colleagues in both, and colleagues in other departments. That's the beauty about Caltech.

ZIERLER: Yes.

ELACHI: It's a relatively small university, which allows faculty and student from many departments, to work together and to jointly do joint projects. I would say, over my career, I probably knew and probably presently now I know at least two-thirds of the faculty individually. I mean that I know them by name and so on. And I do a number of collaborations with the aerospace department, with the mechanical engineering department, with the physics and plan…and astronomy, departments. So, for us, really, it doesn't really matter, what our—what depart…and I think almost the majority of my colleagues feel about the same.

ZIERLER: Maybe a more precise way of asking that is which division chair to you report to?

ELACHI: [laugh] I'm not sure. I report to both of them.

ZIERLER: Oh, you do? OK. [laugh]

ELACHI: That's right. So, when we submit proposals, it has to go and get approval of the division chairs, so it goes to both division chairs because of my dual association. But, again, the process is—because it's so common that there are many faculty which have joint appointments—it's pretty transparent here at Caltech.

ZIERLER: And what year did you go emeritus, Charles?

ELACHI: As soon as I came back from JPL. That was in 2016. So, I decided to go emeritus for a couple of reasons. One is because there are a limited number of tenured slots, in each department. So, I decided I'll go emeritus so that will open my slot to bring a young faculty, here at—and, for me, it didn't really matter because most of my funding comes from my grants that I receive.

Going emeritus, which means Caltech doesn't pay me anything from the Caltech endowment, but that didn't make any difference to me because I have a lot of grants from NASA, international grants. So, I bring in a fair amount of funding, and I get paid from my grants. So, it really was the same from my perspective.

ZIERLER: And, of course, emeritus does not mean being retired and going fishing. [laugh]

ELACHI: That's right. That was one concern I had that people will think, well, he's retired. But I tell people when they ask me, I tell them, "Well, I moved from working 70 hours a week at JPL to working 40 hours a week at Caltech." [laugh]

ZIERLER: Like a mere mortal now. [laugh]

ELACHI: [laugh]

ZIERLER: Charles, in terms of your intellectual tradition and your approach, fundamentally, you're an electrical engineer. That's your home discipline where you start from.

ELACHI: Yeah. No, that's how I started, and that was all my background and my undergraduate, and then when I did my PhD and in my career. So, when I started, at JPL, I was most working with what we call radar, a satellite radar instrument, which basically are radars which can map the surface, and get images similar to photography, but with the technique called Synthetic Aperture Radar, which enable us to do that.

So, as I was started working on that, I started working with geologists and planetary scientists because some of the purpose was actually take photographs or take images of our planet. So, I used to go on field trip with some of my geologist colleagues, and I said, "Wow, that's pretty cool. I can go camping and get paid for it to do that." And I used to love the outdoor, and I still love the outdoor a lot. So, I decided to go back and get a master's degree in geology.

So, I went to UCLA part-time over three years, and I got a degree in geology and planetary science at UCLA. Now, so, I'm very comfortable in being both planetary scientist and electrical engineering. And at JPL, because most of our missions are toward the planets as well as Earth's orbiting, so that helped me a lot to be basically have one foot in the engineering side, and one foot in the geology planetary science side. So, there was a benefit, both a benefit, but also intellectually, it was exciting for me to be in both areas.

ZIERLER: Now, even at a more fundamental level, there's the engineering, and then there's the science. For you and for the research that's most important to you, where are you a scientist, and where are you an engineer?

ELACHI: Well, I would say I'm across the board in doing that. For me, the two don't make any difference. Engineering is you're actually building things, which I would call, the thing that scientists think about, the engineers go and build them. Scientists are the people who are thinking about, new theories, new concepts.

So, the two are completely—for me, it's a continuum between the—matter of fact, the class I used to teach is called physics of remote sensing. And it was both a joint EE, geology or planetary, course. And the students that I had came from both departments, and it was because, to me, make a little bit my career, I used to tell them it's very important for the geology and planetary scientist to understand the engineering of the instrument that they do, and for the engineer to understand their instrument is going to be used by who.

So, to be able to understand the purpose of what you are doing, that will allow you to do a better engineering design. And vice versa, for the scientist to understand the capability of engineering will allow them to come with concepts, engineering concept, and then work with the engineers. So, the same thing at JPL, on our project, we had a mixture of engineers who was a builder and scientist who were kind of planning, the mission.

And at the end, are the users, that—so, for me, I don't even think of myself as being—usually, I think of myself as an explorer. I'm exploring both engineering and science. And the same thing when I was a director of JPL, people used to ask me, "How many employees do you have? And how many engineers"—we have 7,000 explorers.

ZIERLER: [laugh]

ELACHI: we classify people as engineers or scientists.

ZIERLER: And, of course, being an explorer puts you in good company with Captain Cook. [laugh]

ELACHI: [laugh] That's—I never thought about that! But I'm glad I survived. I didn't get killed—

ZIERLER: [laugh]

ELACHI: —when I was in my village. [laugh]

ZIERLER: Charles, I asked you about that in your role of the research. Where do you see the value in being both a scientist and engineer as an administrative leader in your tenure at JPL? Where did that serve as a value?

ELACHI: Well, it clearly—particularly for a place like JPL, which is really the premier institution around the world in exploring the planet and exploring our own planet and doing astronomy, having a strong both engineering and scientific background is very important, even that the function was mostly administrative. But part of that function was to advocate for future missions, with NASA and with government, and therefore having scientific and engineering credibility carried a lot of weight, in doing that. And, also, when dealing with people in Congress, I had to explain to them why it is important for the United States government to invest billions of dollars, in NASA mission. So, I had to explain to them both the scientific aspect in simple terms, for a congressman.

But also, for them, credibility was very important, that this person really knows, what he's talking about. And then internally at JPL, one of the key roles of the director of JPL was to basically oversee the missions, and make sure that we're doing the right thing. So, when I used to meet with the project managers and the project team, which were all engineers and scientists, it was very important for me to understand what they are doing, even though I was not expert in everything, but to understand what they are doing.

And it was important for them to see that their leader really has technical credibility. And I think my background, because the first, I would say, 25, 30 years at JPL, I was mostly doing research, and I published, hundreds of papers. I published half a dozen books. By the age I was 40, I was member of the National Academy of Engineering.

So, that carried a fair amount of importance for the employees to look at their leader, that's somebody who really understands what he's talking about. And that allowed me to also ask the right question, even that I was not the expert. But I have enough engineering and scientific sense that I was able to ask, the right question.

So, having that technical scientific background, I think, is essential for the leadership of JPL. And that's why almost all the directors of JPL, matter of fact all of them through their history, had PhDs from—not necessarily from Caltech, but many of them are from Caltech, but they were also faculty at Caltech, and had PhDs from other locations. So, that is essential in the leadership of a place like JPL.

I mean, it's different than a company. A company, one element of it is to go make profit for the a stockholder. For us, we didn't make profit. I mean, our purpose was to do the right thing, for our country and for NASA. And the stockholder was NASA, and NASA was mostly engineers, and scientists, in there. So, for that kind of function and position, that technical background, in my mind, is essential.

ZIERLER: Charles, this question will ask you to survey all of your research throughout your career in terms of your motivations on taking on any particular project. And that is, for you, when are the questions about the basic research, just understanding how things work, and when is it about applying that basic science toward a specific goal?

ELACHI: Sure. Well, since I was young, I was always fascinated by space and by, the stars. And I remember very clearly when I was like 11 years old, that's when Sputnik was launched. And I remember sitting down listening to the radio. We didn't have TV at that time, but they had a little portable radio. And they reported about Sputnik, and they reported about—and I could hear the beep.

And I think, wow, this is fascinating, you know. We actually can fly in space. I mean, that was a big deal, at that time. And then shortly after, I heard that the US launched a satellite called Explorer, in fact—sorry, 90 days later from a place called JPL. I never had a real idea that I'd be working with the director of JPL. So, from that stage, I was fascinated by the engineering aspect, of how did this work, how satellite work.

But, also at the same time, I was a very curious kid. I was always fascinated by natural things. Like, I was fascinated by flowers. Why is one of them red, and one of them is yellow, and how do they grow? We had a garden. So, I was fascinated by scientific aspect of how this world actually function.

So, as I went up through my career, I was both excited about the technical aspect of things but also the scientific aspects of things. So, in my career, for me, the technical or the engineering part is a tool to achieve a scientific thing. So, for me, it kind of moves, kind of in a continuum, between the two. So, in a sense, I live in both worlds, so I never think about when do I transition? I think scientifically, like in the planetary area, what would be an exciting thing if we want to explore, let's say, the oceans on Europa? Scientifically, that's very important because, these oceans might have life in them.

But then what's engineering? How engineering-wise can we get to those oceans? So, then, I have to transition my thinking from the scientific aspect of drilling through the ice on Europa, and getting to that ocean, to the aspect of technically how do you do that?

So, I have to sit with my engineering colleague, and say, "How can we land on a place on Europa, and can we drill through that ice, if it's many hundreds of feet? And can we get a submarine down in that ice? And what would that submarine look like? What kind of instrument would we use?"

That takes me back to my science of thinking about, OK, for measuring the composition, what kind of mass spectrometer do we need, which operate in that kind of environment? So, for me, the transition between my engineering research and my scientific research was kind of almost—and, really, honestly, I never thought about it, between the two. And most of my public…I mean, I had some publication which were purely engineering, looking at wave—electromagnetic wave propagation. That was my PhD topic about wave propagation in periodic medium.

In the early days, I worked on—I published a number of papers about the theory of wave propagation, which have led to applications like lasers but for distributed feedback lasers, which are lasers in gratings. So, these were purely, if you want, engineering. But then after that, overwhelming majority of my publication were on how scientifically we can use this imaging radar that I worked on?

And, like, as an example, one of the early things we did when we were developing the radar, and we started flying it first on airplanes and then on satellites, we saw that we actually can map the waves in the ocean and see actually all the waves. And one key question was, why do we see them? how—what is the mechanism, the scientific mechanism, which allows us to image those waves?

So, I developed a theory of actually the ocean waves or properties, how they are up. Like, if you go surfing, you see the crest of the wave is rougher than the bottom of the wave, and that allows a different kind of scattering, for the radar. And, so, I developed a scientific theory, and I published a paper on the reason we image the wave because of these little roughnesses that you will see at the top of the wave, at the crest of the wave, versus the trough of the wave.

So, for me, almost—and I had many publications in geology, planetary science, so almost all my papers basically were both on engineering and scientific. And, for me, it was the same. I really never thought of myself one side or the other side.

ZIERLER: Charles, what about the role of theory in your research, in other words, where you establish a problem or a challenge, and you look at the theoretical basis for where you end up going, and then you get there, either scientifically or from an engineering perspective? What have been the most important theoretical propositions in your career?

ELACHI: Well, it's a—as I mentioned, because I work mostly in wave propagation, those were lots of theories, which I had to develop for how the wave actually propagated periodic medias, and develop the Maxwell equations, for that kind of place. And one thing which I remember very clearly from my PhD advisor—his name was Charlie Papas—so, I used to go and, say, develop the theories and all the equations. I used to go to him and go on the board, and write all these equations, and he used to—now, he always had a pipe. He was kind of a very gentleman kind of a person. And then at the end, I come to a conclusion.

And he kept always telling me, "Charles, now, independent of all these equations, does the answer makes sense? does it make physical sense? Does it make scientific sense?" So, for him, the theory was the question of, yes, you need the equations to develop the concept, and quantify it. But does it make physical sense? Does it make theoretical sense?

And that's something I carried always, when I was working with my colleagues at JPL. After they do all kinds of thing, say, "Does this make sense? theoretically, does that fit in what nature tells us, on these things?" And that was kind of the concept I always followed, in developing the theory. And many—and you go back in history for the famous scientist, many of them was basically on intellectual ideas, you know.

Einstein didn't go through 500 equations to come with E = MC2, and relativity. He's just, watching the elevator and watching being in a train. He kind of came with the concept of how things are when you are moving or doing them. And many also about the particles, how we develop the atoms, and the neutron. And many of them came from just thinking intellectually about these things. And, of course, an observation and equations verified some of these things.

So, a lot of the theoretical things some time come from deep thinking, and then you go and verify them with equation or observation. The same thing, you look in astronomy. The whole idea of the Big Bang, and the expansion of the universe, it was a combination of observation and thinking theoretically, are these possible? how does gravity impact them? How does, like, dark energy and dark matter, this—they didn't pop up in an equation that there is dark energy or dark matter, but they came from people thinking about it. And looking into the equations, they were able to scale them or formulate them.

So, in my thinking, yeah, I start thinking about theoretically—I mean, it's not fundamental theory because that's not my field, fundamental elementary particles. But, like, one of the things we were thinking about as I was developing radar instruments, I said, "we use coherent waves. We should be able to do interferometry like we do in Fresnel interferometry. So, if you have two holes"—I remember, I mean, from my physics class— "and then you shine laser lights where you see fringes."

So, I went, if I have two antennas which would simulate having two holes, I should be able to see fringes on the surface, in the images. And if I see fringes, and if the surface has topography in it, the fringes should follow the topography. Ah, I might be able to do a topographic map, out of this thing. So, I went and worked with some colleagues about the theory of how we do that, and then we came to the conclusion that, yeah, we can generate topographic map, if we can fly a radar with two antennas.

So, that led to an experiment on the space shuttle, which we call SRTM for Shuttle Radar Topography Mission, which we launched in the late '90s, early 2000s, where we flew a radar inside the shuttle, and we had a boom about 100 feet long, and we had a second antenna on the other end. And then when we processed the data, we were able to digitally generate topographic map worldwide. So, that revolutionized how we do topography because, before, topography used to be done by taking stereo images. You look into a stereo machine. You do controls by hand.

That's probably the map you used when you were hiking, a long time ago. And here in 12 days, which was the shuttle mission, we were able to generate topographic map immediately digitally, and basically replaced the traditional way, which required thousands of people sitting down, doing control map. So, that came from a theoretical concept, thinking about it that would lead us to a practical engineering concept, which revolutionized how we do topography.

So, today, when you see all these 3D images, when you see weather maps and when you see that you use when you are driving and so on, they were all generated from that mission that we developed. And it came up from just an idea, which traces its background to the class in Fresnel fringes, which was in a completely different area that it was in laser and optics, which translated to developing this technique. So, that's one example where a theoretical concept that can mature, and then lead to an engineering concept, then in an application, and then something that everybody uses now.

ZIERLER: Charles, I'd like to ask some very broad questions about your career in planetary science. So, first, because you have studied the planets in our solar system, including Earth, and many times using the same techniques, when do you treat Earth like any other planet, and when is that impossible just because this is our home, and we can't be disconnected from it?

ELACHI: Now, that's really very interesting. When I did my PhD at Caltech, as I mentioned, I did it in electromagnetic theory, and I started working in the summer at JPL. And then when I got my PhD, I was asked, "Hey, would you like to come and be—work here full-time?" And I said, "Sure, that sounds like a great place to work."

So, the first assignment I got working at JPL was to look at the possibility of putting in imaging radar—because that was my background—in orbit around Venus because Venus was completely cloud-covered. We couldn't see the surface. There were missions which flew by Venus. And the only way you can see the surface is by using radar techniques, imaging radar techniques, because the microwave can penetrate through the cloud. It doesn't matter if it's cloudy or not. It doesn't matter it's illuminated or not because the signal is being generated on the satellite and transmitted.

Similar to your radio, it doesn't matter if it's bad weather or good weather, if it's clear—or your TV—it's clear or cloudy, or if it's morning or night, you still get, transmission, to your TV. So, that was my introduction to Planet Earth, because I worked on that mission, so, I mean, or defining, that mission. And then it took a while to convince NASA, to do that mission. Matter of fact, I started at JPL in '71. The mission occurred in the mid-80s.

When, in the meantime, there was some thought in the early days, maybe we can apply NASA technology to all other missions. So, JPL, convinced NASA to do a mission called Seasat. And the intent of that mission was to image the oceans and study the oceans. So, we had an estimator to do the ocean topography, a scatterometer to do the wind measurement.

But then because of our background in radar imaging, and because, as I mentioned, when we did an airborne flight, we actually saw waves on the images, we started advocating to NASA, "How about if we put an imaging radar in? By the way, we have experience because we have studied, the Venus mission and an Earth-orbiting mission, and that could have, application." And there were some were done on airborne at that time.

So, we were able to convince NASA, and that led to a satellite called Seasat, which was launched in 1978 before the Venus mission. So, I got involved in that one because of my background, in the radar. And by then, I had been at JPL for eight years. And because I was the only person who really understood the theory of wave propagation, I was asked to form a science group. Most of the work was done by engineers.

So, they asked me, "Hey, Charles, why don't you form a science group, and hire some geologists and oceanographers?" So, I was the head of the science group which does interpretation of the scientific data. So, for—so that's when we started doing Earth. So, for us, it was almost the same, because we studied Venus. We applied the same technique on Earth.

And then shortly after that, in the early '80s—as a matter of fact, in the late—'71, we were still working on Seasat building the instrument. That was there when the shuttle was being developed, and NASA was planning to do, first, four shuttle flights with no payload in them just to test the engine, to test environment of the shuttle—purely an engineering flight. And then somebody came with this idea at NASA, and said, "maybe we should put some instrument in there, and we'll put some high-risk instrument. If they work, it's great. If they don't work, that's fine also."

So, they made an announcement nationwide about anybody who has any good ideas. So, I was a young and aggressive, thinking out of the box, so I said, "Ah, let's put a proposal. There's going to be some hardware left from Seasat. We can put it in the shuttle and do geologic mapping."

So, me and a group of my— in my group, we were all in our late 20s. We put in a proposal to NASA and, guess what, it got accepted. So, here we were, a bunch of 20-years-old kids with limited experience, I would say, but there were a few experienced people working with us, responsible for the first experiment ever to be flown on the shuttle. So, anyway, we started developing it. We were told it's high risk.

So, we didn't have all the paperwork which is normally required for a mission at NASA until about a month before the launch. The director at JPL at that time was Bruce Murray, who was a professor from Caltech, called me to his office, and I knew him as a professor. He said, "Charles, I just got a call from the NASA administrator. And he said, this flight is very important because it's going to show the value of the shuttle. We spent billions of dollars on the shuttle, and we've got some NASA administrator speaking"—his name was Jim Beggs.

And Congress always asked me, "How is it going to be useful for us? And this is the first experiment, and it better work." So, here I was, like, gee, we were told this is a big risk, you know. If it work, it's fine; doesn't work, it's fine. And now we're on the front seat, on the hot seat, for NASA.

Fortunately, it worked, and that was a big hit. We got some really exciting data. They made the cover of Science magazine, National Geographic. so, it was all over because one of the things we discovered on that flight, we did images over North Africa. And when we looked at the images, we saw all kinds of rivers or riverbeds. And we said, wow, there are no rivers inside North Africa, in Egypt.

And, so, long story short, what it turned out to be is because we were using microwaves, we were actually penetrating through the sand, and imaging the drainage channels of river which existed thousands of years ago, which are covered by many meters of sand. But the radar was able to penetrate through that and image the bedrock under the sand. So, that was a big deal for archeologists because that allowed them—and anthropologists—that allowed them to trace all the rivers which existed five, six thousand years ago. And that was, for them, that was the place where trade routes used to be, and there were many archeological expeditions, and I participated in some of them.

So, that was the excitement about doing it on Earth, and that led, after, to many shuttle missions, where we did multispectral radar. And then it led to combining the radar and but with imaging system, infrared, and visible—and that's part of the reason why I did my teaching on physics of remote sensing for 20 years, where I basically covered not only radar, which was my expertise, but also imaging systems, imaging spectrometers, all the—across the spectrum, how do we use remote sensing from satellites to learn about our planet and then about [other] planets? And then, after all of this, then the Venus mission happened, so that was in the late '80s.

And then there was another mission, which was Cassini, where they needed to image Titan. Titan was also all cloud-covered, so I phoned the team, and proposed to do the same techniques we were using on Earth to be able to image through the clouds on Titan, and that flew about 14 years ago. I mean, we got to Saturn 14 years ago. The mission lasted 13 years. It just finished about two years ago.

And that allowed us to discover all kind of things on Titan: that there are lakes, that there are rivers—actual lakes, I mean, today's lakes. Not made from water, but—because it's too cold—but made from methane and ethane on the surface. So, that showed—and interpreting that data, we relied a lot on our experience on Earth because on Earth, we got the images. Until you can go to the field and see, what am I seeing here? What are these different features?

Matter of fact, part of my class during the spring break, working with a professor in geology by the name of Arden Albee, we used to take the students to Death Valley and the field, and take the images, both radar, visible infrared, and basically compare the geology to what we are seeing on the satellite. So, in a sense, in addition to the benefit for Earth by using this satellite, doing global mapping, it was a test bed for us, or it was a lab to be able then to interpret the Venus data and the Titan data that we acquired.

ZIERLER: Charles, I asked you to compare studying the Earth with other planets in our solar system. What about taking all of the knowledge that we've learned in our solar system, and applying that to the next chapter, and that is exoplanets? What have we learned about our solar system, and how can we extrapolate that to ask the right questions about where to look, how to look, and what to do with the data we find in this new, exciting field?

ELACHI: Now, exoplanets is a fascinating field. I remember about 30 years ago, people started thinking, I mean, other—I mean, we always thought about other planets, but we had no verification of it. So, about 30 years ago, I was asked—at that time, I was not yet the director but I was the head of science at JPL—head of science and instrument development.

So, I was asked by NASA, "Charles, can you bring a group of scientists, and look at the concept? Can we detect and image other planets—around other stars?" And I remember sitting down, and contacting a number of astronomers, and I got mixed reactions. Some people said, "Oh, that's an esoteric field." Some people who were visionaries said, "Yeah, we'll come to the meeting, and we'll sit down."

So, we formed a group of about 25 scientists, not only from Caltech but from different universities, and we had a series of meeting here at Caltech, matter of fact, at IPAC at the Infrared Processing Center next door to here. And we were kind of brainstorming, number one, can we detect other planets? Can we image them? What kind of instruments do we use? What kind of measurement do you make? And we made some predictions.

Matter of fact, we developed a report on the different techniques that could be done. And shortly after that, one of the techniques was used to detect a planet. That was a group in Switzerland which detected the planet by looking at the wobble of the star. And as the planet goes around them, it kind of moved that star a little bit because of the gravity. And that allows measures of mass of the planet, and the period because it oscillated. And, since that time, basically, there have been now thousands of observations.

And, basically, now, the field is one of the most, I would say, active fields in astronomy in developing both the instruments and the observation. But then, immediately, the next question comes, exactly what you said. How can you characterize? Because, on one hand, by looking at the wobble, you really are not seeing the planet itself. You are looking at its effect, on the star. But that gets you a fair amount of information from it, and that requires instruments which are very, very precise.

So, to be able to measure that wobble, you have to have what we call an astrometric instrument, which is very accurate. And one of the early missions which was flown, which was developed at JPL, was basically to image a field of stars by using a very large array, and then keep imaging it for a very long time, and then take that data, and look at all the bright stars in it, and measure the displacement very accurately. And that's what led to many of the early images—and now there are a number of instruments doing that.

That's how people came with the next idea, and said, "is there any way we can detect what that planet is made of, particularly its atmosphere?" And then some people—always, there are very brilliant people and smart people fighting for a concept—they said, "if we can measure the light from the star, and look at the spectrum, and as the planet goes around it, when the planet is in front of the star, we're measuring a combination of the spectrum from the star and from the planet. And then when it goes behind it, we're now measuring only the spectrum coming from the star. So, if we subtract those two, we should be able to see what was coming from the planet."

And in that way, people have been able to look at the spectrum of what's a planet, and therefore they are able to define some of the composition of that atmosphere. And by knowing the composition, you can kind of develop the concept of, gee, looking at our planet, we have oxygen. We have methane, which is generated mostly from vegetation and from some kind of life, like cows. And methane doesn't stay in the atmosphere for very long. It's kind of many dozens of years. So, if we see methane on another planet, it must be generated from some kind of life; not necessarily life like us but some kind of life on it.

So, that's kind of the track that people are using to be able to get more information about these planets. But, again, all these measurements are very, very tiny because the star is so bright, and the planet is so tiny. So, it led to developing techniques of, how do you measure the spectrum very, very accurately so to be able to get that little, teeny bit, coming from the planet. And then, now, we're developing capability where we will be able—with large telescopes and with techniques that we call a coronagraph—where we will be able to block the light coming from the star so we can see the light just coming from the planet. It's similar to like when you are giving a talk in a big auditorium, and the light is shining in your face. In order to see the people, you should block the light. That's exactly the technique that's being used.

So, we are—we look at the star. We have a little kind of a blockage in the telescope. We block the star, and we'll be able to see the planet. And this technique is being used from the ground. But it's going to require very large telescopes which have this coronagraph around it. Matter of fact, when the Jim Webb telescope will be launched later this year, in the December of 2021, it will have partly that capability, and it will be able to image planet the size of Jupiter and Uranus, that means planets which are far away from the star, and very big. That will allow us to do that.

But there are people studying, as we speak, at JPL on potential telescopes which could be flown in the next decade, which could take us all the way to imaging Earth-sized planets, and that's going to revolutionize our thinking. Because once you'll be able to image it, even if it's just a speckle, as long as you separate it from the star, you'll be able to learn a lot about it. You'll be seeing, are there changes in the atmosphere? Therefore, there might be weather. What is the composition of that atmosphere? What's the temperature that you can get from infrared data? You can learn—and then from the gravity as it rotates from the oscillation, you can measure its mass. So, by combining all of these, and some of our understanding of our own solar system, the different planets or different characteristics and so on, we would be able to learn a lot about other planets. Matter of fact, one of the things which was done was Voyager, and then we did it with Cassini. When we were way out around Jupiter-level distance, we looked back toward the sun and Earth, and we took a picture of Earth, and it was a dot, a little, teeny dot next to the sun.

And that kind of thinking that that's what we're going to see of other planets around other stars, it would be something similar to what Voyager and Cassini saw our planet next to our star. So, that was kind of how some of our missions will shed light hopefully, in the future, about what other planets—what information we can get about the other planets.

ZIERLER: Charles, that's amazing to think that only 30 years ago, the notion of exoplanets was strictly theoretical because there was no imaging.

ELACHI: That's right, and we did not have the technology to do it. I remember, in those days, going to the astronomy symposia, and there was maybe one session on exoplanets, and you go there, and there were only a couple of people. Now, you have dozens and dozens of sessions, and thousands of people.

And a matter of fact, one thing, it's interesting, is when we sit down every year, and look at applicants who want to come and do their PhD in the planetary department here, we usually ask them, "What are you interested in? What you would like to do research in?"—almost two-thirds of the applicant are in exoplanets. Matter of fact, we were starting to get worried that we are going to have too many people—

ZIERLER: [laugh]

ELACHI: —in exoplanets [laugh] versus studying the usual planetary kind of activity.

ZIERLER: So, maybe it's a naïve question, but, just from a commonsense perspective, if we know that our sun is an ordinary star, wouldn't it then follow that exoplanets would be common all over the universe wherever there are stars?

ELACHI: Yeah, I mean, that's kind of intellectually, you think that way, that, we are a little speck at the edge of a little galaxy. And, you have thousands of billions of galaxies, and our galaxy has billions of stars. So, it's perfectly normal, that there would be objects around it. But a scientist, until we prove it, it's kind of always—you have this nagging thing. OK, that's a concept, that we have, and it's a logical concept, it kind of makes sense.

But until you actually prove it, and you make a measurement, you will always have that doubt of this thing. So, now, when I talk with people in the general public—I mean, scientists, now, all of them believe with exoplanets—but with the general public, I have to tell them, we do actually have proof, that actually these planets exist. The next big step is what we talked about a little bit earlier. Do these planets have life on them—

ZIERLER: Yeah.

ELACHI: And, if so life, is it similar to our planet? Is it similar to life here? And, again, the concept when people ask me, do I believe in life in the universe, I say, "Yeah, I think there is life all over the universe, but I cannot prove it yet, you know." And I'm pretty sure there are—or almost sure, until I prove it, again—I'm pretty sure that there are planets like Earth that will be in environments similar to Earth, because you have billions and billions of these planets.

So, even by random choice, by random evolution, you are going to end with a number of planets, which are the size of our planet, which have a solid surface, which will have an atmosphere, which is at the right distance from the sun, so water would be liquid, and, therefore, life—like what we know it, which depends on water—is very likely to exist. Now, there might be life which is not based on water, or it might be a different—I mean, who knows? we have our thinking today about life of our planet.

I remember when I was a student, the key things were water, organic material, and sunlight, for life to evolve. But since that time, we've found that there is life at the bottom of the ocean, and there is no sunlight at the bottom of the ocean. And that's because it turned out—now we say that we need organic material, water, and energy. So, you have heat next to volcanic vents. So, even our kind of life, it has evolved about how it started, and how it developed, and what's the right environment for it. So, I wouldn't be surprised that there would be other ways of life. Matter of fact, my wife is an artist. When I told her we're looking at life on Mars, she kept saying, "Make sure you keep an open mind. Don't only look at life which looks like us"—

ZIERLER: Yeah.

ELACHI: —"evolved like us because, who knows, it might be very different."

ZIERLER: [laugh] Your wife is a wise person. [laugh]

ELACHI: Oh, yeah, no, I tell her she's very wise. That's why I got married to her.

ZIERLER: [laugh] That's right. That's right. Charles, because planetary science is inherently a multidisciplinary endeavor, I wonder if we can take a tour of the sciences to get a sense both of how you've pushed a certain branch of science forward or, alternatively, what you've had to learn about a particular discipline in order to do the work you've done? So, let's start first with physics. Where is physics in your overall approach to planetary science?

ELACHI: Well, the physics drives the fundamental laws of how things happen, and how they move, how they evolve. So, physics is at the foundation of many of our activity of exploring the planets. I mean, you have to learn about how the planets actually move, the gravity field so we can navigate our spacecraft accurately so that we can vent within few tens of a few hundreds of meters.

Let me take the thing of, like, a river—when we see riverbeds on other planets. How do these riverbeds—they are related to rivers, which happened before, which left those traces, of a river. How about erosion? Well, there are lots of physics which happen behind erosion.

Matter of fact, one of my colleagues here uses physics actually to simulate erosion which occurs from rivers. Another colleague is working on the property of soils so we know how to drill and what of kind of drill to develop. So, he studies the physics of little particles in material. How do they flow, the rocks, when you drill in them? The fundamental understanding, the physics which we do—and it's interconnected with engineering, of course—but the physics of writing the equation of how particles move, how sand particles move, or how rock actually moves when you drill it, basically is a major driver of how do we design the instrument that we actually apply to those geologic studies. Another example, the remote sensing instrument, the field that I'm involved in. When we look at spectra when we develop instruments to look at spectra—and we do that because we want to know what's the composition of the rocks on the surface—different rocks have different spectra because they reflect the sun differently, some of them.

That's why we see the colors that we see. Something looks red, something looks blue, and the red is because it reflects mostly the red light, which is from the sun. The blue is because it reflects the blue light. So, we use spectrometers much more accurate than the color, much more accurate than our eyes, and which does this across the spectrum that then goes in the infrared in the submillimeter. So, we use the spectra to look at the composition of the rock or the atmosphere, you know. But spectra is fundamentally based on the physics understanding of what we call the energy levels. So, the reason, for instance, a material absorbs the red is because there are two energy levels in its atoms which are separated by a certain energy. And, therefore, it moves electrons from the lower energy to the higher energy and absorbs that light. So, that's a fundamental physics activity.

That shows a connection between the fundamental physics of understanding how does spectra happen, and what is the spectrum of O2, oxygen? What's the spectrum of carbon dioxide? Their energy levels are all based on fundamental physics, and we use it in the lab, to characterize.

And then how do you use it in our planetary observation and Earth observation? By using spectrometers, which look at the surface in the atmosphere. And when we see those specific spectra which we saw in our physics lab, we can say, well, that's oxygen. There is oxygen there, or it's carbon dioxide. So that shows a trend or the continuum between fundamental physics all the way to interpreting the data, and in the middle develop the instrument, which capitalize on that physics, and allows us to do those observations. And that's where, I mean, in a sense, most of the advances happen in what we call…the interdisciplinary.

ZIERLER: Yes.

ELACHI: Now, if the planetary scientist then goes and talks with the physicist, who is working in their basement lab, looking at these spectra, probably he would have never thought, about doing that. And that's a strong benefit. I mean, my colleagues here, just looking at the geology division, the range for expertise from people who are fundamental geologists or geophysicists to people who work with spectrometers in their lab, I mean, in the—50 years ago, you would've told me they are physicists, not geologists. But that's completely, a continuum. It's completely transparent.

And the same thing with my electrical engineering colleagues, who are working on focal planes and detectors and arrays. They come and talk with a physicist to design the arrays which are particularly beneficial. And that's taking me back to my—why am I in the EE and planetary [divisions] is because I bridge that thing. So, I spend half my time with my EE colleagues, and half my time with my planetary colleagues.

ZIERLER: Charles, let's move on to chemistry, perhaps specifically the nuclear geochemistry of cosmochemistry. Where do you see changes in these fields?

ELACHI: Well, it's, again, the same thing. I focused on physics because I'm more familiar with it. But the chemistry is also what we do when we go to the planets where we're actually analyzing for example, if there are carbon molecules or—and that goes to the chemists who are the people who are—and biologists who, at the end, they are going to tell us, yeah, if you see a molecule of that nature, that might be an early indication of potential life evolving through the chemistry.

If we see carbon-based molecules, who knows, one day, we might find some kind of a helix, which could indicate some biological kind of—or a double helix or a single. And that's where the biologists will come in the picture, also to do that. So, I would imagine in our planetary exploration, almost every division at Caltech, would be involved in this, again.

And one of the missions we are doing now, we are in the first step of actually bringing samples from Mars. So, the latest rover that we landed on Mars earlier this year, in 2021, the key purpose of it is to drive around, look at interesting rocks using spectrometers and gamma-ray spectrometers and a different kind of spectrometer and laser spectrometers. And take samples, and collect two dozen samples, put them in a container.

So, later this decade, we'll be sending a Lander, which will drive around, take that container, put it in the nose of a rocket that will be carried on the Lander, a small rocket, launch it in orbit, put it in orbit. And then we'll send another spacecraft, collect that container, bring it to Earth to do the analysis. And I bet you it's going to be biologists, geochemists, chemists, physicists, all of them, taking pieces of that sample—those samples—and analyzing them for what's their composition, is there any indication or any biological, activity on there?

So, that's where it would be an example of a planetary exploration, which bring people from every discipline to be able to understand how Mars evolved. Did life evolve on it? Was it habitable, in the past? So, that's kind of the culmination of bringing every—all of these different disciplines working together.

ZIERLER: And then finally—

ELACHI: Because Caltech is the perfect place to do that, as well as a few other universities—

ZIERLER: Yeah.

ELACHI: —because we have the talent, amazing talent, in all those disciplines.

ZIERLER: And then finally with biology, you touched on it, but, just to be clear, in the field of astrobiology, to go back to exoplanets where earlier than 30 years ago, it was just a theoretical proposition, is astrobiology in that place now? In other words, before we actually detect biological systems beyond Earth, must it exist purely in a theoretical realm, or are we more advanced than that at this point?

ELACHI: Well, I think we are more advanced because, basically, as of now, two things that astrobiologists do—I mean, they do a lot of things, but two fundamental things. One is to understand, how did life evolve on this planet? And this is probably one of the most fascinating topics because, here's this planet that formed a few billion years ago. It was a bunch of rocks, and then somehow life started evolving little by little. It started maybe from one cell in the ocean. That's not my field of expertise. But, somehow, it evolved, and led to life like us. And, in the meantime, it developed the atmosphere of our planet, and there was a lot of interaction between the rocks, the atmosphere, the ocean, and so on.

So, one element of astrobiology is how did that evolve and how? And by understanding that, then you will start thinking, well, if there is another planet around another star with similar or a different kind of environment, how could life evolve in those kind of environments? So, now, it might be a concept, but it's a concept based on the understanding that we have done by learning more about how things evolved on our planet. And that's what lead to the question you asked earlier: what do you look for, you know? So, as you develop this concept of extrapolating from how life evolved on our planet to possibly life evolving on other planets, then you think, what are the indicators you look for, to be able to say, yeah, maybe life has evolved? Because it's going to be a long time before we actually can travel to those planets, and even sending robots, yeah, because the nearest planet is five light years away from us.

So, with today's technology, it's going to take us something like 60,000 years to get to the nearest star. But, who knows, there might be a big breakthrough in propulsion, and can get us very close to the speed of light, and then we can get there in 50 or 100 years' time, which is during one or two generations. So, you want to know what you look for in those places. And that's where astrobiology, even a part of it is theoretical, but a significant part is actually that work. And a number of colleagues here are working in that field. That's where—so, it is much more advanced or evolved than purely conceptual at this stage.

ZIERLER: Charles, I asked you about planetary science. Now, let's talk about the other major aspect of your career and work, and that is electrical engineering. So, let's start first with imaging radar. Why has this always been central to your focus and really the origin of your scientific life?

ELACHI: It's interesting how you evolve in these things. So, when I came to Caltech, and my thesis…in electrical engineering, was purely theoretical, I never walked into a lab for my thesis. I worked in the summer in one of the labs. So, it was purely theoretical. But then when I applied for a summer job at JPL, that was in my—I was in my—the summer after my second year at Caltech, it just happened by chance that I was interviewed by this group, which had like six, seven people, which was working on radar. So, they told me, they were a whole bunch of engineers building stuff. They said, "Really, we need somebody who understands the theory, wave propagation, and so on. Would you be interested to work with us?" And being a young student, I said sure.

They said, "Do you know anything about radar?" I said, "I can learn, you know." And, to be honest, I knew nothing. I mean, I didn't even hear the words Synthetic Aperture Radar. So, I start working on it, and then I found out that there is one class at Caltech being taught by a professor called Nick George, which was about optics. But part of it would talk about Synthetic Aperture Radar because there was a lot of similarity of coherent wave using lasers with the microwave that you use in radar. So, I took that class. It was one of my last classes. And that's how I started learning a little bit about radar. And I was fascinated by it. Like, when you are a young student, you are fascinated by many things. And I thought, oh, it's really cool that we can use radar instruments which use microwaves to generate images like what I see with my eyes.

And the benefit of them is you can do it day or night because you are using your own radiation—I mean, you are transmitting the signal. We don't use the sun. And then you can see day, or not. So, this would allow us to monitor the changes in our planet and others all the time. So, I was fascinated by the technique, and it had a natural relationship to my PhD because of my background in electromagnetic wave and electromagnetic theory. So, that's how I ended up actually working in that field when I got a full-time job.

So, I started working—I remember when we started, the whole group working on radar used to meet in one office because there were only like eight people, and I was the only theoretician, kind of science-oriented. And then we used to—at that time, it was before the satellite. There was a radar that was built, and we used to fly it on an airplane a jet airplane, all different regions around the world, and take images so we can develop the technique of it. I used to go and fly, and I was fascinated. We flew it to Alaska. Spent a couple of weeks in Alaska. We spent a couple of months in Western Africa also flying over a number of those areas. So, I became curious about looking at these instruments with all these flashing lights and all these signals. So, I used to always push buttons, and people were always worried that I'm going to push the wrong button.

So, they said, "Charles, we're going to have a display especially for you." That's one of the engineers. He was really a funny engineer. So, they put a display for me on the following flight, and it had flashing lights, and I used to push buttons, to realize after it was not connected to anything. So, they kept me busy, but I didn't do any damage for them. So, it was a fascination of the engineering aspect of it. I have to admit, the fun of traveling on that airplane to different parts around the world, the fun of going in the field, and doing that, and that's kind of what got me hooked into that area. Who knows? I could have ended up—if during that summer job application that I did the interview at JPL, it was in the navigation section or some other section, I might have entered a different career.

So, that's what I tell my students, and my two daughters. Don't sit down and plan every step of your career. Take every opportunity which comes to you. Just be imaginative. Just think out of the box. Every opportunity has a benefit. If you work at it, and if you get curious and fascinated about things it will lead you to something exciting. It's irrelevant what it is. And that's perfectly what happened in my career. I didn't go planning to do—I'd never heard of Synthetic Aperture Radar while I was doing my PhD.

ZIERLER: Charles, I'd like to ask about your devotion to remote sensing, and your approach to the field. So, if you can imagine a Venn diagram where remote sensing is in this circle, and then autonomous technology is in this circle, what's the shaded area? What's the connection between remote sensing and the development of autonomous technologies?

ELACHI: Well, I mean, basically, when people ask me first about remote sensing, I tell them we do it all the time, since the beginning of humanity. Our eyes are the perfect remote sensing [devices]. It's basically seeing something far away and monitoring how does it change. That's what remote sensing is about.

But what the technology enabled us in the last century is being able to see across the whole spectrum, not—and our eyes see only in the visible spectrum. We see red, white, and blue, and specific parts of the spectrum. What remote sensing enables us is, one, is to see much finer spectral signatures. like, in the red, there are literally thousands of spectra inside the red. But it also allows us to see in the infrared, in the X-ray, all across the spectrum, so we'll be able to monitor our planet across the whole spectrum.

And what satellite technology enabled us in the last 50 years is we can do that globally, just looking at our planet, we can do that globally. We can see our planet, all the time, everywhere; see what changes are happening on it. And just to give you an example, the next satellite we'll be flying which will have a Synthetic Aperture Radar on it is called NISAR for NASA India Synthetic Aperture Radar, which is jointly between us and the Indian Space Agency. We'll be imaging our planet every week globally at resolutions in the 20 meter [range]. If you calculate how much data that is, that's terabytes of data per day. So, we are going to be deluged with the data. So, then, the next question is, how do you analyze it? And that's where autonomous systems now in artificial intelligence [are] covering the picture, that we're moving to a stage where I look at a picture to see, ah, there is some feature here, or this part of the rocks are made of, whatever you want, some kind of rocks, versus to be able to do that completely autonomously.

So, the data comes down. I mean, what we're working on now, and that's where computer science is coming into the picture, it has nothing to do with the remote sensing, and artificial intelligence comes into the picture. It had nothing to do originally with remote sensing where, actually, data will come down, get processed, and, then, through those techniques, you will get actually the result you want, not just an image. But if I'm an oil explorer, and I'm looking for certain kinds of features, those features will pop out at me, and there will be some kind of signal saying, "Oh, this might be interesting for you. Look at that part of Indonesia or that part of Saudi Arabia." If you are looking at the change in temperature, basically, you don't get an infrared image.

You get a clock of the change of the temperature, that you'll get, and where there are different temperatures. When you look at the ocean rise, you don't get an optimeter. But you'll get a record of the ocean rise, and how it is happening. So, that requires—when you have that huge amount of data, it actually will become a little bit like our brain helping our brain by developing autonomous systems, intelligence systems.

To be able to extract, we have to teach them how we think. What do I think when I look at an image? Teach, the computer to do that, and the computer will do it on a much bigger, massive scale than I would do it, and provide us with an intelligent—and not only me as a scientist. But to get that data set, any person, who's interested in a sort of topic would like to find out what is the source of methane around the world. But basically, you can get data which say, "These are the points around the planet which are generating methane, and that's how much methane is being generated." You don't even have to know that it's a satellite or it's taken by remote sensing, I mean, the person who is using it. The same way, you use your iPhone today, 99% of people don't realize that there is a GPS network which tells you about your location.

People think that, somehow by magic, this little phone tells you about where you are located with certain accuracy. And, so, I think remote sensing and autonomous systems is going to be the same way as what we use on our iPhone. Now that anybody can use their iPhone to be able to generate the data that they are interested in, and they have no idea, and they don't need to, to know what sensor, what remote sensor, what satellite, what computer program developed that information for you. So, that's going to be the era in the next decade and the decade beyond.

ZIERLER: And, Charles, do you see robotics as a branch of remote sensing, or is it a discrete discipline for you?

ELACHI: Well, it's partially a discrete discipline, but it's a tool that we use to carry the instrument. So, robotics, I mean, if we talk about a robotic spacecraft, that's a natural carrier of the remote sensing instrument. But, also, you have robots like rovers, on Mars, and the rovers have instruments on them. They have cameras, on them. So, those are remote sensing techniques.

They have lasers, which turns up rocks far away that you cannot reach, which are on a cliff, and you see what's being emitted from that—what you do—when you zap the rock, what's being emitted from it. So, I look at robotics as basically a tool, basically, to take instruments to do remote sensing, and vice versa. In a sense, robots, intelligent robots depend very heavily on their camera and their visual capability, and these are remote sensors that actually are being used to guide the robot of what to do, and where to go, and so on. So, in a sense, again, it's that the two are complementary, even that the technology is different. I mean, the remote sensing doesn't require wheel technology, and the kind of technologies that robots use. And you can do robotics without having a focal plane. You might still have it for imaging. But these two actually depend on each other, complement each other.

The same thing with the drones, where you do, drones. a few years ago, we didn't even know about drones. Five years ago, drones were a curiosity. Today, they are a tool that we are using for doing remote sensing. A perfect example is a helicopter on Mars that we just sent recently on the latest rover.

So, now, the helicopter actually flies ahead of the rover, surveys the area with its cameras on it, sends the images to the rover, sends it to Earth. The operator looks at it, and then tells the rover, "We want you to go here or go there." And then as we develop things, again, going back to what I was saying earlier, the rovers would get the images, and the rover intelligence would say, "Ah, that looks like an interesting area. I'm going to drive there, without needing"—well, you still need the human in a sense of telling the rover what's important, and program it to recognize important things. So, that's an example of a robotic, in this case, drones and helicopters, work hand-in-hand with the remote sensing and with the rover, which is another robot on the surface.

ZIERLER: Charles, with the proliferation in advances in all of this instrumentation, that leaves us, of course, with having the very big problem of drowning in data, as it were. Where do you see the role of artificial intelligence and deep learning in sifting through all the data in a way that, no matter how many people you put on it, you can never be sure that you've gotten all the important information?

ELACHI: Yeah. No, I mean, that's perfectly where that's going to really help. I mean, let me go back to one example I mentioned earlier when we did the topography. The traditional way of doing topography over the last hundred years was you have hundreds of people—matter of fact, I went and visited USGS where they have people doing contour maps from stereo imaging, literally hundreds of people working for years to generate a map.

All of a sudden, we come with a remote sensing technique with the radar interferometry, and the data is automatically generated as a digital topographic, map. Now, it put a lot of people out of business, but that's what development—I mean, how we evolve in the technology. And, again, as you said, looking at the future, we are talking of literally hundreds and hundreds of satellites, and we are not doing them for the fun of it. We are doing them because we want to monitor our planet all the time, continuously, understanding the changes, which are happening on the planet. It doesn't help us if we get in images, oh, there was an eruption two weeks ago, or there was an earthquake three weeks ago, and look at the damage it did. We want to have it in real time, continuously monitoring the changes, natural hazard, human hazard, to really monitor and be able to react. So, that immediately leads to my little calculation to terabytes, of data coming every day. And no matter even if every person on this planet looks at it, we cannot analyze it in real time also.

So, that's where artificial intelligence, I mean, the benefit of computers—I'm, personally, a little bit skeptical that they would take over the world, because I think it's going to be a while before they become as smart as this little brain that each one of us has. But they can calculate things very fast, and they can do massive amounts of data [analysis] very fast, much more than I can comprehend doing that. So, that's where I think their biggest benefit, and we will train them of how to look at huge amounts of data, and how to extract the information that I extract when I think about this, something, how to extract. It's really, for me, artificial intelligence and computer intelligence is for us to translate how we think, to put it in a computer program that then I can have the computer do it on a massive scale, over terabytes of data in real time. That's the interconnection between the remote sensing and the acquisition of data globally for our planet, and the artificial intelligence, which will allow us to take that data, and then do something—help me in doing smart things with it. Now, 20 years from now, 50 years from now, they might be able to take over from us. But I'm skeptical about that. I might offend my artificial intelligence colleagues.

But, still, it's a critical field for us to have computers be able to do these things, kind of mimic my thinking, a little bit of when I look at images, and extract, not only images but any remote sensing—and extract information. And that's a topic of research we are working on now, matter of fact, with some of my students and some of my colleagues. That's work we are doing on how we are going to analyze, three years from now, these terabytes of data coming from the satellite I mentioned. And that's only one satellite. I mean, imagine when you have hundreds, of these satellites, and be able to do something intelligent with it.

ZIERLER: Charles, of all of the breakthroughs that you've been involved in over the course of your career, I wonder if you can reflect on what some of the deciding factors were in all of them. So, in other words, to be successful in these organizations on a day-to-day basis, you need smart people. You need good administration. You need a good budget. You need good technology. You need a little bit of luck. But in all of the breakthroughs, the things that really pushed our understanding forward, what consistently has always been the deciding factor?

ELACHI: Well, I think, usually, it's what I would consider as thinking out of the box. And one quote which is my favorite quote which comes from Teddy Roosevelt is, "Dare mighty things." And that became the mottos at JPL, that you shouldn't be afraid of daring something which everybody thinks is crazy. Matter of fact—I think with JPL, if you think it's crazy, we love it. That's what we like to work on.

And let me give you a couple of illustrative examples, again, from my theoretical involvement, talking about the Mars helicopter as an example. So, it happened I was at a conference up north of San Francisco. It was at a club called the Bohemian Club. And there was a speaker, about—that was, like, about eight years ago. And there was a speaker which came who talked about drones. It was the first time I heard, I mean, where I watched, and I was absolutely fascinated. And he showed a family of drones which are flying together, and they were playing music. Each drone had a stick, and they were kind of doing [a formation]. I said, wow, this is fascinating.

So, I came back to JPL, brought a couple of young engineers, "Can we do this on Mars?" And the first reaction was, "Are you crazy?" the pressure on Mars is 1% the pressure on Earth. That's the equivalent of flying at 90,000 feet or 30,000 meters. Nobody ever flew a helicopter at that altitude. The highest is—even not at the altitude of Mount Everest, we haven't flown helicopters. So, this is three times higher. And they said, in the typical— I had in my office that quote, "Dare mighty things." So, I said, "Why don't you go and think about it?" So, to their credit, they went and thought about it. They built a little helicopter, put it in a vacuum chamber with low pressure, and this thing flew and hit the wall and broke. And they came back to me and said, "we think we can do it. How about you give us some money and a little time?" Like you said earlier, you need a little funding. So, I did that. Fortunately, as a director at JPL, I could—I had some flexibility with funding, discretionary funding.

So, they went. And after a couple of months, they came back to me, and they showed me a video. They built a scaled-down helicopter, and, actually, we can fly it in an environment like Mars. So, now, the next challenge was to convince NASA to include it as part of the rover because the rover was almost built at that time—well, designed and almost built. So, of course, I went to NASA, and there was all kind of excuses why we cannot do it. It's too late, you know. Any regular person would have given up. Well, having that thing of "dare mighty things," even I wouldn't give up. So, I came back, and I told the project, "Figure out a way of having them include that helicopter on it." And the first reaction was, "Charles, we're already very busy." I told him which part of "figure it out" didn't he hear?

ZIERLER: [laugh]

ELACHI: I end up going in Synthetic Aperture Radar. And who would have thought that those things are going to be in every iPhone in everything that we use today, on doing that? So, this was a professor here at Caltech, he and Gordon Moore after, which was a combination of concepts, developing the basic technology to people who take that basic technology and develop it into practical technology. And look how much it changed our lives. Today, from when I was a student, I used to use a slide rule, to now using my iPhone. When I was in France to call my parents in Lebanon, I had to reserve a time at the post office, go down there so I have a time to do an international phone call. When I tell my daughter about it, she laughs. [laugh]

ZIERLER: [laugh]

ELACHI: The concept to that, tracing it back to the kind of technology that Carver Mead did, and people like him who did that. The other thing I tell people, a further example, is when people ask me what's the benefit of space technology, I tell them, "You all have an iPhone." And they say, "Yeah, of course." "You all have a camera on it." "Yeah, of course, we have a camera."

"Do you know that that focal plane in that iPhone was—that technology was developed at JPL for our astronomy missions because we needed to have very lightweight focal planes which had very little power for our telescope? And guess what, after an entrepreneur came and said, ‘Oh, I can use that technology in cameras.'" And, fortunately, Caltech has a license on it, so I tell them, "Every time you buy an iPhone, Caltech gets maybe half a cent, of that iPhone. But it adds up to many millions of dollars."

So, that's also an example where technology which we were doing for astronomy, had no idea that you can use it in your iPhone. In fact, when we developed it, the iPhones didn't have cameras in them. That was 20 years ago. And now, we use it without thinking about it. For me, this is an example of how the fundamental technology, the fundamental understanding, the fundamental—all of it based on physics. I'm sure Carver Mead had to do a lot of physics behind what he developed for integrated circuits, to lead us to completely revolutionize our life and how we do things, and the economy, which now depends—a majority of it depends a lot on these kinds of inventions that were done. And things are going to move even faster in the future.

I can't conceive what we're going to be developing in the future. But I could envision, you and I wouldn't be on this screen doing Zoom. We'll be in 3D, holograph. You'll be sitting in my office while you're sitting in your office, doing this holographically in 3D. And the same thing, matter of fact, one of the technologies we're doing at JPL that we'll be testing is to do, as the images come from the rover on Mars, is a scientist, instead of looking at the images on a flat screen, we do it in virtual reality. So, they can put a visual camera, virtual reality camera that are starting to be common, and they could be working anywhere around the world. They could be next to the rover. They will see that they are walking with the rover as the rover is driving and exploring. So, that would be—in effect, the rover would be an extension of us in real time, in 3D of the scientists who are exploring with that rover.

ZIERLER: Charles, now, I'd like to ask you some broadly conceived science and society questions, and let's reflect on what's now, a 50-year anniversary of coming to JPL, coming to the United States. So, today, circa 2021, for that Lebanese student who graduated first in his or her class, who's interested in the kinds of things you were interested in 50 years ago, is the United States still the place to be?

ELACHI: Absolutely, I mean, without the slightest doubt. One thing I tell my daughter, my two daughters, "You are fortunate you were born in this country." Because even that the rest of the world has evolved, clearly, in the last 50 years, the technological capability of many countries has evolved significantly in parallel with the United States. But I think it's the combination of not only the technological advances but also the free thinking that we have in our society here. People sometime ask me, "Are you scared of China?" And I say, "they are very smart. They have lots of smart people. And we have lots of Chinese people here. But as long as they keep restriction in their society, I think they will not be able to evolve as fast as we have, even though they have been evolving, with no question."

But in the long-term, it's that freewheeling, free thinking [style] that we have here, the freedom of thinking of whatever we want to think about, the freedom of saying whatever we want to say, the freedom of sitting down with my colleagues, and talking about different ideas without being afraid of offending somebody for some particular reason or so on, is really the strength of the country. And the tolerance. And that's something which worries me a little bit now, because I see some more less…it's the tolerance of other people with other ideas, with other backgrounds, with different backgrounds. We espouse all this diversity, which is really at the heart of the United States. And I hope that we can continue that. And I remember when I was a kid, in Lebanon, never thinking that I would go to the United States. I used to read a magazine that American embassy in Lebanon used to distribute to schools, and it was a little magazine which was in English, and my English was kind of—I was studying it a little bit so I could read it well. And that's the magazine where I saw for the first time in article about launching Explorer from a place called JPL. I still remember it clearly. I still remember the column.

And I thought, what a fascinating place. Look what they can do, in that. I mean, I was in a little village, in Lebanon. And, for me, always, the US was about the future, thinking about how you develop that capability. And, where I grew up, I was very close to Baalbek, which is a big, tourist area, and its Roman temples and so on which were in the middle of Lebanon. And I used to go there reasonably often, and there used to be tourists. And a couple of times, I talked with American tourists, and I was always struck by how upbeat they were always. They were always positive, laughing, you know. I talked with them with my broken English. They were always, positive about the future. And they used to tell me, "Oh, it's just like the future of Lebanon, you know. You are being educated, that you can really make a big difference, in the country."

So, I always had that idea of the United States, even before I ever dreamt of coming here, and before I came here. And then when I came here, I remember also very clearly when I was accepted at Caltech, I get this letter which said, "As a foreign student, this is going to be a big change for you, to adapt to the society here. Would you like to spend a month with an American family? Come early and spend a month with an American family here." So, I said, "Sure, that would be great."

So, I land at LAX, on August 15 in 1968, and this family was meeting me, American family. They took me to their home in Palos Verdes, a beautiful place. I thought every place in America is like that. And they were so welcoming, and they treated me—they had kids about my age. They were a little bit younger, and they treated me like member of the family. So, that's my idea of what the United States—I mean, they had no idea. I mean, I'm from Lebanon, and so on. But they welcomed me and took me to Disneyland. They took me to the Dodgers games, and so on. So, that was the introduction I had to life in the United States.

And, again, what Caltech did to me, the reason I was able to afford to come to the United States is that Caltech gave me a fellowship. Now, there is a long story about how I came to Caltech. We can talk about that later. But, for me, it was, here's this university, a private university, that was giving a fellowship from a student coming from Lebanon, studying in France, but they gave me a fellowship to come and study here. And that's what enabled me to become what I did. And that's why, recently, my wife and I established, an endowment for a fellowship at Caltech, hoping that some young people like me, coming from some place, it will give them the opportunity to come to Caltech, and be able to study. So, this is, for me, the ideals of the United States, and I think [the country is] going to continue to do that. Yes, there are challenges, yes. But I think at the core of us, being a country of immigrants over different generations, I think—hopefully, I hope that that will stay with us.

ZIERLER: Charles, of course, one thing that has changed over the past 50 years is that JPL is no longer the only game in town. I wonder how you see, both from a perspective of cooperation and competition, the role of private companies like SpaceX and Blue Origin as they relate to JPL's long-standing mission.

ELACHI: Yeah. No, I'm delighted now there is much more—there are more players in the field. And it's not only industry, but also there are other NASA centers which are competing with JPL, some universities competing with JPL. So, I address those two a little bit differently.

On the competition from other universities and other NASA centers, usually, I tell the people there—because we were a monopoly for a while. All the planetary missions were at JPL. Almost a majority of the robotic mission were at JPL, and Goddard Space Center, and we used to compete. And my message to the employees at JPL was, "Look, we are in the lead. And the way to stay in the lead is to run faster than anybody else. And I'm glad to share all what I know with everybody else, but I have to run faster." So, that's our advantage, to run faster than everyone. Be more imaginative, more daring, more bold than other people. That's how you stay in the leadership.

You don't stay a leader by protecting—become a monopoly, and then protecting everything. You stay a leader when you share everything you have, because then everybody will look at you as the leader, and then run faster than everybody else. And that's how you stay in the lead. So, that's my philosophy about in the scientific world, how do we work? And the same here at Caltech. The faculty's very open. We share all our ideas in the open literature and so on. Now, industry is a little bit different. The way I think of our space program that our role at NASA in general is to develop the capability and the technology, demonstrate it, and turn it over to the commercial sector to make a business out of it. So, I'm delighted that there is SpaceX and Blue Origin and Lockheed Martin, which are taking the technology that NASA developed—or funded sometime because we do things in industry—and now they are making it, and benefit from it.

So, when people ask me about particularly Elon Musk because he's such a public kind of person, or his personality, people ask me, "Well, look at all the inventions that Elon Musk did for the rocket." I tell them, "I admire Elon Musk. I know him well. He used to come to JPL. He's a visionary. He's the kind of guy I like. "But he didn't invent anything. He only took the technology that NASA has developed, and he's using it in a commercial way, in a much more entrepreneurial way." Because at NASA, we tend to be more on the conservative side for the simple reason that we're using taxpayers' money, to do what the taxpayer is entrusting us to do. So, you have to be much more careful in how you do things.

Elon Musk is [oriented toward] industrial organization or commercial organization. He's using a lot of his own money, so he can take a lot more risk. I couldn't—NASA couldn't say, "Oh, I launch a rocket, and if it blows up, that's fine. I launch another one. If it blows up, that's fine. I launch a"—Congress would be all over this, if that—so, we tend to be a lot more cautious, and take more calculated risks. Elon Musk—and there is benefit of both ways because when you are developing the technology, you want to go to the planet, and you have a $2 billion rover, you have to be much more conservative. But, also, there is a benefit of the Elon Musk approach where, basically, you develop a capability. You test it. If it doesn't work, you move to the next—that's what we do at universities, when we are developing some new experiment. And I tell people, "Don't be afraid of failing, you know. That's part of the process." But when you are involved in a couple of billion dollar missions you have to be a little bit careful, and a little bit thoughtful of how you take this risk. Elon doesn't have to do that, or SpaceX doesn't have to be as thoughtful, as—now, they are much more careful when they have humans on their launch. But for a robotic mission, they can—so, it's a combination of the two. I think it's a natural combination…matter of fact, I chaired Elon Musk when he came and talked with us—and, great, because we want more competition in the rocket business. And if he can do it cheaper than the other companies, that would be great because then I can use more money in the spacecraft, and the science. And he did that, and it became a great competition. And because of what he has done, and what SpaceX is doing, now, all the other companies are cheaper in their launch vehicle. And there are more companies doing launch vehicles. So, it's natural. I don't look at it as competition. I look at it as healthy competition, and collaboration, and exchange of ideas, between different, organizations. So, that's what it's all about, in advancing the technology. ZIERLER: Charles, of course, you came of age during the Cold War where competition and the Space Race meant something very different. So, in the past 30 years, since the end of the Cold War, what opportunities have there been for international cooperation, first, of course, with Russia, but then in a very exciting way for all of these new countries that have their own space programs, major economies like India and Japan, and even smaller countries like Israel and South Africa? What is the broader opportunity at really internationalizing what used to be a two-country game? ELACHI: Yeah. No, I think particularly in the space field, international competition is very important, both on the technical side, on the human side, and on the political side. So, let me start on the technical side. I mean, there are smart people everywhere. we don't have a monopoly on smartness. And as other countries, as the technology evolved in other countries got involved, effectively, almost every mission we have at JPL is international. Sometimes, other countries have instruments which fly on our spacecraft. Sometimes, we fly our instrument on their spacecraft, particularly with the European Space Agency, the French, India, on the upcoming mission that we are doing, with England, Germany, Japan. So, almost every one of these countries that we collaborate with, we see a benefit because we can do—they put their money in. So, when we collaborate, we don't do exchanges for fun. So, we can do more with the limited funds that every country has, scientifically as well as Earth observation in climate change, particularly in the Earth observation because climate change is international. the smog we get here is coming from Beijing, after a few days, and vice versa, going on in the other direction. So, international collaboration is essential. Now, let me go on the kind of the human, political side. Even during the Cold War, we had collaboration with Russia. I remember when in my younger days, when I was working on Venus, the Russians sent a balloon to Venus. Guess who tracked it? It's our Deep Space Network which tracked it, and that was in the midst of the Cold War. And we were encouraged by the government to do that collaboration because it kept a channel between scientists, which also became a channel to the political side. And, later, even though I was not involved in it, I was talking with the director of Los Alamos in the nuclear area. He told me he used to go regularly and visit Russia and talk with the nuclear scientists in Russia. Now, of course, there are secret things and non-secret things. But he said it kept a channel for the politicians, to keep a channel with supposedly our adversaries or our enemy. So, there is that aspect, of keeping—because, at the end, we are all humans. We all have family. We all have kids. We all want the best for our families, for our neighbors. And we have different political system, and that's fine, but we are all sharing this planet. So, the international collaboration, I think, is beneficial for both sides: on the human side, as well as on the technological and the scientific. And the third one, on the political, particularly speaking about NASA, everywhere I travel around the world, when people see a pin that I might have, which says NASA, or if, like, they ask me on the plane, "Who do you work with?" I tell them, JPL. "Oh, is that the place which sends spacecraft to the planets as part of"—even people who are, in India, in other countries—NASA always reflected positive things about the United States. And I remember very clearly a story that our Congressman told me. His name is Adam Schiff. He's the Congressman of the area, where JPL is. He was telling me, when we landed one of the rovers, he was in Pakistan. And he said the day before we landed, he was looking at the paper, and there was all kind of criticisms of the United States, and so on, that you hear in some countries. The day after we landed the rover, he saw there was a headline. What great things the United States does. Look at this country which has allowed us to explore the planets, you know. He said it's really one of the most positive messages, and he called it soft politics. ZIERLER: Yeah. ELACHI: That NASA could be in soft politics like building relationships, working with, and reflecting the positive thing. I mean, that logo, everybody knows it, you know. I said there are two logos that I see everywhere around the world when I travel. It's NASA and Coca-Cola. ZIERLER: [laugh] ELACHI: You see them everywhere, even in the middle of the desert. [laugh] You see those signs, in there. [laugh] So, that's kind of a positive thing that the space program brings to our country. ZIERLER: Charles, a very broad institutional question, there's much confusion even at Caltech, maybe even to some degree at JPL. What do you see fundamentally as the relationship in the triangle between Caltech, JPL, and NASA, and what might illustrate best what is even magical about the way that these relationships work? ELACHI: Yeah, and no question, it's a magical relationship because people ask me when I explain to them, "How could it be that such a small university is in charge of doing the planetary and earth science program? How could that happen?" Well, it had to do a little bit with history, but also with the role of the organization. JPL was started in the mid-30s by a group of students working with a professor at Caltech called von Kármán, and they were mixing chemicals to see which one blows up more so you can put it in a rocket. But the campus got nervous about them blowing up— ZIERLER: [laugh] Yeah. ELACHI: —something, doing these dangerous experiments. So, they said, "Why don't you go to the Arroyo, which is six miles away from here"— ZIERLER: [laugh] ELACHI: —"and do your experiment there?" There was nothing at that time. Now, it's like any other. ZIERLER: Yeah. ELACHI: But at that time, there was nothing. And that's how JPL started. A group of five, six students working with a professor, doing—mixing chemicals. And I love the picture of them. There is a picture of them, taken on Halloween day in 1936. You have these tanks of these dangerous chemical with these tubes coming out of it, going in this nozzle of this little rocket. We would never allow people to do it now. And then it evolved, and then it led to developing rockets during World War II. We worked on building rockets you put under airplanes to help them take off on short runways, like from aircraft carriers or from small islands. This led to a company called Aerojet, which was founded by JPL, and then we moved into actually building missiles. And then in 1957 when Sputnik happened, there was a big panic in the United States about the Russian getting ahead of us. So, within 90 days, we built a spacecraft, a small spacecraft called the Explorer, on a rocket which we worked jointly with a team that von Braun was doing in what became Marshall Space Center. And we launched the first American satellite. NASA did not exist at that time. Through all that time, this was still a JPL—sorry, a Caltech-owned, Caltech-run, funded by the Army, activity. Then, NASA was formed by Eisenhower as a civilian agency to do rockets and human exploration and robotic [research]. So, when NASA was formed in Washington, they looked around to see what places know how to [work in] space, and JPL was one of them. There were a couple of other research centers. So, there was an agreement between Caltech and NASA. I'm told that for$1.00, Caltech sold the JPL to NASA, but Caltech continued to manage it.

Now, I don't know if the story of 1.00 is true, but somebody told me they saw it in the archive of the agreement. So, since that time, JPL has been a NASA-owned facility, but it was managed by Caltech, and all the employees are Caltech employees. Now, then, say, your next question is, what's the benefit? What did Caltech bring to the picture? Well, Caltech brought a number of things to the picture. It created an atmosphere of JPL of a university research atmosphere, which is very amenable for innovation. That's what universities are about, versus a traditional engineering organization. So, really, Caltech brought that spirit, of innovation, working with universities, many of the faculty at Caltech work jointly with JPL, and many employees would come to JPL and were attractive to employees. They liked the idea of being Caltech employees. I mean, they are all coming from universities…even the people coming from MIT, which is our competitor…they love being part of Caltech, of doing that. So, they have a Caltech badge, and so on. So, it allows us to attract people, who, most of the time, don't want to be government employees or don't want to work in an industrial company where profit is a driver and everything. And, here, they can be part of a university, part of exploration, doing something they want to do or they are fascinated about. So, JPL brings that mix, of—I usually say I have two parents. I have NASA, which enables us to explore space by funding us, and Caltech, which give us the intellectual capacity to do it. these are the two parents that we have, and we are fortunate to have the two best parents that you can have anywhere. And many employees feel the same thing, even if they're not graduates from Caltech. And Caltech gets the benefit from it because it enables a faculty with a small lab, able to capitalize on this big organization, which can allow them to build a spacecraft. Matter of fact, one of my colleagues today, her name is Bethany Ehlmann—she's a young faculty here—she's a principal investigator on a mission to go to the moon and do measurements of water on the moon that she conceived, and she's developing the instrument on it. And JPL is helping her manage building that spacecraft. That would have been somewhat hard at other—not impossible but somewhat, and this is only one example. Matter of fact, my office here, I'm sitting in an office that used to be the office of a professor called Jim Westphal, and he had the concept of a camera to put on the Hubble Telescope. Guess who built that camera for him? He designed it, conceived it. JPL built it, for him. So, that was a great benefit for an individual faculty here—and there are many examples. I can give you many dozens of examples, of those. So, that's the advantage of that three-way relationship. It almost doesn't exist anywhere in space, anywhere outside the US, or anywhere in the US. We are effectively the only lab which were at NASA, Caltech University, and JPL, which has that three-way relationship. It's similar to the DOE, Department of Energy, like Los Alamos and Livermore. And that's why these labs are leading labs. I mean, they attract some of the best talent who might not be interested in being part of the government, and it allows us flexibility in many of our procurement, in our approach to human resources, in hiring and so on. And we can take a little bit better, I mean, that's an additional side benefit than government employees. So, it's clearly a win-win situation for Caltech and NASA to have a place like JPL. ZIERLER: Charles, finally, my last question for today's session, I'd like to ask about your commitment to public service. Between the advisory boards that you sit on, all of the lectures you deliver, the emphasis that you place on education, why is that interface with the public so important for you, and why not just stay in your bubble, and get more work done there? ELACHI: Well, it's really for two reasons. But before I say that, when I retired from JPL, I have one assistant who was in charge of preparing my presentations. Her present to me, retirement present, was a copy of all my presentations on disk up to that time. They said, "Charles, do you know you gave two lectures every week in your last 15 years, that you were here, both public and technical, technical lectures?" And I didn't think about it because I love doing it, and I love doing it for a couple of reasons. One is, as a person—when I was a kid, I was fascinated with space, and I want to transmit…and I still have that fascination with it. So, I want to transmit that fascination to the next generation, to the young people, to do that. So, I used to love going to local high schools, not only local but other—to go to the museums, and give public lectures, both in the US and internationally, to tell people about what we are doing. There is also a pragmatic aspect of it because, at the end, we get funded by the public—I mean, we get funded by Congress, but the public [is the real source]. So, it's important to show the public the value of a place like JPL, and the value of what we do at a place like Caltech, JPL. And I always, at the end of my presentations, the last paragraph is a standard. It has the logo of NASA, the logo of JPL, and the logo of Caltech. And the public get fascinated. The public loves doing exploration because everybody remembers when they were a kid, they were exploring all kinds of little things. And as you grow up, you kind of lose it a little bit, that curiosity. And they love seeing that we're still doing that curiosity, that they would love to be there. And every single time at the end, when I ask for questions, people raise their hand, and they say, "that's what I would like my taxpayer money to go to." And my answer is usually, "Make sure you tell your congressman, that—about that." Because we have—we are—basically, I see us, I see JPL, we are doing a service to our country by taking us beyond our limitations. So, we are like a—I tell the employees we are a trust where people are trusting us with their money, to do exploration. We are not doing it only for ourselves. We are doing it for everybody, to do that. And that's kind of the philosophy behind why I'm not sitting in my cocoon enjoying my retirement. And now, particularly now that I'm back at Caltech, and I have more flexibility, with my time, serving on a number of boards, particularly educational boards, university boards, is still—basically shares the benefit of my experience, knowledge, connections, and so on. And every time I go—and I'm on like a dozen university boards—every time I go to it, they always ask me to give a lecture, in Singapore, Australia, Saudi Arabia, Kuwait, Oman, Lebanon, France, and that's part of it. And part of the side benefit, it can give you one simple benefit, which really made me feel good. About eight years ago, I was visiting the French Space Agency Center in Toulouse in France, and they asked me if I can give a lecture at the university. So, I went and gave a lecture about space. And after things, this young guy comes, and he was an undergraduate. He said, "Wow, it's fascinating, you know. I know you're from Caltech, and I would love to do work like what"—and he knew that I graduated from France from Grenoble from the university…"How can I do that?" "Why don't you apply to Caltech?" First, I asked him what grades he is getting. And he told me that he's the top student. So, he applied, he was accepted at Caltech, he came here, he worked, got his PhD here, worked part-time at JPL, and graduated recently. And he came to me one day and said, "Thank you. Just for those few seconds you talked with me changed my life on doing that." So, that's a reward of doing these things, the impact you have on young people who are so thankful. And I can tell you many, many example like this of students who either worked with me in the summer, or something like that, which I took the time to mentor them, and that made a big impact on their lives. So, that's the kind of thing which I find very rewarding. ZIERLER: Charles, that's a great place to pick up for next time when we'll go all the way back to 1947 in Lebanon. [End of recording] ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It's Thursday, September 30th, 2021. Once again, it's my great pleasure to be back with Professor Charles Elachi. Charles, it's wonderful to see you again. Thank you for joining me. ELACHI: Sure, my pleasure, my pleasure. ZIERLER: Charles, today, what we're going to do is follow your personal narrative all the way back to Lebanon. First, I'd like to start with your parents. Tell me about them. ELACHI: Well, my family—I grew up in a town called Riyaq in Lebanon. And it was a small town about like a 1,000, maybe 1,200 people at that time when I was growing up. And the unique thing about this thing, is that town was a hub for the railway in the Middle East. So, there was the route of the railway from Beirut to Damascus, and the railway which goes to Aleppo, and then the section was at that town. That was always the railway. And there was, in addition to the station, there was a large facility, matter of fact, the only facility in that part of the Middle East to repair trains. And, my dad was a director of that station, so he had—maybe there were like a few hundred people, I'm guessing, two or three hundred people working. So, it was a main industry, in that town. My dad was the director of it. And because the railway was built in 1900 to 1910 by a French company, and during that time, when I was growing up, it was still run by the French company, all the interactions and everything was—documentation was all done in French. And then it turned out next to the railway station was the main airport, military airport, in the Middle East, which was also—it had a lot of French presence, particularly between World War I and World War II because that was the period when Lebanon was a French protectorate before Lebanon got its independence. So, my dad grew up in that town, and I remember a little bit. My grandad, he died maybe when I was like 8 or 9 years old, he also lived in that town. And the interesting part on my mother's side, she was from Damascus. And I'm told that the way they met—because my dad, being director of that railway, he used to travel back and forth, a lot. And somehow through some common friends, he was introduced to my mom, and they got married, and then my mom moved to live in Lebanon. Both of my parents didn't even have high school. They had, a middle school level of education, but they were very fluent in French because—Arabic and French—because that was a common way of talking in that part of the world. But, for them, education was very important because they saw it as a way for their kids to move up in the social status. Because even though my dad was reasonably well-to-do, it was still in the middle class, it's Lebanon's middle class, which was not as advanced financially as the American middle class. We didn't have TV. I don't even remember. The first time I saw TV was when I was high school, and it was in a store. We didn't get TV at home until after I left and went to France. We had radios, so that was the main thing for entertainment. And the other main thing was getting friends there. So, almost every night, we used to have cousins or nephews or neighbors or something get together. So, that was the social life that we had. ZIERLER: Charles, did your mom come from the Maronite sect as well? ELACHI: No, she was from—as in the Christian part of the Middle East, there were the Maronite and there were what we call Roman Catholic—that means they follow Rome—and then the Orthodox Catholic. My mom was a Roman Catholic, so she and—Roman Catholics and Maronites were fairly close to each other. In fact, people used to go to either one of the two churches. There were minor differences about who is the cardinal that you follow. The Maronites was pretty unique to Lebanon, and to a small part of Syria. So, there was minor difference but nothing—not that—it still allowed marriage between the two. [laugh] ZIERLER: And what language, primarily, did your parents communicate in? ELACHI: Well, at home, it was mostly in Arabic, but also French was very common. So, it's usually a mixture. And even now in Lebanon when people talk, it's a mixture of Arabic and French, doing that, because the French was very common. But, clearly, when my dad was doing business or interacting with the people at the port, that used to be in French. ZIERLER: Now, did your mom have family still in Damascus? Would you go visit them when you were growing up? ELACHI: Yeah, matter of fact, that was a highlight of when I was—for my summers when I was a kid, I mean, up until, like, 15, 16. I used to take the train, the one I mentioned, to Damascus, and spend like a month in Damascus. And then, a couple of my cousin used to come and spend a month, with us because it was a fairly large family. My mother's side, she had four sisters and two brothers, and then their kids. Some of the family, typically, they had anywhere between four and six kids, and there were a number of them who were almost exactly my age. Matter of fact, one of my cousins was born within a week from my birthday, so we were roughly the same age. So, we would socialize a lot together between my mother—my—all my mother's family in Damascus, and our family in Lebanon. ZIERLER: Charles, is your sense that with better opportunities, your parents would've received more education than they were able? ELACHI: Yeah, could be. You have to remember my dad grew up in the 1910s, 1920s, and my mom in the 1920s, 1930s timeframe. That's when they were in school. And education was common, but mostly in the elementary and middle school. And it was really a treat in that time of somebody going, finishing high school, and then going to college at the time. Not many people went to college in the '20s and the '30s. But there were a lot of missionaries there. Most of the schools were missionary schools. I mean, there was no government requirement for education, so it was really mostly the families wanting to educate their children. And a family which had somebody with a college degree was a special kind of thing. So, it's really not very different than in the US in the late 1800s, early 1900s where many people were in the farming community outside the city. Education was a big deal, and going to college was a big deal. My wife was telling me that she was the first person in her family—she grew up in Waller, Washington—that she was the first in her family to go and get a college, degree. So, we—in Lebanon there, people were maybe a couple of decades behind the evolution in the US. ZIERLER: Did anyone in your family experience World War II directly? ELACHI: Well, clearly, my parents, experienced that. Matter of fact, from what my mother tells me, her uncles—two of her father's brothers—actually died in World War I because of the the Turks. At that time, Turkey was part of the Ottoman Empire. So, they were lining up all the young people, and taking them, to be drafted, to do that. So, my grandfather, my mother's dad, and two of his brothers were drafted. And the two brothers were killed in Southern Syria during the war, World War I, and it was common that my granddad actually took the families of his two brothers—they had young kids—and kind of merged them with his family. So, he kind of took care of them. So, my mother grew up with her cousins. I mean, my mother had, as I mentioned, four sisters and two brothers. So, my grandfather must've had a—taking care of a huge family, taking care of his brothers' kids who had passed away or were killed during that war. ZIERLER: What were your parents' politics? What did they feel about the government of Beirut, for example? ELACHI: [laugh] Well, typically, at that time, people did not get involved. I mean, their approach to politics is, "Leave us alone," that, people take care. So, the government services were very, very limited, much less than the US. I don't even remember, of any major function that the government has done in the day-to-day life of people. And politics was there. I mean, there were elections when I was growing up. And similar to what you see here, there were campaigns, but the campaigns were mostly done in person because there was not much TV or radio, so there was no advertising, if you want, for that. So, I remember, the people running for Congress used to come to the town, and there used to be a meeting with the mayor of the town at his home. And, they invited people, and they talked about what they want to do. Yeah, it was, to some extent, I would say, a little bit feudal at that time. That means there were certain families which were well-known, and it used to be people from those families who used to run for election. But I don't recall. And it was helpful having connections, in those places, since the government was not necessarily evenhanded across the board. So, if you have, a cousin or a family or a friend who is a member of parliament, you used to get, a better connection if you wanted to get a passport or you wanted to get something. So, it was helpful knowing the politician, but it was very limited in what they were doing. So, families were pretty independent. I mean, there was no social security, no health insurance. Almost the majority of the schools at that time were private schools run by missionaries. So, the government played a fairly limited role, in those days. I mean, they played the role of paving the roads, and things of that nature. And the local mayor had probably more influence than the Congressman because they took care of getting some funding from the government, and taking care of the sanitation, water, electricity, things of that nature. ZIERLER: Charles, going even further back, what were your parents' feelings about the French influence on Lebanon, and, even farther back, the influence of the Ottomans? ELACHI: Well, clearly, there was a lot because most of them, whatever education they got was mostly in French schools. So, there was a lot of attachment to the French, background and education. But Ottoman, they had a mixed history in Lebanon in the sense of, treating it as a colony versus part of the Ottoman Empire. So, it used to depend, again, from stories that my dad used to tell me. It used to depend about who the Ottomans put in charge of Lebanon or the different districts in Lebanon. Sometimes, they used to have people who came from Istanbul or Constantinople, and sometimes they used to be local people. Usually, when the local people were in charge, things used to be better. When it's somebody from far away, things were not as good. And there were a number of periods in the late 1880s and by just around World War II, there were a number of famines in the Middle East, similar to what happened in Ireland. So, that was a period where there was a lot of immigration, of going out of Lebanon. And that's why you see a lot of Lebanese all around the world. I mean, there is a large community in the US, a very large community in South America, particularly Brazil and Argentina, and in Western Africa, because many, many of the Lebanese were traders. I mean, that was a kind of—a special thing about Lebanon is that there was a lot of—going back all the way to the Venetian times, Beirut was a hub of trading, with the whole Middle East. So, it was between Beirut and Alexandria, and these were the two main hubs in the Middle East for things coming from India and Asia, and then going to Europe. So, there is a very long tradition of traders, and that led to connections in many parts around the world. So, one, people were immigrating. They used to go to places that they were familiar with, where there was some trading which had happened at that time. So, now, it's—I think it's true that there are more Lebanese outside of Lebanon than inside, of Lebanese, that's strew all around the world, and a number of them did extremely well. a number of them had [achieved prominence] in the US. Senator George Mitchell was the head of the senate. I think his mom was Lebanese. ZIERLER: Yes. ELACHI: There were a number of people who rose in the military, very high in the military, like head of NATO and so on, over the years were Lebanese. And there was one who became a space scientist like me. [laugh] ZIERLER: [laugh] Charles, of course, you would've been too young to remember. But in 1948, with the creation of the state of Israel, and the consequent refugee crisis of displaced Palestinians, how was your area where you grew up? Your family even, how were they affected by these events? ELACHI: Well, as you said, I don't remember the event. I mean, I was one years old, at that time. Most of the immigration ended up—I mean, the Palestinian end up going into southern Lebanon, so there were very few Palestinian in our hometown. We were kind of halfway up in Lebanon, kind of in the middle of the country. So, most of the refugees ended up in southern Lebanon, which is next to the border with Israel. And, to some extent, in Beirut, because that's where a lot of the work was, this is where the people found jobs. So, in our case, I mean, when I was growing up, that—I mean, I used to hear the news, but that was not an issue which affected us, personally. And when I was growing up, and I was in in the middle schools, because that was in the late '50, early '60s, there were a number of Jewish Lebanese who were also at the university. So, there was a fairly good-sized Jewish community. Then after, I think, in the '67 war, but, by then, that was the year—at that time, I was in France—then there were a number of Jewish families who left and went to Israel. So, I did not see it first-hand. The only thing—a vague memory I have, I think, 1956 or 1958 where there was a war between Israel and Egypt, on the Suez Canal, and the French were involved. I remember seeing a number of airplanes taking off from the airport, which was in our town, and a couple of raids, I vaguely remember them, but nothing serious, doing that. So, that's the main memory I have about that part of the politics in the Middle East. ZIERLER: Charles, did your father ever take you to his work? Did that plant a seed in terms of your interest in engineering? ELACHI: Oh, yeah. Oh, yeah. No, that was a lot of fun. I loved doing that because the railway station was literally five minutes' walk from our house. So, I used to go in the machine shop, and watch people, working in the machine shop. And at that age when I was a kid, I mean, a train was like a huge machine— ZIERLER: Yeah. [laugh] ELACHI: —that you will see. And I did a lot of train travel between our town and Damascus to go and visit, all my relatives. So, I was always fascinated by the trains. Even until now, I love trains, because of that memory that I have there. So, I went to—I go—a few years ago, I went—there are some trains next to the zoo here in Los Angeles. So, I used to love doing that. And even I remember, one very fond memory, is there was a circus which was in Beirut, and they were moving to Damascus, so they took all the animals in the train. And they stayed overnight in the station in our hometown. So, my dad took me during the night, and we went there, watching the lions and so on inside the cabins, the train, the transportation train. So, I still remember that event. Well, I think I must've been 8 or 9, at that time. ZIERLER: Did your mom work outside the home at all? ELACHI: No, that was not common at all, you know. Matter of fact, it was very, very rare. So, no, she was at home. She was taking care of the cooking and the cleaning, and raising the kids, and all of this. So, I mean, I love my parents. They were very loving parents. My mom was a great cook. So now, when I do cooking at home, I try to remember what she cooked, and what did she do? So, I try from memory to [laugh] try to mimic her cooking, but her cooking was much better than mine. ZIERLER: What were some of the dishes she made that would bring you right back to childhood? ELACHI: Well, I mean, there were the salads, what's called tabbouleh and fattoush, which were mostly a green kind of salad mixture of cracked wheat and parsley, and that I know how to do. That I do regularly. And others I remember was one dish which was kibbeh, which was meat and cracked wheat which was cooked. And, of course shish kebab, that was very common, in the Middle East, I mean, particularly in our part of the country. The other thing that she used to do is falafel, which is still common now. So, that was something that we used to have. And an interesting part, touching about cooking in general, most of the shopping used to be done where farmers used to come into town. And they had their donkey or their horse, and they used to have bags on it with different vegetables and fruits, and they used to come from home to home, you know. And my mom [would] go out, and decide what she wants, and get them there. So, my wife kiddingly says it's like today's Amazon. ZIERLER: [laugh] ELACHI: Instead of doing it online, they come to you [laugh], instead of going to the market of knowing that. So, that's my memory. And the same thing, so, there was one guy who used to come with the vegetables. Another guy used to come with the milk, that was all fresh, acquired that same day, and he used to come around. So, it's like the Altadena Dairy, except delivered at home, and you get as much as you want. The only thing which she had to go to the town for was meat because it had to be fresh. It was hard to bring it on the back of a donkey. So, there was a place about a couple of hundred yards from our house where she used to go and get the meat, from it. Also, what was kind of common for families was to raise a sheep or couple of sheep, and then on Easter, they used to have somebody come and slaughter the sheep just outside in our yard, and then have a big feast. Because my father was the oldest person in his family, so he used to invite his brother and sisters, and they used to come and have lunch at our house, I mean, shish kebab and so on. So, my mom used to be in charge of putting all of that together. ZIERLER: And the house where you lived, it was more rural or was more urban? ELACHI: Well, it's interesting. The house I grew up in, as I mentioned to you, there was an air base, in our town. And that air base was a French air base. And then when Lebanon got its independence in 1948 also, so the French left, and turned over that base to the Lebanese government, except they took all—a significant part of it, and they turned it over to two orders, religious orders—one for nuns, and one for priests—to have schools in that area. And then the house of the commandant of the base was sold, and that's what my dad bought. And, so, we were living in a house which was the commandant's house, which was built effectively like a French house, a French country house. So, we had a veranda all around the house. We had a bathroom, which was very uncommon in that part. That's the house, so where I grew up, it was more in a bit French country house with a big yard. My grandparents—where my father grew up, which was about half a mile from our house in the middle of the town, that was built in the old-fashioned way. So, the bricks were made of mud, and the roof was a mud roof, to do that. And every year after the first rain, they had to take in big rolling stone and to press the mud, to create—basically to insulate, things. So, most of the town—not all of them but most of the town—was built in old traditional ways. But there were a number of homes which were kind of more on the Western way, of building. ZIERLER: What were Easter and Christmas celebrations like in your family? ELACHI: Yeah, they were big. I mean, that was a big celebration, particularly Easter. Easter even more than Christmas. And Easter was a time to have—well, really, in the morning, we used to have to go to church, for it all dressed up. And then later in the day, we had a big, big lunch at our house with all our—friends and family used to come to our house. Christmas was more on the religious side, you know. It was more a small family event. And we used to have presents, except the big difference, we were happy with one present. That's what [laugh]—now, for our daughter, we have all kinds of presents— ZIERLER: [laugh] Yeah. ELACHI: —under the tree. And we used to have trees. The other thing which was very common was to do a crèche, a nativity scene. We call it crèche because that was the French name for it. So, my older brother used to be in charge of putting it together, to have paper, painted rocks, and have little statues, and build a crèche in our living room, and have the little statue. And as we were getting older and fancier, then we start putting little trains, run by batteries. So, we used to work on preparing for it, like, for three, four months ahead of time, you know. And then we used to build it, like, about two weeks before Christmas, and then keep it for—through Christmas time. And most of the churches used to have a nativity scene also. So, we used to help, because the nun's school where I went in elementary school was literally next door to us, you know. It was only like 20 yards from it. And there was a church there, so I used to go and help, and my brother used to go and help in putting together the nativity scene. ZIERLER: I have to ask, was your Christmas tree a cedar tree or was it a pine tree like in the United States? ELACHI: Well, it was whatever we were able to get. [laugh] ZIERLER: [laugh] ELACHI: I mean, there are lots of small cedar trees, but the cedar trees are fairly rare at that time because Lebanon, a long time ago, used to be covered by cedar trees. But they were cut a lot during the pharaohs' time, and the Temple in Jerusalem was built by cedar trees because they were very…I mean, both the wood was very good, and it had a very fragrant smell. So, for particularly in—for temples, they used to use a lot of the cedar trees, and that led to a lot of cutting. So, the leftover cedar trees which are located in three or four locations are pretty protected, now. ZIERLER: What kind of school did you go to as a young boy? ELACHI: Oh, well, for my elementary school, I went to the nun's school next to us because my parents knew the nuns very well, and they were very good friends with them. Even though it was mostly a girls' school, but for up to about 10 years old, they used to allow, a few boys there. So, the majority of the students were girls, in my class. I think in my class of, like, 20 students, we were, like, 2 or 3 boys, in that school. And it was very well done. I mean, the nuns—it was all taught by the nuns. They were all very well-educated, nuns, and we had the usual curriculum. Typical in Lebanon, particularly at that time, that everything in the morning was in French, so we had French literature, math, French—European history was all taught in French, and everything in the afternoon was taught in Arabic, like Middle Eastern literature and Middle Eastern history. Poetry was done in Arabic. So, that's what was a dual kind of personnel. So, since I was in elementary school, the beginning of elementary school, we used to do both French, and Arabic. Then at, I think, the last year of elementary school, we had to take a third language, so I picked English, and I started learning it. Then after the elementary school, I couldn't go to the girls' school, so my parents put both my older brother and me in a boarding school, which was about an hour drive from our hometown. It was just north of Beirut. It's a place called Jounieh, and it was run by an order of Lebanese priests, which was very similar to the Jesuits. They had a couple of schools in Lebanon, but that was their main school. That was their middle school. And there, as I said, it was a boarding school, and everybody in—people except from that town, everybody was in the boarding school. They came from all around, Lebanon. And, there, we were—probably had like 400 students total. Each class or each level was maybe about 40 students. And it was both elementary, middle, and high school, but I went there for the middle school and the first year, of high school. That was kind of an interesting experience, being in a boarding school. I think it taught me a lot of discipline. The priests were very strict, you know. At 6 o'clock in the morning, the bell rings, everybody has to jump out of their bed, go wash their face or take a shower, and then we had to come and do our beds. And the priest in charge of the dorm used to come and check every student's bed, that it's done very proper, almost like the military. ZIERLER: [laugh] ELACHI: And then immediately after that, we had to go to church, at the school, and I was one of the altar boys, you know. In the Middle East, you have all this incense, and helping the priest, getting dressed, and so on. So, I said later in life that I have enough credit in heaven because I went to church every day— ZIERLER: [laugh] ELACHI: —for four—for five years, to church every day. [laugh] ZIERLER: [laugh] ELACHI: And that was the usual routine in the boarding school. Then we'd go to breakfast. Then we had classes from about 8:30 to noon, and then a break at noon, for lunch and for play. And then from 1:30 to 4:30, again, back to classes, and then doing homework in the evening, and dinner. So, it was very well-regulated. And at that time, we used to go to school five and a half days a week. On Saturday, we used to have half a day. The morning was school. And Saturday afternoon was off, so they used to let us, when we were a little bit older, to go into the town, just for walks. And then on Sunday, regularly, they used to take us for an outing. So, all of us, we used to go in the busses, and go to different parts of Lebanon. So, it was kind of a civic education, if you want, visiting different parts of Lebanon. We went to where the cedars are, to Baalbek where there are many Roman ruins, to southern Lebanon. So, that was—and the nice thing about being in a boarding school is like when you are in college here, is you build a lot of relationships at a young age. So, many of my present friends, even that they live in Lebanon now, but we communicate regularly, go back to my middle school days. We stayed in communication with each other, and some of us went together to France at that time. And then the next thing in my education in Lebanon is the last two years, then there was also a very good school not too far from us for high school. So, I came back, I lived at home, and I used to take the bus every morning to go to my high school the last two years. It was in a town called Zahlé, which was a much bigger town than our town. And it was about like a 15-minute or 20-minute bus ride, to it. So, that's where I did the last two years of high school. ZIERLER: Charles, tell me about Sputnik, what that day was like for you, how this event registered even as a small boy. ELACHI: For which event, sorry? ZIERLER: Sputnik. ELACHI: Oh, Sputnik. Well, that was a very formative event because one of the gifts I got for Christmas when I was a little kid was a portable radio. It's called the Zenith radio, Z-E-N-I-T-H. I still remember it. It was about this big. I used to carry it everywhere with me, listening to news and listening to music on it. And I remember in 1957, I was 10 years old. I was sitting down, listening to the news, and they start talking about this satellite called Sputnik. And they had a recording of the beep from Sputnik. So, for me, I was amazed that, gee, we can actually put something in space. I still remember it until now where I was sitting and listening to that beep, on Sputnik. I never thought that I would be involved in the space program later in life. And then I remember about three months after that, because I was always curious about events around the world, I registered in a magazine that was issued by the American embassy in Beirut, and it was called Life in the United States, or something like that. And it was in English but I knew—both English and Arabic. They used to have it in both. And I used to be able to read English a little bit because of what I was taking at school. And I remember very clearly one day getting the magazine, and looking through it, and it said the US has launched a satellite called Explorer from a place called JPL in Pasadena. I had no idea where Pasadena is but I still remember it until now. I remember the column where it was, because I was fascinated by putting things in space, and doing that. So, that brought both the combination of Sputnik and, three months later, reading about Explorer satellite was—it stuck in my memory very well. And the name JPL stuck in my memory, very well at that time. [laugh] ZIERLER: Charles, even as a 10-year-old, did you have a sense that Sputnik was part of this larger competition between these two giant countries, the United States and the Soviet Union? ELACHI: Yeah. No, because the whole thing of communism and capitalism, democracy, was very much in the news— ZIERLER: Yeah. ELACHI: —in Lebanon, the Middle East. So, yeah, it was—I mean, I kind of—I was not as deeply in it until I got older. But I do remember that there was this competition between communism and the US, and the whole issue of the Cold War, because remember, that was about 1958, the late '50s, early '60s. So, that was at the heart of the Cold War, and the issue of nuclear events. And, I mean, we were not as—we didn't get the training like my wife tells me that she did here where they had to do sit—if anything would happen, you'd duck under the desk…we didn't do any of that. But I was aware of it from my reading because I used to be very curious…I used to read a lot of magazines, when I was a kid, of different kinds of things, political magazine and so on because I was always curious about these events. So, yeah, no, I was pretty aware of those events. We had one of my uncles who immigrated to Argentina, and a number of people in our hometown, they had family which immigrated to the United States. So, we were—I don't recall anybody immigrating to Russia. So, we were more of— ZIERLER: [laugh] ELACHI: —[laugh] the capitalist kind of inclination. So, yeah, I was very much aware of those things. And when I was a kid, in addition to science, I used to love history and geography, so I used to do a lot of reading. Matter of fact, one of the things I remember is I got fascinated by stamps. I collected stamps. It used to be my—I mean, I used to get like—every week, my dad used to give me a quarter or—which was big money at that time. I used to collect them and go and buy stamps from that town close to us, and I arranged them. And I still have them now. My younger brother's son has them. And part of the deal that my dad said to give me the money to collect stamps, he said I have to read about every one of the countries, you know. So, that was kind of an incentive to get educated. And in my younger days when I was in middle school, and even elementary school, a challenge for me was to know the capitol of every country, around the world. And my dad used to be very proud that his son knows the capitol of every country. So, when we used to have friends, visiting, he used to tell them, "OK, name a country, and my son will tell you what the capital is— ZIERLER: [laugh] ELACHI: —"of that country." [laugh] I remember that all the way till now. Even until now, I love geography, and I transmitted that to my grandson. I have a grandson who is 12 years old who lives up in San Francisco. And, for some reason, he got fascinated with coins and money bills. And when I used to travel—when I was director at JPL, I used to travel a lot—I always used to keep a couple of the coins from whatever country I went to. And in my last count, I've been to like 70 or 80 countries. So, I used to collect all of these. And when my grandson told me that he wants to collect, currency and so on for whatever reason, so I sent him a bunch of them but I told him—I remembered what my dad told me. I told him, "OK, you need to write me a page about every country that you get the currency." And he did. ZIERLER: [laugh] ELACHI: He actually sat down and—now, in his case, he went on Google, and figured out— ZIERLER: [laugh] ELACHI: —all the things. In my case, I had to go and read about them. ZIERLER: [laugh] ELACHI: So, he sent me a big package here about every country, and there was a one-page write-up about the name of the country, the capitol, what the government system in that country, and so on. So, it's a good education, for people, I mean, to use either currency or stamps for a young kid to learn about their geography and about the history of those countries. ZIERLER: Charles, what was your reaction when President John Kennedy pledged that we would put a man on the moon by the end of the decade? ELACHI: I think that was—so, by that time, let's see, I was in high school, you know. And I remember very—and I remember, particularly when after I finished the boarding school—so, that was in '63 or '64—when I was in the high school not too far from our town, and it was a fairly good-sized town. And I remember the treat, usually during lunch break, they used to let us to go out into the town. There was a store not too far from the school where they had TV in their display. It was old-fashioned TV. And a lot of the events, flights—before landing on the moon, they used to have them, on the news. We used to be a group of us all go and look at that time, so it was a very fascinating time. And then also in that town, there was what's called a French cultural center. Because of the French influence in about half a dozen towns in Lebanon, the big ones, there was a cultural center, run by the French. And there they used to have a lot of magazines, French magazines, science magazine. So, also, I used to go and spend a lot of time there, and I remember many articles about the space, program in ‘63 and '64. I vaguely remember when Kennedy was shot, that time in '63. But I didn't connect with it as much as people in the US, the impact of it. I mean, I remember Kennedy talking about the Cold War, but I don't remember all the things that he has done, or I was not as engaged in it. But I remember when that event happened. It was a kind of big deal worldwide. But I didn't personally associate with it as much as with the space program. ZIERLER: Between your parents and your teachers or even yourself, how young were you when it became obvious that you had special academic abilities, particularly in math and science? ELACHI: Well, I would say it was a little bit in the elementary school because, all the other girls used to come to me to help them with the little math problems— ZIERLER: [laugh] ELACHI: —that we were doing, so I must've been good because I remember. So, that was kind of—maybe I was too young, but that was fun to help the girls in what I was doing. ZIERLER: [laugh] ELACHI: Then in the middle school, we had a really great science and math teacher. And at that time, I would say, second year in middle school, I started appreciating that, really, I found it a lot of fun, working on my math and science homework. And I remember during the summers—I used to be back at home during the summers—I used to spend my time reading the books that my older brother had. He was like three levels ahead of me, so when I was in middle school, he was in high school. So, the big fun I used to have is to look at his science and math books. And there in Lebanon, they used to give us things to do during the summer, like homework, if you want, that we had to do. And my brother had the same. And I used to challenge myself to see if I can do my brother's homework or his math. So, I kind of started learning algebra about two years before I was taking algebra. So, somehow, I got a passion for it, and my mother used to encourage us, because she was at home more than my father. She used to make—she always made sure that we sit down, do our homework, spend the time doing the homework, and there was time for play, and time, for doing the reading, the homework. So, I would say around middle school, I really started to think that I really love math and science and history and geography. These were my favorite things. I was not good at literature. That used to be my challenging [laugh] job— ZIERLER: [laugh] ELACHI: —is doing, my homework, for literature. Particularly the Arabic language is pretty challenging. I mean, it's very poetic. But it was very challenging to do the grammar, in that one, so that used to be one of my big challenges. Then I think I particularly blossomed when I got in the last two years at high school. I was clearly at the top of my class, in the town next to us. And then there was national exam in Lebanon. To graduate from the last two years of high school, the year before the last year, there was a national exam. And the last year, there was a national exam, and you could not move from one year to the next unless you passed that national exam. So, if the year before the end of high school—we called it première, the year for first—if you don't pass the national exam, you have to stay in that class the following year until you pass the national exam. So, in the last two years, I scored at the top in Lebanon. That was a big deal both at my high school and at my hometown, that I was the first, I got a perfect score in math and science on the exam. The school used to show off. They had it in their brochures that with pictures that this is our student. One of our students was the top in Lebanon. Matter of fact, I still have that brochure with me now. It's sitting in one of—in our basement, which has a picture of all the people who passed the exam and graduated. And at the top is a person with my picture that I was the first, the top scorer in the whole country. And, in a sense, that's what had an impact because the minister of education in Lebanon, just the year where I was doing the final exam, he said that whoever get the top score will get a fellowship to go and study in France, for engineering. So, because I was the first, I got that scholarship, so I had the choice to go anywhere in France that I wanted to get my engineering or science degree. So, that kind of impacted my life. And the other part is, again, I remember my dad was so proud, he—I think he told everybody in town that his son was the first [laugh], that graduated first from high school. ZIERLER: Before we move on to France, your love of Hollywood, did that develop during your time in Lebanon? Was there a local movie theater where you could go and see Hollywood pictures? ELACHI: Yeah, absolutely, and my learning English because international…there was only one movie theater in our hometown. As I said, it's a small hometown. And the movie theater was also very close to our house. I mean, literally at the entrance to our yard, immediately next to it, there was the main street of the town, and the movie theater was there. It didn't have a name, but it was a movie theater. And the owner of the movie theater was best friends with my dad, so he used to allow me to go in for free to the show. So, I took advantage of it, so every weekend—and they used to change the movie every week. It was a different movie. Sometimes, it was an Arabic movie. Sometimes, it was a Western movie. So, I used to go every weekend. I had this slot on Saturday evening, late afternoon or evening to go and see the movies. And that's where I fell in love with all the Western American movies, John Wayne— ZIERLER: [laugh] ELACHI: —or the pirates, Errol Flynn. So, that was my introduction, personal introduction to Hollywood and the US. And it was great for my English because they were all subtitled in Arabic. I mean, the movies were in—so, I used to listen and read the subtitles, you know. So, that kind of connected me to improve my English on doing that. And every once in a while, the nuns used to take, all the students, the young students, to proper movies. That means movies where there was not lots of kissing and so on because we were all 8, 9 years old. And the rule was if you see people, they are going to kiss, we had to put our hands on our eyes— ZIERLER: [laugh] ELACHI: —so we don't [laugh]—I remember that kind of funny thing. There was nothing more than just kissing. ZIERLER: Of course. ELACHI: Otherwise, they wouldn't— ZIERLER: [laugh] ELACHI: —they wouldn't take us there, and they wouldn't have the movies in that area. So, yeah, I had very fond memories of all these movies, and I did the same when I went to France after. And even in the boarding school, they used to have—once a week, they used to take the kids to—that was a bigger town—to one of the movie theaters, in there to watch different movies. And the most common, as I said, were Egyptian movies because it was the biggest production of movies in the Middle East, or French movies, or American movies. And most of the American movies I watched were mostly cowboy, Western kinds of things, which really reflected, in a sense, about the spirit of the United States, particularly the western part, of the United States. ZIERLER: Did you feel conflicted at all about leaving home? ELACHI: Well, not conflicted, but it was a big challenge. So, first, when I went to boarding school, the beginning of it was tough. Even that it was only an hour drive, it seemed like the end of the world— ZIERLER: Yeah. ELACHI: —for a little kid, doing that. I remember—but what helped was that my older brother was also at the same boarding school. He was a few years, ahead of me. But I do remember, when first my parents took me there, and dropped me there. That first couple of days were very tough, you know. I was crying. But other kids my age were [feeling] the same thing. They were coming from all around Lebanon, so it was tough, for them, also. But after a few weeks, it became common because there were lots of other kids your age and so on. And I think living in a boarding school made it a lot easier after when I had to go to France because I was—I used to go to see my parents only during Christmas vacation, Easter vacation, and in the summer. So, it was not like I was going every—so, I had to become somewhat independent and, kind of manage on my own, do my laundry because the school required the kids to go and do their own laundry…so, it was really good training. That was the period when I was 11 to about 15, so it was really a good training being in a boarding school for that. That ended up really, because of other kids my age, after a couple of weeks, it became fairly easy and fairly normal to do that. ZIERLER: Now, the new program that gave you this wonderful opportunity to go to France, anywhere that you wanted, was the stipulation that it needed to be a degree in engineering? ELACHI: Yes, because I think the government at that time was trying a little bit to expand the technical experience in the country. And in Lebanon when you get the last two years of high school, there were two tracks. There was a literature track and—which needed people to become lawyers or authors or businesspeople, and then there was the technical track, which was mostly for engineering. I mean, the big things in the Middle East for educated people were either to become an engineer or to become a doctor or to become a lawyer. So, the engineer and the doctor were the science track, and the lawyers and other function of government officials and so on were the literature track. And that's the same way in France at that time. So, of course, I chose the science and math track, and I got first in those areas. And it was a requirement that the fellowship was—because they wanted to expand the number of engineers, and not scientists in the traditional sense that we think science here because there was not very much research. So, it was really more the engineering side. So, yes, I had to go and do a degree in engineering, which was perfectly fine for me because that's what I wanted to do anyway. So, that's why I end up going to Grenoble. Then an interesting story, the reason I end up going to Grenoble versus Paris or any other place, as I mentioned earlier, there was this French cultural center in the town where I was at the last two years of high school. So, I used to go to it, and it was not too far from our high school. So, during lunch break, I used to go grab a sandwich, and go down to that center, and read the magazine. And there was a lady there which, I mean, she was very nice. She was trying to help students and so on, so I got to know her pretty well. So, when I needed to go to France for the school, I asked her, where does she recommend? And it turned out she came from the region of Grenoble. So, she told me about how beautiful it is there, and there was a school called Institut Polytechnique de Grenoble, which was one of the top schools. So, she said, "If you go there, if you are interested, you have to go for one year at the university, the general university. Then you have to take an exam to be accepted at the École Polytechnique, which is the engineering school, to enter in it. And if you pass, you can enter. If you don't pass, you can continue in the university itself." So, that's what led me to go to Grenoble specifically versus Paris. And she showed me a picture, and it looked like a beautiful place, in there. So, that's how I end up going to Grenoble. ZIERLER: Were there other international students there? ELACHI: Yeah, it was a big international kind of university. There were lots of people from all around the world, particularly studying French—and in the French system, one of the nice things about French university is that if you get a baccalaureate particularly from any of the old French colonies—so Lebanon being one of them, Algeria, Morocco, many countries in Africa—if you pass the French baccalaureate, you're—automatically, you have room at the university, not at the Grand École but at the university itself. So, it was fairly easy to do that, and there were a lot of international students. Matter of fact, a number of students from my high school actually went and graduated and wanted to go to France actually went there. So, there were a couple of us. There was, matter of fact, three of us, we knew each other in high school and were very good friends when we went to that university. So, we were there together. And, matter of fact, the first year, we roomed together, and then we moved to the student housing, after that. And we were in the same building there, so we kind of socialized together a fair amount from there. And then we end up meeting a number of French students and American students and so on when we were in Grenoble. ZIERLER: Relative to your classmates, how well prepared did you feel you were coming from Lebanon? ELACHI: We were pretty well prepared, I would say. But the language was fairly easy for us because that was fairly normal, to speak in French and so that was not a challenge at all. The technical stuff, it was challenging for a number of the students. But, for me, even in the first year I was in Grenoble at the university, I scored the top in both math, physics, and chemistry, the top of the class. So, I was pretty well prepared. And that helped me when I took then the exam to enter the engineering school, the Grand École. Because at the university, the university was about, at that time, like 30,000 students, so it was a huge university. The science part of it was probably about 500, 600 in the first year, and that's the one where I scored the highest. And then the engineering school would accept only 30. It was a very challenging exam to get through it, but I passed it. So, then, I moved from the university into the engineering school, which was on the same campus, but it was separate. So, it was like—the Grand École in France for people familiar particularly in École Polytechnique are the equivalent of Caltech and MIT in the United States, and with Stanford. So, they were very elite. And they were started during the time of Napoléon, and the focus on it was they wanted to train the engineers who would become the top in the government, managing the engineering things. So, even until today, the vast majority of the ministers in France and the top government bureaucrats, officials, all came out from Grand École, either the engineering Grand École or there are some for administration and economics Grand École, so the vast majority, overwhelming majority. So, being in the Grand École is somewhat an elitist thing, and it gives you a big advantage later in one's career [laugh], in doing that. So, all the French presidents came out of the administrative Grand École, in France. ZIERLER: Did you go back home during the summers? ELACHI: Not every year. So, after the first year, I went back home because my dad passed away while I was in my first year, in France. So, I wanted to go back to see—my mom then was by herself, and I had a younger brother and younger sister who were still at home. My older brother came and spent one year also in France for the end of his education. He came also to Grenoble because I was there, so we both went back, went back home, and my brother stayed in Lebanon, and I came back. And then after that for the following two summers, because the Grand École was three years, for the following two summers, I actually ended up working—I was required to work in France…I mean, at the university as—or at a company that was part of the arrangement for the Grand École. So, I did not go back until I graduated from Grenoble before I came to the US. So, I spent those two—so, in one row, three years all in France. ZIERLER: Besides doing so well in the classes, what did you love the most in your curriculum? ELACHI: Well, I mean, in the broader curriculum that was—it happened when I got to France, and so that was 1964. Four years after that, 1968, the Winter Olympics was in Grenoble, so that was a big deal, as you could imagine. I mean, it's a big deal now. It used to be even a bigger deal, at that time. So, there was a lot of development, like ice skating rinks, skiing. So, that was really—it was popular in Grenoble because it was next to the mountains. So, I started learning that. That was my side hobby. I learned ice skating. The main ice-skating rink, the Olympic one, was on the campus itself. It was a very big—it was a brand-new campus. I used to go and do ice skating, in the evenings, and, then during the weekend, to go learn skiing. So, these were my two biggest hobbies, outside education, that I did. And, also, I made a number of friends with American students, who were there mostly for learning English. I remember the first one I met was almost an American. He was from Canada, and he came from Vancouver, and he was a great skier. I used to go with him, skiing, and doing that. So, that was kind of the side hobby. And in the summer, the hobby was to go hiking. There was a lot of hiking in the mountains there. I remember one of the hikes I did was to a monastery not too far from Grenoble where they make the chartreuse. You know the drink, chartreuse? It's a green drink which now is pretty common. We used to go there to do tasting. That was kind of our hiking, an outing that we used to love doing. At that time, we didn't have a car. There were a few students who had a car. And I remember one of my friends had a car, one of these old-fashioned French—what they call them deux chevaux. It's a Citroën car. And deux chevaux means it's two horsepower. And, literally, it had only two horsepower. And when you are going up the hills, steep hills, we used to get out so the car can kind of struggle its way up. So, that's kind of my memory from the early Citroën kind of cars. [laugh] ZIERLER: Was it engineering that was your primary focus in Grenoble, or it was math, physics, engineering altogether? ELACHI: Well, it was mostly engineering. But in the French education, you had to take a broad program, so there was math and chemistry and physics that were part of it. So, basically, you don't focus on the engineering until the last year. They try to do a broad education, in the sciences and the technology. And, matter of fact, one thing I remember very well, the director of our school who taught the physics class, his name was Louis Neél. And while I was there, he got the Nobel Prize for his physics research. It's called—it's a low-temperature transition thing which called the Neél temperature. It's spelled N-E-E-L. And he was well-known. When I came to Caltech, many of the faculty here knew about him. So, it was kind of a special treat of having a Nobel Laureate teaching our physics class and being the director of our school also. ZIERLER: Did the student protests that shook Paris in 1968 and so many other places in the world, did they arrive in Grenoble? ELACHI: Well, 1968 is very historic in France. I mean, even now, as soon as I mention I graduated in 1968, they say, "Oh, yeah, that's when the student revolt was there." And, yes, it was not as—in Paris, it was really a big deal. I mean, they were pulling rocks from the old roads, the pavers and barricades. And it was not that much in Grenoble, but there was a fair amount of protest, at that time. And because of that, we actually did not have a graduation ceremony because the protest happened in May 1968. So, we finished our classes, we finished the school, and then they mailed us our graduation certificate. So, we didn't have the commencement event that normally they would do. So, yeah, it was a big deal, in France at that time, and I remember it very well. And, matter of fact, an interesting thing, fast-forward, when I was a director of JPL, I used to deal a lot with the French Space Agency. And one day, I was speaking with the head of the French Space Agency and, somehow, I mentioned I graduated from Grenoble in '68. They said, "Yeah, I graduated from Paris from École Polytechnique in Paris in 1968." So, that kind of built a little bit of a connection. [laugh] ZIERLER: What about a year earlier with the Six-Day War? Was your family in Lebanon affected by that? ELACHI: Not very much. I mean, I was in France, at that time, and we heard about it. At that time, we had TV, and radio. There was no effect in our hometown, at that time, so it was mostly—and, if you recall that, Lebanon did not play a big role in it. It was mostly between Egypt, Jordan, and Syria. So, we kept track of it, but it was not really a big issue for us. I mean, we were a little bit worried about our parents, but we knew from the news that Lebanon was not affected. And an interesting thing, you triggered an interesting thought, because, at that time, we didn't have iPhones like I have here. So, most of the communication was by letters, which used to take a lot of time. And every once in a while, I used to make a call, because my parents had at home an old-fashioned phone. So, we used to have to go to the local post office in Grenoble, reserve time. So, at that time, we used to go in the phone booth, and they use—the operator used to do a connection, to our home. We used to do it in the evening to make sure my mom is at home. So, when I tell that to our daughter who can communicate with her friends anywhere around the world on her iPhone, she thinks we are ancient, you know [laugh]— ZIERLER: [laugh] ELACHI: —and how we used to do things in those days. [laugh] ZIERLER: [laugh] Charles, as you were explaining, going to France for a degree in engineering came with, I assume, an expectation to come back to Lebanon and pursue a career in engineering to help the country. ELACHI: Yeah. Well, it was an expectation but not a requirement— ZIERLER: Right. ELACHI: —to do that. So, I had the flexibility. There was no requirement for me to go back. And, in Lebanon, there is the philosophy—and in France, to some extent—there is a philosophy that educated people, even if they don't come back, that's a big asset for the country. Matter of fact, one day after, when I was here in the US, and I was dealing with the French, there was a French ambassador here when I arrived. So, I kind of asked the ambassador, the French ambassador in the US, "Why do you educate people in France for free?" Because we paid literally, I remember, I paid 10 French francs for the annual tuition, and it was really for registration. The tuition was free, even though I was not a French citizen. And all the foreign nationals paid nothing, at that time, I mean, except registration. And his answer was very simple. He said, "We want people to be educated in France, and like France because wherever they are in the world, if they are educated, they are going to become senior people in their company. And when they want to import things, guess what they will think?" ZIERLER: Yeah. ELACHI: "They go to French companies because they"—so, he said they figured it out that it's a big return on the investment, you know. By educating people from all around the world is building commercial relationships, scientific relationships. And I have to admit, when I was a director at JPL, even before when I—I had a little tendency to work with the French scientists on doing that—not exclusively. I mean, I worked a lot with Germans and Italians. But the fact that I had a French education, and I grew up through France—a French system, that kind of give you that connection, if you want. So, it pays off. And the same thinking is in Lebanon. I mean, if Lebanese immigrants are educated and so on, they will keep connections with Lebanon. Matter of fact, one of the biggest incomes for Lebanon is people who are outside of Lebanon sending funding to their families, or do trading with Lebanon, and so on. So, they had that broader philosophy, of doing that. ZIERLER: As it was coming time to graduate, what options did you have? What were you considering for your next move? ELACHI: Well, I was very excited about science, and I spent two summers working in physics labs in Grenoble. Matter of fact, I still remember the professor. His name was Professor Pebay-Peroula, and he had a lab where he was doing discharges, electric discharges in different gases, and he looked at the emissions, the spectral emission coming from the different gases, and change the voltage and so on. So, it was kind of a basic physics activity. I worked in that lab for the two summers, so I spent a lot of time measuring the spectra. So, I kind of got fascinated in doing a PhD in that field, which was more—it was not really engineering. It was more a physics kind of area. But because of the broad education that we had, that was equally good. So, I was planning to get—continue for a PhD, and he told me he would be glad to help me in his lab and do my PhD in that area. But then during the last year about—it was late summer, last summer before my last year in France, I was with a friend of mine in the student cafeteria, and these two girls came and sit next to us. And it turned out that they were Americans studying English in—I'm sorry, studying French in Grenoble, and they wanted to chat, in French. So, we started chatting, and they were these two nice girls. One of them, she came from Illinois. And then on one of the days, we were having—we started having lunch together regularly. One of them asked me, "Well, what are you planning to do when you finish?" So, I told her I was planning to get a PhD in Grenoble. She says, "why don't you go to the US?" Because we used to go together to see the movies, and she knew that I love Western movies. She said, "Why don't you come to the US for it?" So, I said, "Well, I'm not familiar with the education system in the US, and how you apply, and so on." So, she said, "Well, my dad is the—he works in the office of the dean of admission at the University of Illinois. I'll have him send you some information." So, when she left at the end of summer, I thought I'll never hear from her. Well, a couple of weeks later, I get this big envelope, from her dad with a bunch of applications for the different schools because I told her what I'm interested in, and explaining that I have to fill these forms, and I have to take, an English exam, in France to—as part of the application. So, I said, heck, there's nothing to lose. I'll sit down and apply. So, I applied to MIT, Stanford, Caltech, University of Illinois, Indiana…Ohio State because they had a lot of work related to telecommunication, which was the area I was [interested in]—and then a few months later, I keep getting—I kept getting these letters of acceptance. Because also in the École Polytechnique, I was at top of the class. I was scoring the highest, at the school. So, I kept getting all these admittances, some of them with fellowships. And, so, I started looking more seriously at these places. MIT I had heard about. Stanford, I've heard about because they are—usually, you hear about that school. But I haven't heard much about Caltech. So, I said, well, let me figure out where in the heck is Caltech. So, I knew it was Pasadena because of the address, so I looked at a map. It was a tourist map. ZIERLER: [laugh] ELACHI: And it had California, Los Angeles, and it had in small letters "Pasadena" with a little Rose Bowl. And then above it, it had in big letter "Hollywood"— ZIERLER: [laugh] ELACHI: —in there, I guess, to attract the tourists. I said, wow. If I go to Caltech, I can go to all see all these movie stars that I— ZIERLER: [laugh] ELACHI: —I remember. I had no idea how big Los Angeles is. ZIERLER: [laugh] ELACHI: I thought it's maybe like a Grenoble, which is about a couple hundred thousand people. So, I went to one of my teachers, a faculty member. I told him, "Do you know this place, Caltech?" And he said, "Oh, yeah, I know it's very world famous. It's a great school." And, matter of fact, he told me, "I know one of the professors, which is exactly the field you're interested in," because it happened when that French professor had a—did a postdoc at Harvard, and he room-mated with another postdoc called Charlie Papas. And that American postdoc ended up becoming a faculty at Caltech, a professor in applied physics at Caltech in exactly the field of electromagnetic waves, electromagnetic theory. He said, "Papas is a great guy. I'm sure he would love to have you, in his group." So, that's how I decided at Caltech, and one factor was the professor knowing a professor here at Caltech. The other fact that Caltech was generous enough to give me a graduate fellowship here because, otherwise, there was no way I could have afforded, coming to the US. So, that's basically the two factors which led me to Caltech, and I'm glad I did that. So, it was Hollywood, knowing a professor here, and the fellowship, and it was probably the best decision I made in my life is coming to Caltech. ZIERLER: Charles, when you accepted the offer to come to Caltech, at some basic level, did you realize that that meant that you would not be returning to Lebanon? ELACHI: It's hard to tell. In actuality, I was thinking—because, at that time, I didn't know the connection between JPL and Caltech. So, I kept track of JPL, I mean, on the news—when I was in France, I kept track of all what's happening in the space program, watching the TV and the news. So, I knew a lot about JPL and NASA, in general. But I didn't know much about Caltech. Part of my thinking, I mean, I really didn't have this long-term plan, to be honest with you. I was thinking, gee, I'll come get my PhD, and, most likely, I'll go back to France, and work in France because in Lebanon, there was not many opportunities for research. And by that time, I was kind of becoming more inclined towards the research versus the traditional engineering, working in an engineering company. So, I was thinking more of going back to France after that. And then I came to Caltech, and, shortly after that, I found out that JPL is next door, about a few miles away, and that Caltech actually manages JPL for NASA. So, I said, wow, look at what a coincidence, how these things happen. So, the second year, I applied for the summer job at JPL, and I was accepted. ZIERLER: And what was your home department at Caltech? ELACHI: It was Electrical Engineering. So, that's where—it was in the steel building at that time. So, that's where my office was, and that's where Charlie Papas—and, for memory, considering you are doing the history, I remember when I came, some of my first classes were in addition to Charlie Papas, which was electromagnetic theory. There was a professor by the name of Roy Gould, who was doing plasma physics. There was a Professor Nick George, who was doing optics. There was Amnon Yariv, who was doing lasers, and Carver Mead, who was doing work in the early days of integrated optics. So, these are the classes. Over two years, I took a lot of those classes. And then there was Professor Caughey, who was giving the math class, so I took his class. And then there was Professor Cornwall, who also gave a math class. So, these are the ones I remember very well, at that time that I took all of these classes for a master's degree, and then the first year of the PhD. But then most of my work was with Charlie Papas, for doing my PhD. ZIERLER: What about the physics program? Did you take any classes in physics? ELACHI: No, not in the tradition—not in the physics department. But these classes that I mentioned were heavy in applied physics. Matter of fact, electrical engineering was effectively called electrical engineering and applied physics. In the building, they had a lot of applied physics. And many of the courses were common. So, I did not—I mean, I knew about the different faculty in physics, like Feynman's class, but I did not take that class. So, I was more in the applied physics, engineering kind of classes. ZIERLER: What was your thesis research on? ELACHI: So, I decided very quickly after this summer degree—I mean, after the master's degree is to work on wave propagation in space and time periodic media. So, that's what the physics, a medium which has a dielectric constant, but dielectric changes as a function of space but also as a function of time. So, it's like you send an electromagnetic wave in a medium which has an acoustic wave. And how do these interact with each other? So, it was purely a theoretical thesis. I don't think I did anything in the lab, at Caltech. I did some at JPL but not at Caltech. It was all theoretical, and I love that, because I like theory, electromagnetic waves. There were lots of integrals that I had to figure out. And in those days, I had to go to the library, to go in Millikan Library and dig up all these math books, about all these different integrals. And I remember one of the integrals which had relevance was called the Hill integral, which was a special kind of an integral. So, I learned a lot about integrals, differential equations, and so on, and I was pretty comfortable with them. One of the things that benefited coming from a French background is the French, they put a lot of emphasis on theory and math and so on. So, I did not have any big issue when I came to Caltech on being—doing well in my classes. It was a challenge speaking English. I mean, I could read English very well, and write it. But speaking it had—it took some while, to really get more articulate. Matter of fact, my wife kind of joked to me. She said, "I think your French is better than your English," even now, you know [laugh]— ZIERLER: [laugh] ELACHI: —even with my grammar. So, that was what was my thesis about, and that had a big impact on how I ended up in the field, how I ended up at JPL. But that's when we get to the time when I went to JPL. The other thing I remember about Caltech is really how friendly it was. Matter of fact, when I came here or when I was accepted, I got a letter from the international office at Caltech saying, "we know you're coming from France, and we have a number of international students. And we have this program if you're willing to come a month before the classes start. We can put you with an American family to learn about American life and get more acclimated." So, I said, well, that's a cool thing to do. So, I accepted. I remember, her name was Ingrid. She was Swedish here. I mean, that was a long time ago. And her office was in what used to be, the main building at Caltech which was damaged by the earthquake, which was the first building that Caltech had. Anyway, I think she connected me with a family. It was called Ziori. That was their last name, and there is a story behind that. So, I land at LAX on August 15, 1968. And I remember flying from France to New York, I spent a night in New York, and then New York to LA on United Airlines. And the family was meeting me there. So, they took me, and they had—they lived in Palos Verdes, so they had this beautiful house overlooking the ocean. And it turned out the husband was of Italian descent, and the wife was of Lebanese descent. And that's part of why they put me—I mean, she was born in the US, and they had kids roughly my age. And I thought that everybody lived like people in Palo Verdes in the US. I mean, that was my first introduction [laugh], to the US and California, and it was great. They took me everywhere, visiting Disneyland. We went to a Dodgers game, which I had no idea what was going on in the game. The only thing I remember were the hotdogs, from that game because I was accustomed to soccer games. And this bizarre thing, hitting a ball with a stick was kind of strange, for somebody coming from a Lebanese and French background. And then they brought me after—they brought me to visit Caltech, so that was my first visit here. And then after I was—I had a room in the student houses. I came around mid-September, and they helped me move. And we stayed friends, you know. I stayed friends so I used to visit them every once in a while, even when I became director at JPL. They were elderly at that time, so I used to go and visit them. And one thing is interesting for the rest of the story, so, it turned out that his name was Gene Zioli. He worked at Hughes Aircraft. at that time, it was Hughes Aircraft. So, I asked him one day, "What do you work on?" He said, "Oh, there is this new fancy technique on aircraft that puts Synthetic Aperture Radar that the satellites…" and fast-forward. Later, we can talk. That's what I end up doing, at JPL. So, it was kind of interesting sometime how events, happen in your life, both going to France and then coming to US, thinking Caltech, staying with a family. So, I always tell the young people, both my kids and the students here that I mentor, "Don't sit down and plan in detail your future because doors will open from left field." You wouldn't know. And the key thing is to be willing to walk into those doors and take the challenges. And some of them might not work, but most of the time, they will work, doing that. So, don't sit down." So, I didn't sit down and plan when I was a kid listening to Sputnik that I'm going to become the director of JPL. ZIERLER: [laugh] ELACHI: [laugh] That was the last thing I would've thought, you know. ZIERLER: [laugh] Charles, what was the moon landing like for you that day? ELACHI: Yeah, that was amazing because that was in my last year at Caltech and that happened, a couple of weeks after I got my PhD. I remember, we all got together in the student house. I was still in the student house at that time. And we were all sitting down watching that little TV in the student house at the moon landing, and that clearly had a big impact. I mean, by then, I was already kind of want to do space—sorry, actually, no, that's not—I'm thinking about it later—the moon landing. So, that was in the first year. ZIERLER: '69. ELACHI: In '69, sorry. So, I remember all of us sitting around, watching the TV in the student house, and that was amazing. And at that time, that was the first year I got a summer job at JPL. So, I mean, it was like heaven— ZIERLER: Yeah. ELACHI: —that it was, happening at that time. ZIERLER: Did JPL feel like, or did you get a sense that JPL felt like it was part of the mission? ELACHI: Oh, yeah, I mean, it was everybody because, remember, JPL before that, I was not involved in it. But before that, they did a number of lunar missions, both the Ranger mission, which were impacting the moon, and the Surveyor mission, which were the landers. Because, at that time, I remember people worrying about what the surface of the moon looks like, and will the astronauts sink, in that powder, on the surface of the moon? So, there was a whole series of missions, of robotic missions, of landers and impactors where JPL was responsible for that. So, even though I was not involved but I knew about that because we were watching that, on TV. Even I knew about them when I was in France before I came, before I came to Caltech. So, I knew there was a field of participation, for JPL playing a key role, and I think that also the mission operation room at JPL was the backup for the mission operation room at Johnson Space Center, and many of the communications were done through the JPL network. So, there was not as much involvement as if you were sitting at Johnson Space Center or what became Johnson Space Center or Cape Kennedy. But the whole country was involved, you know. At that time, it was the biggest event happening in the United States and in the world, the landing. So, really, there was a huge engagement, and there was a big pride, being a little bit—I mean, I'd just started at JPL at that time. I think it was my first week for the summer job. But there was a lot of excitement going on at that time across the country. ZIERLER: Charles, as a graduate student, what was your very first job at JPL? ELACHI: Well, because I was majoring in electromagnetic theory and so on, I applied for a summer job. And, by chance, I got interviewed by this group. The head of the group, his name was Walter Brown. And they said, "Oh, we are working on this new kind of fancy imaging system called Synthetic Aperture Radar"—which clicked in my head because— ZIERLER: Yeah. ELACHI: —the person I knew at Hughes Aircraft— "and we have an airborne system here. And our goal is to develop it so we can put it on spacecraft, both for Earth and particularly for Venus, you know." And they had a study for a mission called Venus Orbiting Imaging Radar, and most of them were engineers. And they said, "we really would like to have somebody who understands electromagnetic wave, how they propagate, how they interact with the surface so we can interpret those images that we are getting from our airborne. Do you know anything about Synthetic Aperture Radar?" And, being a Caltech student, I said, "No, but I can learn very quickly, about that." So, they said, "OK, you are hired, for the summer." I think at that time, they said, "OK, if he doesn't do well, it's only a summer." So, the following year, the school academic year, I found out that Nick George, who was doing the optics class, one segment of his class is about Synthetic Aperture Radar because there was a lot of similarity between lasers and these coherent radar [systems] called Synthetic Aperture Radar. So, I registered in that class, and that's where I learned a little bit more about synthetic aperture, optical processing. At that time, digital capability was very elementary, so there was a lot of technique of doing photographic optical processing. That was a very popular kind of field at that time, and Nick George was the professor teaching that. So, I took his class, and that's how I started, learning about what became my career downstream, which is synthetic aperture, systems. ZIERLER: Now, did you have the job offer at JPL? Was that all lined up even before you defended? ELACHI: Well, it was—so, I worked for two summers so I got to know the people at JPL pretty well. When I was getting to finishing my PhD, and I must have impressed the people at JPL, so Walt Brown said, "Hey, would you like to have a job here? We're planning this mission to go to Venus." It was in the very, very early stage. It was just a study. "Would you like to have a job here?" And I said, "Sure, that sounds like a great thing to do that." And at that time, there was no issue if you are a foreign national or American citizen. It was much easier. Matter of fact, we used to get in at JPL with my student badge. Nobody asked what's your citizenship, doing that. Things have changed significantly, in those days. So, I said, "Sure, I'll be glad. That would be great." So, I got the job. I didn't even have to fill in an application form. My employee thing stayed the same as Caltech, because we are all Caltech. And one thing I always say, I never received a paycheck which didn't say "Caltech" on it— ZIERLER: [laugh] ELACHI: —both when I was a student here, for the fellowship, and then at JPL, when I was working there. So, the transition was almost completely transparent. I didn't have to go and apply for job, and it was my dream job, I mean, working at JPL. And, at that time, to be honest with you, I said, oh, gee, I'll work here for a few years, and who knows what will happen in the future? Fifty years later, I was still there. [laugh] ZIERLER: [laugh] ELACHI: I was still working there. But that was a very exciting time for me as a young researcher. And then also the great thing of the connection between JPL and Caltech, my advisor, he said, "I would like you to write a number of papers about, and continue some research about the field" that I was working in. "So, would you like to be also a research fellow, on the campus?" I was both a research fellow on campus and also working at JPL. And, at that time, I was working 80 hours a week. That was fine. I mean, I enjoyed it. So, I used to work most of my evenings and weekend on campus, and the regular hours I was working at JPL. And the people at JPL were very flexible. For them, it was, you will learn something new, on these things. And they were similar because most of my work was on how waves scatter from ocean surface or land surfaces, so it was of direct benefit also for JPL, being also a research fellow on campus. ZIERLER: Charles, obviously, your degree in electrical engineering would come in very handy at JPL. But coming in for the Venus mission, what kind of catch-up did you need to do in planetary science? ELACHI: Yeah. No, I had to do a lot of catch-up on doing that particularly, not necessarily only planetary science but also learning about spacecraft, about orbits, about launches. So, I remember my first year at JPL, I used to go and look in the phone book, and look at all the different sections at JPL, and the title reflected what they were doing, like the navigation section, the telecommunication section. And I used to pick up the phone, and call the section manager, and say, "Hey, I'm a new employee. Can I talk with you or some of your people to tell me about—and I do—I'm involved in a study about the Venus mission." And they were—I don't recall ever any one of them saying no. They said, "Oh, sure, come over." So, I used to go and sit down and get educated about the different aspects, about different spacecraft. So, the first couple of years were a great education for me, mostly, working with people, who were engineers at JPL in other fields other than the radar. But then what happened, in those early days, we were flying or testing the radars on airplane. It was an airplane based at Ames Research Center at San Francisco. The engineers at JPL, the whole group was like about eight people, including me. The engineers used to do the development and testing on the lab at JPL, and then ship the radar to Ames, and then do a flight out of Ames, to do imaging and test the radar. And it just happened when I started that JPL was involved with a campaign in Alaska where a group of researchers were staying for a year on an ice floe. They had their camp and everything there, and they want to see the change which is happening during the year, and what the ice, and actually be going on it. So, part of our contribution from JPL was to fly the plane four times a year for one month each in the summer, fall, winter, and spring, and take images of the region—using the radar—take images of the region around where the ice floe, where they were on that station, one, because the radar could image day or night, cloudy or not cloudy, so it had a big advantage relative to optical system. I used to go with them. So, that was my first experience outside theory and the engineering, mapping not only the ice but also on the way going up and down, we mapped the geologic areas in Alaska, and the ocean, between coming from Alaska down to Ames. So, that kind of started broadening my interest on not only the theory, but it connected because the images reflected the scattering that the radar transmits a pulse. It reflects from the surface and comes back. And what my interest was, how does it interact with the surface, with the ice, with the vegetation, with the ocean, and how do you interpret those images? I kind of started drifting to that, knowing that when we image Venus, I need to know a little bit about the geology. So, as things were expanding in the group at JPL—now, the Venus mission ended up flying late '80, so it took 15 years before it was approved and flown. In the meantime, JPL got its first orbiting mission. It was called Seasat. So, that was like in '73, I was two years at JPL [at that point]. And the main focus of that mission was on looking at the ocean with a scatterometer to look at the wind, and an altimeter to look at the topography. But then, somehow, we were able to convince NASA to put a Synthetic Aperture Radar to get the images over ocean and over land. So, then, Walter Brown, with another guy by the name of Al Laderman, who were the heads of the group, they said, "Charles, we really need to bring some scientists to work on interpreting the data from this instrument. How about if we form a group that you will head, and try to hire some geologists and oceanographers, so when we fly the mission in the late '70s, we can interpret or participate in interpreting the data?" So, I went ahead and hired a bunch of young geologists, and some were recent graduates, and I started going with them on their field trips. And I said, wow, I can go and camp and get paid for it, you know. What heaven, that's heaven for these geologists. ZIERLER: [laugh] ELACHI: And because they kept explaining to me what this thing, this is a volcanic rock, and this is morphologic features and so on, I thought maybe I better go and learn something about geology. So, that's what led me to go and take part-time classes at UCLA, and I got a master's degree in geology. And JPL was great. They paid for the tuition. They allowed me to go and get the classes during working hours, so I did a lot of shuttling between Pasadena and West Hollywood, you know. ZIERLER: Charles, why not just stay at Caltech for the geology degree? ELACHI: Well, at Caltech, there was a rule that you had to do a PhD, and it had to be full-time. While in my case, I wanted to continue working. And, actually, I came and attended seminars, at Caltech, and got to know a number of the Caltech faculty. But because Caltech required all the students to be full-time except if you are auditing, that's why I didn't end up coming to Caltech. So, there was a good reason for it. ZIERLER: Charles, is your sense when you got to JPL that the era of manned spaceflight was over or was at least paused for the time being? ELACHI: Well, it was interesting because that was the era where missions to the moon were basically done because '71 was the last mission to the moon. And then it shifted more to the space station and the shuttle. So, it was at that time, still, there was a lot of enthusiasm about human missions, and particularly the shuttle. That was a—so, it was slowed down. Basically, it's going to be routine flying up and down to the Earth's orbit, and building a space station, which could be a steppingstone of doing things in space. So, even that kind of the message was the era of going to the moon and potentially Mars is kind of on hold for a while, but the human program was still pretty active, at that time. But really, I got sold more into the robotic program, which is what JPL was doing, both for Earth observation as well as for astronomy and planetary exploration. And that was the early era where telescopes were being put in space for astronomy, because they were small telescopes in the early days. So, I saw a lot of fascination and excitement and doing things in robotics, the robotic activity. But I kept in touch with the human program in the sense that it was kind of inspirational, to some extent, [to plan for] astronauts. At that time, everybody was fascinated by astronauts, and the eras that the shuttle is going to become a, if you want, thinking like an airplane, you know. You just go to Kennedy, and you get on the shuttle with your equipment. You fly on there. It turned out a little bit different, downstream. But at that time, that's kind of what we were—the thinking of what was happening, in the human program. ZIERLER: Charles, I asked you about your sense of the Cold War as a 10-year-old thinking about Sputnik. What about when you arrived at JPL? What was your sense of how JPL fit into the larger space race as the Cold War with the Soviets was continuing? ELACHI: Yeah. I mean, there were two things happening. One is the Cold War, like what you said, and the other one was the Vietnam— ZIERLER: Yeah. ELACHI: —era. When I was a student at Caltech, that was the thing, and, of the Vietnam activity. Now, Caltech was not a place like Berkeley— ZIERLER: Right. ELACHI: —with all the protest. But it clearly was on the mind of people. I mean, that was a factor going on here. And there were a few strikes—I mean, not strikes but kind of talks, and the students, debating that issue. And one of the things I remember, the big event at Caltech, at that time—and that was the hippie period, and all of that kind of period—is a couple of students streaking naked across the campus. ZIERLER: [laugh] ELACHI: So, that was the biggest event— ZIERLER: [laugh] ELACHI: —which was happening on the campus, out of the conventional things. But there was a lot of talk because there was a draft and many of these things happening here. And then at JPL in the late '60s and most of the '70s, yeah, there was the Cold War situation, and, yes, there was—I mean, we have to remember a little of the history of JPL. JPL was very much involved in rocketry, strategic missiles in the '40s and the '50s timeframe. So, there were—there used to be a lot of military activity at JPL. That's the foundation of JPL, and then before it kind of transitioned to be a NASA center in 1969 or 1970. So, yeah, there was that history of military work, and helping the country in the Cold War, and particularly in the competition about who will get first—Luna 1 was set up by the time I went to JPL, and the US got there first. But there was a sense of competition about, who will be going to Venus, a Mars exploration. The Russians were very active in both, particularly the Mars exploration and the Venus exploration. So, there was a little sense of competition going on, but there was also a sense of some collaboration. I mean, interesting, despite the Cold War, and the tension between the two countries, in the scientific world, there was a sense of collaboration or encouraging collaboration because scientists were a good channel of communication, without being too visible. Matter of fact, we—even during the Soviet time, as I moved up in the organization, we had a number of collaborations on the Venus missions. The Russians had a balloon mission, but JPL did the communication for them. As I moved higher up, I did a couple of trips to Russia during the tail end of the Cold War, for potential collaboration. And then when the Soviet Union collapsed, a fair number of Russian scientists, because of the connection we had during the Cold War, ended up coming to JPL, immigrating and coming to work at JPL. So, yes, there was a competition, but also a sense that in the science community, a collaboration—there were a lot of very smart Russian people—that there is a sense of doing collaboration. And, later, I found out because I was a director at JPL, I served on a committee that the secretary of energy put together to go and visit all the national labs, the DOE national labs. And I was put on it because they were very similar to JPL, for we are a FFRDC, a federally funded research and development center, and most of the DOE labs were similar to the JPL one run by the University of California and other universities. When I was talking with some of the lead scientists and the directors of those labs, they said, "Oh, yeah, when we were young doing research, we had a lot of interaction with the Russians, and we had to be careful, about the classification and the nuclear issues. But there was a lot of collaboration to avoid having a misunderstanding leading to a terrible situation in the nuclear field." So, they were walking a thin line, a much thinner line than JPL, about the classified versus unclassified relationship with them. At JPL, we didn't have that much, with issue because we were doing mostly planetary exploration. So, yeah, it was an era where the Cold War was very much in the background. ZIERLER: Charles, were you involved with the Mariner missions at all? ELACHI: Yeah, on some of them. Matter of fact, my first involvement in it was more as an engineer. So, I was a younger engineer at that time, and I remember on one of the Mariners, they were planning to develop, a certain kind of antenna. It was a mission to Mars, and the project manager was John Casani. So, he walks in my office one day, comes—knocks on the door, and he said, "I'm John Casani, and I heard a lot about you that you work on microwaves and radars. We have this antenna, and we have some issues on it. Do you mind coming to a couple of reviews, on the Mariner antenna?" So, that was my first introduction, on that mission. But most of my involvement was mostly, with the Seasat mission, and with what became Magellan, mission. That's where I—that was in the '70s and '80s. Most of my—I was still an engineer at that time, working my way up, and then that was what led to many of my shuttle missions. So, most of my involvement in JPL missions were in what became Magellan because it had the synthetic aperture, the Seasat mission, and then a number of Earth-orbiting missions, which were on the shuttle as well as free flights. So, that was mostly in the '70s and early '80s. So, that's a whole chapter story of my career, at JPL. But I dabbled a little bit in the communication aspect of the Mariners missions. ZIERLER: Charles, so I understand, was Seasat always conceived to be a mission to study Earth, or were the technologies for Seasat outwardly looking and it was only afterwards that it was decided that this could be used for understanding Earth's oceans? ELACHI: That's a very interesting question because you hit right on it. The beginning focus of the airborne radar activity were geared toward Venus because it is a planet in the center. So, that's why the first job when I got to JPL was to do a study which led to the Magellan mission because the Magellan mission relied heavily on the Synthetic Aperture Radar to be able to image through the clouds. You couldn't do the surface energy with the visible in microwave. And that was where most of the funding in the early '70s came to JPL. But then, like any of these missions in the early days, they used to take decades to—basically, from the idea of the concept to convincing NASA, and then NASA convincing Congress. And in the '70s and early '80s, the budget in the robotic work, and a lot of the funding was going to the shuttle, at that time. So, it became apparent that it's going to take a while before we get this Venus mission. So, somehow, the upper management at JPL convinced NASA to give JPL an Earth-orbiting mission to keep employment and the research and the technology on doing that. And that's why NASA decided to assign JPL this mission called Seasat, which NASA was interested in, to study the oceans. And, as I said, it was focused mostly on using a scatterometer to measure the wind, which was also a radar but not an imaging radar, and the altimeter to do the topography. And then we started talking—at that time, I was very early in my career—and we said, we can image ocean waves because we saw that on our airplane radar we can actually see waves and ocean patterns. And people were not sure what we are seeing because the synthetic aperture actually used coherent waves to image. And the ocean movement, kind of could damage—we were not sure how the project would work. And that's where my PhD thesis came smack in, the things that, here, you have a periodic wave, which is changing both in space and in time, and we had electromagnetic waves from the radar coming in, hitting the ocean's surface. So, it was smack straight down my alley for my PhD, which I had no idea that it's going to have an application, in this area. So, I did some early work on how the wave interacts with the ocean wave. And, today, without going too much into technical detail, if you remember, if you surf or you sail, I mean, the ocean wave at the crest is very rough because the wave is breaking. And in the trough, it's very smooth on it. So, the radar signal, which is coming and hitting this wave, scatters a lot from the crest, and very little, from the bottom of the wave. So, that's what creates the images, where we get different scattering from the top as from the bottom of the wave. And that's why we are seeing the wave. And then the other thing, I mean, when you are sailing, and you look behind you, there is a wake, and the ocean roughness is different in different parts of the wake. So, we were actually seeing the wake of ships, on the oceans. And there are all the other phenomena like the weather front, because the wind roughens the ocean differently from one location to another one. So, the radar was a perfect tool to actually image what's happening on the surface of the ocean, not the ocean wave. So, we went through a campaign of convincing oceanographers that this radar could be of great value if we can add it to the payload on Seasat. And I remember many of the oceanographers were very skeptical. They said, "No, all what we need is a bunch of ships, and we can go and make all these measurements in situ." And we kept trying to explain what you need is global coverage. That's what this satellite would do. Fortunately, there was one oceanographer from John Hopkins—his name was John Apel—who got sold on the idea, of doing that. So, we began—and he was very respected, you know. So, he helped us convince NASA of adding a synthetic aperture. But because NASA was not 100% sure, so we called it a technology experiment with the scatterometer and that was the heart of the mission, and the Synthetic Aperture Radar is going to be a demo for doing it. So, that's how we ended up having the first synthetic aperture radar on a satellite. Now, the reason I say first, later, we found out that the military had some activity, so we had to be careful of saying the first civilian, imaging radar which went on—in space for doing that. And that was what led to a lot of capability at JPL and internationally, to develop, first, the shuttle radar, and then all the—now you have maybe 20, 30 radar [instruments] flying. All of them trace their inheritance to the Seasat and the shuttle radar that we can talk about next. ZIERLER: Charles, I'm curious, it's very early but was anybody at the time talking about using these satellites to understand climate change? ELACHI: Not really. I mean, the word "climate change" did not— ZIERLER: I mean, in the mid-70s, people were more concerned about global cooling, if you remember. ELACHI: [laugh] Yeah, that's probably true. But, really, the focus at that time was more on monitoring Earth for, soil moisture, things which were probably about the changes which are happening. And Landsat was a big deal at that time, you know. But very quickly, people realized Landsat had limitations because the Landsats were launched in the late '60s, and they were used to see how cities were changing, how cities were expanding. So, there were practical applications for them. There was some application in geology, looking at geologic mapping. There were almost, until Seasat, there was no ocean application. And there was the start of some interest in the atmosphere, of monitoring the atmosphere. And the big deal at that time in the late '70s, early '80s was the ozone hole, in Antarctica. We discovered that the ozone is being depleted. And if we deplete too much of the ozone layer, that could have impact on how much radiation would hit the Earth, and that could be damaging. So, that was a big thing in the environment, what's happening to the ozone layer? And then there were the beginning of concern about the carbon dioxide, and about the heating of the planet. But it accelerated after that. So, now, the concern is much bigger, climate change, the impact on the climate. But I think in the '70s and the '80s, except for very esoteric researchers, the concern was not at all as big as now, except for the ozone issue. That was a big deal, and that was something that JPL got involved in. And, again, we can talk about it later. But it was mostly about monitoring the changes which are happening on the planet, not the climate change but the vegetation, agriculture, to some extent forest cutting and so on. ZIERLER: And the information for Seasat was for a global audience? I mean, obviously, it's not just the United States that you're looking at. ELACHI: Yeah. No, we had a number of scientists from outside the US who were involved in that mission—not in the technical part but in the data, the data part, particularly being the first satellite. And almost every image on that mission and following on the shuttle image, every image was like a new discovery of what we can do from space. Unfortunately, Seasat failed after 90 days, you know. The solar—there was some kind of a motor at the junction between the solar panel and the power system. It must have arced at that time. So, it only lasted 90 days, so it was a very limited amount of data. But it was—it gave us enough of a flavor, like the appetizer, at a nice French restaurant. But then you are actually anxious for the meal, for doing that. So, it really triggered a lot of interest in it, and even before we launched it. That's what led to the series of missions that I was the principal investigator on, for the space shuttle. But it was enough of an appetizer that it garnered a lot of interest internationally. ZIERLER: Charles, were there national security implications with Seasat, spying, being able to look at military installations, that kind of thing? ELACHI: That was interesting. Yes, there was some concern, particularly over the ocean, because we could see ships very well, you know. You see them very brightly lit up because they are metallic structures, so they reflect the radar very strongly. So, you could be able to monitor ships, and see ships, all over the place, and seeing ship wakes also. So, there was a lot of interest in seeing any wake, on the ocean from any object on the surface or just below the surface. So, yeah, there was nervousness, and there was a lot of briefings which we had to do about the capability of the satellite. So, yes, there was a little bit of concern. But fortunately, the resolution that we had at that time, so, like, about 25 meters, it was not the kind of thing—as good as what the military were interested in. They really were interested more in a couple of meters, that kind of thing. So, they didn't stop us. And there were rumors, but we know that it was not true, that maybe Seasat was failed on purpose. Somebody made it fail, somehow. But it turned out that that was not the case. But the rumors were because of that thing, that you can image day and night, it doesn't matter if it's cloudy or not, you can image ships in the ocean. So, yeah, there were a few kinds of rumbling about the capability of space-borne synthetic aperture radar at that time. ZIERLER: What in your mind were the major technological innovations that allowed Seasat to be so successful? ELACHI: Well, it was a lot. It was the beginning of electronic technology and building high-powered transmitters in a relatively lightweight way. In those days, it was relative. I mean, today, we do them far better. Still, that instrument weighed many tons. But that was a huge step in that direction. So, it was the advances in solar panels so to be able to generate a fair amount of energy, and the advances in efficient microwave transmitters so you can transmit a lot of power, through that radar, and the development of relatively lightweight antennas or lightweight structures because for radar, you needed fairly big antennas. If I remember, the Seasat antenna was about 2 meters by 10 meters. So, that's a pretty big structure. And we needed to fold it and deploy it. It's all these advances in technology and lighter weight—I mean, today, it's ridiculous. It looks like a truck. But in those days, it was very lightweight, relatively speaking. And the advances in microwave technology and the very early stage of electronics. ZIERLER: Tell me about the short circuit that ended Seasat. ELACHI: Yeah, again, we—because we never had a direct measurement. But what we believe happened is there was some kind of a "whiskers" because the solar panels had to rotate, to be able to track the sun. So, there was a junction between the fixed spacecraft and the cables coming from the rotating antennas, and they were a kind of metal brushes, if you want to think, which kind of communicated electricity coming from them. So, we think that it was an arcing which had happened because it was a very sudden loss of power for the whole satellite, unfortunately, not only for the instrument. But the whole satellite was relying on it. And the best we could tell is that most likely that's the only thing which was moving and, therefore, could lead to a short. There was never confirmation 100% that that's what happened because the whole satellite went black, in a sense, or went dead, in that sense. But, as I said, there was enough discoveries made by that satellite, enough technology development, which have led then to the shuttle radar and then led to the future. So, it was an iconic mission, and that happened in late '78. ZIERLER: And to be clear, Seasat was going strong. There was no plan for it to end any time soon when the short circuit happened. ELACHI: That's right. That's right. It was planned for three years, with the expectation it will live for many, many years beyond that. ZIERLER: So, given that, was there any consideration for just launching another one, and fixing the short circuit issue? ELACHI: Well, at that time, not as a free flyer because what happened at that time—two things have happened at that time. So, just before 1978, like 1976, NASA was preparing for the shuttle era. So, the shuttle was being built, and it was scheduled to start launching in late '70s, early '80s. And the plan was for the first four shuttle flights, they are going to be flown completely empty, except for two astronauts, just to test the engine, to test that they work, test the landing. And then around '76, somebody came with the idea at NASA, "Why are we sending them empty? Why don't we put some hardware that we can develop quickly, high-risk, and so on? And if it doesn't work, it doesn't work, but it will be a shame to send them empty." So, NASA issued a call for what we call Opportunity for the second shuttle flight. The first one, they decided it's going to be completely empty. But on the second one, they would put scientific instruments in it. So, at that time, when it was issued, I was like 28 years old, and I was involved in Seasat, and I knew there was going to be a fair amount of leftover hardware from Seasat because at JPL, we tend to build an engineering model and also build a flight model. So, I said, "Maybe, let's put a proposal, and say that, we'll use the leftover hardware from Seasat, and upgrade it a little bit." So, I formed a team, mostly my age, and we submitted a proposal, and we said our chances are very low that we get accepted. And guess what, we were selected. ZIERLER: [laugh] ELACHI: So, I remember getting that letter from the NASA administrator saying, "Congratulations, you have been selected for the first shuttle flight to put a radar in it, and your proposal is accepted." So, here, we sat down. I remember we sat down and said, "Oh, gosh, now, we are going to be on the first shuttle flight." ZIERLER: [laugh] ELACHI: And, as I said, we were a whole bunch of 20-year-olds. There were a couple of people who were more experienced than us, because almost everybody was working on Seasat. So, we started working on planning for the shuttle experiment, and we were effectively the only experiment because the radar antenna was so big, it took the whole bay of the shuttle, to fit it in. And then it was scheduled to launch first in 1980. Then it ended up being in 1981. So, that was my first opening of being the top dog, if you want [laugh], on an experiment in my late 20s, and, being a Caltech graduate who was never intimidated by anything, on doing that. And one of my—throughout my career, even when I was young at that time at Caltech and after—one of my favorite things was my hobby to read biographies of American presidents. And my favorite one was Teddy Roosevelt. ZIERLER: Sure. ELACHI: And I remember a quote from Teddy Roosevelt which said something like, "Far better to dare mighty things than even though checkered with failures than to sit down in the twilight of neither victory nor defeat." So, I started telling my team, "Hey, we are daring mighty things here, and, plus, anyway, it's high risk. NASA will not pay attention to us. If it doesn't work, it doesn't work. But we need to do our best, to make it work." So, that led during that period where we had to do a lot of flying to the Johnson Space Center because we had to be with the astronaut and the shuttle, a lot to the Cape, for interacting with the shuttle. And then it led to that mission to fly in 1981. So, going back to your question, and then I can expand on the shuttle, so NASA's philosophy at that time for the radar is, "Gee, we're going to do this shuttle mission, so let's see what we can do with it before we move toward a free flyer." And then they focused on doing the altimeter and the scatterometer on dedicated missions, which would be a smaller spacecraft. And that was what led to a series of missions called TOPEX/Poseidon, jointly with the French Space Agency. So, that went that track, for the other instrument, and the radar's track was to do the shuttle. Here we come to 1981, getting ready for the shuttle flight. And, of course, we were nervous, but we were all excited about it. And I remember very clearly about a month before the launch when we had built everything, it was [tense]. Bruce Murray used to be—he was the director at that time. This was 1981, and Bruce Murray was one of the faculty members in planetary science at Caltech that I got to know a little bit, from Caltech. He calls me to his office, so I think, oh, I wonder why Bruce wants to chat with me. So, I walk in his office, and he was—Bruce was talking about the history. The most casual director you ever had. ZIERLER: [laugh] ELACHI: He was in his shorts, in his flip-flops. His feet were on the desk. Completely opposite of his predecessor, Pickering, who was always in a tie and suit, or his successor, which was Lew Allen, who was always in a tie. So, Bruce said, "Charles, I just got a call from the administrator of NASA, asking me about this ‘A' mission for Shuttle Imaging Radar," ‘A' because it was the first in a series. And he said a lot of people are asking him question about the benefit of the shuttle. Why are we spending? "So, you'd better be successful"— ZIERLER: [laugh] ELACHI: —"in this mission." I said, "Oh, sure, here we go." Nobody—it was supposedly high risk. ZIERLER: [laugh] ELACHI: nobody was paying attention to us. We took a few shortcuts on it because it was a high-risk mission. And now, the NASA shuttle depends on us being successful. So, anyway, fortunately, it was successful. [laugh] So, we flew. The radar worked perfectly for the whole—the mission was, I think, four or five days. It worked perfectly. But the interesting thing is that, at that time, digital recorders were very much in their infancy. we didn't have the kind of bit rate that we needed for the radar, so we had an optical recorder. So, the radar signal was coming in the instrument. The instrument, it kind of modulated the—a laser or an optical beam, and then we wrote the signal on an optical film in the optical recorder. So, we knew we were receiving echoes, but we didn't know that we actually were recording the data on it because we didn't have that capability. And there was no link to the ground to transmit the data to the ground, for the instrument. We were in the blind until the shuttle landed, and engineers went inside the shuttle and forgot to tell—because we needed to pull it out quickly because of the landing and it was—the temperature was not very amenable to optical film. They drove it during the night to JPL. We developed the film. We looked at it, and we could see a signal on it. So, that was a big relief. Then we had to process it through an optical correlator that I learned about from Nick George, in the class at Caltech, and we saw beautiful images on it. So, we developed the film. The program manager from Headquarters got around in the morning to the airplane, went to Headquarters, and showed it to the NASA administrator. So, it was a big deal. ZIERLER: Yeah. ELACHI: So, I was a hero— ZIERLER: [laugh] ELACHI: —it was not the plan, but it happened that way. And then the next thing other than we were successful, and got beautiful images, and this one, the focus was more on the land, mapping geology, and you get to see beautiful features on it. A couple of days later, we were looking at an image which we'd taken over Egypt, in North Africa. And it looked like there are rivers on it all over the place. ZIERLER: Yeah. ELACHI: And, so, some of my team members were from the Geologic Survey, in Flagstaff, and they had done a lot of work in Egypt. And they said, "There are no rivers there. We have never seen anything." So, to make a long story short, it turned out that the radar was actually penetrating through the sand and mapping the old riverbeds which had been then covered because of the change in the environment—talking about the global change—because of the change in the environment in North Africa where the belief was it was much more humid 5,000 years ago. And then with the change, then the sand covered all these riverbeds. And the radar was penetrating through the sand and imaging the remnants of those riverbeds on it. It immediately clicked, being an electromagnetic wave, first, of course, sand is very dry. It has a very low lost tangent, so we should be able to penetrate through it, and see what's below the surface. So, I did some quick calculation, and said, "Yeah, you should be able to penetrate many, many meters, below the surface." So, we quickly wrote an article, scientific article about it. And guess what, it made the front cover of Science Magazine ZIERLER: [laugh] ELACHI: —the front cover of National Geographic. And, mostly, their interest was not because of radar penetrating. The interest was about the archeological implications— ZIERLER: Yeah, yeah. ELACHI: —about it. That if we know what that was, these rivers in those days, that could benefit a lot. That's why National Geographic was interested. ZIERLER: [laugh] ELACHI: Why that would lead to a lot of things. ZIERLER: Charles, you're a principal investigator at this point. The radar is going to be pointed back to Earth, and you're on the cover of magazines. It's a great point to pick up for next time when you're clearly on a trajectory of the things that are going to come. [End of recording] ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It's Tuesday, October 5th, 2021. Once again, it's my great pleasure to be back with Professor Charles Elachi. Charles, wonderful to be with you. Thank you for joining me. ELACHI: It's my pleasure, my pleasure. ZIERLER: Charles, today, what I'd like to do is go over in a bit more detail the wonderful description you gave me of your time at JPL in the 1970s where you came essentially as a newly minted PhD, and then, by the end of decade, you are a principal investigator. As you say, you and a bunch of other kids, quote, unquote, are running these hugely important and expensive missions. This begs the broader question about the culture of hierarchy and promotions at JPL. So, maybe what we could do as a starting point is if you could tell me a little bit about that formative interview that you had with Walter Brown back in the spring of 1970, and Brown's subsequent decision to put you on the Venus imaging radar instrument. Do you think that he immediately connected that work to the research that would ultimately become the Magellan mission, and did you see even at that very early stage that he was putting you on a trajectory of leadership? ELACHI: Well, I'm not sure I immediately saw the trajectory. At that time, being a student, getting a job at a place like JPL was already a great start. [laugh] But I remember very clearly that interview because I went to his office. I mean, I put an application, and then, I was called to go and interview with him. I mean, what's the chance? I mean, there are hundreds of positions at JPL during the summer. So, I went to the interview in his office, and we chatted a little bit. He asked about my background. What's my experience? And I think the timing was probably perfect because my background was looking at electromagnetic waves, and wave propagation, and they were getting ready to start this study of using an imaging radar to see if it can be used on Venus. They wanted somebody who had a little bit of background in electromagnetic waves. And the other aspect of it, he was telling me, is that they had this airborne radar that they had just developed, and that they are going to start flying, and they are a group of engineers. I think the whole group was like seven or eight people, and all their background was in engineering, and they really would like to have somebody with a little bit of [of background in] electromagnetic theory and wave propagation activity. So, I just fit the bill very well. So, he said, "Sure. Why don't you come and work for the summer here?" I mean, things were so easy bureaucratically at that time. And, for me, it was just getting a job at JPL—I thought it was irrelevant what it was—was already a big step, and to do something which is a fit exactly with my background was even a better step. I had no idea at the beginning, about what trajectory I would follow. But then a few years after that, after they offered me a job, I must have done a good job for the summer, and then after that, I started working one day a week, during the school year because I thought it was a lot of fun. And then after the manager—Walter Brown was kind of the lead program manager, but the group supervisor, his name was Al Laderman, called me in his office. He said, "Hey, Charles, would you like to come and work here?" So, I told him, "What would I do?" And he said, "Well, we will put you in charge of the radar part of the study about potentially using imaging for Venus." And I remember very clearly that study was like a 300-case study, which was big money at that time. And we had a year to do the study and the analysis, and then make a report to NASA Headquarters. That was my first job, working there, and it was a lot of fun because I had to look not only at the radar but at the orbit, the mission, the navigation. So, I started going and visiting different technical people at JPL to learn about all of these things. And it was, I mean, it was probably a dream job for me at that time. And at the end of that year, we—it was my first trip to NASA Headquarters because they invited me to go and do the presentation to the people at NASA. That was a big deal, being at the Headquarters of NASA, going to Washington, my first trip, to Washington. So, it was really a very fortunate circumstance, but it was a lot of fun. ZIERLER: What year was that Charles, when you went to NASA Headquarters? ELACHI: Oh, that was 1971. So, I graduate in '70, so it might have been early '72, that was my first trip to DC— ZIERLER: Who was in the audience at NASA Headquarters? Who did you present to? ELACHI: Well, it was more program managers, so it was kind of middle level people. So, it was a person—I can't remember now his name—who sponsored that study. He was in charge of what they used to call at that time advanced study for planetary missions. So, he was funding different activities to look at potential future, planetary missions, and this was one of them. It was called PIRS for Planetary Imaging Radar Study. And shortly after that, they must have liked what we were doing, so they funded a little bit more advanced study, and they wanted to get a little bit more specific, so they called it Venus Orbiting Imaging Radar Study. And I thought that was cool because V-O-I-R in French means to see. ZIERLER: [laugh] ELACHI: And that kind of connected with being able to see through the cloud of Venus. I thought that was kind of a cool study. [laugh] ZIERLER: Charles, even from that early visit to NASA Headquarters, what did you learn about the strategic relationship between JPL and Headquarters, how those things worked together? ELACHI: Yeah, by then, I kind of learned a lot about JPL. I was always curious, so I started talking with people, and thinking about what's the relationship of JPL with NASA, the relationship of JPL with Caltech, because it was kind of neat that, when I was offered the job, I didn't have to do anything because I was already a Caltech student. So, they just shifted me to be Caltech staff, and I didn't even have to fill a job application, to do that. I got very curious about the history and the connection between NASA and JPL. And at that time, you have to remember, that was only—so, that only like 12 or 13 years since JPL became a NASA center because that all happened in '59, 1960, when—because up to the late '50, early '60, JPL was still a Caltech, lab; fully owned, fully operated by Caltech. And then in 1959 or 1960, the JPL facility was transferred to NASA, but all the staff stayed as Caltech employees, and Caltech continued to manage it. It was an interesting arrangement that, here, a small private university is actually managing the major, planetary program of the nation. And the people at NASA Headquarters were still part of that early process, so they all knew the transition, the history of JPL. So, they were very, very excited about having a leading university being at the foundation, of NASA in general, and particularly at a NASA lab. So, the relationship was great, at that time. ZIERLER: Charles, just to get a sense of your own rise at JPL, going from a graduate student to a principal investigator, so, if we were to visualize this on an organizational chart, how many steps were there from where you started— ELACHI: [laugh] ZIERLER: —to where you would become as PI? ELACHI: Well, first, the step—well, for the PI, it was really—usually, the principal investigators are leading scientists, who work on the scientific experiment. So, there was no hierarchy per se. It was on the reputation of the person, and their experience. Now, to the director, that was multiple steps. I mean, there was—beyond being a regular researcher where I started—there were the groups provider, section manager, division manager, program manager, assistant lab director, and director. So, there were six steps. The director at that time would have been Pickering, so he was like God, you know. Barely, you know—I didn't interact with him but knew about him or saw him, across the lab. So, what led to the PI is—so, as I started and we're doing the study on Venus, it became quickly apparent it's not going to happen overnight, that it's going to take many years to do the detail of the study, and so on. So, the group's provider, Al Laderman, said, "you might want to—we are going to be flying this radar. It would be very helpful if you can be engaged in how to interpret the data from it, from the airborne, system, and it would be a good experience for you to participate in some of the flights." And the way they were doing the flights at that time, the instrument was being developed at JPL, I mean, on the facility, and then shipped to Ames Research Center outside San Francisco, and put it on an airplane there. It was a Convair 990, one of the early jet airplanes. Put it there, and then fly to wherever, they were conducting scientific experiments. And in the first couple of years, the two areas where we were involved in was, one, to monitor the motion of ice in the polar regions. So, we went four times in one year at different season, and were stationed in Fairbanks, and flew out of Fairbanks to get the ice—I mean, mapping the ice. And the other one was to image wave after we found out that we can image waves under a hurricane. So, we were stationed in Dakar West in Senegal, and spent a month there, and we were flying out of there, to fly the hurricanes. And I remember there was one technician by the name of Ed Caro. He was a relatively young technician, probably a few years older than me, but brilliant. He didn't even have a high school degree, but it was—he was a great technician. So, somehow, he took me under his wing, and every time we were flying, he was explaining to me the different pieces of hardware, what we are seeing. So, that's where I gained, where I starting to gain experience in understanding how the radar system actually works in practice versus theoretically or doing a study, and it was great fun. And I remember being curious. there were the displays, so I kept pushing buttons. And Ed Caro got nervous about me pushing the wrong button at the wrong time. ZIERLER: [laugh] ELACHI: So, what they did, I remember, they took a display with buttons on it, and put it in front of my seat, and it had a light on it and so on, and I was pushing buttons, to realize later that it was not connected to anything. ZIERLER: [laugh] ELACHI: So, that's like that's the way they keep me happy but [laugh]— ZIERLER: [laugh] ELACHI: —I thought it was a lot of fun even with [laugh], doing that. ZIERLER: [laugh] ELACHI: So, one of the things which is special about JPL, and I think partly because it was started by students, Caltech students in the late '30s. It kept that spirit of welcoming young people. We were part of a university, so we had the attitude of academia, even if they were not [all] Caltech graduates, but the environment was very much like a university environment. And like at Caltech and at different universities, you don't hesitate to take a graduate student, and put them in charge of an experiment, to do that, because that's how they learn. It was the same kind of general attitude, even that was a little bit more hierarchical, because we had to build the hardware and build spacecraft and so on. But the attitude was very welcoming, and it gave people responsibility very quickly. So, that's what kind of put me on a track to being a principal investigator. ZIERLER: And who in the early years were some of the senior people at JPL who you would've considered a mentor, or who championed your work and really promoted what you were doing? ELACHI: Well, clearly, Walter Brown was a—he was an experienced guy. He did a lot of work in the '50s on rocket radars. They were launching rockets with radars and they were looking at how much it scattered from the surface. And he was involved in one radar experiment which went in orbit around the moon on one of the Apollo missions, in—sometime in late '60s, early '70s. So, he was pretty well-known in the field, as a radar person. And then Al Laderman, Ed Caro, they were the people who were actually doing the work. They were the people sitting in the lab, doing the assembly. So, I would say these three people were kind of the technical mentors for me. And there was another guy by the name of Elmer McMillan—he passed away now, and Walter Brown has passed away—Elmer McMillan who was the operator of the radar. He was not the person building it, but, on the airplane, he was the guy operating it. Between Elmer and Ed Caro, when we were not flying, we used to go out together to the bars, and particularly in the winter in Fairbanks, you really need to get something warm, [laugh] to go out there. That was my first experience with that kind of cold. I mean, I grew up in Lebanon in the mountains, and that was pretty cold, and snow, but nothing like Fairbanks in the middle of winter. So, that was kind of an interesting experience. fast-forward, it turned out my wife was born in Alaska in Anchorage because her dad used to be in the Army Corps of Engineers, so she was born in Anchorage, and stayed there for a couple of years. And then she told me after that her dad used to do maps, and he had a map of the air base in Fairbanks, as part of the Army Corps of Engineers. That's where I was stationed, or the airplane was stationed there. So, it's interesting how things come back [laugh], in a couple of decades later or a decade later. ZIERLER: Charles, we would use the word "diversity" today to think about these things. But back in the 1970s at JPL, was there anyone else who was not American born? ELACHI: Well, yeah, there were a few, and the reason is because still the culture of Caltech was there. And at that time, immigrants—it was perfectly normal to have immigrants. So, yeah, there were a number of people, particularly from Europe, because the area I was in—now, the group I was in myself, Ed Caro was from the Philippines, but he came…he moved here when he was very young. Most of the rest, let's see, were all American, I mean, American born here. So, I was the only one who, other than Ed Caro, who was born outside the US. But in the overall science activity and instrument activity, there were a fair number of internationals, particularly British. I remember there was a fair number of British people working on optical instrument sand atmospheric instruments. And it was encouraged to have postdocs, so there were a number of postdocs who used to come and spend a year or two, at JPL from France and Greece and other places. So, yeah, there were some internationals, but not as much as the campus, you know. At the campus, there were a lot of international, students. And building on my relationship with the campus because, usually, during Christmas and New Year's, most of the Americans on the campus left for a couple of weeks. There was a group of French students and Greek students who were staying here. We used to get together and kind of celebrate together so that we had a group of international students at Caltech and some at JPL—not as many—who got together. And some of them—one of them is still a professor at Caltech by the name of Paul Dimotakis. He's roughly my age, so he was a student at that time, and then joined the faculty, and now he's a great friend, here. He's in the aerospace department. ZIERLER: And in your path to leadership, obviously, having an accent, having a name, a last name that might be difficult to pronounce, that was never seen as a hurdle for you? You were never made to feel excluded in any way? ELACHI: No, not at all. Matter of fact, kind of the reverse because as I was—after a couple of years at JPL, and I was going to NASA Headquarters, making presentations, and clearly, I mean, everybody knew from my accent that I was not born in the US, so Al Laderman said, "you might want to go and take a speech class. maybe you can improve your English pronunciation." And they had that at JPL because there were a number of internationals. So, I went and started taking the class. And after I think a couple of classes, the teacher told me, "Why don't you go back? Having an accent is always helpful." ZIERLER: [laugh] ELACHI: He said, "in the past, German accents, that reflects that you are a scientist and so on, and French accents also are kind of intriguing to people." ZIERLER: [laugh] ELACHI: "So, keep your accent. You don't have to come and take my class." [laugh] ZIERLER: [laugh] ELACHI: So, after that, I didn't make any effort. And even until now, as soon as I meet somebody new, and I say hello, first question, "Oh, where are you from?" ZIERLER: Yeah. ELACHI: [laugh] And, usually, I tell them, "Well, guess, from my name." And they say, "Oh, you must be Italian." ZIERLER: Right. [laugh] ELACHI: Elachi, they have some Italian. I go, "Well, not exactly. We used to be an Italian colony 2,000 years ago when the Romans were"— ZIERLER: [laugh] ELACHI: —"all over the Mediterranean." [laugh] ZIERLER: [laugh] ELACHI: And then I tell them I'm Lebanese, and the reaction is always, "Oh, wow, Beirut is such a great place." It's either, "My parents," (or if it's an older person), "have been to Lebanon, visited there, and what a beautiful place. It's a shame, what's happening with all the economic issues now." So, still, fortunately still, the people reflect on Lebanon and Beirut as a positive reflection on a beautiful country. Anybody who's read the Bible would know that that was used for the temples, in Jerusalem, or used for the temples during the pharaohs. So, I think people probably from their education, they have mental [association] with the cedars of Lebanon. ZIERLER: Charles, to get a sense of the long-range planning culture at JPL, again, to go back to your initial work on the imaging radar instrument for Venus, at what point does a particular research project blossom into a major mission? In other words, what are the dots that can be connected from the Venus imaging radar instrument leading all the way to Magellan? How does that work? ELACHI: Well, remember, at that time, particularly—I mean, it's still now—but at that time, we were in the early stage of space exploration and planetary exploration. So, one of the major activities at JPL funded by NASA was to think about where we can go. By that time when I joined JPL—I mean, we had been to Mars, and we had been to Venus. But then there was a lot of interest, well, can we go to Jupiter? Can we go to Saturn, to Uranus? And can we land on these planets? Can we orbit them? Because up to that stage, it was mostly flybys, you fly by them. There was a fairly well-funded program at NASA to look at what are the possibilities, in space exploration for robotic in parallel with the human program, which was kind of—by then, we had landed on the moon. And JPL was one of the main centers that NASA was supporting to look at the planetary missions. Now, an interesting story, I'm told, that when NASA was formed in 1959 or 1960, nobody had done a planetary mission at that time. So, there was a meeting at NASA Headquarters or at different centers which joined NASA and formed NASA—and the JPL director, his name was Pickering—and they were going, saying, "What would you like to do? What would you like to do?" And Pickering raised his hand, said, "I'd like to do the planetary"—at least, that's what I'm told. And that's how JPL became the planetary. It was so easy at that time. [laugh] So, there was a big shift toward during planetary missions. And JPL did lunar missions in preparation for the Apollo, landing. But planetary mission was still very exotic. We had done one Venus flyby and one Mars flyby. So, there was a whole office at JPL where their goal was to look at all the different possibilities, and what technologies needed to be developed to be able to do these missions. Now, we knew that Venus was cloud-covered from the flyby that was done, and, therefore, you need some kind of a radar system. If we want to image it, we need some kind of radar system. So, that's why there was funding to do this, what's called Synthetic Aperture Radar, to put on a Venus mission, and not only the studies but to develop the hardware, gain the experience of how to image the surface, and how to learn about building a space-borne radar. But, still, there was an issue with the funding. These missions were relatively expensive. So, the process was to start for doing studies, figure out what technologies are needed, develop those technologies, demonstrate them so we know that they would work in preparation to putting a program together, and then sell it to NASA. So, that program was put together by the mid-70s but, still, it was a challenge to go and convince NASA to do the mission because also you had the Mars one. You had the—Voyager was in the early stage of planning. It was called at that time the Grand Tour. There were studies for missions to go to comets. So, there were a number of ideas, for missions. And the question was, OK, what would the order be for these missions, and would it be implemented with the budget available? So, Voyager really got the priority because it was a unique—or what used to be called the Grand Tour. It was a unique alignment of the planets of Jupiter, Saturn, Uranus, and Neptune, which happened only once every hundred and some years. So, the idea was to be able to fly by all of them, and that—for a good reason—that took, the priority. And Mars, remember, at that time, people still thought that there were canals on Mars, and maybe some inhabitants, so that was also a priority. We knew that Venus was very hot and so on, so it was scientifically interesting. But from a public appeal [perspective], the Grant Tour/Voyager, Mars was more timely. And that's when…I was involved in that process and in the two things, one, flying on the airplane and analyzing the images, and publishing papers on it, and the Venus study. And that's why in the mid-70s, maybe like around 1973 or '74, there was growing interest in the oceans, to study the oceans. So, NASA said, "Well, we're going to do a mission called Seasat to look at the oceans," and it did not have an imaging radar on it. But then because of the publication that I did, and the interest for a Venus mission, and demonstrating space-borne radar, we were able to convince NASA to add a Synthetic Aperture Radar on Seasat, both for its own merit but also as a demonstration for the Venus mission, to show that we'll be able to get images from space. So, that's how Seasat got started before we end up doing the Venus mission. ZIERLER: Charles, we talked about this a little last time, but it bears further discussion. The technology that went into Shuttle Imaging Radar, particularly going from SIR-A to SIR-B, at what point was there an appreciation that this technology would be useful to be pointed at the Earth directly? When did that become apparent to you and your colleagues? ELACHI: Well, I think with the airborne activity, we started getting convinced that, look, there could be something really useful here, and aircraft can only go over very limited regions, and it would be great if we can get that kind of data on a global basis. And, at that time, it was still strictly scientific. Climate change still was not a big issue at that time. I mean, people were aware of it, and thinking about it, but it was not heavily driven by that. So, it was really the interest that, gee, we can do geologic mapping across the planet. We can look at vegetation. We can look at the ocean waves, how they interact with islands, with ships. So, there was a growing awareness, from the airborne imagery and data that this could be a great field for space-borne, activity. And the benefit to me, or what put me in that position to be a PI is, coming out of Caltech, I was very much—and, at that time, it was very important to publish. So, almost all the results we were getting, we were publishing papers, analyzing the data, and publishing papers. And I was in a pretty fortunate situation because, by that time, by the mid-70s, I was asked to form a group of scientists so we can analyze that data we're receiving. So, I was in a perfect position, being the first person to get all that data coming from the airborne instrument. So, I published very widely at that time. I was publishing maybe five, six papers every year. And the benefit of it, other than, feeling good about publishing papers, it made me very quickly known to a broader community, be it at NASA or at a university or in academia, among researchers, and not only int the US but also internationally. And JPL had that cache internationally. It was very well-known in Europe. So, we end up with a lot of collaborations, particularly with German scientists. Matter of fact, one of the people we collaborated with just got the Nobel Prize in physics today, Klaus Hasselmann. So, he was, middle aged—not young. He was in his 40s, researching at the Max Planck Institute in Germany, and he was interested in the interaction of the atmosphere with the ocean. And when he saw the radar images we were getting out of the ocean, there was some interaction with them. So, I remember him well, he visited JPL a few times to look at that data. And, matter of fact, one of his postdocs came and spent a year—or his young researcher came and spent a year, at JPL. So, it was at that time a very active scientific time for me, which really kind of set me—when we decided to propose the shuttle, I was reasonably well-known in the scientific, community, and the connection I had with the radar group, being part of the radar activity, so put one foot on the engineering side, and one foot on the science side. So, I think it gave me kind of an advantage…even that I was still in my 20s, it kind of gave me a reputation and an advantage of being selected as a principal investigator. ZIERLER: Charles, how did you discover that the imaging technology could go through cloud cover and even the Earth's topsoil, and then how did you communicate this amazing technology to people like archeologists who could utilize it for working in ways that were never imaginable before? ELACHI: Yeah, I think going through clouds was pretty well-known, because radar worked. Penetrating below the surface was not as known—only for people who were very, very much into electromagnetic theory and electromagnetic waves. So, the way—and there were two ways I was explaining it to them in simple term. I told them, when you have a radio, and you go down in a cave, if it's not too deep, you still can receive, the radio. Or if you are inside the building, you still can receive your radio signal. So, those microwaves actually penetrate through those areas. The other one I was explaining to them, I thought it's exactly like when you have—you put pictures on a desk under a glass, you know. You do that. Many people do that, put pictures under it. So, you still can see through the glass, and that's because visible waves can penetrate through the glass, the same way radar wave can penetrate through the sand. So, I think of the sand like a layer of glass that you put on your desk, and you have pictures under it, and that how you can see those pictures. So, that way, people immediately kind of caught on it. They said, "Oh, yeah, that kind of makes sense." ZIERLER: And in terms of communicating this to archeologists, were you attending conferences? Were you writing articles that were specifically geared toward the archeological community? How did you get this message out? ELACHI: Well, in actuality, it kind of almost came in reverse. When we were doing the Shuttle Imaging Radar, and we saw those drainage channels in Egypt, I was approaching it purely from a scientific—I mean, as an interesting geologic tool. And when it was published in National Geographic and then in Science magazine, archeologists started calling us instead of us contacting them because they saw that it was intriguing. And there were a couple of archeologists who got really interested in the idea, of knowing that, so they approached us more than them. And I was curious. One interesting thing, I grew up as I mentioned in a place called Riyaq in Lebanon, and it's only a few miles from a place called Baalbek, which is a famous archeological temple left from the Roman time. So, having grown up in Lebanon where there were a lot of old ruins, archeology was kind of something interesting, and exotic about doing that. I was intrigued, when a few archeologists contacted us, and said, "Gee, can you do this?" That was intriguing. And then when the group of geologists from the Geologic Survey, we decided to go to Egypt and do that, I was the first one to volunteer because I thought that would be a cool expedition, to do that. And, I was at an age where I was—well, I'm still now, I hope—but I was very curious at that time of everything, you know. So, I thought doing some archeological expeditions would be something really cool. ZIERLER: Charles, just a technical question so I understand, the satellites that we're talking about, the ones that were pointed toward the Earth and the ones that were pointed out toward space, are they the same satellites, and you just control where they're looking, or are these different satellites for these different purposes? ELACHI: No, they are different satellites. So, for Earth, usually, we fly them in Earth's orbit, and they are looking toward the Earth, and we transmit radar signals, and we receive the echo back, and then analyze it. For planetary [satellites], I mean, we had to go to the planet. We couldn't use a radar all the way from the ground, except with one exception that I'll mention in a minute. So, we actually sent a spacecraft which went in orbit around Venus, and a spacecraft which went to Jupiter—I mean, to Titan, to send a spacecraft to Mars. The only exception is that in the '60s, to start communicating with deep missions, JPL had to develop what's called the Deep Space Network, so these are very big antennas which can communicate. It was purely for communication purpose so we can send signals to spacecraft and receive the echo back. And because of the distances we are talking about, we had to build huge antennas, and there are three stations around the world: one in Madrid; one in Canberra, Australia; and one in California. So, as the Earth rotates, these stations can always be in communication with our spacecraft. That's how people came up with the idea, and said, "Oh, if we can do that, maybe let's point that toward a planet, and see if we can get an echo back." So, there was an engineer at JPL by the name of Dick Goldstein. He got some time on these antennas, pointed them toward Venus, sent a signal, and they got an echo back—a very, very weak echo. But these were very sensitive antennas, and they were able to generate some images, but not to the resolution because of the far distance. So, they were getting images which are many tens of kilometer in resolution, while the orbiting system, we were getting down to like 20 meters, to do that. But it verified the concept that we can actually generate images with these ground-based radar systems. And they are still being used now, I mean, because we use them to look at different planets, and different satellites. But the resolution—to get the kind of resolution we need—we have to send a spacecraft to go to those planets. ZIERLER: Charles, tell me about working on the Challenger shuttle. What was the coordination that was required to work on the shuttle, and was it the only available option? Was it essentially the only game in town for Shuttling Imaging Radar? ELACHI: Yes, in general, it was, yes, because, at that time, a lot of money was going into the shuttle development. In the 1970s after the Apollo program, the big game in town was the shuttle. And, at that time, everybody was thinking, oh, we are going to be like airplanes. These shuttles are going to be flying every week. There'll be scientific instruments on them. NASA put a big emphasis on using the shuttle both for a scientific instrument but also for launching spacecraft. Matter of fact, the Magellan mission and the Galileo mission were launched to Earth's orbit first inside the shuttle bay, and then they pulled out, and there was a smaller rocket which put them on a trajectory, to get to the planet. So, in the '70s and the '80s, the shuttle was the big game in town. Now, it had advantages and disadvantages. The advantage was that the plan—even after reality set in, the shuttle still was flying five, six, seven, eight times a year, so there were regular opportunities to do it. The disadvantage, for what I was doing, was that it used to fly for only a week or maybe two weeks, so we couldn't get the global coverage that a free-flying satellite is capable of doing. But the fact that it was flying regularly allowed us to quickly develop the technologies. So, after SIR-A, we had a series, SIR-B, SIR-C, and SRPM, so it was a series. SIR-C flew twice. So, I had a series of five missions. Each one was a significant leap of technology relative to the previous one because we were able to move them fairly quickly, and we were able to fly fairly quickly on the shuttle. And the shuttle gave us big volume, you know. The bay of the shuttle was very big, so big volume. So, the interaction was of two aspects: one, we had to interact with NASA Headquarters to get the funding to build the instrument, to get it approved to build the instrument, and then I had to deal with the Johnson Space Center where all the coordination of the shuttle, coordination with astronauts, took place. We had to train the astronauts on how to operate the radar, in case we didn't have communication. And astronauts were a curious group. I mean, they were very smart, curious people. So, they went with us a couple times on field trips so they could see actually what are we trying to do, with this radar, what kind of imaging we could get. So, I had to go fairly often to Houston. And I remember that other than the scientific—I used to hate it because it was so humid and hot, in [laugh] Houston. So, we used to spend a lot of time inside the mission control, center. But it was a great experience, building a relationship, interacting with the astronauts, interacting with people in the human program. Once we built the instrument, we had to ship it to Cape Kennedy, and that's where we actually put the instrument inside the shuttle before it was getting ready for flying. So, it was a very exciting period for a young person, you know. You're interacting with the astronaut, with this big shuttle, machine. It was a very, very exciting and interesting period. ZIERLER: Charles, of course, Richard Feynman was famous for many decades in the physics world, but following the Challenger disaster, and the subsequent investigation, he really became a national figure. I wonder if you ever talked with him about the disaster. ELACHI: Well, not directly, no. I mean, I chatted with him a couple of times. My interaction with him was a little bit different. It was kind of interesting because he lived in Altadena, not too far from where we live. And I remember a couple of times we were at a faculty event at faculty houses, in Altadena. And I remember one, our daughter, younger daughter, was like three years old, so we took her with us to this event. And Feynman was there, and then we saw Feynman disappear. He took our daughter to the yard, and he was playing with her, you know. She was three years old. So, he was the kind of person who was a down-to-earth, very friendly, kind of person. But, no, I did not interact with him on the Challenger issue. There was another impact of the Challenger incident. Just before the Challenger tragedy, NASA was drifting toward letting PIs who have instruments on the shuttle to fly on the shuttle and who operate the instruments. So, I was—I had the opportunity—either me or a member of my team—to actually potentially fly on the shuttle to operate the instrument. But then after the Challenger accident, NASA took the attitude, "Now, we're only going to fly astronauts," because, if you recall, there was a teacher, on that flight. And that was a big issue that still it's too risky, and flying the general public is too risky. So, anyway, I lost potential opportunity of having flown on the shuttle. ZIERLER: Were you ever involved in the investigation yourself? ELACHI: No. No, I was not. I was not involved because, on that flight, it was something completely different that NASA was doing, and I was coming from the scientific aspect of using the shuttle. And on that investigation, they had mostly people who knew the details of the shuttle itself, and the hardware, which was operating on the shuttle itself. ZIERLER: And more broadly, at the institutional level, how was JPL involved in the investigation? ELACHI: Well, there was consulting. There were a number of people at JPL who knew about things. They were not on the panel itself, but they were kind of advising NASA. But that whole incident had a big impact on JPL because the Galileo mission was supposed to be launched from the shuttle after the Challenger. And the Challenger incident actually delayed—there were no flights for almost two years. So, a lot of the missions which were planning to be launched from the shuttle, or some of the instruments we were planning to launch, got delayed after the Challenger incident. So, this had an indirect impact on us. But I remember clearly when that incident happened. At that time, I was a division manager at JPL, and I remember we were sitting in a meeting of all the division managers, which we used to do once a week with the assistant director for the technical division. And the assistant director was called out. He went out, came back. He said, "We just had a major accident, you know." And I remember the shock because everybody was thinking, oh, the shuttle is now so well-developed. There were all these flights. It looked like it was working perfectly, and it was a big shock, for everybody at that time. ZIERLER: Were you ever concerned that the shuttle would never come back online? Was this an existential threat to the programs you were working on? ELACHI: There was a little concern. But, really, very quickly, the commitment—NASA made a commitment to build another one and get back online. So, that was during the Reagan administration. And Reagan gave a great speech…I mean, it was a sad period for the whole country. It was a sad period, and he gave a great speech about, exploration, and that's what makes us human. We are about exploring. There is always a risk, doing that. So, fairly quickly, our spirits were uplifted. And NASA very quickly committed, and the funding very quickly was put together, to actually build another shuttle. But it still took, a couple of years because people needed to understand, what was the issue? How did it happen? What was in the culture which led to make that kind of decision? So, it took a little while to get back on our feet. But the commitment to the shuttle was pretty, pretty strong. It was not until a decade later that people started realizing, not because of the risk, but the shuttle was a pretty expensive machine, to do that, to do all the launches on it. Another impact which came from it is the Air Force was planning to modify a launchpad at Bundaberg to be able to launch the shuttle from Bundaberg because from Cape Kennedy, you can only launch up to an inclination of 58 degrees. So, you can cover most of the land but not the whole planet. From Bundaberg, you can launch in polar orbit, so you can put it in an orbit which does a global coverage, of the planet. But then after the Challenger accident, the Air Force decided not to use the shuttle for launches. So, still, there were a lot of launches happening with traditional rockets, but most of the NASA launches, were—particularly the planetary—were happening using the shuttle. ZIERLER: For you as an outside observer but just in talking to colleagues, what is your sense fundamentally of why the disaster happened? Where was the human error? Where was the technical error? ELACHI: Well, clearly, people found that on the technical error that there were these rings, which were—what happened during very cold weather, the rings became rigid, and they were the connection between different sections of the solid rocket which helped the shuttle launch. And because they became very rigid, it ended up with leaks which were happening, and that was—Feynman made that experiment where he asked people to give him one of these called O-rings, and he asked them to get him some iced water. And he put the O-ring in it for a few minutes, and then took it, and it cracked while he did that. So, he was always amazing about doing those kinds of experiments, which are very—what seems simple, down-to-earth but which follow the laws of physics. So, clearly, there was a technical misunderstanding of how these O-rings operate in a cold environment. And the human issue was the pressure on launching, even that there was a warning. I mean, there were some people who were concerned about the cold weather, which was, at that time, unfortunately, that was the case that morning. But there was the pressure of, "hey, let's get moving." And I think sometimes a false confidence, that, we are immune from those things. And that left a long-term impact. When I was director, at JPL, that kind of stayed in my—in the background of my mind that, we have to be thoughtful before we launch things, or we shift them to the Cape to launch them. We have to make sure we think of everything, and it's important to listen to people who have different opinions or dissenting opinions. Because what actually happened, one of the things which came out of the shuttle investigation, was that many credible engineers said, "we might want to wait another day or two until it warms up a little bit." But the upper ups, didn't take—either it was not communicated to them, or they did not take it seriously. So, one of the things I used to do when I was director at JPL is before we confirmed—because I had to sign a letter to NASA saying we are ready, to launch, as the director JPL for JPL missions, that the spacecraft is ready. I used to bring all the key engineers, and go one-by-one, ask them, "Is there anything which worries you? Tell me now. It's far better to do it now than after we launch." And not only about launch but also about any subsystem or activities…or hardware. So, I used to go one at a time. There used to be like 40 people, and I had to look at each one of them, and ask them, "Is there any issue that is on your mind that worries you that keeps you…"—of course, we would never be 100% sure. But have we done everything we know how, to fix any issue? Have we done all the tests? That kind of stuck in my mind—I mean, and many people's minds, not only in my case—of making sure we listen to all the people at the working level, not only the people who're reporting to me but everybody at the working level, because they are the people who are actually doing the hardware, and they are the people who understand the weakness of that hardware, and what testing was done and verified, and are we ready, to launch? And it doesn't mean that everybody was saying, "Oh, yeah, it's safe." But if there was an issue, they would say, "OK, this is the issue that we still have. But we think the risk is very low. The likelihood of it happening is very low." Or: "We have a redundant system. If something happened on this track, we have—we can—we have a backup, for it." So, a lot of those [protocols] partly came from the investigation of the shuttle. ZIERLER: Charles, when the shuttle came back online in 1988, besides obviously addressing those concerns as the source of the disaster in 1986, in what ways was this a new and improved shuttle that allowed for new opportunities that might not have existed absent the disaster? ELACHI: Well, it was mostly focused on the safety of the shuttle more than more capability. So, the focus was—and NASA went through every subsystem, every part, not only the launch, the solid rockets, but everything through the shuttle, made sure that they were testing that everything—and it created a culture that was more safety-oriented. And then, unfortunately, a decade later, things got relaxed a little bit, and then there was a second disaster which happened in there. So, that also had another impact, on the way I approached things. I used to tell people, "Look, if we fly a mission and it works, and then we are doing another one identical to it, don't think the second one is going to work like the first one. Always assume this is the first time you are doing it. Check everything, recheck, because a lot of these things come from human errors." I mean, we are not perfect. We are after all humans. Even if you are doing something for the hundredth time, sometimes you might miss something particularly when you've become—let me call the word—blasé, about it a little bit. Oh, yeah, it worked a hundred times. Hundred and one, it should work. That's where we get caught. And many times, when I always looked at failures which happened/which didn't happen, at JPL, it's usually not advanced technology which fails because that technology, we pay a lot of attention to it. It's usually routine things, which kind of slip through the cracks because people were not paying very careful attention, or they thought it worked before, so it's going to work again, and just a little error happens, or somebody missed something on doing that. It's like the O-rings. It was not a technology thing. Everybody knew about it and used it. But, somehow, they didn't appreciate the impact when it was very cold—because that was not common. I mean, when you launch from Florida, things don't freeze in there. I had four or five principles when I was director at JPL when it related to missions, and this was one of them. Treat every mission as if it's the first time you are doing it. ZIERLER: Charles, of course, the new shuttle in 1988, it was not a foregone conclusion. Conceivably, NASA could've said, "We're done." So, at the national level, even from the White House on down to officials at NASA, who were some of the heroes? Who were some of the people who were brave enough to say, "We're going to rebuild this. We're not abandoning the shuttle program"? ELACHI: Yeah, clearly, there was a national commitment of pride, and the shuttle still was viewed at that time that it could lead to a—let me call it—routine. Nothing is routine in space. But that way of thinking was that that's going to be our main vehicle of launching things, and going in orbit, and put in the station. And remember, the shuttle was the main tool to put the space station in orbit. It was the only way to be able to do it and assemble the space station. So, there was a lot of implication not only for launching science but also to assemble the space station. So, there was a deep commitment at NASA to do that. Clearly, the key players are at the political level. I mean, you had—President Reagan was very committed to do it; a number of people in Congress also. And a key thing, sometime, I hate to say it, but there is a lot of politics in space—not as much in the robotic and scientific missions if they were driven by science. But when you come to the human program, you had powerful senators from Alabama and Texas and Florida, and this was a huge business, in those states. So, they made sure that there is funding to continue that activity—and, of course, commercial companies, which built the shuttle. So, it was a combination. I would say there were three aspects in the shuttle and human program in general. Clearly, there is the pride of the nation for exploring, and sending astronauts in space, then to the moon, and now we're talking about the moon and Mars. And that's why I support the human program because all people ask me, particularly when I was a director at JPL, "Why do we need the human program? We can do everything robotically." And my answer usually is, "Yes, you are right. For scientific purpose, we can do all of these things with robots, because we can send robots to places where humans cannot go. But as a pride of the nation, and inspiring young people, astronauts play a big role. And, therefore, for a nation like our nation, we need to have that exploration and that human spirit of going exploring. So, I support the human program." So, that was one factor, and many people felt that way, including in Congress. The second aspect is, clearly, the employment, at these big states, Texas and Florida and Alabama. So, there was—there is a political employment aspect. And the third one is international pride. I mean, remember, we were at that time still in the Cold War, or at the tail end of the Cold War, so still there was a pride of the US. And I think many people still remember the days that Sputnik was launched first by the Russians. So, being first and being at the leading edge of technology and capability was a factor. So, I think it's a combination of all this which kept the shuttle on track. But then by the year 2000 or the period of 2000, it became apparent that this was going to be very expensive, that this is not necessarily the best way of doing space exploration. ZIERLER: Charles, on a different topic, tell me about JPL Director Lew Allen, how you developed your relationship with him, and what you might've learned from his leadership style that stayed with you during your own tenure as director? ELACHI: Yeah, that was very interesting, about that period, because after Pickering, who was the director for many years from the mid-50s to the mid-70s, and he was really what I would call the founder of the modern JPL, as a space activity. And he was a professor in EE in the same department that I was in, and he had done very similar kind of things related to electromagnetic waves and communication. Then after him came Bruce Murray, who was a planetary scientist, and I'm sitting next door to his office at that time, as now, where I'm sitting in my office in the planetary building. And then Bruce Murray decided to step down in 1982. So, there was a search which happened like Caltech always does. There was a committee of the board of trustees, and they decided to bring in Lew Allen. And that was a big surprise, at that time because Lew Allen was the chief of staff of the Air Force. Always, a director of JPL was a scientist, or an engineer who was not necessarily a military person. So, everybody was anxious to see what Lew Allen would do. And it was 1982—that was after the SIR-A flight, and there were a lot of articles about SIR-A. So, I remember very clearly when I was in Washington one day, and I was at the airport waiting. And, here, I see Lew Allen, who was coming on the same flight, because I've seen his picture. So, I went and introduced myself. I told him I'm Charles Elachi, and welcome to JPL. And he said, "Oh, yeah, I remember seeing images from SIR-A." So, it immediately made easy connections with him because him being from the Air Force, I'm sure, they kept track of what we are doing in imaging radar in the Air Force. So, we sat down and chatted. And he was a really down-to-earth person, considering, he was big both physically and big, from his position of chief of staff of the Air Force. I remember asking him—I told him, "What should we call you? Should we call you General Allen or Dr. Allen?" Because he was a physicist, also. He said, "No, you call me Dr. Allen." So, that was my first introduction, you know. So, then, we flew back. And then, of course, at JPL at that time, I didn't have very many interactions with the big boss or anything. But every once in a while, we used to brief him, and he was the most delightfully experienced person there. And before I tell you what I learned from him—or maybe it's part of what I learned from him. So, shortly after that, in 1984—he was director until 1990—in 1984 after we did the second shuttle flight, he called me to his office to show him the data that we were getting from it. And shortly after that, I was appointed the head of the technical division at JPL—sorry, the science division at JPL. So, I had in my division all the instruments and the scientists. So, that led to a little bit more interaction because now, I was only one—there is one person between me and the director. That was the assistant director for the technical division. So, it led to a little bit more interaction. But then two things impressed me about him. I remember at that time—so, in 1987—sorry, let me make sure—no, 1985, our younger daughter was born. And I remember one day shortly after that—I don't know how he kept track; maybe he had some assistant—I got a call that said, "Dr. Allen wants to see if you are in your office." So, I said, "Yeah." They said, "Well, he's going to come and stop by." So, he came by, and he had this little toy and he said, "Well, we just found that you had a new child, and my wife just asked me to bring in this little toy for your daughter." I mean, I was blown away— ZIERLER: [laugh] ELACHI: —to be honest with you. I was absolutely blown away that, here, this—the director, the big boss, somehow found out that we have a, we have a daughter just recently born, and he brought this toy. And I think that probably reflected the spirit of—particularly from his wife of being the wife of a general in the Air Force, of taking care of all the military people who worked for them. So, that left a long-lasting impact on me. So, when I was director, I used to tell my assistant, "Find out for me every wedding and every child born on the lab." And I always used to send a note or, depending how well I knew them, to congratulate the employees. The other thing then, in 1988, yeah, late '87, I was in Japan, and I got a call. And they said, "When you come back, Dr. Allen would like to talk to you." So, when I came back, I made an appointment, went to his office, and that's when he told me, "Look, we know you have been very successful in building instruments, and this is going to become a big business at the lab. We are going to form a whole directorate which covers all the instrument work and the science work at the lab, and we would like you to be the director for it." So, remember, that was—I was 40 years old at that time, and the director for that, being as part of the executive council…so these are 10 people who report to the director. It was a big promotion, moving up, at that age and at that level. And that's what led to meeting with Lew Allen every week. We used to put all the executive council members—there was one person responsible for the flight project. I was responsible for science and instruments. Another person responsible for the Deep Space Network. Another person was responsible for the technical division at JPL. Another person responsible for technology work. Another person responsible for the human resources and contracting. So, it was an elite group, and I was by far the youngest, person in that group. And one other thing I learned from him at that time, he used to be very quiet. He used to sit down, and always ask opinions from everybody. But then when he made a decision, you knew exactly that the decision was made. I remember one of my colleagues one day, after we talked and debated, and Lew Allen said, "We are going to do it this way," one of the people said, "Yeah, but how about this?" And Lew Allen looked at him, and said, "I heard all of you, and which part of my decision didn't you understand?" And that was the end of the discussion. [laugh] So, I learned from that, of asking people, engaging everybody. And the other thing which I learned from him, part of that, when he used to make his decision, he used to explain why he made it, because he used to get different opinions. And then he used to say, "OK, that's what we are going to do, and my reasoning is so-and-so." These were the two big lessons that I learned from him. ZIERLER: Did Lew Allen have a military bearing about him? Was he very formal and upright in the way he carried himself? ELACHI: Yeah, I mean, the way he walked, he was straight up, he walked, and it was interesting. At the beginning, people used to run, and open the door for him because he was accustomed to it. But after a while, he started opening the door himself. [laugh] But you could tell. When he walked in the room, you could tell it was the director who walked in the room. I mean, a couple of things I learned from him, a secondary—up to that time, the director used to sit at the head—we had this big, long table—he used to sit at the head of the table. When Lew Allen came, he used to sit in the middle of the table, like the president sits when they are in the White House. And that way, he can seem closer to everybody. He and his wife were absolutely delightful. We became good friends because they used to have events at their house, and they used to invite a number of people, every once in a while. So, a couple of times, we were invited. And, matter of fact, our daughter now is 35 years old. We still have that toy that they gave us— ZIERLER: [laugh] ELACHI: —you know. No, he was an absolute—both as a person—delightful, and also technically very, very astute and very knowledgeable. Matter of fact, he chaired the committee when the Hubble Telescope was launched, and they found that there was an error in the mirror, which led for it not operating properly. He was asked to chair the committee which studied it, and which found out the reason for the error. And that was the time when, as I said, I was on the executive council, and we had built the main imaging for one of the cameras which does that. And immediately after that, I formed this small team, and we figured out a way of how we can build another instrument and put correcting glasses on it, which allowed us to fix the shuttle. And he was very engaged in making sure that that happened. The other thing I remember is also we launched—by that time—we launched Magellan during that time. So, Magellan went in orbit, and at the beginning, there was some issue with the radar which was not functioning well, which is not unusual. I remember walking with him, going to a meeting to get a briefing on it. And we got the briefing, and then we were walking back to the building, and he said, "Charles, you're a radar expert. What do you think? Do you think this is going to work?" I told him—I used to always call him Dr. Allen—"Dr. Allen, I think it will work. I think we can resolve that issue." He said, "Good," and then he kept going. [laugh] ZIERLER: [laugh] Charles, on the question of the military, of course, in the 1980s, there was lots of discussion about Star Wars, and SDI, and bringing the Cold War to space. Were you involved in any of that? Was JPL involved? What did you think about all of these debates? ELACHI: Well, no, I mean, it was an interesting debate. I was not directly involved, per se, because I was too busy with the NASA activity and all that during the SIR-A and SIR-B. But there was an element of people at JPL who were working with the military. There was always about 5, 10%, at JPL who were working with them, but mostly on the technology. So, our interest was, are there technologies which get enabled by the Star Wars [idea] which we can use for our activity? Clearly, lasers were thought up for communication at that time. And, clearly, there was a lot of investment in technological development, which was of also benefit to the kind of things that JPL does. So, there was a fair amount of interaction, but not personally. But at JPL, there was a fair amount of interaction, mostly on the technology part. We were not involved in building, in any of that activity, but more on developing what we call common technology at that time. And remember, JPL, before NASA was formed, was mainly funded by the Army. So, the relationship with the military goes back through all the history of JPL. So, then, after NASA was formed, most of the time—not always—but most of the time, the deputy director at JPL used to come from the military. It used to be generals from the military, either the Army or the Air Force. Even during my tenure, during all my tenure, I had two deputies, and both of them were three-star generals, from the Air Force—were retired, by that time—because there are lots of similarities, I mean, what you do for the military, and what we do for civilians. The technologies are almost the same. It's really—what's the application or what purpose you use them for. So, there was a close collaboration with the public part of the military activity. ZIERLER: Charles, you mentioned the Deep Space Network, which is definitely a topic I wanted to ask you about. What is your sense of the origins of this program, and what were its goals during this time? ELACHI: Yeah, I mean, no question, the Deep Space Network is your eyes and ears to communicate with your spacecraft. I mean, there is no way you can survive, without it. So, people realized from the beginning, even during the Apollo program, that we need some pretty advanced antennas, transmitters, receivers on the ground to be able to communicate with them. And some people listening to this might remember a movie called The Dish, that was about the station in Australia, that we did. So at JPL, and particularly the connection with Caltech, there were a number of faculty members in the Electrical Engineering department working on coding—how do you code the signal to enhance it to get signals from it?—microwaves, antennas. There were a number of faculty here working in that area, so it was natural, for JPL to develop that. ZIERLER: Charles, which faculty members specifically? Who was involved? Who comes to mind? ELACHI: Well, let me think about it for a second. I have to think about it a little bit, I mean, because that was before my days, before even I came, to Caltech, at that time. Well, there was Dick Goldstein, the person I mentioned earlier, he came from Caltech doing that. And then there were a number of people working in the coding that I would remember later. So, JPL, with the support of NASA, built a number of stations around the world. They started with the Goldstone, which is here in California. Then, they added the station in Madrid, and the station in Canberra. And at that time, because when we launched planetary space stuff, we used to launch them almost toward the south, there was a station in Africa, in South Africa. And JPL was a center, even from the days of Explorer, kind of the center, which coordinated all these antennas. And over the years, in the '60s, they expanded. We built some very large antennas, like almost the size of a football field. So, it's an amazing technology that went into them, and regularly they were upgraded, all the time. When people come to the mission operations room at JPL, and you are sitting there, and you see signals coming from Voyager or coming from Cassini or coming from the rovers, they are all coming to these stations which then link to the mission operation room at JPL. And many times, I mean, the mission operation room used to be my favorite place when I had guest, because you sit there, and you are seeing the signals coming from all around the universe, all around the planets, coming through these antennas, and doing that. So, I used to call it the center of the universe. And I remember when I was director, there was, you know—the manager of that facility heard me one day saying, "Wow, this looks like the center of the universe." A couple of weeks later, I come in, and they built on the floor this icon about the size, I would say, about two feet in diameter…and it had written on it, "Here is the center of the universe." [laugh] Probably one of the best—kind of fast-forward—one of the best things I got when I retired from JPL is they renamed that mission operation center as the Charles Elachi Mission Control Center. So, that's probably—because I used to spend so much time there—that's probably the best gift I could have gotten, from my retirement from NASA and from Caltech. But, yeah, the Deep Space Network was absolutely essential, for communicating with our space missions…and still absolutely essential, to do that. ZIERLER: Charles, to go back to that quest…that fundamental question about basic science and applied research, what aspects of the technology that went into the Deep Space Network were designed specifically with that application in mind, and what aspects were just part of the general culture of engineering and science at Caltech, and particular people had the bright idea to connect this to what JPL was doing? ELACHI: Well, the technology of building the transmitters, the receivers, the antennas, that was a broad technology. I mean, it's being used by communication companies and so on. So, it was not done uniquely for this thing. What the DSN drove is the whole fundamental work on information theory and coding, developing different codes. How do you code the signal, you know? We don't transmit just a simple signal. There are codes that you do it. And that was done because we knew we were going to get very weak signals, and to be able to extract that signal from the noise—the noise is very random, and the signal, if it's coded, then it has a certain pattern to it. So, it's a technology of recognizing that pattern, which allow you extract the actual signal, even if it's overwhelmed by noise. That was the work done at Caltech and JPL for it, and now it's commonly used, you know. Then it translated to the telecommunication companies—but, at that time, it was very, very exotic, to be able to do that. And now I remember one of the faculty. His name was [Dan] McCleese, who was one of the people working on the coding at that time. So, yeah, there was a lot of fundamental development done by the Electrical Engineering department at Caltech, particularly on the coding and the information theory of extracting the information from it. The pieces of hardware, that was when Caltech was not very heavily involved in it. That was more an industrial, commercial kind of activity. ZIERLER: Charles, tell me about JPL's executive council. What function does it fulfill for JPL overall? ELACHI: Yeah, basically, the executive council is the top leadership which oversees the lab. The director of JPL is heavily involved—I mean, different directors have different styles—but the director is heavily involved in dealing with NASA, dealing with Congress, and kind of overseeing at the high level the activities at the lab. But then the day-to-day operations of the lab was done by members of the executive council, as well as interaction with NASA, not at the policy level but at the strategy level. And, so, when I was on the executive council, really, I had two roles. One is dealing with NASA about making sure we get the instruments, we get funding, that we are managing the day-to-day interactions with NASA. And the other part was overseeing the day-to-day, making sure that things were developed at JPL. We asked: what are our strategic needs? In a sense, the executive council was the strategic body which [executed] the policy developed by the director. It was a strategic body which advises the director but also takes the policy and the strategy developed by the council, and it makes sure it's implemented at JPL. And, basically, it was the highest level you can get to at JPL, short of being the director of the lab. And they were brilliant people who were at that level. I mean, you don't get up to that level unless you had extensive experience. And, effectively, almost all the members of the executive council grew up through JPL, so they moved up. The only exception where we got people from outside, it was for human resources and for contracting—those kinds of activities. That was more a—I don't want to call it an industrial function. That was a more commercial kind of function. And we did it because we wanted to bring some outside perspective. But as far as all the other, the technical roles, I don't recall at any time that I was on the council, or even when I was director, that we brought anybody from outside JPL and Caltech. Usually, the chief scientist at JPL, we used to bring them from the campus, to build a relationship with the campus and with the chief scientist and chief technologist. Also, we used to bring them from the campus. And a fair number of members of the executive council, particularly in the early days, used to be Caltech graduates, you know. So, there was a lot of interplay and interconnection, from Caltech. ZIERLER: Now, when you were named to the executive council, was this before or after you were appointed associate director? ELACHI: No, it's the same. I was never an associate director. It used to be called—in those days, it was called assistant lab director. That was the term, all of that, or ASD, that was the common—then, when I became director, I changed the name because I thought assistant director was misleading a little bit. So, I changed the title to be associate director—because that was a better reflection of the role of those people. So, that was—that happened when I became director. ZIERLER: Now, at this level, at the strategic level, to go back to this unique relationship, the triangle between JPL and Caltech and NASA, what is the reporting structure? Who reports to who? Where is Caltech, the president, the board of trustees, the provost, the division chairs? Where is the hierarchy and authority vested in Caltech relevant in the decision-making and policy-making process at JPL? ELACHI: Yeah, that's a very good question. Now, the JPL director—only the director—is appointed by the Caltech president on the advice of the board of trustees. So, the search for the director is conducted by a committee of the board of trustees, chaired by a member of the board of trustees, and has faculty on it, and sometimes [this includes] some JPL employees to broaden the search. And then it's appointed. Then the board of trustees [convenes a] search committee, filters it, makes recommendations to the president, and then the president makes the final decision, of course, with the approval of the board of trustees. I remember when I was appointed, my letter of appointment said, "You serve at the pleasure of the board of trustees," which means, "if we want to fire you, we can fire you any time we want to do that." It was not a term limit. And the director officially reports to the Caltech president. But as a Caltech faculty member, I can speak mostly about my tenure, you know. As a Caltech faculty, basically, Caltech and the board of trustees entrusted me to running JPL. So, there was no day-to-day decisions made by Caltech. It was really—and that's why the director of JPL is also vice president of Caltech for JPL. In a sense, the board of trustees and the president empower the director of JPL to make the decisions on behalf of Caltech. So, very rarely, I had to come back and ask for permission to do something or—matter of fact, when Tom Rosenbaum became the president, I told him, "Tom, if I come to you every week for a decision, I'm the wrong director." ZIERLER: [laugh] ELACHI: "You have to trust me that I will be making the right decision and that I am looking at the benefit of Caltech as well as NASA." So, Caltech plays a major role in establishing the policies for hiring at JPL, or the standard, to make sure we have the top-notch employees, to make sure we're doing things properly, we are operating properly. But Caltech institutionally does not get involved in what missions do we do. That's NASA's role because NASA funds the JPL. JPL and Caltech are supposed to execute the missions that NASA defines. Now, of course, there is a lot of interaction back and forth. I mean, at JPL, we had an organization which looked at all the future missions, studied them. We interacted—I used to interact with the head, of—the different heads at NASA, who were running the different programs literally on a weekly basis. There was one organization which is called the Space and Earth Science Organization at NASA. The head of that organization reported to the administrator. That person was responsible for all the robotic missions at NASA. I used to talk with him every week on a routine basis, sometime more often, than that. So, it was really a team relationship, and that's what's critical is the team relationship between JPL leadership and the NASA leadership. Caltech does not get involved on a daily or regular basis. But Caltech had the fiduciary responsibility that we're doing the right thing with the right ethic with the right, approach, and that permeated the culture at JPL. The Caltech culture got permeated, at JPL—a culture of excellence, integrity, being open, being candid—similar to what a university actually does, and [this included] how to interact with the employees. Now, of course, every once in a while, there were big issues which had to be—which typically happened maybe once a year, once every other year—which had to be elevated to the NASA administrator. And if there is pushback at NASA, then the Caltech president used to get involved, or the board of trustees used to get involved. Matter of fact, there was a committee of the board of trustees—a subcommittee, which oversaw JPL, which used to come and spend twice a year for a day at JPL to be briefed so they're aware of the issue. I mean, they are very distinguished people on the board of trustees. And once a year, a couple of the members of the board of trustees used to have dinner with the NASA administrator so to—and senior leadership so to hear from them how do they feel is JPL doing, and are there any big issues? And every once in a while, the NASA administrator used to ask some member of the board of trustees for help with Congress because many of them were very well connected, with either the administration or with Congress. I mean, we have to remember, a couple of times, presidents of Caltech end up being members of the cabinet, in the government. Lee DuBridge was the advisor for President Nixon, and then a number of people, end up being in presidential administrations. So, Caltech is very well connected in that way, so Caltech used to help but we had to be careful not to go around NASA. We had to do it in coordination. Every once in a while, I used to go around when it was really needed, and I talked with our congressmen on the Hill. So, there was a good relationship between NASA, the leadership of Caltech, and the director at JPL. Now, where there was more interaction on a daily basis was with the faculty because there are lots of very distinguished faculty at Caltech, many of them involved both in engineering, in astronomy, in planetary science. So, we used to have a lot of interaction at the scientific level and the engineering level. When I became director, one key objective was to enhance—I mean, there was good interaction during my predecessor and so on, and during the Lew Allen period. But I really wanted to expand that significantly, and that's where we developed the concept of having joint appointments where there were a number of faculty who had joint appointments also at JPL, I mean, formal joint appointments between the campus and JPL, even during the search for faculty, if it was an area of joint interest. So, these were faculty who had—they spent a couple of days at JPL, and they had labs at JPL, and then spent the rest of their time on the campus. And that's why we've kept the emphasis—not only during my time, even before that—of having Caltech faculty as chief scientist and chief technologist at JPL. So, it's really the benefit between the three points on the triangle, if you want, that you mentioned, is, really, is across all levels at Caltech on campus. Matter of fact, I usually don't call it Caltech. I say campus and JPL. We are all Caltech. Caltech is really the umbrella for both places, so it's campus and JPL as part of Caltech. JPL, normally, it's called a division of Caltech in the formal documents. And NASA appreciated that, or I would say the majority of the people at NASA, appreciated that because we were able to attract top-notch researchers to JPL who would have been hard to attract as civil servants, you know. And that's why the Department of Energy, all its labs are similar to JPL. It's called a federally funded research and development center, which are managed by universities, mostly University of California, and some of them by the University of Chicago. But they are a government facility, funded by the government. So, JPL is unique among the NASA centers in that way, and it gave the JPL director a fair amount of flexibility, for example, in how we hire people. If people are not cutting it, let them go. Our salary structure is the same as the campus. It's not a civil servant structure. It had a lot of flexibility…the way we contract, usually, at a NASA center, it takes six to nine months to do a contract. I used to tell them, jokingly, "Oh, by the time I get to JPL, we can issue a contract to industry, during my five hours' flight"—I mean, we had—it was a little bit more than that, and we had a process. But we were not governed by the detail of the government rules. We lived in the spirit of it, of making sure we had competition. I don't pick a contracting company that I like, but we had competition…but we used to move much faster in our process because when we issued contract, to build spacecraft—it was a contract with Caltech, not a contract with NASA. And industry could not appeal that contract, like you do in the government, and that slowed down everything. So, most of the people at NASA appreciated the benefit that you would get from it. ZIERLER: Charles, what you're saying is before you became director, you saw opportunity to deepen ties with Caltech, and this had political and scientific advantages? ELACHI: Well, yeah, sure. I mean, also, being a Caltech graduate, I mean, that was normal. And during that whole period before I became director, I was not tenured faculty. I became tenured faculty later. But, also, I was teaching at Caltech, so I was lecturer, and then I was senior research fellow. So, I used to come to the campus literally every week, for my classes here. And I had an office here in Electrical Engineering, and I interacted with a lot of my colleagues here at Caltech. And I had a number of Caltech faculty members on kind of an advisory board, and then it was more formal when I became director. So, it was perfectly normal. The interaction with the campus was perfectly normal. And a number of the faculty, as I mentioned, were students with me when I was a student, at Caltech. So for me, it was a natural connection. ZIERLER: Charles, to pull a little further on the thread of who really has the power in this relationship, so, just theoretically, if Caltech nominated a JPL director that, for whatever reason, was totally unacceptable to NASA, does NASA have the authority at that point to step in and veto that decision? ELACHI: Yeah, for the JPL director, they have that. In the contract, it said that the JPL director selection is subject to concurrence by Headquarters. I think these are roughly the right words. So, of course, a smart president—which all of them were very smart presidents—will check with NASA before they announce their final decision. ZIERLER: Right. ELACHI: And, matter of fact, I think, you know—I mean, I was not involved in the selection, per se—they will check with NASA to see, does NASA have any ideas? Does NASA have any suggestions? But not define—so, we were careful about using the word. We said "concurrence" not "appointment." So, the appointment was done by Caltech and the board of trustees, but it was with concurrence [from NASA]. So, I remember when I was selected, that was on—let's see, this was January 27, 2001, and David Baltimore wanted to announce it the following day. He had checked with NASA already. But the administrator of NASA, who I knew pretty well, I mean, even when I was on the executive council, they had a lot of interaction with the administrator and senior people— ZIERLER: That was Sean—was that Sean O'Keefe? ELACHI: No, Dan Goldin. Sean O'Keefe came after that; it was Dan Goldin. So, Dan asked Baltimore, he said, "Can you wait a day because I want to be physically at JPL when the announcement is made for the employees?" So, we delayed my appointment by one day until January 30th, so Dan Goldin could fly in. And after Baltimore made the announcement, and then Goldin gave a talk about his support for JPL, his support for me, he knew me for a long time, and then I gave my talk to the employees. So, yeah, there is an intimate relationship between the board of trustees, NASA, the Caltech president—but not on the day-to-day decisions. That's left for the director of JPL. ZIERLER: Charles, to get back to the historical narrative in the late 1980s, so in 1988, the NASA scientist, James Hansen, famously rang the alarm bell about climate change in the halls of the US Congress. I'm curious if climate change was on your radar that early, if JPL was thinking about missions as they related to the greenhouse effect and climate change on planet Earth. ELACHI: Yeah, by that time, that was the late '80s, yes, that was already on the screens of a lot of people. And then by then, at the end of 1988, I was on the executive council, overseeing all the scientific instruments at JPL. And there were a number of researchers at JPL who were looking at the impact on climate change, and what kinds of instruments we would need to be able to monitor our planet. In the early '80s, the big deal was the ozone, the issue of depleting the ozone layer which protects us from ultraviolet radiation. And there was the whole issue of the ozone hole in Antarctica. So, there were a couple of researchers at JPL who were building an instrument to fly on spacecraft to monitor that. One of them, his name was Joe Waters, was working on using submillimeter technology, working, by the way, with some people from the campus on developing that technology because that technology was of interest also for astronomy with Professor Tom Phillips, here at Caltech who was working on the devices for it—he was looking for astronomical, observations. And then we had Joe Waters at JPL looking at similar technology to be able to look at Earth. And that instrument was developed and then flown, and this allowed us to monitor what was happening. And then we had a number of people at JPL who were working on infrared observation, looking at our planet to be able to measure the temperature. One of them was Mous Chahine. He was the head of the—before me—the head of the engineering division, and later, at the tail end of Lew Allen days, he became the chief scientist. So, he was looking at the Earth's temperature changes both in the atmosphere and on the surface. So, it was very much—by the late '80s, it was very much on our radar screen. And that was one factor, indirectly, which led for JPL to form that directorate, and appoint me as the head of the directorate because we were seeing that the field of building instruments, particularly for Earth observation, was really growing. And there was more and more interest at NASA about developing a capability to monitor our planet, and understand what was happening, on our planet. And that was interesting because many of—as I mentioned earlier, we had a lot of people from England. There was very close collaboration between JPL and University of Oxford because there were a number of people at University of Oxford working on atmospheric research. So, many of their graduates came as postdocs to JPL, and they ended up staying at JPL. ZIERLER: Charles, tell me about being elected to the National Academy of Engineering in 1989. Besides the gratification of being bestowed with such an honor at such a young age, I'm curious, in what ways did this honor open doors for you, establish new contacts, and perhaps even expand what you were able to do at JPL? ELACHI: Well, clearly, that was exciting. I mean, I was not expecting it. I mean, I was busy doing my research and publishing papers. And then by then, I was what we called assistant lab director, heading up that directorate. And I remember because that was during the time of Lew Allen. He was a member of that Academy. I remember him calling me. We were in an executive council meeting, and at the end of it, he said, "Charles, I would like to see you." So, I remember walking to his office, and he said, "Oh, you are going to be hearing tomorrow that you have been elected to the National Academy." Because usually what happen, all the members of the academy have to vote for any new member, so he knew—him being a member of the academy—knew that my name, was part of that, and that I was going to be selected. And they usually say what date they will be announcing it publicly. So, he said, "You'll be receiving tomorrow a big envelope from the academy. Make sure you open it, you know." So, that was clearly a very exciting time for a young—I mean, I was 41 years old, so that was very exciting. And then later, I found I was one of the youngest people ever elected to the academy. And then over my career after that, I got very engaged in the Academy, so I served in almost every role that the Academy had. So, I chaired the nomination committee for my section. Then I chaired the selection committee for the Academy. I spent two years doing that. And then I was on the Academy council. By then, I was the director of JPL. So, that was kind of like the board of trustees of the academy. Usually, you serve three years, renewable only once, so I served for six years, on that council. So, I served my duties on the Academy. And the other thing which I did because I thought that was an important honor for the kind of things we do at JPL, and in general, the Academy tended—because of its membership—it tended to more have academics because they publish. They are well known. People at JPL, the engineers, they are known by their peers, but they are not more broadly known for their engineering. So, I made it as a rule that I'm going to make sure there is at least four or five nominations every year, to the academy of people at JPL like project managers. And I'm really pleased that almost every year—not exactly every year—but almost every year, we end up having a person from JPL. So, up to when I became director, I think there were maybe two or three people members of the Academy. I mean, clearly, Bill Pickering was one of the founding members, matter of fact, of the Academy. But after that, there were only very few people. And then when I was selected, it happened to two JPL-ers, me and John Casani, who was my equivalent for the flight projects, you know. He was project manager on Galileo. And then after that, John and I always made sure we have nominations from JPL. And I think now, there is about a dozen members of the National Academy who are actually working, active employees at JPL. ZIERLER: Charles, another cultural question as it relates to your rapid ascent at JPL, and that is, you're elected to the National Academy. You are so young relative to so many of your colleagues. There are even newspaper articles that refer to you as the Golden Boy of JPL. ELACHI: [laugh] ZIERLER: So, the question there is, do you have to manage any sense of jealousy from your coworkers, people who are senior to you? Was that something that you were sensitive to? Were you politically aware? Were these things that you tried to mitigate? Or was the culture at JPL really just celebratory of excellence, and that if you had the goods, people were excited to support you in any way that they could? ELACHI: Yeah, it was the second. I really—I don't recall ever, ever being kind of—let me say—discriminated against. But, no, that's not exactly the word that I mean. But— ZIERLER: That people were grumbling about you, right? ELACHI: —about my background or where I came from or my accent. People loved my accent, being a little bit of a French accent. And people were always very supportive. And I think part of it—again, I don't want to show off much because I'm very gregarious. I mean, I'm always very friendly with people. And I always looked at the career of the people working with me, of helping them in their career, and encouraging them. So, I think I had a very good relationship with—very friendly with everybody. And it's the culture at JPL. We celebrate. At JPL, the culture is we are a team. We are all working on building these tools for exploring the universe. We are all explorers, and we all depend on each other, in getting things done. So, I think always people were cheering for me. So, yeah, I was called, Golden Boy in the earlier days. Also, there was an article in the L.A. Times saying there's a rising star, you know. And, also, people after told me that when they want something done, they tell people, "Well, Charles wants this," you know. That was when I was on the executive council and as director. And everybody told me every time they see that they get whatever they want, on that. ZIERLER: [laugh] ELACHI: So, I think throughout my career, I created an environment where we are part of the team, and we worked all together, on doing that. And when I was director—again, a little bit influenced by Lew Allen—I used to always emphasize that every single employee, every one of the 7,000, is critical for our mission. And I used to emphasize that all the way from the PhDs to the project manager, to the landscape people who are doing our landscaping, to the administrative people who actually make sure we get our paychecks, that everybody is important, and everybody is part of the team. And I think part of it also—now, it's not—at a later time, I had to be a little bit more careful. Coming from an Oriental and then a French background, when I see people that I knew a little bit, I used to give them a hug, kiss on the cheeks. I mean, that was something very common, to do, male or female, for that matter. Unfortunately, now, people are a little bit more cautious, about these things. But, for me, it was—and I was very passionate about JPL, and it shows. I mean, I absolutely love JPL, and what we do and the missions that we do. So, I was very passionate, and it showed to all the employees how passionate, I was. I used to try to make sure I remember the first name of people. I couldn't do it for 7,000 employees. But I remember one employee who used to drive me to the airport. that was one of the privileges of being on the executive council. And I got to know him, that he was—he's Hispanic. His name was José, and we used to chat about his son who played soccer. And I would always ask him, "How is your son doing?" And even after I became director, every time I used to see him, I'd say, "Hey, José, how are you doing?" And people saw that. The other thing which people appreciated, there was one of the guards, at JPL, and I used to—when I drive, I used to stop and say hello always then, "How are you doing today?" And I got to know this one guard in there, and I told him, "Well, what is your dream?" He said, "I really would like to go and get a college degree." And I told him, "Why don't you do that? JPL would pay for it." Seven, eight years later, after I stepped down, I was going to a meeting at JPL, and he waved at me, and he stopped, and he said, "Guess what? I just got my college degree." ZIERLER: Oh, wow. ELACHI: I felt great. So, that was the kind of atmosphere which surrounded me. So, that's why I people were—they were cheering for me, you know. ZIERLER: Charles, back to the missions, tell me about your work on the radar mapping team for Magellan. What were the circumstances of you joining the mission, and what were some of the biggest questions about Venus that you and your team set out to answer with Magellan? ELACHI: Well, clearly, I mean, the most fundamental thing was to get images of Venus to see what it looks like, because that's the first thing you look at. And from it, you can infer a lot about the geology of that planet, and the evolution of that planet. So, really, the focus was on just getting images from it at about a 50- to 100-meter resolution. And we mapped the whole planet, you know. It was a mission which I think lasted like four years. Now, by that time, by the time we launched it, I was on the executive council, so I was not as involved in the day-to-day. I mean, I published a couple of papers. I was very involved in the design of the instrument because then I was still doing research at that time in the early '80s. Then, the data is distributed, and everybody in the country, in the world, for that matter, can do the analysis of the data. So, really, the focus of the teams at JPL for the planetary missions is to conceive the missions and to look at what kind of instruments [were needed], working with the science community, developing the instrument. In the case of the radar, we were the main institution because of our experience. So, the radars were either designed or actually built, at JPL. So, we were the people who defined the instrument: how does it meet the scientific requirement, processing the data, and then make sure the broad community does that. So, in almost every paper, if you look at my CV, almost every paper, there were people not only at JPL from our team but from outside, JPL because it was a team effort. And the philosophy I always followed—and that could be part of why people cheered for me, even from outside JPL—is what I used to call at JPL, we are a trust. Our job is to enable the broad community to achieve their vision. This is not our—it is our mission but it's not for our self-satisfaction. It's for helping the broader community achieve the exploration, and the country achieve that. So, we run a very open kind of organization. One example, when we flew the radar to map Titan, that's on the Cassini mission, where the concept of the mission started in the early '80s. And then NASA asked for a proposal for instrument in the mid-80s. I was still a working researcher, so I formed a team which included scientists internally and outside of JPL, and we proposed, and it was selected. By the time we got to Saturn, I was already the director of JPL. That's how long these missions would take. But I stayed engaged, in the scientific leadership of it. And my role was, one, as soon as we get the data, we're going to distribute it to everybody. We'll make it public. And number two, every year, I had half a dozen young scientists from different universities to come and be part of the team, so they can participate in the analysis of the data. And that was almost unique at that time because, usually, the principal investigator has the right to keep the data for six months so they can publish it and get the credit for it. For me, that was not important. I mean, the credit was that we have been successful and whether—and I don't have—and by then, I had published a couple hundred papers, so it was not a big deal for me to be an author. Now, they are all senior—more senior scientists. And many times, when there are discussions, they all say—many of them say, "Let's follow the model that Charles has," making the data immediately public, bringing young students, to do that. Matter of fact, one of the ones who I became a very close colleague with was across the hall from me here at Caltech, his name is Alex Hayes. He was a student working with—not with me, with another professor. But he used to come to my office, Alex, and I said, "As soon as we get the data, I'm going to give it to you." And he did his PhD on that data, and now he's a professor at Cornell University, and one of the leaders in planetary exploration. So, he's now his own PI, doing that. So, I think being—that attitude of being open, feeling that we are doing a broad service for the community really built a lot of goodwill, and people remember that, at a later time. ZIERLER: Were you surprised at all of what you saw on Venus? ELACHI: Yeah, because we had a limited idea of what—I mean, we had very—except for what we saw from the ground, which was very low resolution. But it looked like what looks like lava flows. It looks like volcanoes. Now, a number of scientists would say, "Yeah, there is a possibility there is this, or a possibility there is that." But until you see it, you cannot tell what is really there. So, yeah, there were a number of surprises, and I would say the biggest—the biggest surprise was what we saw on Titan because on Titan, people—also it's the same as Venus. I mean, it is cloud covered, or haze covered—not cloud covered. So, there were all kinds of speculation of what's on it. There were some ground-based radar activities. And based on that, people thought, "Oh, there might be a global ocean on it." Well, when we got there, and took the radar images, it was not a global ocean but there were lakes, and you can see rivers. And because Titan was so cold, we knew that water, H2O, could not be liquid on that planet. That, really, the solid surface is H2O, but then the lakes and the rivers were mostly, methane and ethane, hydrocarbon, because even at that low temperature of roughly -90 degrees Fahrenheit, the methane and ethane are liquid in it. So, that was a big surprise, seeing all these lakes and the river traces, on it. And the other big surprise was actually seeing sand dunes. It looked very much like Earth, except it's not liquid water and solid rocks. It was liquid methane and solid water. But other than that, almost all the phenomena that we see here. And it looked like, in some places, there are some volcanic explosions, and some other places, we see impact craters. But, clearly, because of the heavy atmosphere, it had been worked out a lot, so we didn't see a lot of craters. There were a lot of them. But that was—almost every image was a surprise. Of course, now, people will say, "Oh, of course, that makes sense." But that's normally in any discovery or exploration in the retrospective, of course, it makes sense. Like what we did in Egypt, of course, we should have thought that we could penetrate [laugh] below the sand. But, at that time, it was a surprise. ZIERLER: Charles, with Magellan and Venus, was there any optimism even at a very basic level that Magellan would detect any evidence of life, current or past? ELACHI: No, I mean, we knew that the surface of Venus is very, very hot, so we knew that the likelihood of present life is almost nil. Now, there is always the question, was there life in the early days, of Venus? Because all the planets formed roughly at the same time. They had—the terrestrial planet had similar kinds of starting points, if you want. Some of them were a little bit warmer. And Venus is not a whole lot closer to the sun than Earth, so even that we did expect it to be warmer, we didn't expect for it to be 300, 400 degrees Fahrenheit. And that's where it evolved, for the greenhouse gas. So, there was a lot of talk at that time on, you know. Is the Earth evolving for global warming in a similar way that Venus most likely evolved with the carbon dioxide in the atmosphere? There were a lot of speculation then, and still now. Could have been a different environment on Venus in the early days, which, by then, because of whatever reason of the carbon dioxide emissions, that it led to global warming, and it led to a "hell," now of the temperature? So, there is still interest in the possibility of life. Matter of fact, recently, there was talk, maybe there is life or organic matter in the atmosphere of Venus. So, as you go up in the atmosphere, it get cooler and cooler, and then you get to a level where the temperature of water could be liquid. So, there was detection of, I think, phosphene, one of the gases which usually is generated by organic material, in the atmosphere. There is still some speculation, could there be life in the atmosphere, or maybe a different life than ours, or could there be life, which existed a long time ago? So, that's leading to a couple of missions now. One of them from JPL that I worked on in the early days was to send another mission similar to Magellan but to get us much, much higher resolution of the surface, getting down to the 20, 25-meter [level] where you could possibly see traces of old drainage channels, if they existed, in the past. And then there is, in combination with it, there is a mission from Goddard Space Center which is to send a probe to get the detail of the composition of the atmosphere. Ultimately, as technology is being worked on, is to put a lander, maybe a rover similar to what we are doing on Mars, to go and explore Venus. It will be a big technological challenge because of the temperature, but it's not impossible to do that. ZIERLER: Charles, moving across the solar system, tell me about the Galileo mission to Jupiter, how that got started, and what your involvement may have been in that. ELACHI: Well, the Galileo mission, again, I was not involved in the early definition of it. All of that was happening when I was too busy with radars, and so on, on Earth, and preparing for Venus. So, the Galileo mission was the first. Then after Voyager, there were lots of surprises all across [the Solar System] as we were for the first time, seeing Jupiter and its satellites, and then Saturn. And I remember, because I was a researcher at JPL, when there were images of volcanic eruption on Io. I mean, that was a big deal. That was the first time that we were seeing actual eruptions, I mean, volcanic activity happening now outside of Earth, and doing that. So, that was a big deal, on Io. Then, there was a strong interest in doing a more intensive exploration of Jupiter and, to do that, you needed to put an orbit in. So, that was the development, the background after the Voyager data of the developing the Galileo mission, and that was planned to be launched by the shuttle. Then the Challenger accident happened, so it got delayed, for a time. And my only involvement in it a little bit was on looking at the antennas and the communication with Earth. I was not really involved in any scientific aspect of it. And that's the mission which, unfortunately, we think because of the delays and for too long being packaged, that when the antenna was—after launch, the antenna was stuck. It was like an umbrella, to open it. And I remember clearly when that happened because that was a very concerning event. I mean, I was not involved in it, but it was a very concerning event. And that reflects on the ingenuity of the people at JPL. I mean, we tried and tried and tried, and it didn't open. So, for a while, people thought it was completely lost, that there was no way to communicate with it. But then some smart people came up with an idea, because that mission had also a probe, and the probe was going to drop in the atmosphere, and there was going to—there was a small antenna to communicate with the probe. It was never intended to communicate with Earth. It was at low data rate. So, somebody came with the ingenuity—hey, if we can develop a coding system to code the data, we can send a lot more data to Earth, even with a small antenna than—no, not as much as the bigger antenna but significantly more than what normally was with the small antenna. So, that's where there was a lot of work; very ingenious people in communication theory going tracing back to the Caltech connection in coding and information theory. A group of employees at JPL, who were experts in that field, came up with that idea, and almost got the same—almost the same—amount of data that we would have gotten if the antenna happened. So, this is a reflection of the ingenuity of JPL employees, and the work with Caltech, the close relationship with the campus, that led to effectively saving the Galileo mission. ZIERLER: Thinking about the Galileo mission, and your efforts to further integrate Caltech faculty into JPL's mission—I'm thinking of, for example, a leading authority like Dave Stevenson on Jupiter—what opportunities did you have where there was a particular mission, and you saw somebody with such specific and relevant expertise in that topic where they might not have had an official connection to JPL but you saw opportunity to bring them in? How did you foster those kinds of relationships? ELACHI: Well, that's a key thing, a key benefit for the campus, of having JPL connected with the campus. So, the way I used to put it is JPL enables small teams or individuals on the campus to do great things because it enables. Dave Stevenson is a great example. Dave is mostly a theoretician, I mean, his office is next door to mine, and he's one of the leading thinkers about Jupiter, the other planets, and planetary formation in general. And a place like JPL, by being able to do those missions, enabled the faculty here to be closely associated with those missions, even in—not only in analyzing the data but in defining the mission. So, usually, when we are studying new ideas, new things, I mean, which what is important, there are lots of ideas, far more than can be done with the funding that NASA has. So, you need to develop prioritization, buy-in in the science community, and Caltech faculty plays a significant role because they are leaders in the field. And, so, they get involved from the early days, of doing this mission. What are the right instruments, the right orbit? How do we analyze the data? And then, later, once they are developed, they are involved in the analysis of the data. And I would say almost the vast majority of the faculty—let me take the planetary department where I have one of my feet now in the planetary department, as well as electrical engineering—almost all of them have been involved. I mean, there is Andy Ingersoll who is here, who was very heavily involved in the Cassini mission; Yuk Yung, who was very involved in Earth observations for atmospheric modeling as well as planetary missions; Bethany Ehlmann, who is involved in the Mars rover. Matter of fact, the most recent rovers, both Curiosity and Perseverance, the chief scientist for the mission, what we call project scientist, are Caltech faculty. In the case of Perseverance, it's John Grotzinger, who is the lead scientist on it. And in the case of Perseverance, Farley, Ken Farley, who's the chief scientist. So, that's why I said it enabled the faculty here really to do even greater things, because they can do great things, by doing the science. Matter of fact, people like John Grotzinger told me that he came to Caltech because he wanted the connection with JPL. And many other faculty members have told me the same thing, particularly in astronomy and in planetary science. And in astronomy, you say, why would they come? It is because Caltech is heavily instrumentalist. So, these are astronomers who like to build instruments, to develop the latest technology in detectors. And that's one of the strengths of JPL, because we build instruments. So, we have a lab which is called the Microdevices Lab, which is really at the leading edge of developing advanced technology for detectors and for integrated circuits. And that lab was started by Lew Allen; he arranged the funding for it. And many faculty have told me they came to Caltech because of their access to the Microdevices Lab at JPL, and working on instruments and missions at JPL. Matter of fact, I would say, looking at memories of Caltech, I'm sitting now in the office that Jim Westphal used to have. He was a very well-known, one of the leaders, in the field. I'm sitting in the office of Jim Westphal, and he's the guy who conceived and worked with JPL to build the main camera for the Hubble Telescope. ZIERLER: Right. ELACHI: So, he was the intellectual leader, and JPL actually built it, for him. ZIERLER: Charles, another mission-oriented question I wanted to ask about was Ulysses. I'm especially curious about the way that a spacecraft is designed to study the sun in a different way than one that's designed to study a planet. What are some of the technical challenges in getting reliable data from a spacecraft that, by definition, if it gets too close to the target, it's going to burn up? ELACHI: Yeah, in actuality, it's interesting because, I mean, the solar system is big. And as you get closer to the sun, you have a different environment than if you're going to Mars or you're going to Jupiter. But one thing interesting about Ulysses was it really didn't get very close to the sun, but we put it in a polar orbit, which allowed us to image the sun from above. Now, the challenge of almost all our missions, like Ulysses or the mission which we sent to Venus or the mission that we sent to Mercury, is you are going to get a lot of heat coming from the sun. And you cannot hide. There is no shade. You cannot go under a tree and hide from the sun's illumination. ZIERLER: [laugh] ELACHI: So, the sun is shining on you all the time. So, for the mission which are getting closer to the sun, or roughly the distance of the sun, even when we are, at Mars's altitude, we have to put blankets, on it, which—like aluminum foil—which tend to reflect the sunlight and protect the spacecraft, to keep the electronics at a reasonable temperature. So, that's why you see a lot of these spacecraft have what looks like aluminum foil, on them, and you see louvers, which allows us to control how much energy is emitted. Now, the fortunate thing is it's not the shade but the part of the spacecraft looking away from the sun gets very cold because it's not getting the sunlight. So, there is a lot of challenge of how you manage your thermal environment. When you are going away from the sunlight, going on Galileo or on Cassini, you would see black blankets because, in that case, we are getting so cold, we want to keep the heat. So, we have the reverse problem, of doing that. So, managing the temperature on the spacecraft is probably one of the most challenging areas to develop expertise, if you want, and there is a whole group at JPL which works on managing the thermal properties of the spacecraft. And the same thing for the rovers, on Mars. The environment is very cold. And, even worse, the challenge we have is when the spacecraft is spinning, so a bit of it goes from dark to light, dark to light, so you have a big excursion of the temperature. And when you are on Mars, you have excursion of temperatures every day. So, managing the thermal environment is one of the key challengers on the spacecraft. ZIERLER: And why the sun's poles? Why the focus for Ulysses on the poles of the sun? ELACHI: Well, because we cannot see them from Earth. So, I mean, there is a lot of work in understanding the sun which has been happening from ground telescopes. I mean, matter of fact, that one of the foundations of Caltech was the solar telescope on Mount Wilson, close to Pasadena. So, we owe something to the sun, in that. ZIERLER: [laugh] ELACHI: I mean, it was broader than the sun in doing that. But you cannot see the poles from the ground. And the other part is not only taking images of the sun itself, but also looking at what's being emitted from the sun. So, the whole environment between us and the sun actually doing in situ measurements, and seeing what's being emitted from the sun, and what's the composition, how does it impact Earth and impact the planet? So, it's a broader thing than just imaging the sun. I mean, now, there are missions that are being developed which actually go much closer to the sun, than Ulysses. So, we can get much higher imaging resolution than from ground telescopes, on the sun, and to study very close environments. And those have their own challenges because, basically, you have to put a heat shield, and you still have to see through that heat shield or have a hole to be able to see through it because the temperature can go very high. It's a little bit like the heat shield that we built for the entry in Mars. That heat shield had to sustain temperatures up to like 2,000 degrees centigrade. That's the kind of temperature and heat shield that is needed as you get closer to the sun to protect the spacecraft. ZIERLER: So, with this newfound visibility, that Ulysses saw the poles, what do we now know about the sun as a result? ELACHI: Well, I should say I'm not an expert in the sun. But we find that the sun is not—like, when I grew up, it was this hot, big ball. I mean, there is a lot of activity happening on the sun, very heavily driven by the magnetic field of the sun. You see all kinds of dynamic cells which are happening. So, the sun is a very dynamic and active object. So, it's giving us insight about stars. I mean, think about it as a nuclear reactor which is active. You have nuclear reaction happening, in near time in this big ball, and the atmosphere is very dynamic. The solar flares, similar a little bit to what we see on Jupiter, that it's a very dynamic atmosphere, and what looks like big hurricanes which are happening. So, it's a very dynamic object. That's about the extent of my knowledge about it. [laugh] ZIERLER: What about the specific question of the threat posed by solar flares? Did the Ulysses mission yield additional insight into this? ELACHI: Yes, it was to understand how often solar flares happen. What's being emitted from the sun? Because solar flares have significant impact particularly on modern Earth because we use a lot of telecommunications [technology]. We have a lot of satellite in orbit. So, solar flares, the particles being emitted for solar flares could have a lot of impact on orbiting spacecraft and on the communication network we have on Earth. So, being able to understand and predict solar flares has a lot of practical implications. Matter of fact, one of the things we keep attention to, on many of our mission, not only on Earth but in deeper space missions, is if we see flares happening, I mean, it takes them a while to propagate. They are not moving at the speed of light, but they are moving at significant speeds. So, we get a warning for our spacecraft that solar flares are happening, so we tend to turn the spacecraft in a geometry, like having the antenna kind of looking toward the sun because that gives us some protection because it's a piece of metal. So, that gives the electronic some protection from these solar flares. So, it had a lot of practical applications for both our spacecraft as well as the communication networks on Earth. ZIERLER: Charles, back to planet Earth and a topic for which you were intimately involved, and that is the mission to find the lost city of Ubar. Tell me how you got involved in that, and how initially did you connect with Nicholas Clapp? ELACHI: Well, it's interesting. After the work in Egypt, which got all the attention in National Geographic, one day, a member of my team by the name of Ron Blum at JPL got a call from Nick Clapp because he knew him a little bit. And he was kind of—how to say?—an amateur archeologist, but also involved in making documentaries. So, Nick Clapp, I mean, he didn't want to contact me directly, so I thought, because he knew Ron Blum a little bit, he went through Ron. And he told Ron, "Nick Clapp, he was doing some research at the Huntington Library, looking at all the documents. And there are a number of these maps which refer to this city called Ubar, which was the center of trade, 2,000 years ago, and that's where the frankincense caravans used to stop through that city." So, it had connections to the Bible, and it was mentioned in the Bible for the frankincense trade, and it's located very close to the boundary between Oman and Saudi Arabia. And, so, a lot of the frankincense used to come from Oman and from Yemen. It's the sap of these specific kinds of trees. And he heard that we are planning this SIR-B mission at that time. So, Ron Blum comes to me, and he says, "would you be willing to meet with this guy, Nick Clapp?" I tell him sure. I was always interested, and particularly if it had a connection with the Middle East and archeology. So, he came over, and he brought copies of these documents showing, the maps, and they go all the way back to the maps by Ptolemy, showing what looked like a city in that area. And he said, "Is there any chance you can turn on the radar on SIR-B over that area to see what it would see?" I was intrigued by it, and I said, "What the heck, what is there to lose? We most likely will be flying over that area. It's a question of turning on the radar." So, we planned to do this. We had no idea what to expect or what to see. So, we turn on the radar over that region. The data came back. We started looking at it, and then we looked both at the radar data and the Landsat data, so we had both, some penetration with the radar, and surface images. And we saw these features roughly in that area. We saw long, linear features, which later we found that it's an indication of where camel caravans used to travel. And it is amazing how many remnants from them stays even after 2,000 years or—and that's where you see some of the trade routes in many areas because I then did a lot of work in Saudi Arabia. Even from that time, it kind of disrupts the surface a little bit, and they get covered by sand. But with the penetration of the radar, you can see some of the pebbles. They reflect differently than the sand. So, anyway, we said, "Well, let's go there." And it turned out, there were a couple of archeologists who had connections in Oman, so we arranged to go and do a field trip. And the archeologists and Ron Blum, they planned on spending a month. I couldn't, spend that long of a time in there. By then, I was the head of the division. So, I went for a week, and it was a great trip. I remember landing in Muscat, Oman. And that trip was in the—there were some people who had connections to the sultan of Oman. We had a couple of British explorers who came with us, and they knew the sultan. So, they put me in this super fancy hotel. I mean, it was a complete contrast with Egypt where I stayed in a tent. ZIERLER: [laugh] ELACHI: I stayed in this fancy hotel, and then flew from there to a town called Salalah, which is southern, close to the Yemen border. And that's where we all got together, and then we drove about maybe about six, seven hours away from it toward the area where we saw the features. And there in that area, effectively, to make a long story short, what we found out that there were wells which are still explored now, and there was some—a small town, with agricultural field around that oasis. But we found the foundation of what looked like a major fort. So, really, the city of Ubar was more likely a fort where, surrounding that well, and that was common in that part because many of the caravans, they wanted to protect the wells area. So, they used to travel in caravans, get into those forts, and that's where they got supplies of water. And then it led to almost 15 years of excavation of getting the foundation, a much more extensive area of the foundation of those forts. And more recently, I got involved in helping the foundation of the University of Oman. I got to know people, so they asked me to be on the advisory board. And when I mention Ubar, they say, "Oh, were you part of that expedition?" Some people knew it, and some younger people didn't know that. And now it's one of the main tourist attractions in Ubar. So, recently, about four or five months ago, I went and Googled "Ubar" and, of course, it comes to the Omani tourist office, and they had pictures of people in that area and, tourists visiting that area. So, that was one of the exciting benefits, similar to what happened in Egypt. And to close the loop on how things happened, I always was a big fan of the Huntington Library. When I was a student, I used to go there to the garden, and do my homework, sitting in the garden, and I was a member. And then, recently, they asked me to join the board of governors, the Huntington. So, I told all of them, "That's how we—led us to the city of Ubar. it's an archeologist doing research in the old documents, at the Huntington, which led to this." So, it's amazing how these events interconnect, at different times. ZIERLER: Is it understood that Ubar when it was inhabited was a different climate than it currently is? ELACHI: I don't know about that part. But clearly, it was the whole route from Ubar to Petra which were trade routes coming from the frankincense because not only frankincense was in the Bible, but it was very valuable by the pharaohs because it was used in—after the pharaohs died, I think that's one of the things [used for embalming]. I don't remember the chemistry of it. And it was used a lot in the early churches. Matter of fact, as I said earlier, I was in a boarding school in Lebanon, and every day, I used to go to the mass, and we used to use that incense—the incense at the Oriental churches. that was very common. So, incense was a very valuable product at that time. And the caravans used to go from Yemen, Oman, came to where Ubar is now, and then there were a series of forts in Saudi Arabia, which even exist until now, that used to lead all the way to where Petra, is, where that was a main center for the trading, during the Roman times and before that. And, more recently, about seven, eight years ago, because I was visiting a university in Jeddah, they took us on a tour to an area, an archeologic area, called Mada'in Salih, and that was exactly like Petra but not as developed or explored. And now it's becoming one of the main tourism areas. So, it's kind of all tied up with the caravans which used to travel there. ZIERLER: Charles, this question would connect all of your work in the Middle East, in the Sahara, in Egypt, in the Arabian Peninsula, and that is the value of your Middle Eastern heritage and, of course, your Arabic language abilities. In what ways did that make your work more productive, more satisfying, more successful? ELACHI: Yeah, it did help me a lot because, particularly as I became the director of JPL, there was a lot of coverage and I was all over the magazines, you know. Matter of fact, one of the magazines in the Arab Emirates, which was purely a kind of fashion magazine, they used to do this every year, who are the most influential Arabs in the world? And I was always in the top five of this thing because it was exciting to have a person from Arab descent, Lebanese descent being the director of JPL, and doing the explorations, because, space exploration is fascinating, all over the world, not only in the US. So, yeah, it did help, a fair amount, because people here are kind of associated with it. So, I remember, at one time, the CEO of Aramco, the biggest company in the world…no, second biggest, after Apple, was visiting Caltech. I arranged for him to come and visit Caltech and JPL. And they were chatting, and he was telling them, "Charles is the most famous Arab in the Middle East." [laugh] ZIERLER: [laugh] ELACHI: So, it made me feel good and, yeah, it opened doors. The other very famous one was Ahmed Zewail, he was professor here at Caltech, he passed away a number of years ago, and he was the first Nobel Laureate, he was Egyptian from Egypt. So, Ahmed and I were two very well-known people in the Middle East because of that kind of scientific connection. And that led to a number—particularly after I stepped down from JPL, now I'm on the advisory board of a number of universities in the Middle East. AUB is one of them, which is the American University of Beirut, which, by the way, today's announcement of the Nobel Laureate [Dr. Ardem Patapoutian] did his early undergraduate study in the American University of Beirut. ZIERLER: Oh. ELACHI: And he's the other—now, he's a Lebanese American, very famous. he's now at Scripps, and he was an undergraduate, sorry, graduate at Caltech. So, he got the Nobel Laureate—no, sorry, not physics but physiology and medicine that was announced yesterday or before yesterday. So, that's another famous Lebanese American, involved in science and Caltech. Caltech "owns" all three famous Lebanese American or Egyptian American, with [laugh] Ahmed Zewail, myself, and the recent Nobel Laureate. So, I'm involved in a number of universities now in Saudi Arabia, Kuwait, Oman, United Arab Emirate, on their advisory boards, on those, as well as in the young space agency in Arab Emirate and Saudi Arabia. Also, I serve on their advisory boards. ZIERLER: Charles, I'm curious about the value of knowing where there are oil deposits, and focusing radar technology in those areas. Based on the simple deductive reasoning that oil deposits come from carbon, carbon comes from life, this must have been a heavily forested area full of flora and fauna at some point. I wonder if that's really central to thinking about how climates change over time. ELACHI: Yeah, I mean, it's a long time ago that there were forests in those areas. But, clearly, like the work in Egypt, where we saw those drainage channels, is an indication of the climate change which happened locally in a region in that case, you know. And, now, where radar from my background serves more beneficially is being able to not only image geologic features, which then geologists interpret to look at oil locations and oil fields, but one of the most recent technologies that have been developed using radars, one is being able to measure the biomass in forests. So, basically, because the radar penetrates through a forest, and scatters from the trees, by doing some certain analysis, what we call polarization and multispectral, we can derive the amount of biomass which is in the trees. And by monitoring that over the long term, and [measuring] the connection between biomass and carbon dioxide, in the atmosphere, a number of researchers are starting to use that as a tool of prediction of how much damage we are doing, if you want, or for finding solutions for climate change of being able to suck in carbon dioxide from the atmosphere or the emissions by the cutting of the destruction of the forest. So, that's one whole area where, when I was doing my earlier research, we didn't know about this very well. But then there was some work that I did at the tail end of my research career, and now it has evolved significantly in being able to measure biomass. And that traces its background, the technique, to when we did SIR-C, which was much more advanced than SIR-A and SIR-B. The other one which is even more recent, and that traces its legacy to the shuttle radar topography mission, which is the one with the long boom and doing interferometry. Some of my colleagues here, like Mark Simons, who's a professor, at Caltech, and Paul Rosen, who is a visiting professor but is at JPL— they are developing and using a technique we call radar interferometry. And what that technique does is we take a radar image. If we come back a couple of days later or a couple of week or a couple of months, and take an image of the same area, and by comparing the two, we can measure surface changes down to centimeter. Now, you would say, well, what's the benefit of that, and what does that have to do with global change? Well, it turned out, when you are pumping water from under the surface, the surface subsides a little bit. And when you put water back in, there's an aquifer, let's say, and the surface goes up a little bit. When you pump oil, the surface goes down a little bit. So, by monitoring over the long term how the surface is changing, we can infer how much water is being pumped, and that's a big deal particularly in the Middle East about depleting the water tables. And that's why now I get a fair amount of funding from Saudi Arabia to do research in that area of monitoring the depletion of the water across the Middle East, and how to manage the water better. And that's the activity that being done with my colleagues, Mark Simons and Jean-Philippe Avouac, who's another professor here. Yeah, so, the three of us are involved. Now that I have time to do research again, we are involved in using satellite radar images to monitor one element being impacted by climate change and the depletion, of water. So, it's interesting how these early developments—SIR-A, SIR-B, SIR-C, SRTM—which were done in the '80s, led to technology that now is being used internationally by many, many space agencies, many commercial companies, to actually look at things which impact our environment. And all of them trace back their technological, history back to these shuttle series of missions. And it's interesting because I remember about four, five years ago, even after I stepped down from being the director of JPL, I knew a number of people internationally. I was in Paris, and I went to visit the head of ESA, the European Space Agency. He told me, he said, "Oh, I want you to meet the guy who's the head of the Earth science." So, he took me to his office. His name is Aschbacher. I walk in his office, and he said, "Hi, Dr. Elachi, I'm Josef Aschbacher," and he pulls a book, and he said, "I studied in your book," (the textbook that I have on remote sensing). So, that kind of—people trace a lot of those activities [to this work]. And now, Josef Aschbacher is the new head of the European Space Agency. ZIERLER: Oh, wow. ELACHI: I usually communicate with him on that, and we became kind of—not close friends but reasonably good friends. And he keeps reminding me, about the traceability of the European missions, back to these shuttle missions that were done. ZIERLER: Charles, I can't help but ask, but in your work studying the water crisis in the Middle East, if this research is relevant closer to home for our own water crisis here in the American West. ELACHI: Oh, yeah, absolutely because, matter of fact, the technique was perfected in the Central Valley of California, you know. So, we have been monitoring the Central Valley for the last seven years now, and you can see we have plots which show during the summer, the surface depletes a little bit, goes down a little bit; during the winter when the Sierra Mountains [receive snow], you can see the water going up. But on the average, it's going down because of all the water pumping. And now, the Department of Agriculture and Water department in California is starting to use that data to help manage more intelligently about doing the pumping. And many of the large farmers are starting to use that data. Some of them are on the board of trustees at Caltech where they are starting to use that data to gain a better understanding of how the water is being pumped out and utilized. ZIERLER: Charles, back to outer space, let's go to Mars. ELACHI: [laugh] OK. ZIERLER: In the early 1990s, to put the Mars mission in perspective, the Mars Observer, what was our knowledge of the surface of Mars up to that point, and how did that knowledge inform the technology and engineering that went into the Mars Observer? ELACHI: Well, I mean, the knowledge in the early days, I mean, from the Mariner spacecraft, was fairly limited except when we did Viking. When we did Viking—and, again, I was not involved in Viking—that was the first time we put a lander on the surface of Mars, so it gave us a first look, on the surface. But, even then, our resolving powers, the imaging that was done from satellites was not as exquisite as what we have done subsequently. So, when we started, then I would say in—let me get my years right—in the late—in the early '90s, we started putting more and more sophisticated instruments on our orbiter, around Mars, and we started seeing features that we didn't expect, or we didn't see, what looked like volcanic flows, what looked like riverbeds, on the surface of Mars, alluvial fans. So, suddenly, we were seeing a lot more features. And that got inputted into the mission which we did in the year 2000 timeframe, like Mars Observer and the series of missions after that. And now, we are at the capability where we can image down to literally [to the level of] meters. I mean, matter of fact, we have almost better resolving images of Mars than of Earth because of we are not limited by any classification or restriction, literary restriction, on Mars. So, we have cameras which can get us down to the meter level, couple of meters, resolving power on that. So, yeah, I mean, the progression is amazing, what happened in the last 20 to 30 years about the size of cameras that we put on, the sensitivity of the focal plane. And a key factor is the data that we can transmit because it doesn't help you to take very high-resolution images if you cannot send them down to Earth because that brings you back to the Deep Space Network, and the advances which happened in being able to get significantly more data and using high frequency because in the communications [realm], the higher frequency you do, the more data you can bring to Earth. So, in the old days, we used what we call L-band, which is like one gigahertz, and that had limitation. Then we moved to X-band, which was about 10 gigahertz, so that gave us an order of magnitude more data capacity. Then we developed, we went to what we call K-band, which is in the 30—20 to 30 gigahertz range. So, it was both an evolution of getting higher and higher and higher frequency, and then getting the capability of coding and the power to be able to transmit a lot more data. So, now, we get—I mean, on Voyager, we—the data rate, I could type maybe faster than the data rate of Voyager. Now, you can get a deluge of data coming down [laugh], from space, based on the advances in technology. So, that translated to getting much more detailed images, much more understanding, you know. And that helped tremendously in planning our landers. Where do we land our spacecraft? ZIERLER: Similar question as to Venus but much more plausible, given the fact that it's Mars, when the Mars Observer mission was launched, what was some of the optimism both in terms of finding evidence of life on Mars, but then, additionally, long-term thinking, about the possibility of habitability of Mars through terraforming or other means? ELACHI: Yeah. Well, all across the Mars program—I mean, Mars Observer is one element of it, and there were a number before that, the Mariner missions, and the mission that we have now—there is always this dream that there might be life on Mars. And all the scientific indication kind of supports that Mars was habitable. As scientists, we have to be very careful, what words we use, I mean, particularly when we communicate with the public. So, even at that time, there was a lot—well, after Viking, it was kind of like a setback because there was a lot of expectation and hope. And then when Viking landed, and made the experiments, I mean, they measured if there is organic material, and it came up with no organic material. So, a number of people immediately said, well, there is no life. Mars is not habitable. But when we look at the images from satellites, there was all kinds of indication which looked very much like Egypt, you know. As I said, you see these riverbeds. You see, what looks like features which were carved by rivers. So, it led many people to think, maybe in the early days, Mars was much more humid, if you want, and, therefore, much more amenable to life. And then when we landed in the polar region, and we did land very close to the polar cap, just digging a few centimeters from the surface, we saw H2O, frozen water in the surface. So, it goes by logic that if there was water which created those rivers, and now it's frozen, then maybe at an early time, Mars might have been warmer than it is today, and, therefore, maybe it was very similar to Earth. Because the two were formed roughly at the same time, and Mars is not much farther than Earth, so the environment, is—even today, during the day on Mars at noon, the temperature is a little bit like what we have in Pasadena, in the winter months. So, it's very amenable. And the key question is, could have life evolved, in those early days, when water was flowing on the surface? And in some locations, we do see what looks like flows because there is change. You see it one day, and then the following day, it looked like a flow happened. So, people think maybe water, or the ice has melted, and there was some flow which happened. And that came from being able to observe globally at very high resolution, and on continuous basis. That's where the different missions, that orbiter that we put around Mars enabled us to do that, to do a continuous monitoring too see what's happening on Mars. As humans, we really want to think that there might be life somewhere else. So, it is a combination of scientific facts and a little bit of wishful thinking, and there is nothing bad about that in science! It's always kind of a little bit of science fiction which keeps us to be thinking outside the box and outside of the normal limitations. This leads to major discoveries. So, I wouldn't be surprised, I would be delighted, if the latest rover Perseverance which is collecting samples, we might see some indication, of past life, or when we bring the sample back. Of course, it will be a major thing, but I wouldn't be saying, oh, it's a miracle. No, I would say it's a surprise but not a miracle. ZIERLER: Charles, what were some of the biggest surprises yielded by Mars Observer? ELACHI: Well, I mean, the biggest surprises on all of them were these channels that we see because up to, I mean, until the first early Mariner mission, we didn't have the details. So, at least from my perspective—I mean, other scientists would have different perspectives—is what you see is that these alluvial fans are very common. you see them everywhere, and they clearly happened due to water flows, similar to what we see in Death Valley, the extensive network of rivers, of dry rivers, that you see in there, and what looks like dry lakes. And it reminds me because I drive a lot. I love Death Valley. I used to take my students there for field work, and then driving up to Mammoth Lakes through the Owens Valley where there are lots of dry lakes. So, these are things that I used to see. And then when we look at Mars, we see something very similar. Of course, we saw much more detail with the rover than with the orbiters, but the orbiters gave us a very clear indication that there are dry lakes and dry rivers. These lakes are mostly made of salt, leftover salt, on the surface. So, these are probably one of the biggest surprises which happened as we were getting better and better resolution. ZIERLER: Charles, to put exploration on Mars in historical context, in the early 1990s, was anybody thinking of the possibility that mega-billionaires like Elon Musk or Jeff Bezos would become major players in questions about Mars research and habitability? Did anybody think along those lines 30, 40 years ago? ELACHI: Not really. I mean, there was a lot of thought about science fiction, and there were movies, and all these things, and not only for Mars but also for the moon, and even for Europa. So, there was a lot of, science fiction kind of movies. But the question of the private sector really didn't start until, like, maybe 10 years ago when you had people like Elon Musk. And I think part of it is this is a generation of people which grew up through the space exploration era, where we had exploration of Mars, and we talk about habitability on Mars, and having stations on the moon. So, I think the young people who were young when we were landing on the moon and exploring Mars, and so on, some people grew up through it, and then they became millionaires completely outside of the space mission program. I mean, Elon Musk had nothing to do with space. He started with PayPal. So, having visionary people like this, and Jeff Bezos doing that kind of is more a recent event, I would say, in the last decade. And it's great to have visionary people like this, to be thinking out of the box, and doing that. Now, sometimes, they go overboard, in talking about we are going to inhabit Mars in the next decade. Matter of fact, I remember a discussion with Elon Musk because he used to come regularly to JPL. And he was telling me one day, "Oh, I'm going to have a human on Mars, within five years." I thought—I quietly looked at him. I told him, "Elon, it's great to have your vision. But I landed stuff on Mars, the rovers"— ZIERLER: [laugh] ELACHI: —"and I know how tough it is." ZIERLER: [laugh] ELACHI: "You are talking about 15 to 20 years." And that was in the 19…in 2008 that he was going to land people on Mars in 2022. Well, we are in 2021, and we are 10 years away from then. ZIERLER: [laugh] ELACHI: So, reality hit him. ZIERLER: [laugh] ELACHI: But I still love people who are always optimist…I mean, I'm an optimist, and I'm always thinking out of the box. Elon thinks way out of the box— ZIERLER: [laugh] ELACHI: —way out of the box. But we need people like that— ZIERLER: Yeah. ELACHI: —to keep that kind of spirit of innovation. But, usually, I tell people—because I get asked a lot about Elon Musk and going to Mars—I tell people, yeah, it's great to have visionaries like this. But I wouldn't put my retirement money in his Mars company. [laugh] ZIERLER: [laugh] Charles, the last topic I'd like to engage with you today is the overall political and budgetary environment of JPL as the Cold War was drawing to a close. We already talked about the influence, first of all, for you, of Sputnik, and the birth of NASA from a military organization, the influence of Lew Allen. So, when the Soviet threat and the Soviet competition was no longer there, how did that change in, 1992, 1993? Did you feel those changes at JPL? ELACHI: Yeah. No, they did happen, both during the Cold War and somewhat after it. So, during the Cold War, as things were coming, relaxing a little bit, there was a significant reduction in—I mean, there was big funding for NASA in the '60s and early '70s. Then came late '70s and in the '80s, and there was a significant decrease in the funding. Part of it was going to the shuttle; part of it was that the competition was less. And it's interesting because, indirectly and retrospectively, that impacted my career because as things in the '80s started coming down, there was less and less funding for planetary explorers…because planetary was one of the aspects of the overall competition with the Russians to get to Mars first. And then it became apparent at JPL that maybe we need to diversify what we do at JPL. And that's what got us to be more involved in Earth observations. We had a little bit already, with Seasat and the Shuttle Imaging Radar. So, we ended up expanding significantly in building instruments which went on the Goddard Space Center spacecraft, not necessarily on JPL's spacecraft. And for a couple of years when I was the head of instruments—and that's what led to forming that directorate, and Lew Allen appointing me to it. So, it had some traceability to the Cold War, not directly but indirectly to it. And for some years, we were doing more business at JPL in instruments than we were doing with spacecraft. So, it was kind of the reverse of what happened. Then as things progressed, and the Cold War ended, there was still competition, and the US wanted to build relationships with different countries. So, I remember during the Bush I administration, there was a lot of encouragement to start working with India. Matter of fact, before that, during the Nixon administration, we were encouraged to work with China. So, there is always a political factor which comes in. I mean, we'd love to think everything is purist. But there is a little bit of political factor. I mean, clearly, our relations with Europe had political [elements] because of friendliness and collaboration and partnership. But then during the Nixon administration and shortly after that, there was encouragement to work with China. Things have changed by now. It's the opposite. And then during the Bush II administration, there was a lot of relationship building with India, which have led to collaborations with India. And we have, matter of fact, we have a mission, a radar mission that I started on when I was director, and now it will be launched, two years from now in 2023, jointly with the Indian Space Agency. So, yeah, these had impacts at JPL. And the budget went up and down depending how proactive NASA wanted to be, not only for exploration but also building relationships with international organizations. ZIERLER: Did the end of the Cold War allow for new opportunities of collaboration with the Russians? ELACHI: Yeah. No, for a while, it did do that. The biggest benefit of it came from the human program. It came with the space station, which led to it. And even before that, there was a little bit of collaboration. I mean, the science community always collaborated to a certain extent, and it was encouraged because—by the politicians—because that was a channel of communicating with the scientists at different places. So, we had—the Russian did a mission to do a balloon on Venus, and JPL was involved in the communication on it. Matter of fact, on Curiosity, there was some instruments from the Russians. It was a magnetometer or some instrument which was done by the Russian. And there were discussions of collaboration. It was not as extensive in the robotic program. It was much more extensive in the human program which, as I said, led to the space station collaboration. [laugh] Who makes up the collaboration? Ironically, it came from—this is after the Soviet Union collapsed, and Russia was going through tough times, there was a significant immigration of Russian scientists, space scientists. And a number of them ended up at JPL, coming in, and working at JPL. And many of them were—when we were trying to reduce arms and nuclear arms, where many of the scientists in the research labs in Russia, there was less and less work for them. So, they built on their connection with the US, and scientists in the US, [encouraged them] to actually immigrate, and to come and work in the US. ZIERLER: Charles, finally, a budgetary question, one that I've heard from several physicists in thinking about why funding for the SSC in Texas never came through. I've heard it, and this is something that I haven't been able to confirm, that the Clinton administration saw these things in binary terms, that either it was going all in to fund the SSC, or it was going all in to fund the space station. Do you have any insight on that, and the issues that the Clinton administration was facing? ELACHI: Yeah. No, I heard all of these things too. And now I don't have a direct proof that this was really what happened, the space station versus the SSC. I mean, clearly, the SSC is much more esoteric for a politician in Washington, understanding all these elementary particles, versus a space station which flies up in the sky, and has a lot of what I call soft power, which is clearly that's space exploration, astronaut. You can see it. Space has a lot more soft power than elementary particles, even though they are both very important, I mean, no question. So, yeah, there was those considerations and there was an impact on NASA also. The infamous Magellan that we were talking about, the mission, when the Reagan administration came in in 1980, we were just starting to work on what became Magellan. And then there was a big cut for NASA, and Magellan was canceled. And then we had to really struggle both politically and technically to figure out a way to do it significantly cheaper than it was before. So, we did changes of configuration, like using the antenna for communication as well for the radar. It was challenging to revive it. Many missions at NASA, planetary missions, depending on who is in politics, saw kind of a temporary death for them, and then they were revived. And that's where maybe at a future time we can talk about the key role of building relationships that the JPL director, as well as NASA in general, and the Caltech board, building relationship with the political part, of the government, and get them excited about it. So, it's not only because it's in their district but also because it's a great thing for the nation. And the JPL director plays a key role in making that happen, and that made me travel to Washington almost every other week. [laugh] ZIERLER: Well, Charles, on that note, we'll pick up for next time, the five years leading to your directorship at JPL. [End of recording] ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It is Thursday, October 7th, 2021. Once again, it's my great pleasure to be back with Professor Charles Elachi. Charles, wonderful to see you again. ELACHI: Yes, thank you. Same here. ZIERLER: Charles, today, I want to return very briefly to something interesting you said in our last discussion about the decisions between funding the space station and the SSC, and you emphasize the importance of soft power, the representation of soft power as it relates to space flight. Now, diplomats, political scientists, they use the term "soft power" but I'm curious, for you, what does that term mean in the context of NASA? ELACHI: Well, in the context of NASA, it means that the NASA image across the world is always very positive, particularly in the period in the '80s and '90s and up to now. Many nations would love to work with NASA on joint missions, because they see it as a positive reflection of the things that the United States does. It's uplifting, and it's not something which is political. And not only working with the US, but as you travel around the world, and as I traveled around the world, NASA is always viewed as a positive symbol. I mean, I remember almost every time I was on an airplane, and I talked with somebody sitting next to me, and I tell them I'm working at JPL NASA Center, they get all excited, and they want to know about exploration, what we are doing. So, it has been something positive. And to take, for instance, a specific example, during the Bush II administration, there was a move to build a close collaboration with India. And one of the approaches in doing that was to work on possibly doing a joint mission between NASA and India. As a matter of fact, that mission would be launched two years from now. JPL will be involved in it. The other one, another specific example is during the Reagan administration, there were a push with Argentina, which was dabbling with nuclear power or possibly nuclear armaments. So, the administration, the Reagan administration, was trying to convince the Argentinians to stop doing that, and the way they worked it is that we would do a joint space project between NASA and Argentina, and to move the nuclear scientists in Argentina to move and work on space, instead of it. And that actually happened, and we had a joint mission also with the Argentinians. So, it was a diplomatic tool, if you want, a positive tool, of what we call soft power, and it was always received very well, I mean, with the other countries. They always love to work with the US through space missions and the [benefits this gives for] public reputation. At one time, Congressman Adam Schiff, who is the Congressman which covers the JPL, was telling me that he was in Pakistan before we did one of the landings. And the day before, there was the usual criticism of the US. But then the second day, the headline was the great success that NASA did in landing, I think, either Spirit or Opportunity—I don't remember now—of landing that on Mars, and it was all positive. So, he was one of the key people in Congress who kept promoting NASA and supporting NASA as a way of having soft power across the world. ZIERLER: And, Charles, as you say, as important as the SSC would have been, and as exciting as the string theorists would've found perhaps the discovery of supersymmetry, it could never compete on the world stage in terms of bringing— ELACHI: [laugh] ZIERLER: —people in, and getting them excited about America and science, like NASA. ELACHI: Yeah, because, I mean, you look at the space station, for instance. I mean, today, any kid around the world or any person around the world can Google, "When can I see the space station from my hometown?" And they can sit in the evening, and actually see a station visible, so it's reachable to every single inhabitant of our planet, I mean, if they have an iPhone or a way of searching on the computer, and just to think about it that there are people flying over it. And extending the soft power, the US invited—as well as Russia, for that matter—invited astronauts from many nations, to come and fly. So, I mean, I know very well an astronaut from Saudi Arabia who flew on the space station, an astronaut from the United Arab Emirates, and that was a big deal, in those countries. And that's the kind of thing that space missions like the space station enable doing. The supercolliders, they are equally important scientifically, but it's important for the scientists. The general public, the average person, it's hard to associate with it, or to see it, in a sense. ZIERLER: Charles, tell me about the development of Synthetic Aperture Radar. In what ways was this a logical evolution from SIR-A and SIR-B, and in what ways was this really a new direction for the imaging radar program? ELACHI: Well, we started—the legacy goes back to Seasat, SIR-A, SIR-B, and this was the first time that imaging radar were flown on civilian spacecraft. At that time, we thought they were the first ever flown. But then we found out later that there was some work on the military side. But then, what the shuttle enabled is on a very quick turnaround, couple of years, we were significantly advancing the capability. So, we moved from SIR-A, which was one frequency, similar to what you see black and white photography, to SIR-C, which was multispectral, which means that we had color photography. And that significantly enhanced our ability to map surfaces, recognize their composition, which is similar to what we do with photography. I mean, black and white, you have a little hard time differentiating prairie from forest, except if you have very high resolution. The same with the radar, but once we went to the multispectral level, then we were able to really map, discriminate forest from kind of vegetation, different fields, detecting there is moisture in the ground, so to help farmers if they need to farm. And it added also the twist of having polarization, so it's like polarized glasses. So, SIR-C had both spectral and polarization diversity in it, which was a huge step forward. And then after that was the SRTM, for Shuttle Radar Topography Mission, which demonstrated the interferometry that we use in two radars on the same spacecraft at that time, but later it could be done on separate spacecraft, which allows us to generate 3D images, including the topography of the surface, and to measure surface motion. So, these advances were enabled, and they trace their legacy to the SIR-A, SIR-B, SIR-C. And if you look today in 2001, there is about, I would say, eight or nine free-flying spacecraft by different nations, Canada, the European Space Agency, Japan, and India. And then there is a whole commercial field of which is flying Synthetic Aperture Radar for actual commercial, benefit. So, when you look at all of them, there is probably like 20, 25 spacecraft today which have Synthetic Aperture Radar, and all of them…everybody says these trace their history back to the shuttle series, which enabled all these advantages and the technology behind them. ZIERLER: Charles, you mentioned interferometry. This makes me wonder if this program was relevant for LIGO at all. ELACHI: Well, kind of because the concept of interferometry goes back to the idea, if you shine a coherent line, on a piece of paper with two holes, in it, you see fringes on the other side, and that's used in laser systems. So, the concept came from that thinking, that, gee, if it works, in the visible and the optical [range], it should be able to work also in the microwave [range]. And in the microwave, we had a key advantage, similar to lasers, that we can control the phase because that's important to do that with a few millimeters or centimeters measurement because the phase of the signal basically is driven by the transmitter. I mean, the instrument on the spacecraft actually controls the frequency and the phase, and we can measure that phase once the signal comes back. So, by measuring the phase, and processing it, we can get down to a fraction of the wavelength. So, if we are using a three-centimeter wavelength, we can see changes which are in the centimeter [range] or less. If we use 25-centimeter wavelengths, we can measure displacement in a few centimeters. So, it's that ability to control, the phase of the signal which enable the interferometry, added to the benefit that the radar doesn't rely on the sun. We can do our own transmission. It works day or night. It works if it's cloudy. So, it's really truly an all-weather, all-time imaging instrument. ZIERLER: Charles, how did SIR-C fit in overall with NASA's space-based laboratory program? ELACHI: With which laboratory? ZIERLER: The Space Radar Laboratory. ELACHI: Oh, it's the same. I mean, that was more a generic name to it. So, the Space Radar Lab really was a general name for the series of SIR-A, SIR-B, SIR-C, and SRTM, mission. ZIERLER: So, Space Radar Laboratory was entirely housed within JPL? ELACHI: Correct. ZIERLER: I see. OK. OK. What aspects of SIR-C were specifically geared toward studying Earth, and which ones were geared toward pointing outward to space? ELACHI: Well, the SIR-C and all the shuttle ones were specifically to look at the Earth. So, through them, we were able not only to develop the technology but also to develop our interpretation ability, to be able to measure different phenomena on the Earth like, as I mentioned, soil moisture, vegetation, bio-content in trees, the height of trees. A whole spectrum of applications were developed and evolved, during those missions. Now, the planetary work benefited from the technology, and the understanding of what the radar images mean. So, these series of missions themselves, the shuttle mission were Earth-looking. But for instance, when we planned the mission Cassini to Saturn, and we proposed a radar instrument to map Titan, we relied a lot on the technology which was developed in the SIR-C and the shuttle imaging radar series. The same thing with Magellan for Venus, where we also relied on that technology to do that. So, in a sense, we used the Earth mission, one, for their own benefit but also as a steppingstone technologically for the planetary radar missions. ZIERLER: Charles, totally different question, when did you first learn about Hubble's mirror flaw, and how did JPL contribute to fixing it? ELACHI: Yeah, that's very interesting. That's very still sharp in my memory. So, in 1987, because it became apparent that at JPL in the early '80s and by the mid-80s that we are doing more and more instruments at JPL, and many of them were flying on other centers' spacecraft, particularly Goddard Space Center, there was a whole group of innovators at JPL developing different kinds of instrument, including the radar, and my team was one of them. And we had Joe Waters working in sub-millimeters, Barney Farmer working infrared, Reinhard Beer also working in infrared, Mous Chahine working also in thermal measurement, Dave Diner working on aerosol, Alex Katz, working on imaging spectrometer, and there was a professor at Caltech by the name of Jim Westphal who was working to design the main instrument which goes on the Hubble. So, at that time, because it was part of the expansion of the activity at JPL, Lew Allen, the director in '87, decided to form a whole directorate at JPL to oversee all the instrument work, and the science which goes with it for advanced missions. That means thinking about what future mission we might want to do. And in November of that year, he asked me to be the head of that new directorate. I remember shortly after that, about maybe a year after, that's when the Hubble was launched, and JPL was involved because we built the main instrument, on it. And I remember a scientist at JPL by the name of John Trauger, who was part of the team with Westphal, he comes one day to me and said, "We have big trouble. It looks like the images we're getting from the Hubble are fuzzy, and now there is a belief maybe the mirror," (which was not built by JPL [laugh] but built by the Marshall Space Center,) "that the mirror is faulty, and that's why we get—we are getting this hazy image." And that was a big blow for NASA because the Hubble Telescope was the biggest telescope ever built, it cost billions of dollars, maybe six, seven, eight billion in in today's money, and it was a huge embarrassment. And I remember at that time, one of the big advocates was a senator, from Maryland by the name of Barbara Mikulski, who was a big champion for it. And it was delayed, and she kept defending it. It got delayed, she kept defending it, saying how great this thing is going to be. And then, here you go, you have a faulty telescope on that. So, it was really a blow across the board, at NASA, in the science community, politically. But then literally within a couple of days, John Trauger, who was a scientist at JPL, came to me, and he said, "Charles, if we can figure out what is the fault in that mirror, we can put it on the next instrument," because we were building a second, more advanced instrument, for imaging. Westphal said, "we can put correcting glasses, similar to your eyes, what you do when, your retina is not exactly—you are not seeing well, you can put correctives—but we need to know that recipe." So, I immediately called the person in charge at Headquarters, his name was Ed Weiler, and I told him, "Ed, you know," I mean, he was really depressed, so I told him, "Ed, we have John Trauger here, and he really believes if we can figure out the recipe, for the mirror, the exact curvature, we can fix it." And, there was some skepticism at the beginning, but, quickly, people said, wow, this would be great. Now, in the meantime, NASA asked Lew Allen, the director of JPL, to chair a committee to figure out what was the problem? How did it happen? So, over a period of a couple of months, Lew Allen [led a] committee that investigated what happened. They came to the conclusion that it was a faulty mirror, and they were able to really determine exactly what was the recipe for that mirror. So, that led a to big rush. Then Ed Weiler's boss—his name was Charlie Pellerin, he was in charge of all the astrophysics missions at NASA, he came to JPL to see me here. I'm relatively new at that point. I was just appointed about a year earlier, to head all the instruments. And they said, "Charles, whatever you need, we'll give you whatever money you need to get this new instrument, or replacement instrument, fixed very quickly." And, as I said, John Trauger gets a lot of the credit, of figuring it out. Then once we knew the recipe, then we knew what kind of glasses…what kind of, if you want, lens, we needed to put in the front. In the meantime, there were other instruments also, and that's when people said, "Gee, we can add an additional structure to the shuttle, which could correct, in the same way that we're correcting for the lens for the imaging instrument, which can correct for the other instruments on it." And there was a big effort, over that period of two or three years, at that time, both from builders at JPL and with that repair. And then, they took the shuttle up. Fortunately, the Hubble was in an orbit that the shuttle can reach it. So, it went there, and did the correction, and then the data came out just perfect after that. So, that was a very intense, time, that—matter of fact, that instrument which fixed the Hubble, I mean, operated—I don't remember now—for like 10, 12 years, and then it was replaced by another which is even more advanced. And that instrument was brought back, and now it's in the Aerospace Museum. ZIERLER: How did we know that it was the mirror? What were the sensors? Because I know you know a lot about sensors, how could we tell from planet Earth exactly what the issue was with Hubble? ELACHI: Well, the scientists, as soon as they looked at the image, looked at a star, and they saw kind of the fuzziness around it, and a pattern around it, they knew exactly that that was a mirror issue, on it because of the focusing, that you do on it. It's the same way when if you can start realizing you need glasses when you cannot read from far away. You say, yeah, now it's time that I need glasses. So, it's almost exactly the same. By looking at point stars, I mean, stars which were like one point, looking at the halo around them and the fuzziness—I mean, I remember somebody told me they were all of them around the TV screen waiting for the first image. And as soon as that image came, he said within a minute, everybody realized there is a problem with the mirror. ZIERLER: Yeah, yeah. Charles, if anybody were to tell you during this low point in 1987 that in 2021, Hubble would still be sending beautiful images back to Earth, would you have ever believed it? ELACHI: No, people would have never thought of that because, I mean, there was—I mean, number one, for a few weeks, people thought it was gone, that there is no hope, for the Hubble. And then even when we found a solution, for it, people were talking about 5, 10, 15 years. I mean, here we are almost 32 years, 33 years, it's still working! And that's in a sense one benefit of having things like the shuttle, at that time because the shuttle has gone, I think, three times and replaced instruments, and also replaced electronics. Because, I mean, the electronics would age, and you get less capability. The solar panels will age, and you get less power. So, having the shuttle and the ability of sending astronauts to replace hardware, to fix hardware—I think there was a replacement of the gyros on there for pointing—this really extended the life of the Hubble. And, at that time, people really did not have good appreciation of the ability of the astronauts in doing those repairs. I mean, people thought, yeah, maybe it's possible. Now, we don't have the shuttle anymore, so you can't repair it. But there is a possibility always that if we send a human into Earth's orbit in capsules, like we are doing, now, that's—these capsules might be able to rendezvous with the Hubble, and actually do some fixing. So, having a human going in orbit really enables a number of capabilities. Now, as we progress, this could possibly be done robotically. Now, there is work which is happening on, let's say, repair spacecraft, if you want to call them, and fueling spacecraft, which can go robotically and rendezvous, with another spacecraft, and transfer fuel, or do some repairs, on it. I think that probably within the next decade, that will become much more common. ZIERLER: Charles, as we look to the end of 2021, excitement builds for the launch of the James Webb Telescope. I'm curious, once that's operational, are there going to be aspects of Hubble's mission that will be rendered obsolete, or do you see them still as complementary? ELACHI: No, I think they will be complementary. It's similar to ground telescopes, you know. The astronomers have big appetites [laugh], for getting time, on telescopes of different capabilities, different resolutions. So, I think the Hubble—I mean, the Jim Webb is going to be a huge step in getting significantly more resolution because there is a much larger mirror that is on it. But the demand is going to be tremendous, I mean, more than what you can do in 24 hours per day. So, I believe the Hubble Telescope will still be useful for a number of applications, and for allowing more astronomers to be able to access observation time. So, it's a—I mean, demand on the telescope will be at a premium. That's why Caltech is a leader in astronomy in the world. It is because we have access to some of the best telescopes, in Hawaii and, I mean, through its history, going all the way to early founders of Caltech at Mount Wilson, Mount Palomar, then in Hawaii. So, Caltech kept its leadership in astrophysics and astronomy because of access to the leading-edge telescopes. I think it's going to be the same with the Hubble and JWST. The demand will be tremendous. ZIERLER: Charles, back to the 1990s, as of course, there were many missions that were geared towards studying the Earth's oceans. What was all of the interest in learning about the Earth, the Earth's oceans from space, and who were some of JPL's key institutional partners in these missions? ELACHI: Well, starting in the '80s, and it bloomed in the '90s, there was a great interest in monitoring our planet, and observing the planet. At the beginning, it was mostly used as with Landsat of just seeing what the patterns on the surface are, doing geologic mapping, studying the changes which are happening. When there was expansion of cities, you'd see pictures of cities, like particularly Las Vegas or Phoenix, over every couple of years, you'd see the expansion of the urban areas. So, it was more used from that kind of practical, purpose. But then there became a big awareness about the changes happening, first, in the atmosphere, but then with the changes of temperature, in other words, global warming. So, it started, first, the one which got a lot of attention was the ozone layer and the ozone hole. And that, the observation for that mission led to rules and laws about limiting emissions of, what we have in our refrigerator, CFCs, which because they are one of the major destructors, of ozone, any leaks from refrigerator. So, there were laws and policies because of space observations, particularly instruments built at JPL by Joe Waters, which led to those policies. And then there was the issue of the global warming, and the issue of ocean circulation. So, all of that blossomed in the '80s. And JPL was—it turned out—we were at the heart of building those instruments. So, to repeat it, I mean, the key players, as I said, there was a group of us. We were all in our 20s, 30s, coming up with new concepts of instruments. That was a period where new detectors were coming online in the infrared and the submillimeter [range], which enabled us to do these measurements which were not possible before. So, we had people like Joe Waters, Barney Farmer, Mous Chahine, Alex Katz, David Diner conceiving those instruments, and developing them, and we were flying them mostly on Goddard's spacecraft. We had a collaboration, with Goddard as a partner, to fly on their spacecraft. But, also, there was international collaboration, particularly from Oxford University, there was a lot of work, going on there on atmospheric science. So, people like Barney Farmer and Reinhard Beer had many, many postdocs, from Oxford, one of them by the name of Dan McCleese, who later became the chief scientist at JPL when I was a director. So, there was a lot of international collaboration. There was also collaboration with the French. And with industry, we had a lot of collaboration, particularly on the detectors. And the reason industry was really playing here was because of the military. The military was funding a lot of companies, to develop the latest detectors which are sensitive, particularly arrays of detectors, which, now, I mean, we see they are somewhat more common. Like, in your iPhone, you have a little array. But in those days, they were being developed a lot for doing digital imaging. So, instead of film, actually putting images on an array. By now—I mean, before the array, there used to be a couple of hundred elements. Now, we are talking about literally millions of elements on there. And at JPL, we were in a position of capitalizing on that, and credit goes to Lew Allen because he perceived that, coming from the Air Force. He could see that there is that evolution of larger, more sensitive arrays. So, he arranged to get funding from NASA and from DOD for the Microdevices Lab. So, that was a lab, really, at the leading edge of detector technology, which was used for conceiving new ideas and testing the detectors coming from industry. So, we were not building detectors at JPL. We were conceiving them, coming up with tests to see which one are the best systems. And then when industry built them, we were testing them at JPL, and calibrating them, and, of course, using them. And that, in a sense, led to a big step in my career because of the—it became apparent this is going to be a multi-hundred-million-dollar business at JPL. Matter of fact, it was starting to get even almost more than the spacecraft business. That's what led Lew Allen to decide to do that directorate, and he asked me to head that directorate. ZIERLER: Charles, what is your recollection of the earliest discussions about sending a wheeled rover to Mars? How far back does that go? ELACHI: Well, I mean, first, the concept was talked about in the—after Viking, on doing that. But it became a reality—let's see—in the early '90s. So, after I became director for space science and instruments, that also included technology at JPL. So, I was overseeing the technology. Then, I think, when we had a major setback in 1992, where we lost, a mission called the Mars Observer, it never made it to Mars. Well, shortly after that, Headquarters asked the director at JPL, Ed Stone, at that time, to conduct a study of what should be our plan for future missions to Mars. So, he asked me, Ed Stone asked me to chair committee, which is not only JPL but people from outside, and some international researchers, to look at what should NASA be doing next for exploring Mars. And two things came from that committee. It continued over a number of years. One is to send another orbiter, to Mars, and to send a lander demonstrating some new ways of placing landers. So, the orbiter which came out of it was the Mars Surveyor, which was successful, and then there was a lander which was called Pathfinder. As the name indicates, its [purpose] is find pathways of landing on Mars, more innovative ways to land on it. So, that Pathfinder—at that time, Dan Goldin was the NASA administrator. He's a very visionary person. So, the idea was to just put a lander, do airbags around it, have it bounce on the surface, and that's a new way of landing on Mars. Then one of our technologists at JPL came and chatted with me, and I was visiting her lab, and she showed me this little rover that she was building, which is, man, it sure would be great if we can put that rover on the Pathfinder mission to go to Mars. And, considering I always—I think always, "dare mighty thing," I said, "Wow, that's great, you know. Let me go and figure out a way how to convince, NASA and the people at JPL…" because they were already starting to build or to design the landing spacecraft. So, I went to the project manager first on it. His name was Tony Spear, and his first reaction, said, "Charles, look, we just came from a failed mission. We want to make sure this mission is successful. I don't want to complicate it by adding a rover to it, and I don't have the money." I did the same thing to my equivalent, the head of the flight mission. His name is John Casani. I got the same reaction. So, I told him, "Well, if I can get you the money, will you put it on?" He said, "Well, we'll consider it." So, I went to Headquarters, and the person in charge of all these mission at Headquarters, his name was Wes Huntress. And Wes Huntress and I were good friends because Wes used to be a scientist at JPL. He was in my division when I was a division manager. And then he left, went to NASA Headquarters, and became the head of the science activity. Wes was intrigued with the idea, and he said, "Well, but the key thing, this, we have to call it a technology experiment, so it's not—if it doesn't work, it's not part—it wouldn't look like a failure. And, number two, Charles, I don't have the money." So, I said, "Well, if it's a technology experiment, let me go to the head of technology at NASA," because I dealt with both of them doing technology and instruments, and see if I can get funding from him. So, I went to the head of the technology, and he was also an out-of-the-box kind of crazy thinker. His name was Sam Venneri. Sam Venneri immediately picked on it, and he saw that it would be a great advertising for his technology work, at NASA because he was funding the rover technology work at JPL. So, he said, "Give me a day." And I knew what he wanted to do. He wanted to go to Dan Goldin, who's the big boss, to ask him. And this is the kind of thing that Dan Goldin loves. I mean, he eats up that kind of stuff. So, within a day, Sam Venneri came back, and he said, "Charles, I will fund it." He said, "how much is it going to be?" I vaguely remember I told him around25 million. He said, "Done. We'll find the money for it." I went back to Wes Huntress and told him, "Wes, we got the money." He said, "OK." So, he called the people at JPL, John Casani and Tony Spear.

He said, "Look, we are going to add that rover. We'll go and figure out a way how to do it." And to their credit, they started seeing the benefit. I mean, once NASA bought into it, they got the funding, for it, and we knew we have the technology. And that's how the first wheeled rover which was added to the Pathfinder mission. It was about the size of a shoebox, and it was purely to demonstrate how we can move a rover on the surface of Mars from Earth because you had to do it completely autonomously because we cannot joystick it. So, that was the first—one of my first contributions [laugh] in my position on the executive council in addition to the Hubble camera issue. And that's what led to then Spirit and Opportunity and Curiosity and Ingenuity getting bigger and bigger rovers, more capable rovers. Sometimes, things don't get planned very carefully. As I kind of mentioned before, one of my key philosophies is you don't plan the detail on everything, but be prepared if a door opens for you, and there is an opportunity to jump in even if it's risky to do that. So, that was a perfect example of the early things in the '90s that were done. And led to the helicopter, which we can talk about it later.

ZIERLER: Yeah. What were some of the engineering challenges in figuring out how to build a pathfinder that would effectively navigate on the surface of Mars?

ELACHI: Well, clearly, the autonomy was a key factor. I mean, this is the first time that we were driving something autonomously. I mean, people now talk about autonomous cars. So, that was in the '90s that we had to develop the technology of recognizing the terrain in front of you, so we had to use a camera, to do that. And then the environment on Mars, I mean, in one day—a day on Mars, you go from being like 25 degrees centigrade. During the night, it goes down to like -90, -100 degrees. So, that really has a big impact particularly on the electronics and, to some extent, the material that you are using, on this thing, on the devices for doing that. And, fortunately, at JPL, we had a lot of experience with spacecraft in deep space. What kind of electronics do we use? So, that's where most of the challenges were in the electronics and the material.

But we kept emphasizing that this is a technology experiment because we really were not absolutely sure, we are going to be able to successfully do it for a long period of time. So, I think, if I recall, we said it will operate for only like few days. It ended up being many months, after that because we tend to be very thoughtful in how we build our hardware and test it. So, if we promise, let's say, one week, we test it for like three weeks, to make sure it can survive that long. If it's for one year, we test the equivalent of three years, on our mission. So, that was embedded in the thinking, at JPL.

ZIERLER: And what was the range envisioned for the Pathfinder? In other words, how wide a distance would the Pathfinder need to be able to travel to make that ability worthwhile?

ELACHI: Oh, we thought if we drive a few meters, that will be good enough—

ZIERLER: Really?

ELACHI: —to do that, yeah, I mean, because that kind of demonstrate the function, that way. And, at that time, again, because it was the first time we were doing it, and the wheels were very small, I mean, the whole thing was a shoebox, so it couldn't climb on rocks and so on. We were carefully taking images from the lander, looking around to see where the easiest place is to drive, and send that little rover to drive around that area. So, it was, yes, autonomous, but it was hand-held. We were planning every day, where do we drive it? And I don't remember the exact—I think we drove maybe 100 meters on it. And we had a little instrument on it because we wanted to do a little science, which was some kind of an X-ray or a gamma ray instrument. I don't recall now. So, we drove to a big rock, and had the rover stick its nose, which is the nose of the instrument, on that rock. We did a little bit of science but the whole purpose was to demonstrate our ability to navigate, communicate, to be able to control it from the ground. And that's what laid the foundation for Spirit and Opportunity later.

ZIERLER: So, it was proof of concept more than anything else?

ELACHI: Yeah, and we repeated that a lot. But the public loved it.

ZIERLER: Sure.

ELACHI: The first time a rover, this little buggy is—similar to the toy that our kids and grandkids play with.

ZIERLER: Sure.

ELACHI: This is how it was.

ZIERLER: [laugh] Charles, the development of space very-long-baseline-interferometry, or VLBI, I'm curious if Caltech's strength in electrical engineering was an asset for this program.

ELACHI: Yeah, absolutely, I mean, at Caltech, both in electrical engineering and in astronomy, it was really a combination, of the two because that relied heavily on communication, coherent processing, and this was started all on the ground, you know. The VLBI, as of now, it's used for space exploration or planetary, but it's all done on the ground. There are talks about doing that in space missions, and there are people conceiving mission, to do that in space. But as of now, it has been mostly on the ground. I think people were able to connect a spacecraft where you had one telescope on it with the ground…a radio telescope, with the ground, a ground telescope. But most of the work of the radio telescope was heavily on the ground activity. And JPL—both Caltech and JPL played a major role in it because the main, particularly in radio astronomy, was—well, also in communication—was using the big antennas that JPL had for communication.

So, particularly, it came when Voyager started, going farther and farther, and we were getting weaker and weaker signal from it, people came up, with the idea at JPL, and many of them were Caltech graduate, of maybe taking multiple antennas, and combine the signal from them, exactly like what would you do with radio astronomy, or interferometry. So, by that, now, you get the power of two antennas or three antennas or four antennas. And after that, that became a routine process which now we use commonly. So, that led to the thinking that maybe we don't need these big antennas which cost a lot of money. We can build a bunch of smaller antennas, and combine the signals, coming from them. So, it was kind of a step together between the communication guys and the astronomers. And, again, at Caltech, having that interplay between different departments, in this case EE and astronomy, radio astronomy, makes a very powerful combination—and JPL, which enabled then the implementation of these things.

ZIERLER: And what have we learned as a result of VLBI?

ELACHI: Well, the VLBI allowed to do much higher resolution in radio astronomy. Again, it's all—when it comes to astronomy—it's all about aperture.

ZIERLER: Yeah.

ELACHI: How big is your aperture? There is a limit to how big a physical aperture you can build. The big antennas we have at JPL, they are at about 70 meters in diameter. But then when people look—and these cost in today's dollars hundreds of millions of dollars—to build these big antenna, because you have to have them point-able so you can look at different parts of the sky. But the ability of being able then to use a lot of smaller antennas, which you can do cheaply, and then combine them electronically, really enabled a whole new way of doing things. And one example is Caltech, Owens Valley Radio Observatory where Professor Gregg Hallinan was that director of that facility.

He's using hundreds of little antennas, and he combined them, and that's the equivalent of the whole size of that array. So, by having antennas which are in the one-meter or two-meter size, spread over many tens of kilometers, would allow you the equivalent of ten-kilometers aperture of doing that. So, that allows us to see much, much higher resolution, the same way optical telescopes are allowing higher resolution. And it's used for a whole spectrum of phenomena. I'm not an astronomer on that. But you can see a lot more detail. And it's a technique which has allowed the imaging of the black hole. By using VLBI, not only in one location but around the world, different antennas that you can connect by recording very accurately the signals, and coherently, and then being able to combine them as it's like a big array.

ZIERLER: So, the Event Horizon Telescope has Caltech and JPL DNA in it.

ELACHI: Oh, absolutely, I mean, that technique—I would say, I mean, arguably, that Caltech and JPL are the founders of this interferometry technique. But other people thought about it also, so it was not unique. But what was unique here is the interplay between the different departments and JPL, and the ingenuity of the faculty and the people at JPL, which enabled that to happen.

ZIERLER: Charles, tell me about the conclusion of the Cassini mission. What were some of the most important things that we learned from Cassini, what were some of the engineering feats that kept the spacecraft operational for 20 years, and what was important about the mission as a US and European collaboration? So, let's start first with the science. What did we learn from Cassini?

ELACHI: Well, Cassini was literally an observatory of Saturn. So, we spent almost 13 years in orbit around Saturn and, basically, looked at the dynamic of the atmosphere, the composition of the rings, and flew by all the different satellites, either image them remotely or by flying by them, very closely. So, it really was an exploration of an equivalent of a solar system, if you want. So, people here like at Caltech, Andy Ingersoll was one of the key players in furthering our understanding of the atmosphere, both its composition and its dynamic. There was a lot of work done on the rings, and we concluded that they are made of little, icy rocks, and they are dynamic. They change because of the gravity field of Saturn. So, as they go in orbit, you see waves in those rings that you cannot see from the ground. And then particularly, at least for me personally, the dramatic thing was the exploration of Titan because Titan is a satellite bigger than our moon. We knew it was completely hazy, so we didn't see the surface.

We couldn't see it in the visible [range], and that's why we included a radar instrument to map it. And that's what led to discoveries of lakes and rivers on Titan. I usually say that Titan is exactly like Earth, except the rocks are made of ice, and the water is made of methane and ethane, the rivers and the lakes. And that basically gave us an image of—and there is curiosity now about, potential habitability of life on it because this is a whole satellite which is made of organic material, meaning, the methane and the ethane. And there are people who think that could have been in the past or at some time some kind of life which have evolved in it. And because of that, now, NASA is planning a follow-up mission to go to Titan using basically a helicopter, which would allow to fly, and explore it further. The other dramatic one, which is not my direct instrument but there was a lot of involvement from Caltech and JPL, is when we flew by Enceladus, which is a small satellite a couple of hundred kilometers in size, and we knew it was made of ice because when we took imaging spectroscopy on it, we see plumes which are shooting from it.

So, that also led, to make a long story short, to the concept that, Enceladus probably either has water in the inside, liquid water, and, as it goes around Saturn, because of the tide, the satellite is pumped back and forth, and that what lead to geysers, so similar geysers as like the one that you see in Yellowstone. And one of the things we did—because all of this, by the way, was happening when I was director at JPL. I was the director when it arrived, to Saturn, and the mission had a couple of years after I stepped down. So, we had a meeting and a very heavy discussion. Should we target the spacecraft to fly through that plume, because there was the concern, could it damage the spacecraft? Well, after some analysis, we decided that it would be a cool idea because we had an instrument which could measure the composition of that vapor, and the particle coming from it. So, we ended up flying. We adjusted one orbit to fly through that plume, and, guess what, we found that there were organic material in it. I mean, we didn't see life. We didn't see bugs. But there was organic material. So, now, there is all kinds of discussion. Could there be life inside that ocean in a similar way to what we think Europa has, around Jupiter? So, Europa around Jupiter, well, we are sending a mission to it in two years from now. And Enceladus around Saturn, where people are thinking of future missions for it, are two potential places where there could be life in these oceans below the surface. So, the Cassini mission was, from the beginning, conceived, as a matter of fact, it was conceived in 1983 or '84.

I remember the first meeting where a group of us scientists were talking of such a mission. And there was involvement from the European Space Agency, scientists from Europe, and then the decision was to go and do it jointly where NASA would build the spacecraft, the orbiter, and ESA would build the probe to drop it in the atmosphere of Titan. And that was a great collaboration. It's probably one of the best collaborations that I have been involved in addition to some with the French Space Agency. So, yeah, it was developed, and it ended, being launched in the late '90s. It went in orbit in—it took like six or seven years to get there. It went in orbit in the early 2000s when I was a director. And that was a nervous time, I can tell you, because the spacecraft has been flying for seven years. And when we sent the command for the engine to fire, [hoping] it has to work. Otherwise, we'll end with a flyby, not an orbiter, around Saturn. So, fortunately, it all worked. And then, the mission kept going. I mean, the spacecraft was built very well. We kept extending the mission. It was supposed to be three years. It ended up being 13 years. But, like everything, there is going to be an end, you know. The propeller on the spacecraft, which is used to do the altitude control, was being depleted, and we had—as a rule, we decided that we want to make sure we do a controlled crashing in Saturn's atmosphere so it gets burned because we didn't want it to—if we lose control of it, it might crash on Titan or on Enceladus, and we could contaminate those satellites. And we want to make sure we don't bring any bugs from Earth, with us, and contaminate the satellite. So, on purpose, it was directed to actually go into the atmosphere, and that happened about two years ago, two and a half years ago.

ZIERLER: And when you talk about avoiding contamination, this is because there's the idea that there could be life there?

ELACHI: Well, that's true because, I mean, either life or some kind of life, at the bacterial level or at the microorganism level. So, we are also—NASA as a rule is very careful on any contamination on other planet, particularly if there is a possibility of life on them.

ZIERLER: How close did Cassini get to the rings themselves?

ELACHI: Oh, we came very close, we came very close. Particularly at the tail end of it, we got between the rings and Saturn itself. We came so close to them that we were between the rings and Saturn. That was required because of celestial mechanics because we had to slow the spacecraft so it crashes into Saturn. So, the magicians at—I called them the magicians—at JPL, the navigation people had to come with a scheme of how to slowly bring the orbit down, and actually crash it, into Saturn.

ZIERLER: What do the rings look like at that scale?

ELACHI: Well, you could see, I mean, almost you can make the size of the particles, that are there. I mean, the particles are in the meter scale, so we could see the fine detail of the gaps between the rings. We can almost see the particles. Matter of fact, some of the particles or what we call the ringlets, were kind of a few hundred meters in size, and these are the ones which create the gaps, because they sweep through those gaps. Those, we could actually see them, and see the detail on them. The rest of the rings, it was much smaller, so we can see…it looked like a sheet, but we knew they were made of a variety of particles.

ZIERLER: And, finally, on Cassini, from the diplomatic or international side, what do you see as the value of Cassini as a US and European collaboration?

ELACHI: Well, there are a couple of aspects of the value. You are always very perceptive. There are both scientific and financial and political benefits. On the scientific side, there are smart people all across the world, and therefore there is a benefit of bringing the thoughts and the ideas and the perspective of people, in this case, mostly from Europe who worked with us. And things are done vice versa, I mean, we have scientists involved. On the financial side, basically, we do what we call when we do collaboration with no exchange of funds. That means whatever European contribute, they pay for it. Whatever we contribute, NASA pays for it. And in this way, the probe, which was developed by the Europeans, was fully built in Europe, you know. And that was many hundreds of millions of dollars to do that. So, that way this will enable us to do more for, less money, in a sense.

So, there is that benefit where we all benefit because the data is public, you know. So, both the European and the US side benefited from both elements. And then, every once in a while, there is a political factor, and where that comes in, like, particularly in the case of Cassini, we worked in agreement between NASA and the European Space Agency to work together on that mission. Then I think after we started working on it—I don't remember now which administration; it might have been the Clinton administration—there was talk of cutting NASA's budget, and canceling Cassini. As you could imagine, the ambassadors from many, many countries in Europe were [laugh] at NASA, they were at Congress, and they were at that mission saying, "What do you mean you are going to cancel it? We have an agreement. We have almost like a treaty, if you want to call it that, to do this thing together." So, of course, the administration immediately backed off from doing that. So, there is some benefit, political benefit. It doesn't happen on every mission. But every once in a while, that political factor comes to play.

ZIERLER: Was Cassini conceived to be part of a series of missions that would be collaborated on between the United States and Europe?

ELACHI: Not exactly, but it led to that, because there couldn't be long-term commitments made on these things. Europe is usually better than us, the European Space Agency. The countries usually define the budget for the European Space Agency every five years, and the budget is fixed, you know. It cannot be changed by different governments and so on.

Here in the US, every year, we have to still go to Congress, and work on the budget. In general, the commitment for a mission, stays [fixed] to do that. But it's a challenge—on a regular basis. It's a challenge to keep the commitment on doing that. So, it was more conceived on examples of missions that we can jointly do with the Europeans. And after that, there have been a number of missions also which have been done jointly.

ZIERLER: Different topic, Charles, can you explain the science behind the ion engine propulsion system for Deep Space One? How does that work?

ELACHI: Well, the—one of the biggest challenges we have in space exploration is basically being able to propel heavy masses across the solar system. And the chemical approach has effectively reached its limit of efficiency, which means how much push we can get for a certain number of kilograms. So, for many years, all the way from the '60s, people thought of the idea of using electric propulsion where you take a gas, like xenon, you ionize it, and then you put it into place where there is a voltage, and you can push the ions at very high speed. The advantage of it is that you can push, if you want, your propeller at extremely high speeds, which means it would push the spacecraft or the rest of it in the other way. And it turned out that ion propulsion is much more efficient. It's not more powerful. It doesn't—you cannot use it to launch rockets from the ground. But it's very efficient. So, per kilogram, once you are in space, you can get a lot more push for the spacecraft, than you can do with chemicals.

A couple of NASA centers, particularly Glenn Research Center, and at JPL were working on ion propulsion. And then came the time that we have to demonstrate it, in space because no spacecraft—I mean, no science mission would agree to it unless it has been demonstrated, because it was esoteric technology. So, in that period when I was the assistant lab director, and, as I mentioned, I had technology in my office, I was working a lot with NASA on advancing technology in addition to instruments for the benefit of future missions. So, NASA started a program which was called a technology demo program. I sat down with the person responsible at NASA, her name was Mary Kicza, and we thought, OK, what kind of mission can we demonstrate with that technology that will enable us to verify, the electric propulsion? And we came up with the idea of Deep Space 1 to be a technology demo spacecraft, not a scientific mission, and we will demonstrate electric propulsion on it. JPL got the responsibility to do that mission, and that's how we ended up flying and demonstrating it. And then once we demonstrated it, then a number of future missions, or missions that were conducted since then, actually used electric propulsion.

ZIERLER: Is this going to be the propulsion system for future missions that are geared towards going farther out than JPL or NASA has ever been before?

ELACHI: Yeah. No, I think that electric propulsion is one of the major contenders for doing that. Matter of fact, after that we conducted a major study of doing a Jupiter orbiter using electric propulsion, and to get sufficient power in it, the idea was to use a nuclear reactor, to ionize the gas so you get enough power. Because as you go—well, one of the challenges on electric propulsion is that you need the power. So, if you are using solar power to ionize the gas, as you go farther and farther out in the solar system, you are getting less and less solar power. So, the idea was that we have two ways of getting the power. I mean, one, you can use solar panels, and that works well for missions to comets and asteroids. And then for outer planets, we explored looking at nuclear reactors to actually generate the power. And that study evolved fairly well.

Then there was a change in administration, so they stopped doing that. But now, recently, the last couple of years, there is a renewed interest, in building nuclear reactors which can go—I mean, it's safe enough to travel in space. And there we had the perfect kind of marriage in working with the US Navy, because they had a lot of experience of building safe nuclear reactors, and we had a collaboration to kind of take that thinking and that technology, and see how to apply it in deep space.

ZIERLER: Given all of the excitement now around nuclear fusion, do you see that as contributing to JPL's mission in the future?

ELACHI: Maybe. Maybe one day. [laugh] But we have [laugh] to remember that nuclear fusion had been next year—

ZIERLER: [laugh]

ELACHI: —for the last 30 years.

ZIERLER: Right! [laugh]

ELACHI: But it looks like progress is happening, so that could happen. That could happen.

ZIERLER: Charles, different question, what were some of the big curiosities around comets that motivated Stardust and Stardust-NExT?

ELACHI: Yeah. Well, the interest in comets goes back to the '70s when we were told that Halley, the Comet Halley was coming back, it was very much in the public, and there was the history of being able to predict when a comet comes back. So, there was a big study about—at that time in the '70s, I was not involved in it—is was to look at a mission to go to a comet. Unfortunately, it ended up not being approved at NASA, you know. But the Europeans decided to send a mission, and they did do a flyby of the Comet Halley. But then there was the interest on what are comet made of? what can—what is their composition? So, we came at JPL with two concepts, and they were both won competitively. This was started like in the 2000 timeframe or a little bit before that. NASA was starting to say, "Look, the big missions, we will assign them to a place like JPL. But smaller missions, we want to get all the ideas of the science community instead of just NASA and JPL defining them." So, they started a series called Discovery, where anybody can propose a mission. NASA will say, "Hey, we have 500 million or whatever." People can form teams, and propose that there should be a competition, and then some people will win based on that.

So, through that process—again, that was the period when, I was the director for that—that was kind of my responsibility of coming with the new ideas. We came with two concepts, for studying comets, as well as a bunch of other concepts. One was called Stardust, which was to actually fly through the tail of a comet and to bring samples back. And the other one, we called it Deep Impact, which was to send a mission to a comet, and actually hit it, and see what comes out of that comet. In the case of Stardust, the principal investigator was from the University of Washington. We worked together with him, and we actually built a mission which flew through the tail of a comet, and we had aerogel on it, which is a kind of material. I have a piece of aerogel here sitting in my office. It's basically like smoke but it has the ability that it can slow down and embed particles in it without damaging them.

Because that was the big risk, that if you try to—we are flying at high speed through the tail of that comet, and any technique you can use will actually destroy whatever you are trying to collect because they are coming at a thousand meters per second. So, a scientist at JPL came up with this aerogel, which enabled [us] actually to collect those particles. So, we flew through the tail of that comet. The probe came back, and the way we got back into the atmosphere, on Earth, we actually came with a parachute, and that's how—similar to how we land rovers on Mars, except, on Earth, we have a heavy atmosphere, so a parachute will allow us to slow down after we slow down with the heat shield. So, that was Stardust.

Then we had Deep Impact, and that was even a more dramatic mission because what we wanted to do was to send a spacecraft to get very close to the nucleus of a comet, and then shoot a bullet into that comet while the spacecraft is watching to see what's going to happen, and what the ejector which is coming from it? Now, imagine that that comet is coming down at tens of thousands of kilometers per hour. The spacecraft is coming at tens of thousands of kilometers per hour, and the comet is only about a couple of kilometers in size, and we have to shoot that bullet and hit it. So, we used to call it, hitting a bullet with a bullet. That's almost the exact comparison, between the two. This required a lot of optical navigation, so the mother spacecraft gets a comet, tracks it, and makes sure we are following it. And the bullet is a little bit smart so it will also have a camera on it so it homes in on that nucleus to be able to hit it. And that was very successful. I mean, it was a great mission, on doing that. And, as you could imagine, a lot of technologies came out of it, particularly on tracking. How do you do very accurate tracking so you'll be able to hit a bullet with a bullet? And, as you could imagine, the military was very interested in that kind of intercept. We call it interceptor. But in our case, it was mostly done for scientific purposes. And that led to a lot of understanding of what the comets are made of, the dust and the H2O and the organic material, because that plume which was emitted actually enabled us with instruments on the mother spacecraft to determine its composition. That, I would say, was one of the more tense and exciting missions, that we did. [laugh]

ZIERLER: Charles, while we're on the topic of comets, it's outside of the historical chronology but maybe now is as good a time as any to ask, when we first discovered ʻOumuamua, and there was so much excitement because it didn't exactly have the properties of a comet or an asteroid, and that raised the possibility maybe it's—

ELACHI: [laugh]

ZIERLER: —maybe it's a sign of life.

ELACHI: [laugh]

ZIERLER: What—first of all, in that moment of excitement, what were JPL's contributions both to understanding asteroids and comets leading to this assertion it's not either one because we know how comets and asteroids behave?

ELACHI: Yeah. Well, we have a whole program at JPL for ground observation of comets and asteroids, and it's an international program. It's not only at JPL, but we have a team at JPL which works on this activity. And we had a lead scientist by the name of Steve Ostro who was one of the key astronomers doing that. He passed away many years ago. And then we have a center at JPL which keeps track of any comet or asteroid discovered by anybody. And the contribution from JPL, because of our navigation experience, we can project where these asteroids are and where these comets will be flying by. Particularly there is the interest, would any of them hit Earth? And then we had a number of missions which flew by asteroids, in the '80s, '90s, and the 2000s. And, matter of fact, now we have a mission which is going to be going rendezvousing with an asteroid, and the Europeans did something recently of rendezvousing, with a comet. So, there was a fair amount of understanding of what comets looked like, what asteroids looked like. We used ground-based radars. There was a guy by the name Steve Ostro at JPL, who was using the radars on the ground to take a radar image, of the asteroids, and the comet. But there is a lot of these things, you know. You cannot see or track, all of them. And many of them, we actually detected them after they flew by Earth, and they were leaving, Earth.

So, now, there is a program, a much more extensive program of monitoring and being able to track these tens and thousands of asteroids and comets. And, matter of fact, there is a mission under development at JPL to put a spacecraft in orbit to be able to survey the sky. And part of the reason that it's challenging is that some of them usually are coming from the sun side, so they are coming toward Earth from the day side, so you don't see them very well. We want them to be coming from the night side because that's how ground telescopes can see them. If you have a spacecraft, out in space, then you can see from everywhere, you know. You are not limited to doing that.

So, I think that comet came as a surprise. I mean, we didn't know about it, earlier. So, it came, and I think it came from a trajectory which says it's coming from outside our solar system because you can tell from the trajectory how it's coming. If it's an orbiter around the sun, that means it's part of our solar system, or it's coming from outside the solar system from its orbit. So, yes, that led—and it had an odd shape, that. Now, we have seen different odd shapes, from asteroids and comets, but this one was really odd because it was more like a cigar kind of thing. So, of course, that led to people talking, well, maybe it's coming from somewhere else. Maybe it's not the traditional comet or asteroid. So, there is still debate about what was it made of? Where did it come from? Is it human-made or is it natural made?

I'm sure there are people, who love the science fiction thing, who say this is a UFO. And the more conservative scientists would say, "Look, it could be any shape, it could, depending on how part of that solar system actually formed." But that became a trigger, if you want, for more proactive programs to monitor asteroids and comets there coming, both to understand them, see them well early enough that you can really work, near telescopes to observe them more extensively, or to have satellites outside in Earth's orbit or on orbit around the sun, which will be able to survey the sky much more extensively.

ZIERLER: Charles, if I understand correctly, it's sounds what you're saying, really, is that our understanding of comets and asteroids is not yet complete enough to definitively rule out that ‘Oumuamua is neither one.

ELACHI: Yeah, I would say it's yet not complete enough, to do that, and there are plans to get better understanding of comets. So, as I mentioned, the Europeans rendezvoused with a comet, and actually landed on it, a couple of years ago. There is discussion at NASA for a potential mission for bringing samples from comets. That means to go and land on the nucleus, and dig—drill, if you want, instead of digging—drilling down below the surface, and bring the samples back to Earth; similar to Stardust, except Stardust was from the tail of the comet. So, these were the things which are being evaporating. The intent on the comet sample return is to drill and go deeper so you can see what the original material is made of.

ZIERLER: Charles, back to the 1990s, in the years running up to your directorship, of course, JPL experienced some failed missions, like the Mars Climate Orbiter, and the Wide-Field Infrared Explorer. In what ways is failure, even big failure, in what ways is that useful for JPL institutionally, and how would these failures affect your sense of risk versus reward for when you assumed ultimate responsibility as director?

ELACHI: Yeah. Well, let me repeat what I said earlier about what Teddy Roosevelt said. He said, "It's far better to dare mighty things, even that they are checkered by failure, than to sit in the twilight that knows neither victory nor defeat."

ZIERLER: Yeah.

ELACHI: I think he was a little bit more elegant than what I just said but I think that's the essence, of it, which became during my directorship kind of the logo for JPL. Space business is risky. When you are exploring, it's risky. So, I always say, describe to the employees, if you read—and I'm a big fan of reading biographies, both of president and explorers—all those explorers who were very successful and famous who had a hell of a time doing their exploration, and they failed many times. And a dramatic example, we all think Magellan is the first person who went around, the Earth, with a ship. Magellan didn't make it all around the Earth. He died in the Philippines, or he was killed in the Philippines. Captain Cook is another example. So, even there is life risked which happens [laugh], when you do exploration. The same thing when we do our exploration, we are doing things for the first time. We are humans. There is always a risk, and risk could lead to failure, particularly when you are pushing the limit. Now, we are very careful about it, you know. We do everything we humanly can to avoid those risks and to be successful. But we have to be prepared that risks could happen sometime, and the key thing is not to be discouraged but to learn from them, to and be able to do things better.

So, that leads me to reflect on the question that you just asked. So, in the 1990s, I was the what we call the assistant lab director for science, instrument, and technology. I think that was the title. I don't remember it now. So, during that period, my responsibility was mostly on the scientific instruments, building instruments, providing them to both JPL and other spacecraft, at Goddard and internationally. In the late 1990s, unfortunately, we had a failure on two…matter of fact, in 1992, we lost Mars Observer, and that one, I think, even until now, we are not sure. I mean, that was not in my directorate. That was in the flight system directorate. Shortly before we got to Mars, and we turned the engines on to go in orbit, and the spacecraft disappeared. We lost communication. The most indirect—it was likely that there was a failure in the propulsion system, but we could never tell, if that is what the case was. And that led to me heading that committee I mentioned earlier to lay out the plan for the future, and that is what led to doing the Pathfinder, and then to the Mars Surveyor, which was successful in 1996. We learn from that. And then in 1999, we had two missions, the Polar Lander and Climate Orbiter, which were developed during the second half of the '90s. Again, that was in our flight directorate at JPL and, unfortunately, we lost both of them. The lander, we don't know for sure what happened, and that will lead to a lesson that I will mention in a minute.

The Climate Orbiter, there, it was one of these human failing errors which happened. We had a company which was building it, it was Lockheed Martin, and, basically, we asked—we were doing the navigation, the trajectory. So, we asked in our contract, written in the contract, that we need to use a metric system, so all the data that's given to us to do that had to be in the metric system.

Unfortunately, Lockheed and the people who built the propulsion system—which I think was not Lockheed; it was a subcontractor—they put all the parameters in imperial because that was their tradition. So, the navigation group at JPL, when they got, what we call the impulse of the rocket and, I mean, onboard propulsion system, they took the number, translated it into our table, thinking they are all in metric because that's what the contract said, on it. And, unfortunately, that led to erroneous navigation parameters. So, then, what happened, we were assuming it's metric for how much propulsion to put it in orbit while, in reality, the numbers were in imperial. So, it was not that somebody they didn't know how to translate from one to the other one. It was one of these failings where somebody was contracted to write something in a certain language, and the other person who is doing the navigation thought it's a different language that was doing that. And that should have been picked up. So, it was a failure which had happened. And as soon as we lost that spacecraft, literally within hours, we formed, at JPL a group to review it, and within hours, they realized what actually happened. So, if it was properly reviewed earlier, we could've caught it.

Now, the lander, then we didn't know exactly what happened because it was landing in an area where we could not communicate with Earth in real time. So, basically, it was all in the blind. So, the landing happened. We were waiting the following day to get a signal, and nothing was coming, from it. So, we concluded—after trying for many months, we concluded that, actually, it had failed. And then shortly after that, I became the director at JPL, so that was in—so, all of this happened in late '99, early 2000. And then I was selected as the director in 2001. And from these two, I learned—not only me but all of us at JPL—we learned two key lessons. One, on the lander, I established a rule that we will not land unless we have a direct link to Earth, so we see in real time, I mean, with the time delay of actually what was happening. So, if we have a failure, we will know when did it happen, what caused it to happen, that failure? So, that was a golden rule that I put in—assuming celestial mechanic allows it—that every critical event going in orbit, landing, has to be in view of Earth, or having communication [capability].

And the other one, it was just to be more careful. We had to do more extensive reviews, always have more than one eye or pair of eyes, if you want, on every aspect. And even then, human mistakes do happen. I mean, we have to be prepared that human errors can happen. But we put together a much more extensive review process to make sure not only that this doesn't happen but other things, don't happen because of it. And these are the lessons we learned, and that led to a period when I was director for 25 missions, plus missions after I became—after I stepped down, which were all successful, except for some minor, minor issues. There was one mission where we had a little mistake, on it. But, effectively, they were all successful.

ZIERLER: And this gets to a work culture question. So, when there is that mistake, and that mistake is so clearly traceable to an individual, a team where, like you said, we're human, they just messed up, are there repercussions? Are people—I mean, what is the reaction? Do people…obviously, everybody feels badly, but are there repercussions for people who make mistakes?

ELACHI: Well, yes and no, in the following sense, at least for my philosophy, is to really understand what led to that failure. And if that was a god-honest mistake or what—then, there is no repercussion, at least for the people. If it was because somebody was dumb or irresponsible, then that's different—

ZIERLER: Yeah.

ELACHI: —to do that. So, no, that philosophy was—and, clearly, on that mission, part of—not a direct but indirect reason for it. That was a period where NASA pushing to do what we call faster, better, cheaper. There was a big push of being able to do missions much less expensively. So, really, the project managers at JPL, the people responsible for doing these missions, were under a lot of pressure, both of time and funding. And the only way you get funding is by having fewer people working on a piece of hardware.

ZIERLER: You're inviting mistakes is what you're doing.

ELACHI: Yeah, and, therefore, you don't have the checks and balance—

ZIERLER: Right.

ELACHI: —that you normally have. It's like, my wife always says, "Measure twice and cut once"—

ZIERLER: [laugh] Yeah.

ELACHI: —and doing that. I mean, many people use that approach.

ZIERLER: [laugh]

ELACHI: So, to measure twice, usually, we need a couple of people watching, to make sure people don't miss something before you cut it or before you solder it or before you fly it. So, I think that was kind of an indirect implication because there was the pressure, you know. On these Mars missions, you have time, which is, by definition, fixed, and then you didn't have as much budget. So, I think it was a failure, a little bit of the institution of not pushing back on NASA, and saying, "Hey, wait a minute. We are pushing too far. We are pushing these employees too far. We have too few people working on these missions." So, I think that was part of the reason.

And then immediately after I became director, I did get an inquiry from Headquarters, "Who are you going to fire for the failure which happened a few months ago?" I told them, "I'm not going to fire anybody. These are the most experienced people anywhere around the world. They learn from their mistakes. These were honest mistakes, kind of almost imposed on them," I mean, not the mistake but the environment which led to the mistake, "and if anybody needs to be fired, you have to fire me. As a director, I establish the policy, I establish the approach, and it's my responsibility in the future that if I see that you are pushing us too far, or we are being cutting corners, to tell you, ‘Wait. Stop. We are not going to continue doing this.'" And, to their credit, NASA accepted that. And, matter of fact, it's interesting, the project manager on these two missions, his name was John McNamee, and, of course, he was very depressed because of, because of the failure. But he was one of our top project managers. So, then, I appointed him to become the project manager on Mars 2020, the biggest mission that we have at JPL, which became Perseverance, which landed about six months ago or nine months ago successfully.

And that's an example of the philosophy at JPL, not only me, but that was the philosophy that we had at JPL is that, look, we learn. We are in a risky business, and, every once in a while, there is a failure. And if that failure happened beyond our control, I mean, we did everything humanly possible, to do that, then people will not get punished for it.

ZIERLER: It's also, of course, a beautiful story of redemption.

ELACHI: Yeah, no, absolutely. And, again, because we want to have a spirit of daring, of really pushing the limit, I mean, thoughtfully to do it. I mean, the last thing I wanted when I was a director, or even before that, is for people to become too shy so we do routine things. Then it's not the JPL that we all know, which is the leader in exploration. So, also, upper management has to show not only by words but by action that, actually, we stand behind our employees, you know. And when they are taking a risk that we agreed on, we stand behind them. So, my quote always used to be to the team, "Hey, look, if this is going to be successful, you are going to be on the podium. If it fails, I will be on the podium"—

ZIERLER: [laugh]

ELACHI: —"standing there." And that has a big impact on culture, at JPL, and the attitude of the people towards daring mighty things.

ZIERLER: Now, because both the Mars Climate Orbiter and the Wide-Field Infrared Explorer were such significant projects, were the things that we were going to learn as a result from both of them, did they get learned, resolved in subsequent missions?

ELACHI: Oh, absolutely, absolutely, I mean, our process and so on. And I have to say, to kind of expand on the previous point, the pressure was both not only from NASA—I mean, of course, everybody was disappointed about the failure—but also OMB which controlled the budget, and Congress. And I remember two, which I think are extremely important, two events. When I became director, I went and started visiting these different organizations because I'd have to deal with them. So, when I went to OMB, Office of Management and Budget, which fixed NASA's budget, the person in charge of the NASA part of the budget, his name was Steve Isakowitz. And Steve said, "Charles, we know they are very depressing, about the failure but we don't want you guys to shy away from doing the"—he didn't use the word "dare mighty things"—"but doing—really pushing the limit, and be able to do some exciting missions." And that came from somebody who's tracking the budget; not a technical person. Now, he had a technical background. He was from MIT, so he loved Caltech, even though he was [laugh] an MIT graduate. And, now, he's the equivalent of the director of the Aerospace Corporation, which is the equivalent of JPL for the Air Force. But, at that time, he was an OMB manager.

And then when I went to the Hill, there was a congressman from the local area—it happened that JPL was in his district—by the name of David Dreier. And he told me the same thing. He said, "Charles, we don't want you as the new director to shy away because you had two failures on that. We want to really be at the forefront of exploration." So, this question of risk, and acknowledging that risk does happen in our business, was across people. I mean, smart people realize that.

And, now, David Dreier is on the Caltech board of trustees, and he regularly reminded me of my visit to him when I first became a director of JPL. Now, what lessons did we learn from these? I mean, I hinted to one of them. So, the rule was that we—basically, what I established is when we start a project, just on day one, I want the project manager to work a list of what we call incompressible testers. That mean these are the things we are going to do, no matter what's the schedule of pressure, no matter what's the budget pressure. We are going to test—make those tests before we launch. And I told him, "You give me a copy of that list. I'm going to put it in my drawer. And as we come to the end of the mission, five years from now when we are ready to ship to Cape Kennedy, I'm going to pull that list, and I'm going to go through each item, and you're going to tell me if we have done those tests successfully. And if, for some reason, you had to waive one, I have to approve it. you cannot approve because then I have to go to Headquarters, and tell them, ‘Look, this was something important, but because of whatever reason, we cannot do it. And, therefore, I want to make sure we all understand the risk of it.'"

And that led to a situation where when we had push on the budget, I was able to stand up and say, "Hey, wait a minute, guys. We really need additional funding because this is a critical test or a critical activity we have to do." And NASA bought into it. I mean, this was all done in a collaborative way with NASA because they want to be successful also, you know. So, that was one rule which is still followed even after I left JPL, and people talk about the incompressible testers.

The other one which is, as I mentioned, is that we have to be in view of the landing or getting in orbit from Earth, so if something happened, we will know the cause, for it. Now, fortunately, nothing has happened. But that rule was used as a golden rule also to follow. And the third one is we said always treat a mission like it's the first time we are doing it.

ZIERLER: Right.

ELACHI: Don't relax because I've done it three, four times before, I can skip a test, or I can do something, or I don't need two people watching, what I'm doing. We are going to treat everything as if it's the first time. And that's why sometime people—when I have visitors, I used to take them to the viewing area where we assembled spacecraft. And they also ask me the question, "Gee, we see somebody working on some system, and there is somebody watching him. What does he do, that person?"

And, "Well, that's a quality control person. He's the guy who is checking to make sure the person who's actually doing the work is actually following procedure, doing it properly, and basically doing a double check, on these things." So, yeah, that kind of grew through the culture but it got emphasized…what happens is you go through a culture, and every once in a while, you have a failure. And then you say shoot, my culture is getting too relaxed—

ZIERLER: [laugh]

ELACHI: —or maybe we are becoming too blasé about these things. So, that kind of is always a reminder of the challenge we have in doing space exploration.

ZIERLER: Charles, we talked previously about James Hansen, and NASA's early leadership on studying climate change in the late 1980s. Ten years later, with the multi-angle imaging spectroradiometer, would you say that JPL at that point was fully integrated in national and international efforts to understand climate change at the broadest possible scale?

ELACHI: Yes, we were—now, the whole issue of climate change started really getting attention in the late '80s. And then it picked up a lot in the 1990s. And then it led to what we are doing now. And where JPL came from, because we had a very powerful group of atmospheric scientists working at JPL, now, they all came to JPL to work on planetary research. But then there were not as many planetary missions. Not everybody could get an instrument on the planetary missions, so they turned their attention to Earth. So, the group I mentioned earlier, matter of fact, the instrument you just mentioned was the baby instrument of David Diner, who's still at JPL today. But there was this group of young people in their 20s and 30s who came to JPL to fly instruments on planetary mission, but, because opportunity were not as frequent, they turned their attention to Earth. Maybe in one example, I mean, I went to JPL to work on the Venus mission, but it took 16 years from the time I joined JPL until it happened.

In the meantime, I did Seasat, SIR-A, SIR-B, SIR-C, all these Earth oriented mission. So, there were many people, a number of people at JPL who were doing that. And our power at JPL came definitely from the science, but also from our technological capability on understanding the use of instruments and detectors. And that had a connection to Caltech also because here at Caltech, part of the leadership that Caltech got in astronomy was because of the ability at developing advanced detectors. So, you had people like Gerry Neugebauer, who was working on infrared detectors; Tom Phillips, who was working on sub-millimeter detectors to use on ground telescopes, you know. And here at JPL, we had the collaboration, and capitalized on those detectors to do them for a space mission. And that's what led to a lot of instruments from JPL observing Earth, which had direct relevance to the climate change, to understanding the temperature change, to understanding ocean circulation. Ice melting, how is that impacted by temperature change?

So, yes, I would say JPL, even that JPL was viewed as a planetary organization, at some time, particularly when I was assistant lab director, and then when I became director, because of my partial background in Earth science in addition to planetary, we actually, at a number of years, we had more funding in Earth observation than we had in planetary, or what we call the directorate which is in charge of Earth observation and Earth instrument and Earth mission became larger than the directorate which was involved in planetary exploration.

ZIERLER: Charles, would you include JPL's work on solar radiation with missions like Active Cavity Irradiance Monitor Satellite as part of the broader climate change mission?

ELACHI: Yeah, matter of fact, that mission—this was built at JPL. There was a scientist at JPL who was the lead in developing that capability. And, yes, because climate change has multiple aspects, of it, it's not like one measurement. You measure the temperature. You say there is global warming. The important thing is what's leading to that change, and what are the atmospheric gases which are leading to that increasing temperature? Is it coming because of the sun's radiation? Because many people say, "Well, the sun is changing. It's not humans which are doing it. It's really what's happening from the sun." It leads to implications for the ocean. The ocean is a big heat sink, for the heat. So, that plays a role. The polar ice, that plays a role, because, I mean, when you sit down, and think about the impact of climate change, or the reason for it, it's a very complex situation. I mean, the Earth is a complex machine and you study that, I mean, all the way down.

Recently, I was talking with a colleague of mine who is working on snow, and how much water there is from snowing this year, so the state can manage the dams more effectively. He said, "Yeah, everybody thinks about the snow, and the sun melting it. A key factor is how much dust you have on it." And I said to him, "How could that be?" He said, "Well, just when you go skiing, you find that areas which are dusty melt differently than the areas which is not dusty."

So, it turned out dust in the atmosphere can lead to impacts about how the snow melts, and how fast it melts, which leads to how you manage the dams in California about releasing water. So, that's one small example of how the interplay…and that scientist is using satellite data to be able to map not only the thickness of the snow and the temperature, but how much dust there is on it to go into a model of how quickly and how effectively it melts. So, yeah, and the thing at JPL is we had scientists from all kinds of background that came to JPL particularly in the Earth science, which allowed us to understand better that interaction. And, again, it's a connection, with Caltech in many areas. I mean, you have, a leading climate modeler at Caltech by the name of Tapio Schneider who develop models, and he works with people at JPL because he uses measurements from JPL, you know. And many, many of the scientists, on campus who are involved in climate change have very close connections with JPL, and vice versa.

ZIERLER: Charles, in the 1990s, given his focus on climate change, I'm curious if Al Gore took an interest in what was happening at JPL.

ELACHI: Yeah. No, he was interested, and he came to a number of our landings. Matter of fact, I had a picture of my wife shaking his hand because she was in the viewing area. I think it was either Spirit or Opportunity. I don't remember now.

He expressed interest in being there, as we were landing, because he was familiar with our work in Earth science. So, we invited him so he was in the viewing area over the mission control room. And it happened, we seated him next to my wife because she was very much into the environment and, what's happening in our environment. So, yeah, no, we had a fair amount of connection with the bigwigs in Washington, either present or past. [laugh]

ZIERLER: Charles, it's amazing to think that even in the year 2000, there were still major aspects that were not understood about Earth's topography. What did we learn from the Shuttle Radar Topography Mission?

ELACHI: Well, up to that time, basically, generating topographic maps was done by stereo imaging. You take photographs in a stereo. Then you have somebody sitting under a stereo viewer, and they delineate the contours, on it. That was a very work-extensive approach. I mean, I went once to where the US does it, and there was almost this hangar with hundreds of people sitting down and doing that. And then when SRTM came, using the interferometric technique, we were able to generate the topography immediately in digital format, completely by computers, because of taking the images and doing it. So, it was a revolution into doing that. So, we put a lot of people out of business, unfortunately. But it was the ability to get the global topography in digital format at very high resolution. And that was the era also where digital processing, digital visualization was maturing. So, in this way, for all the viewing, like when you are getting images or you want to look at perspectives of areas, like geologists want to look at perspective, you have the digital data already there.

Then we want the next step where we superimpose a Landsat image on it. So, now, it's like you are getting Landsat images but in 3D. It was used extensively in, for pilots, like flying during the night. Now, you can put in front of you a map of the area you are in, even if you cannot see, you can see where the mountains are. And, as you recall, there were a number of cases where aircraft crashed into mountains in an area which are not well mapped topographically. Now, you don't have that issue because, irrelevant if you see or don't see, you have a topographic map of where you are.

So, if you locate yourself with GPS, where you are, you can see exactly what you are not seeing, in front of you. And it's used in atmospheric science as, the wind blows, and it flows over mountains. You can model actually where the condensation happens because that happens very much at the—from topographic factor. It led to a wide spectrum of applications, which was possible before but much harder to generate that topographic map. And, now, it's, when you look at 3D images of the Los Angeles Basin when they show you on TV, what is the weather in that time, it's all coming from that system, from what we did in 2000.

ZIERLER: [laugh] Charles, now that we've worked up to the year 2000, the last theme that I want to touch on for today's discussion is the general sense of when you started to first understand that you might become the next director of JPL. So, as an entrée to that, I'll remind you in earlier discussions the way you talked both about yourself as a kid among kids, and in talking about directors like Pickering and Allen, like, these were giants. These were the big men, up on the mountain. So, the question there is, in your own mind of squaring that circle, do you have a memory, from a modest perspective? From a modest perspective, do you have a memory when you said to yourself or when you looked in the mirror and said, "Oh, my god, I might become director one day"?

ELACHI: [laugh] Well, let me put it this way. First, I mean, clearly, in the '80s and the '90s, I was not thinking about that. Up to, I would say, when I was division manager, I was enjoying doing my science, you know. And, as you said, these were giants, up there, particularly Pickering, Bruce Murray, then Lew Allen, and then Ed Stone. But Ed Stone, I was already on the executive council at that time.

And then in 1987, that's when Lew Allen asked me to be on the executive council. So, then, it started dawning on me that, gee, I'm one step away from the director. But even then, I didn't think about it very much. Then in 1990—and the thing which really kind of led to it, even though I didn't think about it, is the great success we had with scientific instruments. So, when I was in charge of science, they became even more than our spacecraft, funding wise. Then I was—I became member of the National Academy, I built relationships with all the international partners.

So, I started becoming one of the key players at JPL, and I became a figure for JPL on an international, NASA, Congress, and national basis. Then in 1990 when Lew Allen retired, and there was a search happening for the next director, I found out later that I was on the list, as potential, possible director.

ZIERLER: How do you find that information out? Who tells you?

ELACHI: I was told about it, you know. And then after, I remember very clearly, the chairman of the board—I think his name was Anderson. I don't remember it exactly. I mean, that was a while ago. I remember him calling me at home, and he said, "I want to give you a heads-up," because I was a senior, "that we have looked at you as potential director. You are still very early in your career, I mean, as the senior management, and you have an opportunity the next time, and we decided on selecting Ed Stone," which was great because Ed Stone was another one of the giants—

ZIERLER: Yeah.

ELACHI: —in the field. So, that was the time when I started kind of thinking, oh, maybe I have a shot at it. So, at that time, so that was 1990, so I was 43 years old. So, I still had another 22, 25 years before I get into the traditional retirement age. So, that was when I started thinking, gee, I might have a shot, at doing that. And, to the credit of Caltech, Caltech does think in the long-term, about nurturing the next generation. So, I had a lot of interaction when Ed Stone was the director. He was always giving me, challenging responsibility, making me more visible. When he was out of town, I used to come and brief the board of trustees about the work we are doing at JPL, or when a member of the board used to visit JPL, Ed Stone used to include me in the discussion on it.

And I remember I interacted a lot with the president at that time. His name was Tom Everhart, and Tom used to always kid me. He said, "Charles, you are the youngest person in the executive council." Two years later, "Charles, you are still the youngest person in the executive council." [laugh]

ZIERLER: [laugh]

ELACHI: So, I think, not to say that, I was sure. I mean, you are never sure how things will evolve in the future. But it was at a time where I think I was given the opportunity, and I was given the runway, to kind of show my capabilities. And that's why by the time it came to the year 2000, when they started looking, after Ed Stone decided to retire, and started the—I was pretty—I would say I was kind of running almost half the lab because of the expanded responsibility of instrument, flight, future flight mission, advanced concept. I knew the lab very well. I was very well connected at NASA Headquarters—all the way up to the administrator, Dan Goldin. I knew on a personal basis every head of agency around the world because we were doing a lot of collaborations on instrument, be it the European Space Agency, the French Space Agency, Italian, German, Japanese. I knew a lot of people on the Hill because I interacted regularly with them. When they visit JPL, I used to participate. So, I think, in a sense, being on the executive council over a decade kind of really prepared me from all aspects to be a leading candidate, for being the director, of JPL.

But, again, it was not sure because, I mean, the role of Caltech is to pick the best person they can find to help, because it's a huge responsibility, for running—not only running the lab but also the public image and the international image of JPL, and its implication to the overall Caltech activity. So, it's taken very, very seriously, both—and, a matter of fact, after when I was director, one of the key things was to keep saying how are we nurturing young people to become senior managers at JPL? Not necessarily only director, I mean, there was only one director, but there are many members of the executive council. And that was a key thing on nurturing people, and I kind of did it because, also, I felt it was done in my case. I was helped and nurtured, during—as I moved up, first, to become division manager, then to become member of the executive council. So, that was one of the key areas of focus I did when I was director is how to nurture people to move to higher position.

ZIERLER: Charles, how does the timing of it work? Is it that Ed Stone says that he's thinking about stepping down, and that's when the work begins of thinking about successors?

ELACHI: Yeah. No, that's a process for all the directors in the past, I mean, myself, before me, Ed Stone, Lew Allen. They usually tell the president at Caltech and the board that they are planning to retire in, let's say, four to six months downstream. And that had always been in the past done that way. So, that gives a chance, and then the president and the chairman of the board appoint a committee to do a search, which consists of members of the board, some members of the faculty, and some staff at JPL. And that committee then has about four, five, six months, to do the search.

They hire a search company, which kind of looks all around the country, about who potentially are people like that, collect their résumé to do some filtering. Then that search committee interviews four, five people who are the finalists. And then, at the end, the board and the president of Caltech decide on who they will appoint as the next director. Up to that stage, it's not—it's all done by Caltech without NASA's, involvement but without NASA's involvement, but at the end, they have to get the concurrence, of NASA, for the—because it's one of the NASA centers, so NASA has to feel comfortable with that person. And then, in actuality, usually, the director will announce like about a year ahead of time, when they plan to retire. I mean, it's kind of obvious a little bit from their age. But they announce it about a year ahead of time. And then it takes about six to seven months to appoint a new director. And then, traditionally, there was always an overlap of about, like, four, five months to bring the new director up to speed for that position. So, that's in effect how it happened when Ed Stone did that, and then when Lew Allen did that, and when Bruce Murray, and when Pickering, did that.

ZIERLER: Another question—

ELACHI: And when I finished, I gave Tom Rosenbaum I think nine months' to ten months' notice ahead of time, and made it public so everybody knew that, in ten months from now, there'll be a new director.

ZIERLER: And another question on timing, Charles, do you indicate your interest, or are you approached to ask if you're interested?

ELACHI: Well, the process allows people to express their interest. But, in general, people are approached to do it. So, in my case, I didn't go to the committee and tell them I'm interested, you know. I was approached, for that.

ZIERLER: So, in that moment, clearly, you know that you will be a serious contender. What are your feelings about this? Are you nervous at all? Maybe most importantly, how does your wife feel about this?

ELACHI: Well [laugh], it's a combination of nervousness but excitement also. But at this age, I mean, I—for me, through my career, I love JPL. I mean, literally, I would say, I was in love with JPL. And it was a very—I mean, I knew it would be an exciting position. And the fact that I was for 10 years or 12 years on the executive council, I got a pretty good feel of what that position entailed, both the challenges but also the reward, you know. I mean, it's really—I usually say it's the best job in the world, to be the director of JPL, and there is only one JPL, and there is only one director at JPL. And I kiddingly tell my congressman, "Well, there are 400 of you, and there are 100 senators, but there is only one director of JPL." [laugh]

ZIERLER: [laugh]

ELACHI: So, it's really, clearly, it's a very exciting, exciting position, to do. So, yeah, look, I was nervous, of course, because you can never tell that it's for sure. And my wife had kind of mixed feelings…because she—I mean, when I was on the executive council, she got engaged with a lot of the activity at JPL, so she looked at it as something very exciting. She knew I would love to do it, and she has been always very supportive, of what I'm doing. But, also, she knew it's going to involve a lot of travel, a lot of commitment, so it was kind of an interesting situation. But, anyway, it ended well, so [laugh] it was a great outcome.

ZIERLER: Charles, in making that final decision about your willingness and excitement to do this, to the extent that you created like a mental balance sheet of, on the one hand, the most exciting opportunities but, on the other hand, the most daunting challenges, what stands out in your memory as you were thinking about all of these things that would become ultimately your responsibility as JPL director?

ELACHI: Well, again, it's hard to quantify these things, again, because I watched very carefully…I mean, I was involved at the senior management at JPL for 12 years, so I had a pretty good understanding of what are the challenges. And remember, it was a time where it was just after we had two failures that happened in 1999. So, I knew it's going to be a major responsibility. And I know that, with the discussion with the board of trustees and so on, they really felt that there is a need for some rejuvenation at JPL. We had these failures, you know. We should have figured out a way to avoid them. It is irrelevant how much you support risk, there is always nervousness, about failures, and the image. So, I knew it's going to be a daunting job. And the morale at JPL kind of got a hit, because of the failures.

I mean, that's human nature, you know. Everybody will do that. So, I knew it was going to be a challenge of re-lifting up the morale at JPL, of interacting with NASA. And then, like, you always think about it, OK, you are forgiven if you fail once. You are forgiven if you fail twice. You might not be forgiven if you fail three times.

ZIERLER: Yeah.

ELACHI: So, I knew in that position, we have to succeed, on the upcoming mission, at least for a while, to get back. So, I knew there is going to be a major responsibility for it. But I thought I was pretty prepared for it, you know. I was a kind of person where, I work well under pressure because, I mean, I did—I was principal investigator on a number of these missions, which were very high-pressure missions.

So, I think my growth through JPL, and moving through the organization with more and more responsibility, kind of prepared me for the job, to be able to do that job, both from connections, from being familiar with what's going on at JPL, what are the strengths and the weaknesses. So, it was kind of natural, which kind—and even with that, I used the four months of overlap with Ed Stone that—to go and visit every organization at JPL, and to try to understand what their challenges are. So, by the first day I became director, I was ready to run with it.

ZIERLER: And, Charles, to be—so I understand correctly, you were appointed and not anointed. In other words, it was really an open position, and there were other applicants competing for it.

ELACHI: Yeah. No, I mean, it was that way. Yeah, there was a search which happened across the nation, and I got some hints of some other people who were very good, who were being considered. And then in their wisdom, I mean, the search committee and then David Baltimore, who knew me pretty well, because of the interaction with the executive council, he knew me pretty well [and he thought] that I'm the right person. And I remember David, when he made the appointment, he said, "We searched across the country, and it turned out the best person was one of us." [laugh]

ZIERLER: Charles, in both your discussions with the trustees and with David Baltimore, what were some of the most important and useful conversations in articulating your vision for JPL? That'll be our very next question for next time.

ELACHI: OK.

[End of recording]

ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It's Friday, October 15th, 2021. Once again, it's my great pleasure to be with Professor Charles Elachi. Charles, wonderful to see you again. Thanks for joining me.

ELACHI: Sure.

ZIERLER: Charles, today, I'd like to pick up on a topic from last time, and that is during the selection process to become JPL director, what was the vision that you articulated to the selection committee, and were there any sensitivities insofar as you wanted to convey your own vision without necessarily being critical of your predecessor?

ELACHI: Well, I think the main thing—and I was not critical of my predecessor at all because I think Ed Stone was a great director also. And failures do happen. It happened at the time of almost every director at JPL. So, that's not unusual in what we are doing. But the key thing—I kind of articulated, a few items, when I talked with them. One is the vision of keeping and expanding the leadership of JPL in robotic space exploration. That, as a federal lab managed by a university, and responsible for robotic exploration of the planets including our planet, it's very important that we work constructively with the science community to really strengthen the overall program. And by strengthening the program, JPL would be better. So, it's not a question of only JPL, and we are looking at our own thing, but really being kind of a trustee of the broad science community and the country's [interest in] exploration. The same way when we talk about Caltech, we don't talk about the benefit to Caltech, we talk about the benefit to science, exploration, engineering, so really taking a big picture. And I think that had a positive impact.

The second one was on inspiring the employees at JPL because people have opportunities. They are very smart people who come to JPL, and they have opportunities in many places. You want to show them that JPL is absolutely unique, and it really can achieve the vision of young kids of exploring space. So, creating the environment which encourages innovation, and gives the employees opportunity to reach the maximum of their intellectual capacity is very important, not only for the employees but it makes JPL a great place, you know. Also, because, at the end, if you have the best people, nothing else matters, and if you don't have the best people, nothing else matters.

The third one is strengthening relationships between the campus and JPL. We have a very unique capability at Caltech, and many brilliant, faculty, and building more bridges and a closer relationship was high on my priority list. The next one I mentioned is building a good relationship with NASA, and there we have to have the right balance if, one, we are looking at NASA's interest because we are in a NASA center. But we want to protect Caltech's interest, also being part of Caltech, and working a balance between the two by being constructive but firm, about Caltech's interest, and to do it in a constructive way. So, at the end, it will be a win-win situation, not a win-lose or lose-win, situation. We want it to be a win-win situation.

And the last one I mentioned, I mean, from the big ones is building a relationship with our representative and the public because, at the end, we're spending the public's money, because we are being paid by the taxpayer money, and the public could have influence on their representative. And Congress is the final decider on how much budget goes to NASA, how much goes to the planetary program. And doing that by multiple ways, one, inviting people from different organizations to visit JPL, be it students, be it senior associations, be it, Boy Scouts, and then also going and giving talks and regularly visiting people in Congress. So, it was a combination of these that I discussed, and we expanded on that, more if they asked me, specifically. And one of the questions I think one of the members asked me is what would keep me up at night? And my answer is, look, if I do a really good job, I should be able to sleep well.

ZIERLER: [laugh]

ELACHI: But, still, the concern always nagging is being, what if a failure happens? What do we do to make sure there are no failures which happen, even that the risk is there? And I told them it's very likely there will be problems during my tenure, and the question is, how do we address them, not 100% avoid it because the only way you can be 100% safe is never to fly, just sit on the ground. But to be prepared that failure could happen even that we do everything possible to avoid them, and to be prepared of how to react on that without really having a big negative, impact. And I could talk later about some examples of how we have done that.

One additional thing I just recalled is, also, because we were coming out of two failures which happened about nine months before the interviews were started is how to uplift the morale of the employees, what ideas they have about uplifting, the morale of the employees, and how to work constructively with NASA, about how to help us also, uplifting the morale, of the employees. And that requires doing some changes because when I was interviewing, when I became member of the executive council, two years—ten years earlier or eleven years earlier, I was the youngest on the executive council. And when I was being interviewed, I was still the youngest. After 11 years, I was still the youngest. I was 52 or 53 when I was interviewed.

And I told them, we really need to bring the next generation to the leadership of the lab. There are a number of members of the executive council who were retiring or planning to retire shortly. So, my intent is to bring the next generation, not only to bring new ideas but also to be the leaders over the next decade, and how to nurture leaders continuously so we are always having, the next generation being prepared to lead the lab.

ZIERLER: Charles, where were you when you received the news that you were selected, and who told you?

ELACHI: Well, it was an interesting situation because I was giving my class because I was still lecturing twice a week. So, that must have been on a Thursday. And as I was giving my class, the president's secretary walks in the office and hands me a little note. So, I looked at it. It said, "President Baltimore would like to see you after you are done with your class." So, I kind of knew it's related to the director selection, but I didn't know what the answer was going to be. [laugh]

So, after the class, I walked to David Baltimore's office, walked in his office, and he said, "Charles, I'm going to go straight to the point. We would like you to be the next director at JPL. Now, sit down, and let's chat about it." So, we sat down and chatted for an hour about, the challenges, and what's involved, and so on. But, of course, I was very excited, and David was the most delightful person, both to select me but also to work with, downstream.

ZIERLER: Was it difficult for you to give up your beloved course, the physics of remote sensing?

ELACHI: [laugh]

ZIERLER: Was that simply not feasible to continue teaching?

ELACHI: Well, at the beginning, naively, I thought, oh, I can still give my course. But after a few months after I became director, I realized that's not realistic, because, really, the directorship at JPL requires full-time attention, a lot of travel. Matter of fact, David told me that. "You're going to be traveling a lot, both internationally and in the US." So, shortly after that, I was appointed in January. So, by the summer, I decided—I had my previous TA, who was also continuing to be my TA during the teaching, and he became a senior manager at JPL. His name is Jakob van Zyl. So, he took over the class, and continued the class for, like, 20 years after that.

ZIERLER: Charles, was there anything significant about the confluence of timing between your being named director, and the incoming Bush administration?

ELACHI: That's kind of interesting because, yeah, when I became director, when I was appointed, it was the beginning of the Bush II administration. There was nothing—no correlation between the two. Maybe the more important thing was the engagement of the NASA administrator who was appointed during the Clinton administration. His name was Dan Goldin, and he was renewed during the Bush administration, and he stayed for about a year or a year and a half after I became director. And to his credit, I mean, Dan Goldin was one of the most imaginative people I ever met, out-of-the-box thinker, moves at 10,000 miles an hour, loves advanced technology. And I had interacted with him before I became director, a fair amount, because, as I mentioned previously, I chaired a couple of committees after there was a failure in the Mars, the Mars Observer mission, about eight years earlier.

And to Dan's credit, the meeting with Baltimore happened on January 28th. He said, "We are planning to announce it on January 30th." So, they were preparing the announcement and the public release, and they were ready to send a note to the employees saying that David Baltimore will be coming to JPL to announce that. And Dan Goldin sent an email, saying, "Well, can you delay it by one day because I'd like to be present, myself?"

So, it was delayed to January 31st at 11 o'clock. Dan Goldin showed up. So, here, first David Baltimore and Dan Goldin came to the meeting of the executive council to give them a heads-up. And then at 11 o'clock, we walked down to von Kármán auditorium, which is the main auditorium at JPL, and all the employees were there, and that's when David announced it, and then this was followed by a talk by Dan Goldin, and then I gave my talk. So, it was a great day. Of course, after David Baltimore told me, and I left the meeting, I immediately called my wife to tell her about the big event. And that evening, I called my two daughters [laugh], to tell them about it. My wife was very excited because she knew that was very important for me. My daughter, the older one was very excited because she had lived through it. The younger one was still in high school. She said, "Oh, Dad, that's great," and that was it. [laugh] And she was very excited about it also.

ZIERLER: Charles, to the extent you've thought about it much, had you not been selected, what would your plan have been? Would you have stayed in your role at the time at JPL?

ELACHI: I don't know. That's hard to say, what you have done because I tend to always think of the positive part of things. So, I really didn't think about what I would do. I mean, I love JPL, and I most likely would have stayed. But [laugh], interesting enough, just a few months before the selection, I got an email from a distinguished university asking me if I'm interested in being the provost. So, I sent them back an email telling them, "No, at this time, I'm still waiting, for the JPL selection on doing that." So, I didn't think much about it.

I had no doubt if I was not happy in continuing, I would have had a number of opportunities. And even when I was director, I got a number of exciting opportunities. I was approached by a number of search firms, but I told them, "Look, the best job in the world is being the director of JPL [laugh], so I'm not interested."

ZIERLER: Charles, in addition to the official channels for people advising you as JPL director, did you think about having what we call a kitchen cabinet, an informal group of colleagues within and outside JPL that you could consult, you could bounce around ideas, even vent if necessary?

ELACHI: Well, yes and no. I mean, it was semi-formal but it was a group. So, when I became director, immediately after, I formed an advisory board, which consisted of about 20 people, mostly external, some of them from the campus, but the majority of them external. Some of them were previous heads of the space science at NASA Headquarters. Some of them were previous directors at other NASA centers, leaders in the science community, CEOs from companies.

And that group used to meet twice a year—we used to brief them on all the issues and the challenges, and they used to give me their assessment. And then I use some of those individuals informally. I used to call them, to get their advice, or when they visited JPL, they used to come, and we used to have lunch, in my office, and talk about the challenges. So, it was a combination of a formal and informal kind of advice group. So, it was, in a sense, a broad kitchen cabinet. And, of course, I had the executive council at JPL, who were my leading kitchen cabinet, if you want.

ZIERLER: So, the day is February 1st, 2001. What's top on your agenda? What's the most important thing to deal with?

ELACHI: Well, clearly, it was very exciting. I mean, it took me a few days to kind of come down from the clouds. And then the first thing I did, after that is I asked Ed Stone that I'd like to step down from my formal position as the head of the science and instrument and technology at JPL, and have my deputy act in that position. His name was Larry Simmons: very, very experienced person. And I want to spend the four months between February 1st and June 1st, which is the official—sorry, May 1st, which is the official date of me starting, just meeting with employees at the lab, and meeting with people outside to get the general feel of what the challenges are perceived by other people, any recommendation they have.

So, I spent those—February, March, April—those three months where I went to NASA Headquarters, and I talked with different people at different levels about their vision. Where do they see the lab going? What do they recommend? I went, talked with a number of people in Congress also about how do they see particularly our congressman—David Dreier at that time—and our neighborhood Congressman, Adam Schiff? Spent time with them. Went to OMB, Office of Management and Budget, talked with Steve Isakowitz, who was in charge of the NASA budget. And then internally, I went and met with every organization at JPL in groups. So, effectively, I reached out to every one of the 6,000 employees, to hear what's their vision, what's their dreams, what—where do they see the issue and the challenges at JPL and how I can be of help to them? Now, many of those issues I knew because I've lived through JPL. But also seeing it from the employees' perspective was very important.

And the other side of it, the employees really appreciated that, that here I am, coming, taking their opinion about, what are the issues that they see. And, of course, I got a whole string of issues from administrative paperwork. It takes too much to get something done, parking—

ZIERLER: [laugh]

ELACHI: —is a challenge, to big things about the missions that we are doing. So, it was probably a very, very valuable three months. So, by the time I walked in the director office, in actuality on June 1st—not May 1st, sorry—on June 1st, I started moving very quickly. And the other thing which took some effort is the deputy director under Ed Stone, Larry Dumas, was planning to retire shortly after that. So, I also went with some members of the board of trustees and the administration at Caltech to start looking for a deputy director, fairly quickly, to do that. And one of the things I remember during that period, Kent Kresa was the chairman of the board of trustees, and he was the CEO of Northrop Grumman, as well as Bobby Inman was the chairman of the search committee. Both of them told me, "Charles, if you want to any chat or seek any advice, we are available to you." So, I took advantage of that. Gail Wilson also was on the search committee and on the board. And I remember going and having lunch with Kent Kresa. The Headquarters of Northrop Grumman at that time was in Century City. And he generously spent two hours with me, talking about his style of management, and what advice, he has for me.

ZIERLER: Of all of the big things that the employees talked to you about during your listening tour about the missions, what were your hearing? What was most important that the rank and file of JPL were conveying to you?

ELACHI: Well, a couple of things. One, I mean, they wanted to get over those two failures that we had. So, for them, it was important to create an environment an uplifting environment. They wanted to hear my vision, and, of course, they added to it. I mean, they are smart employees. So, I laid out, what areas, and what part of the vision I had—because, also, I mean, the employees, they want to do something exciting but they won't see opportunities of things coming in, of future mission.

And, particularly with the new administration, people were nervous a little bit, about—because every new administration sits down, and particularly moving from a Democratic to a Republican administration, they always review all the programs, and they want to change this, and cancel this, or add these things. So, I had to assure the employees that, look, I have been talking with people in Congress. We have very strong support, and I'm optimistic about the future. And the other one was that, look, one other thing I have as a vision is to really expand the portfolio of JPL so it's not relying [exclusively] on planetary work but also is very active in Earth science and astrophysics and in technology. And by having this broad portfolio, still all space exploration, but having this broad portfolio, we have more resiliency against things moving up and down. Because in general, NASA budget was pretty stable. It's the emphasis, you know.

Do you do more planetary? Do you do more Earth science? Do you do more human? And by having this diverse portfolio of, leading missions, that will give us more resilience. Yeah, there were a number of employees who loved doing Earth observation, also, so they loved that message. There are a number of employees who loved doing technology. So, it's not everybody who's doing planetary, at JPL. So, all the other ones were, also were excited about broadening the portfolio. And that was the time when we just started working on Spirit and Opportunity. So, we talked a fair amount about how we make sure those missions will be successful, what is my approach about improving, I mean, improving our ability to do successful missions.

And a key thing which came out from the employees is that they felt on the previous missions—the two which failed—that even that we had a top-notch team working on that, that there was a lot of pressure from Headquarters on schedule and budget. I mean, schedule is driven by the planets, by the orbit. But on the budget, there was a lot of pressure, which led to basically fewer people doing checks and balances, and that what we believe led to those failures. So, I assured them that I intend to take a very proactive approach to make sure we get the appropriate funding and the appropriate personnel, I mean, number of personnel to make sure we are successful, particularly on the upcoming rovers, Spirit and Opportunity, because those were going to be, if you want, our way of getting out, of, the discouragement which happened, from the failures. And the employees loved that message. And two other things I told them, look, I'm going to be very reachable so I can hear always your issue. Number one, this is my email address. any one of you can send me an email. I'll make sure either me or a member of the executive council will respond.

And number two, I intend to come and walk around the lab on a regular basis and hold at least two all-hands meeting a year. And then I intend at least—because an all-hands meeting is too many people—I intend to come and meet in smaller groups on a regular basis, like once every couple of weeks, and kind of rotate through the whole lab. And people believed me because I used to do it when I was on the executive council. I used to be proactive in going and visiting the people working in my directorate.

ZIERLER: Charles, in thinking about long-range planning and research for Mars with Spirit and Opportunity, and in light of, more recent talk from people like Elon Musk about terraforming and colonizing Mars, was anybody 20 years ago thinking about JPL as the first in to that long-term mission?

ELACHI: Well, sure, I mean, the people at JPL are very visionary, out-of-the-box, and they come to JPL because they want to explore space. But, also, they are reasonably realistic, you know. I mean, they all have work on mission, particularly the people who have been there for a little while, and they know the challenges about doing some of these things. So, even that in our long-term vision, we were looking at, inhabiting Mars, inhabiting the planets, terraforming, but they were realistic on their timeframe of when that can be done. Elon thinks that he's going to —inhabit Mars in the next four, five years. And I kept telling him, "Elon, I love your vision. But we are the only people who landed things on Mars, and even they're only robots. And we know what's the challenge of doing that. So, be more realistic [laugh] about the timeframe of doing that."

It's all feasible. It's all possible. But the timeframe is going to take a fair amount, you know. It's in the decades, not in the year of inhabiting, Mars. Exploring it with robots, yeah, it's within our reach, and we demonstrated that with Spirit and Opportunity and Curiosity and, more recently, the helicopter and Perseverance. So, robotically, we know how to do that, and explore, Mars. With a human, it's going to be a little while.

ZIERLER: Charles, to the extent that there's a real distinction in motivation from an organization like SpaceX, which looks at colonizing Mars as a plan B for humanity, right, that we need someplace else to land if human civilization is going to continue, and you compare that with, for example, Blue Origin, whose institutional ethos is much more, "We're going to outer space because we're going to make long-term habitability of planet Earth much more feasible," to the extent that JPL has an institutional ethos about these things, where would you put JPL on that range?

ELACHI: Well, I think both of are great visions, to do in the long-term. And both organizations came and consulted with JPL, and both organizations have a number of [former] JPL employees who went to those organizations. But I would put my priority, both when I was at JPL and now, that, first, we need to make sure we take good care of our planet, you know. This is the only planet in the solar system where we know humans, are committed for the long-term. And the next step is to live in space, but it's going to be limited, in space. I mean, remember, we have eight billion people on this planet. We'll be lucky over the next 20 years if we can put a couple of hundred, maybe a few thousand living in space, and about Mars, to have a place where you can have in the next 30, 40 years to have a few hundred or maybe a few thousand people. So, to think about Mars or space that's going to be our savior from a catastrophe happening on our planet is somewhat unrealistic. It's a great vision, and it is for maybe five, six generation from now. But in the foreseeable future, that's not credible.

So, really, I always say our first priority now is make sure we save our planet. We make sure global climate change is, is manageable to make sure we—global warming, you know—we take actions on reducing, the emission of gases in the atmosphere. And NASA can play a major a role, and is playing a major role, and JPL and Caltech are playing a major role in that area. And then the next step is, even if global warming continues, is how do we manage our life here on it? I mean, how do we kind of adjust to it? And we're doing research in that environment, doing research on avoiding asteroids coming and hitting Earth by monitoring it and then diverting it. So, all of these are activities which should be going first, and are getting a lot of attention, and there is a lot of innovation in doing that. So, for the foreseeable, I would say, many decades, that's a primary thing. Having said that, we need to keep in our mind also to work both for scientific exploration, for commercial exploration, and maybe ultimately to expand the environments where humans can live. But that's a very long-term goal, and I wouldn't put it as a high priority at the present time.

ZIERLER: Charles, one of the first missions after you were named director—we talked about this a little previously—was the Keck interferometer. This was happening at a time when LIGO was really ramping up. Did you see any special opportunity in the field of interferometry to combine all this brain power at JPL and Caltech?

ELACHI: Oh, absolutely. Matter of fact, one of the missions we started looking at, almost even before I became director, but I put emphasis on it as director, is to do a LIGO in space, because even though LIGO at that time had not detected yet gravitational waves but it was a big project on the campus. Matter of fact, they brought some people from JPL who had project management experience to help on the campus with it. And the next vision was that we want to do a similar thing but in space because in space, you can get your baseline much, much bigger, than, I mean, the interferometry baseline much bigger, and then space is much quieter than here on Earth. So, it allows to improve the detection. But it was a huge challenge because, again, remember, we're talking about measuring distances between platforms down to the atomic-size level.

So, we put a big investment on developing technologies, and we spent a lot of effort at JPL in developing technology to prepare us, for doing a space mission. And we had a lot of collaboration with the campus. One of the first people we worked with on the campus was Tom Prince, who was a professor in astrophysics here at Caltech. Matter of fact, shortly after that, after I became director, I knew Tom before, and I was so impressed working with him that I asked him to come and be the chief scientist, at JPL. So, yeah, no, we were very involved. And as I mentioned earlier, the concept of interferometry was very familiar to us at JPL because one of the techniques we used to enhance our communication with our spacecraft as they go deeper and deeper in space is to combine the signal from multiple antennas, receiving antennas by combining them effectively in interferometry. By combining that, it allowed us to get even more signal and more sensitivity to detect. And now it's very common. we use, five, six, seven antennas as interferometer, and we combine the data from all of them.

ZIERLER: Charles, tell me about the selection of Eugene Tattini as deputy director.

ELACHI: Yeah. That was one of the first, matter of fact, probably the first appointment I made, because still before—during the transition period, as I mentioned, Larry Dumas told me that he's planning to retire shortly after I become director. So, we formed a group of people, a couple of members of the executive council—a couple of members of the board of trustees, a couple of members, of the staff, senior staff on campus, and we started looking.

And then, I remember one day, a member of the executive council by the name of Mike Sanders—he was in charge of technology and some of our DOD work, which was with the Air Force—he came to me and said, "Charles, I just heard that Gene Tattini," who was the commander of the base down, in Redondo Beach, which is the Air Force base which is the equivalent of JPL for the Air Force—they did all the Air Force launches, all the Air Force missions—"that he's retiring." And Mike Sanders said he knows him or about him, and he's a great guy, and he could be a great candidate. So, it didn't take us long to contact him, and Gene came over. So, I had a meeting with him, and I was very impressed. He was very—he was still—he was going to retire like a few weeks after that. So, he walks in with his military bearing and with three stars, so that's impressive a little bit. But I was more impressed with his personality. He never worked in the civilian. He worked all his life in the military. So, he told me about his experience, what he could bring to JPL. He was a big fan of JPL, even though he had only [visited] once or twice. But the technology work we did with the Air Force impressed him a fair amount, so he came and met with David Baltimore on campus.

And, also, it turned out that Kent Kresa, the CEO of Northrop Grumman, knew him very well because Northrop Grumman did a lot of work, for the Air Force. So, it was a perfect timing, from all aspects. And, we made him an offer, and he started, I think, in August of that year, so only like about a month or two months after I became director. And also, we did a transition period between him and Larry Dumas. And I'm so glad I selected him because he was the perfect deputy director, you know. He basically did a lot of the internal managing for a large organization. Matter of fact, the air base, in El Segundo where he was—it was about the size of JPL, both budget-wise—maybe budget, it was somewhat bigger, but the number of people was about the same. And we relied a lot of Bundaberg to do our launches. So, the transition was fairly, fairly smooth, except for, him calling me, "Yes, sir, no, sir."

ZIERLER: [laugh]

ELACHI: Like, being on campus, they call me Charles, you know.

ZIERLER: [laugh]

ELACHI: But it took him a while [laugh], even now when I talk with him, I guess that's the training, in the Air Force, and it took him a little while to get a little bit more relaxed about debate and argument in the executive council. But the employees loved him because he had a very genial personality. And his wife, who is called also Jene, and my wife got along very quickly together, so it was a great choice.

ZIERLER: Charles, with the launch in July of 2001 of the earthquake monitoring program, was it important for you as the newly named director to have a program that was valuable in the here and now, on planet Earth?

ELACHI: Yeah, no question, because my background was heavily related to Earth, or most of my personal research was Earth in addition to Venus and Titan. And with Caltech being a major player in the area of earthquakes, monitoring earthquakes, and seismology, it was a double whammy, JPL helping with this technology, and building more relationships with the campus. And living in California, matter of fact, a major fault passes, I think like 10 yards from the building where I was [laugh], where my office is. So, we're always very sensitive about earthquakes or about any capability which can enhance our ability to survive earthquakes to be able to monitor them. So, yeah, no, that was clearly always one of the exciting things to look at for our planet, and to improve life on our planet.

ZIERLER: And given that you no longer were able to teach the class on remote sensing, was this a way for you to stay involved in remote sensing for such an important area?

ELACHI: Well, yes, and, in actuality, almost everything we did had remote sensing in it, because every satellite we launch has cameras or radar or imaging spectrometers or instrument which actually do remote sensing. So, effectively, even that I didn't do it technically, but I was still heavily involved, in all the remote sensing because every mission had remote sensing instruments on it.

ZIERLER: As director, would you have opportunity to interact directly with PIs, for example, Don Burnett and the Genesis mission?

ELACHI: Oh, yeah, absolutely. I mean, that was a high priority because, as I said, one of my philosophies was that JPL is a trust given to us by the taxpayer to help the country in general, and the science community in particular, to achieve their vision. So, I made the point of regularly meeting with leading scientists, and then I made the point to meet with every PI that I worked with individually. And, of course, Don being from campus, that was one additional, aspect of it. But I made sure to meet with every PI, to understand the issues. How can I help them at JPL? How can JPL be more help? And it had two aspects. One aspect is we want to make sure our missions are successful, scientifically as well as engineering-wise. I mean, clearly, JPL's job was to get the spacecraft to the planet and—but it's not a success unless we get all the science from it, and that's what the PIs—either for the overall mission or for the individual instruments.

The other part, as we were getting into a more competitive environment, we want the best scientists to immediately think of JPL when they are proposing, be it for instruments or be it for missions. So, building a goodwill relationship with the leading science members or the broad science community was a very high priority. And that's one of the key roles of the chief scientist was to regularly interact with them, and to always survey them about how good JPL is with them. How are we, serving them? Are they—do they have issues? And we made sure that every PI would have a badge to enter JPL, as any JPL employee—we call them affiliates—really to give them the [feeling] that they are part of the family, not just some outside scientist visiting, but they are part of the family. And a number of the PIs, we had them come and spend many weeks at JPL as visiting researchers.

ZIERLER: Charles, there are many questions I'd like to ask about September 11th for you. Let's start first at the very beginning. Where were you when it first became apparent that this was not an accident, and it was a terrorist attack?

ELACHI: Yeah. No, that, I have my memory very clear because that happened basically four months after I became director, and two months after Gene became deputy director. No, I remember, I was at home, early in the morning, and I get this phone call from a friend of ours. Her name is Andre Helou. We are very good friends. They live not too far from us, and her husband is at Caltech, on the faculty at Caltech. And she said, "Charles, turn on your TV. There is a catastrophe happening in New York." So, I went and turned on the TV, and the first picture was the tower with smoke going out of it. And shortly after, they were replaying the airplane. And I immediately realize this is a major, major issue. So, I immediately got dressed, and headed to the lab. And I called Gene Tattini in the meantime, so he and I met, including the security people at JPL, because we were—very quickly, we started being concerned about how broad is this thing, you know? And the news was really making it, a couple of buildings, and then the Pentagon, then the other plane which crash.

And the other concern we had was [determining if] there any JPL employees flying on those aircraft because some of them were coming from Washington, and regularly almost every day, we have JPL employees flying back and forth. And then, immediately, Gene Tattini told me, we got a call from the FBI, and said, "JPL, you really [need to] take appropriate action because the three biggest, highest-visibility places in Los Angeles are LAX, Disneyland, and JPL. And if a terrorist want to get on the news"—because that's what they were trying to do is to get a big impact—"you have to be very careful. These are probably the highest targets." So, immediately, we met with the security, and we agreed to send the employees home for that day, just to be on the safe side. We effectively closed the lab, except for essential workers for that one day. And then immediately after it, a couple of days after that, because we were concerned…I mean, people were depressed and angry. I mean, I was angry about all that was happening—concerned about the safety of the employees, I had an all-hands meeting a little later that week in von Kármán, and emphasized to the employees, one, how terrible that situation is. But we need to keep our spirit up.

But the other one is to make sure we treat all of us as Americans because there are many immigrants, and a number of immigrants were from the Middle East. So, several them told me they were concerned about what the reaction is going to be from their colleagues. So, I emphasized to everybody that, "Look, we are all Americans. We are all part of this country. We all love the country here, and we ought to treat everybody, with compassion and respect." And, also, we had our human resources, which had a couple—they have a couple of people for trauma or when there are some serious issues—and we told the employees—because many people were shocked about it, and very saddened. So, we gave opportunity for the employees to go and talk with people, about that. So, yeah, no, that probably was one of the biggest challenges I faced, nontechnical, if you want, challenges, after I became director.

ZIERLER: Were you in contact with NASA Headquarters? What were they saying?

ELACHI: Well, absolutely, I mean, they were concerned also, being—I mean, they knew from the FBI that, JPL could be a high-visibility target. So, they wanted to make sure, that we have the appropriate security at JPL. We coordinated with them about sending employees away. And NASA has an office at JPL, so they have a few NASA employees at JPL, which are involved in our contracts and agreement. So, we met with them, and we—for a few days—we had some careful security. And then after, NASA established more and more security, like what happened across the country, particularly for federal facilities because JPL, even though we are managed by Caltech, but the facility is a government facility. So, it's like entering on a federal facility when you go at JPL. And there is—there was concern, about if any damage would happen. We have a control center which monitors all of these spacecraft around the world, so we always have a backup place remote from JPL in Azusa in case of earthquakes, as a backup in case there is damage. So, we made sure that that facility is properly staffed in case there is any damage at JPL because we didn't know what's going to be the next step. Nobody knew what's going to be the next issue which could happen.

ZIERLER: Charles, did you see in the immediate term any role that JPL could play in securing the United States during this time of crisis?

ELACHI: Well, after that, there were a number of things related on using some monitoring technology, that we have developed at JPL, like imaging along the border, or any of those kinds of technologies. That's not our field of involvement. But some of our technologies were applicable. Some of the imaging spectroscopy to look at, or X-ray imaging for security at airports. So, it was not our major activity, but we talked with a number of government organization about what technology we had which could be of help, of help for them.

ZIERLER: Charles, you've mentioned many times that JPL and NASA is one of those areas of soft power that can serve as a way of uniting humanity. I wonder if after September 11th, and all of the discord and all of the fear, redoubled your resolve as leader of JPL to use JPL as a means of uniting humanity?

ELACHI: Yeah, absolutely, because, we had many international contacts. So, we proactively continued and expanded our international collaboration. But, also, [engaged in a] program with the State Department where a number of our employees were going to consulates or embassies in many countries around the world, to talk about the benefits of the space program. So, we had a number of employees, half a dozen employees that the State Department via NASA called on us, as well as other NASA centers, called on us to actually send employees to give talks, show how this could benefit, not only because of the terrorism but in general, I mean, creating, as you said, soft power and goodwill.

One example, like remote sensing, was we became aware that it could be useful in monitoring areas like in Africa where malaria could expand in swamps and so on, and we could monitor this from space and provide that information. So, NASA developed a program and JPL was part of it, and not only tell these different countries about what space can do for them, but also to train some of the locals to actually be able to use that data, and apply it, internally in their country. So, yeah, there was a significant expansion. I wouldn't say only because of 9/11. But 9/11 kind of emphasized the importance of showing goodwill relative to the rest of the world. And I made the point myself as I was visiting different agencies around the world who we collaborate with to actually tell them, "Hey, look, I'll be glad to go and give talks at local university or local organization." And I regularly did that, for the public, you know. Like, every time I went to Australia, we give a public lecture, in Canberra, and the same thing in Madrid. The same thing of any other organization that we worked with, to go and give public talks—myself or any of the other people from JPL visiting. And I believe that created a lot of goodwill, for the US, or strengthened the goodwill for the US.

ZIERLER: Were there missions that were delayed or even canceled as a result of 9/11?

ELACHI: No, I don't recall of any mission which was canceled, as a result. Matter of fact, during my tenure as JPL director, I don't recall any mission which was started and then got canceled. Some of them got delayed a little bit, but it was purely driven by budget profiles. But, in general, the funding for NASA stayed pretty good, during that period. And, as I said, we had very good friends on the Hill, you know. David Dreier was a very, very senior member of the Republican delegation in Washington. I think he was like the number three, in the—in Congress under the Republicans. And he was very engaged. He used to come and visit JPL regularly. I used to meet with him all the time, both at JPL and when I was in Washington. And then we had Adam Schiff, also played a key role. Matter of fact, he ended up being on the committee which oversees the NASA budget, as a member of that, committee. So, we had both Republicans and Democrats who were very good friends at JPL. And when it came to JPL, they worked together, very well.

And not too long after that, John Culberson from Texas, who was a Republican, became a member of that committee, and later became chairman of the Appropriation Committee, which oversees NASA. And even though he was a Republican, Adam Schiff was Democrat, when I used to go to Washington, they both used to meet with me, and invite me for lunch, where the Congressmen actually have lunch. So, when it came to NASA in general, and JPL in particular, I think we had bipartisan support in the House. And Senator Dianne Feinstein, also in the Senate, was a very strong supporter, and a kind of regular visitor—not as often as the Congressmen, but she regularly visited JPL. So, people appreciated on the Hill the value of JPL, both as an organization but also as contribution to the overall exploration and Earth observation that NASA was doing.

ZIERLER: Charles, as you well know, in the aftermath of September 11th, one of the really dark chapters in American history was the discrimination and hatred, or even worse, that so many Americans of Middle Eastern and South Asian descent experienced. For you, as one of the highest profile Americans of Middle Eastern descent, did you see an opportunity for leadership beyond JPL to demonstrate the opportunity that this country gave you, and the love that you felt for this country?

ELACHI: Yeah. No, absolutely. So, in all my talks, that I gave, I always said a few words about my background. And I always said, I'm Lebanese, I come from the Middle East, and I'm so thankful for this country for welcoming me with open arms here. And, matter of fact, it was a few years after that, I was approached by the Washington Post. They were doing a series about what immigrants contributed to the United States. So, I wrote an article about how I came from a small village in Lebanon, and I became a leader in space exploration thanks to this great country. And I have that article just outside my office on my wall because I'm very proud of it, and I use it regularly. And many people saw it, and many people sent me emails, about how I appreciate. So, I would say, one, I was proactive playing this role. I really did not see any discrimination whatsoever.

There was only one incident two days or three days after 9/11. I got an email from an employee who was angry, frustrated. And the employee, the email said, "Yeah, I know you are from the Middle East, and, I wonder, are you on our side or their side?" So, it kind of irritated me, to be candid with you. But I responded back to him, quietly talked with him. So, I told him, "Look, I became a citizen by choice because I love this country, and I consider myself American like everybody here. And my allegiance is to the United States, no doubt about it, no question about it." And then he sent me an email thanking me, and apologizing that he was really angry, depressed, frustrated about what happened, and I understood that. I was sympathetic toward it because I was angry with the people who really did that, and about the negative images they gave about the Middle East and about the Muslim religion because we had a number of people who were Muslim at JPL, a number of them, even though myself, I was Christian. But I had a lot of friends who were Muslim. I know how compassionate they are. They are like anybody else. And I pointed out when we had discussions about it that, look, there are extremists in every religion. It's not only unique to the Muslim religion. I mean, not too much before that, I mean, there were all the issues in Ireland, Catholics and Protestants, fighting against each other. In the Balkans, Orthodox and Catholics fighting—and Muslims fighting against each other.

So, I emphasize that, look, don't take extremism to reflect on any religion, you know. There are peaceful people in every religion, which is the overwhelming majority, and there are extremists in every religion. We just have to work on getting rid—at least not necessarily by killing them, but really by educating them extremism, that none of the religions [really] support that. And many countries in the Middle East were very sympathetic with the US in what was happening because of 9/11.

ZIERLER: Of course, President Bush was very careful to delineate exactly that point, that the War on Terror, and the response to 9/11, was not a war against Islam or against Arabs. Did anybody in the Bush administration reach out to you from a public relations perspective to emphasize this point?

ELACHI: Not directly, not directly. But people at NASA, I mean, they all knew that I'm Lebanese, you know. And many of them, did tell me that we really have no issues with people from the Middle East, or any religion. I mean, most of them knew I'm Christian because my first name is Charles, so that kind of—anybody who knows the Middle East, would know that. And, matter of fact, when—not on purpose but—a number of the people, as I mentioned earlier, went and visited many countries around the world, and gave talks about what we do, Muslims...because a number of them came from the Middle East. And we kind of—not uniquely—but we arranged it in a way that some people from the Middle East were Americans working at NASA to go back to countries in the Middle East, and talk about what NASA is doing, because then people associate with them a little bit better, on doing that. And we had—I don't know the number because we never asked people their religion—but I would say there were a few hundred people at JPL who were born in the Middle East who were working at JPL. And they could be a mixture of Christian or Muslim or Jewish, but, I mean, because we never asked their religion. So, we had a reasonable mixture of people coming from the Middle East who were immigrants, and who were then working at JPL.

ZIERLER: Charles, to hearken back to your earliest days at JPL, 30 years prior, where, as you painted the picture, you could just walk into JPL, and there was—security, if it existed at all, was quite lax. What changed as a result of 9/11, which obviously needed to happen for JPL's security—was anything lost in the new heightened security environment?

ELACHI: Yeah, unfortunately, yes, there have been a number of things lost, but it was necessary to do that. I mean, clearly, there was a question of security of the facility, and security for the employees. I mean, the last thing in the world I wanted is something exploding at JPL, or somebody being hurt at JPL. And even though I had full trust in the JPL employees, but all it takes is one person going nonlinear. It doesn't have to be a terrorist, but somebody who got really upset about what's happening, gets mad at a colleague, and who could do some damage. So, yes, we had to increase the security, so a couple of things going from the soft to the hard. I made sure, particularly for a couple of years after that, every time I talk, to emphasize that we are all part of one team. We are all Americans, and we welcome immigrants. We welcome our foreign nationals who come and visit, because always we had foreign scientists coming and spending time at JPL, and that is very important. And, of course, we increased the security, at the gates at JPL, and particularly entrances to key buildings, like where we had the mission operation. And then a few years after that, part of the overall NASA and the country's security, like what was happening at airports and everywhere, we had to do some background check for our employees. And it was fairly soft. And that upset a number of employees because everybody said, "Well, we're part of the university." But I kept reminding them that we're at a federal facility.

ZIERLER: And to be clear, this was coming from you, these directives? This was not from Caltech or from NASA?

ELACHI: Oh, no, it came from NASA, you know. I mean, NASA added that requirement because it's their facility. But they said, "JPL, we rely on you to implement it." So, it's not that they sent guards from NASA, but they relied on the JPL security to get through that process. And, yes, we had discussions on the campus. I talked with David Baltimore about it. And a couple of the faculty were not happy about it, because, again, they emphasized that we are an educational institution. So, I actually came and met with a couple of the faculty who were very strong against it, and I explained to them the rationale that this is federal facility, and access to it had to be controlled. I mean, now, it's not an issue at all, you know. I mean, every faculty, I mean, anytime you go into a federal building, you have to show—either you have an escort, or to show some kind of a badge, which shows a security background on it. Because, also, some of the faculty wanted to go to JPL regularly, so they had to go through the same, process, of doing that. But I would say the overwhelming majority thought that was perfectly appropriate.

Matter of fact, a very good test [laugh], I did, I went to my two daughters, and I told them, "Look," I mean, they were younger, "these are the questions that we have to fill the form in there. Do you think that's intrusive?" [laugh] And I remember my younger daughter said, "Well, I'm sure everybody has my social security number. Every time I go to the bank, or I go to the doctor, I have to fill in the social security. I don't see anything intrusive." And that was the early days of, Facebook or the equivalent. I don't remember. So, for her, for a young person at least, that's part of normal life. There is nothing—there was no question more intrusive than when you go to the doctor's office, or you go and fill an application for a loan or anything of that nature. But people who were older, who were not accustomed to this, that was a bigger issue for them.

ZIERLER: Charles, when did you first get notice that Dan Goldin would be stepping down?

ELACHI: That was about—it was about a year after I was director at JPL. It was on—we used to have weekly meetings every Monday morning, all the center directors with Dan Goldin, and the senior people at NASA. It was an hour-long meeting. It was done, via video, and that's basically to talk about the big issues which are happening. And during one of those, Dan Goldin said, "I just informed the president that I'm planning to step down as the administrator at NASA." I was not very surprised, because he was the longest serving NASA administrator. He was appointed, in actuality, by the Bush I administration, then during the Clinton administration, then it was the first year of the Bush administration. I don't think there was any issue with it, after 12 years, being the NASA administrator. And I remember many times, I talked with Dan, and we became good friends, continued, and, even until now, we are very good friends.

And he was telling me, "It had a lot of demand on my family," on—particularly on his wife, with all his travel. He used to go to every launch, traveling around the world. So, it was kind of like the JPL director but maybe more intense, that, that they really had—it—12 years was long enough, he felt of doing that. And there were a lot of things which happened during his watch, great—I mean, there were some failures but also great, great advances which happened during his watch.

ZIERLER: How did you go about establishing a relationship with his successor, Sean O'Keefe?

ELACHI: Well, that was interesting. So, Sean O'Keefe came, and he had no background in NASA, and no background in technical areas. But he was a very friendly person. So, I remember, at the beginning, it took some while to get to be comfortable, and meet, with him, discuss with him. He came and visited JPL, so we explained to him. And it turned out Sean O'Keefe had a good relationship with Bobby Inman, who was on the board at Caltech, because Bobby was an admiral in the Navy—retired admiral—and Sean O'Keefe for a while served as the secretary of the Navy, also. So, they knew each other pretty well. So, Bobby was helpful, in the discussion. But it took, like any time you have a new person, particularly where they don't have that background. And it was interesting that then it ended in an intense discussion, because I think a year or two after Sean became the administrator, then there was discussion about the Caltech contract because every five years, we had to renew the contract. And up to that time, the Caltech contract was renewed almost automatically.

With Sean coming from more an administrative, contracting, background, said, "Well, why should we renew it automatically? Why don't we compete it?" And that took us aback, I mean, I have to say, both at Caltech and at JPL. So, we sat down, and had a number of discussions, and, for a while, he was serious about competing the contract. And we had to explain to him the benefit of the campus doing that. I remember preparing a brochure about what the Caltech campus is bringing to the table, interactions with the faculty, joint activities. And then Sean said, "OK, I'm going to have my friend in legal counsel"—his name was Paul—I can't remember now the second name. Very nice guy. So, I end up spending the time meeting, with him. And he came a couple of time to JPL. I explained to him the benefit of the campus. And then at the end, they agreed, to go ahead and do a single-source contract.

And, interesting enough, then, not too long after that, there was the accident, the shuttle accident, which happened. And everybody was saying, oh, NASA lost its recipe…the vision of NASA, NASA became too bureaucratic, you know. And it was really a very depressing and negative thing for NASA. And Sean O'Keefe here was really hurt with all of this, which was happening on his watch. Then shortly after that, we had the Spirit and Opportunity landing. So, that kind of flipped Sean O'Keefe on thinking JPL is the greatest place, and working with Caltech is a great thing, and they did the right decision, about continuing. We were in the middle of developing those two rovers, and having a new contractor coming and managing JPL, that would be a big perturbation, for the development of the rover. So, in effect, we were Sean O'Keefe's savior, and he mentioned that, because after we landed Spirit, the following day, on every newspaper in the US was a picture of Sean O'Keefe smiling in the mission operation room. And he said, "Charles, man, you saved me. You guys at JPL"—

ZIERLER: [laugh]

ELACHI: —"saved me." And then he told me later that he got a message from President Bush, saying, "Sean, it's good to see your face smiling, on all these newspapers." And after that, he fell in love with JPL, and we built a very good relationship. Even until now, we are good friends. He's now back at Syracuse University, and we still communicate regularly.

ZIERLER: To be clear, when he was thinking about competing the JPL contract, this was obviously at a time when he was looking to eliminate the $5 billion cost overrun that had been happening with the International Space Station. Was he seeing cost overruns at JPL, or he was just in that budgetary frame of mind? ELACHI: No, he was in budgetary frame of mind. He was not at all thinking about any overrun at JPL. And most of our missions were doing fine, including Spirit and Opportunity which were doing fine. I mean, like every mission, there were some budget issues but within the reserve that we had. So, no, he was coming to it from somebody who lived all his life that, look, the government need to get the best deal, the lowest-cost contractor, and why are we renewing Caltech without competing it? And I see his logic, so I didn't tell him that he was illogical or something. So, the emphasis was on what is the value that Caltech has brought, and what Caltech can bring in the future, and the perturbation that it will create on operations. So, that's the logic, I followed that, but nothing that it's the right of Caltech, the God-given right to Caltech to manage JPL. But I emphasize the importance across the spectrum, from collaboration, attracting employees, to come and who love to be part of a university, the benefit that the university brings to the picture. And, slowly, he saw it, that really was a big benefit, you know. And then, let's see, he was still there for the next contract, and it was never an issue, you know. That never came back, as an issue. ZIERLER: Charles, I wonder if, in that moment, when you had to think about defending Caltech's contract, if that was useful as director to take stock of actually having to make the point that the contract should need to be renewed? ELACHI: Yeah, no, I mean, in a sense, as a JPL director, I'm effectively Caltech, I'm a vice president of Caltech. That comes with the JPL director position. So, effectively, I'm representing Caltech, toward NASA. And I emphasized to Sean O'Keefe and the people at—I always emphasize my goal is a win-win. My goal is not to get NASA in trouble, and benefit Caltech, or vice versa. My goal is a win-win, and we have a very unique arrangement here where we have the best of both worlds, the NASA world and the Caltech world. And another thing I emphasize to them is the fact that we are part of Caltech, and we have different flexibility in trying different things administratively, be it in the IT situation, in how do we do contract, and so on. NASA should look at it as we experiment, and they might learn from it. They might benefit from the results of our experimentation of how we do things. So, again, always I emphasize to them what's the benefit to NASA also for continuing this, not—again—not that this is our right, and you should give it to us. But it is in your advantage if I put myself in your shoes. It is in your advantage to continue with Caltech, to make the argument for it. And, in general, one thing which always helps is that, in general, the heads of the space science divisions work very closely with university, and they see the value of Caltech. They know Caltech, and they see the value. And, again, David Baltimore knew it even before I became director. But when Jean-Lou Chameau became the president, and then when Tom Rosenbaum became president, I emphasized to them that they should regularly call the NASA administrator, and the head of science, and say, "How are doing? Is there anything that's on your mind related to JPL?" Again, to build that relationship, because, at the end, personal relationships go a long way. Matter of fact, almost regularly, we used to have a group of the board of trustees which is very close with JPL, they used to go once a year and visit the NASA administrator and ask him, "How can we help you? How is JPL doing? Anything you want to tell us about your interaction with JPL?" And the NASA administrator appreciated that, that, really, they care. And, of course, many members of the board of trustees were very influential, both in industry as well as politically. And every once in a while, the NASA administrator used to say, "Hey, we need your help a little bit here," without really asking them directly. But, things like, it sure would be helpful if David Dreier can really advocate for NASA, or something like that [laugh], or facilitate a meeting, between some people at NASA, and people on the Hill. And the board of trustees used to go out of their way to be helpful. ZIERLER: Charles, going into 2002, between the findings of Jason 1, the Gravity Recovery and Climate Experiment, and the Atmospheric Infrared Sounder, JPL was really at the cutting edge of climate change research. What was some of the impetus of this research, and some—what were some of the key findings? ELACHI: Well, no question, I mean, one of the things which I think led to my rise at JPL was my heavy involvement in Earth observation instruments. And when I was division manager of the science division at JPL, we had a group of some brilliant young researchers, which were very heavily what I called instrument researchers. So, they were Earth observation people. In actuality, the majority of them came to JPL to put instruments on planetary missions, but the competition was very stiff, and there were very few planetary missions. So, they had to turn their attention to put those instruments on Earth orbiting missions. There were atmospheric remote sensing projects in the sub-millimeter, like Joe Waters' imaging spectroscopy, like Alex Katz's atmospheric infrared, like Barney Farmer, Mous Chahine. So, these were all scientists in general using remote sensing in instrument, which they started in planetary research but then they started applying it to Earth. And JPL activity in Earth observation expanded significantly when I was the director for science and instruments, to the point that just before I became director early in my directorship, there was almost more funding in Earth observation than in planetary, at JPL. And for a number of years, they were about the same, between the two activities. And it was heavily driven by what was happening on our planet, with global warming—the ozone hole was a major, major issue—better understanding of the oceans. So, a mission like TOPEX/Poseidon, which kind of got started when I was on the executive council, and continued when I was director, the GRACE mission, many of the atmospheric instruments really early in my tenure, they were active. They were launched, and we learned a lot. I mean, starting with the AIRS instrument, we were able to monitor the Earth's temperature on almost a daily basis, and then over long-term to see the change which were happening. We were able to monitor the amount of carbon dioxide in the atmosphere, and the amount of ozone in the higher atmosphere, you know—what was that doing to it?—and monitoring the temperatures in the ocean. And shortly after that, when the whole El Niño thing start becoming more visible because we were able to see many months ahead of time the warming in the ocean in the Western Pacific, and how that warming wave was propagating toward the West Coast. And then people started making connections between the warming of the ocean in the tropics, and the El Niño, the heavy rain, in Southern California, and vice versa, La Niña when we get more cold water. So, it became very quickly apparent that a lot of the data that JPL missions were acquiring were actually allowing us to do some predictions about the climate and the changes happening in our environment. In the case of GRACE, by measuring very accurately the gravity field, we were able to determine the ice melting in Greenland, and then putting one plus one equals two [its relation to] the ocean rise. So, TOPEX/Poseidon was measuring how much the oceans are rising. GRACE was measuring how much land ice is melting. And we put one and one together, and the temperature change, and we measured by determining how much rise is happening because of the temperature change, and how much is happening because of the ice melting. They matched exactly what TOPEX/Poseidon was seeing at the ocean rise. So, it was a perfect instrument experiment about the global change which is happening on our planet. ZIERLER: Charles, moving into 2003, with the Galaxy Evolution Explorer, to what extent did this serve as an expansion of JPL's mission beyond the solar system, beyond planetary science, and to become more involved in fundamental questions of astrophysics and cosmology? ELACHI: Yeah, I mean, the astrophysics program was the third leg at NASA Science, and part of the strategy that I had is I want to be a major player in some of those areas, and a significant player in the rest of them. Clearly, we want to be the lead in planetary, we want to be equal lead with Goddard in the Earth science, and we want to be a major player in astrophysics, even that Goddard was a big player particularly with the Hubble Telescope, and particularly with the campus having a very powerful astrophysics capability. So, when NASA started competing in more missions, we started discussing with some of the leaders here on campus about working with them, and having JPL being their partner in implementing their mission. And we had already done some astrophysics missions. we did IRAS in the 1980s. Then we did what was called SIRTF, which was an infrared mission which we started working on in the 1990s. And for both of those missions, the mission operations center, particularly for the data, not the spacecraft was placed here at Caltech, on the campus. And that's what's called IPAC for the Infrared Processing and Analysis Center. So, that was an arm of the campus basically working on these two missions. So, when we started approaching the Caltech faculty in astrophysics, it was not unusual, that we would work with them. And they already knew about the strength of JPL in instruments, and that's what brought JPL in the picture. Matter of fact, a couple of faculty told me they came to Caltech because they can have access to JPL to have JPL implement either their instrument or their mission. So, on the ultraviolet mission, JPL was doing work on ultraviolet detectors in there, so it was natural then for us to actually be responsible for that mission. It was a challenge, I have to admit, because JPL was accustomed to big missions, multi-hundred-million-dollar mission, and our processes were geared toward very big missions, high-visibility mission [for which] we want to have very low risk. Things like GALEX, that was a mission I don't remember how much it was, but it was in the many tens of million, not many hundreds of million. So, we had to adapt to be able to do that. And one of the arrangements we did was that we moved the project manager to be on the campus, and issue the contract from the campus, even that a lot of the work was at JPL, because that allowed us to take advantage of the lower rate on campus, for a contract. So, you find every way which can help you in that approach. But, still, I treated it like a JPL mission, and the president at Caltech expected me to treat it like a Caltech mission. ZIERLER: Charles, I'm sorry that I have to ask about another disaster. But, of course, in 2003, the space shuttle Columbia disaster happened. What was that day like for you, and how did it change things at JPL? ELACHI: Yeah, I mean, the impact was like everywhere else, you know. I mean, it was a shock, for everybody. And that one, I remember, somebody walking in my office, and say, "It looks like there is a problem on the shuttle." Because, many people were watching it regularly, as the shuttle comes in, so it was almost like in real time. And then, usually, in these things, particularly on the internal NASA channel, they put like the mission operation room at Johnson Space Center and at Cape Kennedy. And you can tell very quickly from watching the faces of people that there is a problem, which is happening because they lost contact with it, or when they were supposed to get contact after it enters the atmosphere. Nothing was happening. There was no signal. And that's the kind of really heavy feeling that you get on a—and I do sympathize with it, even that this is more dramatic because it's human, because we see it in planetary, you know. When we are landing or when we are going in orbit, usually, we predict at what time we start getting signals. For instance, when we go in orbit around a planet, we fire the engine. We can see that. Then the spacecraft goes behind the planet, and we calculate exactly if the engine shuts off at the right time, when would the spacecraft show up, and we can get the signal? And if we don't get the signal within the first five, ten seconds, you start worrying about it. Now, it's normal. It happens. Even that we know it's normal, because it takes a while for the antennas to lock on the signal, but you get this heavy feeling, you know. But, here, it was even heavier because there were a number of astronauts on that mission. So, immediately, somebody walked in the office and said, "Look, it looks like there is some potentially bad news." So, we turned on—I had a TV in my office. I turned it on, and we kind of followed it step-by-step, and it was very depressing, even that JPL was not part of it. But this is our agency. We are all part of NASA, part of the country. So, that was a very depressing time. And then it took a little while for people to figure out what actually happened. And then by going back and playing the movie of the launch, then they realized that there was a piece of foam, which kind of sounded bizarre at the beginning because you think of foam as something very light. But it was a very high speed, and hit one of the tiles, and actually damaged it. So, after a few days, they quickly realized actually what happened, and it was a sad moment, I mean, no question about it. This was really a sad moment, when that happened. ZIERLER: As you said earlier, of course, if you don't fly, there's no risk. ELACHI: Yes. ZIERLER: I wonder if you took the opportunity to emphasize that while these tragedies happen, it's part of the mission. ELACHI: Yeah. No, it is true, and not to take it lightly because, I mean, humans get damaged. I mean, we kept…I think part of the issue was that NASA did not emphasize heavily that this is a risk. The shuttle is risky. Because we had so many successful flights, people started thinking of it like airplane, going to LAX, and getting on an airplane. But, in reality, it was more like test pilots in the early jet, era in the '50s. There were many pilots which were lost, you know. There were accidents, and pilots were lost. And people at that time appreciated the risk. And you go back even earlier, in the early days of aviation, lots of people were lost in the early days of aviation because of accidents. And, so, I think somehow, unfortunately, we all—not only NASA but the country came a little bit blasé about the shuttle. Because after you do 10, 15, 20 flight, everything works perfectly as planned, people start taking it as, gee, that's like a regular airplane, not appreciating that airplanes, you have literally thousands of them flying, and there have been a lot of, decade of [cumulative] experience. And here at the shuttle, they had maybe dozens of flights, and you are in a much harsher environment. So, it was a big shock, and that really, got the agency again, to [a policy] effectively doing no flights for a couple of years. So, yes, it was a tragedy, but I kept emphasizing, and that was one of the things I kept emphasizing—not only the shuttle but also the two failures we had on Mars, is it's very important to keep sending the message that we are in a risky business. And when you are in a risky business, by definition, that means accidents are going to happen, you know. It's not—you are not taking a risk if everything works then before 15, 20 years, and nothing happened. Then you don't push the limit of doing that. So, again, with the shuttle, I met with the employees, and emphasized that this is a tragedy, but that's how we can push the limit. And I'm sure NASA's going to rise up, and learn from this, and continue with exploration, because we were heavily dependent on the shuttle, for launches and for experiments on the shuttle. ZIERLER: Charles, what opportunities did you have to work with your counterparts in Japan on the Hayabusa mission? ELACHI: Well, we had—international [partnership] was a high priority for a variety of reasons. I mean, number one, there are smart people everywhere, and we can capitalize on that. Number two, we can achieve even more, by—with the limited amount of money that we have or the international community has. And then there is the soft, power, diplomacy. So, international was an important element at NASA as well as at JPL. And, clearly, Japan was one of the key players in space exploration, and we had—I had a lot of experience with them because we did a number of Earth orbiting joint experiments with them, one of them being an ocean scatterometer that we flew on a Japanese spacecraft, and they flew some of their instruments on our mission. And Hayabusa, we felt that was a very daring mission, an exciting mission because they were trying to land on an asteroid. And, matter of fact, they wanted to do a rover on it. They approached us about possibly JPL doing the rover for it. Unfortunately, because of funding limitations, NASA was not able to do it. But we worked closely with them, particularly on navigation, and then we had a number of their scientists hosted at JPL. And I visited a couple of times their space center, the planetary space center. At that time, Japan really had two agencies: one which does planetary; and then one which does mostly Earth observations—the Earth observation being much bigger than the planetary research. Matter of fact, the planetary work was almost run—it's called ISAS. It was run like a university environment, and most of the people there were faculty members, and they were able to be successful with it. We helped them. Our Deep Space Network helped in the communication and the navigation, for their antennas. We had a number of people from JPL who went and spent many months at their institution. So, yeah, we had very close collaboration…matter of fact, I'd say, the first launch I ever watched—because many launches I go to, they get delayed. So, after a while, I started saying maybe I shouldn't go to JPL launches because they'll get delayed. The first launch I ever saw was from Japan, you know. I went to the mission that launched the scatterometer that we developed, and it was in an island, so they flew us down to the island. And that's the first time I watched a launch, a successful launch. ZIERLER: Charles, to return to Mars exploration, in what ways were Spirit and Opportunity designed to be redundant, because there's a value in that, and then what extent were they separate, and they had separate missions? ELACHI: That's a very interesting question. Let me tell you the history about it because it reflects on that. As I mentioned, we had the two failures in late 1999. So, shortly after that, there was a discussion—Dan Goldin was the administrator—about how do we get back up from that? That was the tail end of [the directorship] of Ed Stone; the early end of his tenure. So, at JPL, we asked Firouz Naderi, who was one of the senior people, to kind of have an office we call the Mars Program Office to look at the strategy for the following decade, and what missions should we be doing? And the rover mission basically was a mission that NASA was just recently selected to do it. But we were suddenly figuring out, with these failures, what can we do to make it successful? I remember Firouz went to NASA Headquarters, and there was a meeting with Dan Goldin, and there was a presentation about the rover, how we're going to do it, and so on. And then Dan said—it was one rover at that time. It's called MER for Mars Exploration Rover, and Steve Squyres was the PI, and JPL was developing it, and Pete Theisinger was the project manager, and Firouz was the program manager. At the end of the meeting, Dan said, "this landing is very risky. What would it take to build a second one?" So, everybody was taken aback, because nobody was thinking of doing a second one. Dan said, "Why don't you guys go back for a week, and come back, to me, and tell me what would it cost to have a second one?" Of course, it was a combination of excitement and, number two is, would we be able to do a second one in time for the launch in 2004? And being typical for JPL, people figured out a way, and within a week, we went back to Dan Goldin, and we told him—I don't remember the exact number—but that's how much it will cost. So, he said, "OK. I'll come back to you in a weekend." Then, after, I was told Dan went to a meeting with all the senior managers, the human and space science and the technology leaders, and then he said, "What do you guys think about having a second one just to have redundancy for it?" It was driven by redundancy at that point. And, of course, everybody thought, oh, yeah, that would make sense. He said, "Great. I'm going to come and tax each one of you to get that additional money [laugh] so to do that, so to move money into the space science so we have the funding." He calls JPL. I said, "OK. You guys, you have two missions. Start working on it." [laugh] And, of course, there was a science benefit, so the two were identical: same exact way of landing; same exact way of the roving; same exact instruments. But the idea, so, the primary driver really, honestly, was the redundancy, because the risk of the landing, and it was the first time we are landing a rover of that of that size. I mean, we did Pathfinder, a few years before, but this was much bigger than Pathfinder. But, of course, there was a scientific benefit of being able to land in two different sites on Mars. So, really…it was not the science driving the decision. The science was a beneficiary of having the redundancy and being able to assure that at least we'll have one success. And then, as I mentioned earlier, one of the rovers—so, we were just starting on it when I became director, so this really got a lot of my attention. I mean, I was meeting literally every week with the project team—not to tell them what to do, because they were—we had the best experts and the smartest people. And Pete Theisinger, who was the project manager, was one of our best people…and he was a Caltech graduate, so that helped a little bit, on doing that from the mechanical engineering division here. But it was more on, what I can do to help you, you know? Do you need more workforce? Do you need funding? Do we have the appropriate funding facilities, all those things? And, of course, I regularly asked the key questions. And that's when I started the approach to telling them, "Look, tell me, what are the incompressible testers? What are the things that we need absolutely to make sure we do before we give the green light to ship it, and then launch it? Because I want to make sure that all the tests are executed, and we don't take any shortcut because of schedule or because of funding, you know." And the other one I told them when they were working on the landing site, "Make sure we will be able to watch it in real time, as we are landing, and the signal, that we can see the signal—not on the other side of the planet." So, that was another driver into the selection of the landing site, and the arrival time. But it was an exciting time because this was—here was an opportunity, a very dramatic opportunity to rise from being in a penalty box, let's say, even that we were not physically really in a penalty box. But after the two failures, we wanted to show that JPL can do it. We can rise to the occasion. ZIERLER: Charles, what accounts for the pleasant surprise that Spirit lasted as long as it did? ELACHI: [laugh] That was a surprise. Basically, what we committed is for 90 days, and the science worked its plan so they can do a majority of the science in that local area, in 90 days. And then before we launched, there was, I remember, there was a board where every member of the team was betting how long they will survive the mission. And I don't remember the exact number but some of them around to about, like, one year. And the people who talked about a year, other people were saying, "Oh, you guys are being optimistic about doing that." And the reason was not that we didn't have trust in what we were doing, because we really did very good engineering. But the rover was solar-powered. Spirit and Opportunity were solar-powered. And we knew, every once in a while, there are dust storms on Mars, and we thought it would be dust which will get deposited on the solar panels, and therefore we will lose power little by little, and, after a while, we fall below the minimum survival power [level]. Well, like everything I say, everything, every once in a while, it helps to be lucky. But somebody reminded me that luck comes to people who work very hard, that are not just—so, what we found that on Mars, there are dust devils like what happen in the desert here, which are like little tornadoes which come over. And every time, every once in a while, a little dust devil comes over the rover, and cleans the solar panels. Matter of fact, we could see that power was going down, and when a dust devil comes by, there is a sudden jump. And we took pictures of the solar panel, and you can see dust accumulating, and then immediately after a dust devil, they are crystal clear. it is like they are brand new. So, there was a little bit of luck, into—it was a power issue, and of course there was a design issue, and that's what led to Spirit surviving about 6 years and—or 5 years, and Opportunity going like 12 to 14 years. I mean, we were all amazed, that they survive for so long. But, again, that kind of tells us about the good engineering work that JPL does. Sometime, people joke because they had the foils on them which were gold color, for heat—for thermal properties. Sometimes, people at Headquarters say, "Oh, yeah, you guys at JPL gold-plate everything you do." But everybody loved the fact that they survived for that—and we learned a lot from them—because we were able to drive much larger areas, and go many kilometers instead of a few hundred meters, and saw a diversity of geologic features on Mars. ZIERLER: Charles, because JPL had been involved in Mars research for so long, how did that research that preceded Spirit and Opportunity enhance what Spirit and Opportunity were able to accomplish? ELACHI: Yeah, clearly, it was very valuable. I mean, the orbiting high-resolution data was a major factor in selecting the sites, because the objective was to land in sites where potentially there was water in the past, like either lakes which have dried up, or rivers which have, kind of dried up, or areas where the composition of the rock gave hints that they were formed in a watery environment. So, no question, the previous missions, the orbiting missions, were very critical, for selecting the sites. And then the other one was on—we wanted to land in a relatively safe site, so it was a balance between a high science payoff site but also a site which did not have huge rocks all over the place, you know. So, the imagery also was a factor in doing the site selection, and then also learning about the topography of Mars from previous mission because we wanted to land at relatively low altitude area. That means we have enough atmosphere to slow us down. We didn't want to land at the top of the mountain where we don't have very much atmosphere so it doesn't slow you down, with the parachute. So, there were a number, of factors—scientific, and engineering factors—which really were enlightened by the previous orbiting mission. And then, of course, there was the communication. We had to rely heavily on the orbiting spacecraft as a relay because, on the rover, we can put only a relatively small antenna. But by—to communicate with Earth, we cannot get a lot of bits. We were able to get maybe a few kilobits per second. But then with the orbiting spacecraft, then we were able to relay from the rover to the orbiting spacecraft, and then the orbiting spacecraft to Earth. And the orbiting spacecraft had much more power and relatively bigger antennas, and that allowed us, after a while, to get down to the many megahertz or megabits, per second, literally two orders of magnitude more data, in doing that. And that was important, even that we relied on the direct link, but having the relays was very important. ZIERLER: Charles, to what extent was the rover missions' interest in past water activity on Mars the interest in and of itself, and to what extent was the interest in water about looking for possible signs of life on Mars? ELACHI: Yeah. No, clearly, I mean, we are all—we think about life here on Earth—that's what we are familiar with—and we know that water is a critical element for life's evolution on our planet. So, our goal is effectively to look at what we call habitable environments. That means an environment where life could have evolved, I mean, we don't know for sure, but an environment where life could have evolved, and then extrapolating from what we learn on Earth. To find a habitable place, we wanted to look at place where water existed in the past or could exist today either on the surface or below the surface, because the belief by looking at the dry drainage channels and the dry lakes, there is a belief that water could have flown on the surface—was flowing on the surface, a few billion years ago when Mars was warmer. So, clearly, we were driven by looking at places there which were like alluvial fans like we see in Death Valley, which are eroded by water in the past, or dry riverbeds, or places where lakes look like were there but got evaporated. So, that was a heavy driver behind the science looking at those areas. But, also, we wanted to look at areas where we can see different kind of rocks, which are stacked like when you go to the Grand Canyon, and you see the different layers of rocks, because that tells us about the history by going from one area to the next to the next to the next, which were deposited at different times. It will tell us about the history. I mean, you can see, like, if you see rounded pebbles that most likely were formed in a flowing water, this tells you about volcanic areas where there was volcanic flow. So, the geologists have worked on a process of what kind of rock and what kind of morphology has the highest likelihood of habitability, and that's what drove the selection of the landing sites. And, of course, the same thing we did after Curiosity and and Perseverance. ZIERLER: What did we learn about Mars as a result of the rover missions that we did not know before? ELACHI: Well, a couple of things we have learned. Number one, we had a verification that, actually, there was water flowing in the past, again, through a variety of factors, by looking at dry lakes, composition of rocks, salt composition, by looking at pebbles which are rounded. And then, on one of the landers—not the rovers—one of the landers that we landed close to the polar region, just by digging a little bit, literally a few centimeters, we actually found ice, water ice just, below the surface. And then with Curiosity, by analyzing the composition by drilling and putting them in ovens and measuring the composition, we found that, effectively, every component of our—any basic element of our bodies exists on Mars: carbon, hydrogen, phosphorous. Everything which makes our bodies on Earth actually exist on Mars. We haven't seen DNAs, or cells yet. But we did see small organic molecules, on analysis. So, at least, there is the possibility that, actually, you have all the ingredients. You had the water, and you had the beginning of organic molecules. So, the next puzzling question is, could that have evolved to a level where cells could have formed? And that's the key focus about Perseverance and the sample return where you can do a much more detailed analysis of, could some of these have evolved to have a habitable environment or possibly life started and maybe stopped at a certain level? And the other part is to dig for the ice below the surface, and to see which area there is ice, because there is a possibility that during warm periods, during the summer on Mars during the day, ice might melt a little bit. And we did see features at the edge of craters where we see what looks like flow features which have happened, which potentially could be from ice, having melted, on the warm side looking toward the sun. So, these are the intriguing questions that are being pursued now. ZIERLER: Charles, tell me about the value of the Deep Space Network for the Mars Exploration missions. ELACHI: Well, no question, the Deep Space Network is essential element to communicate with any of the deep space missions, not only the rovers but any of our missions. So, it is a network of three stations around the world. We have one in Australia, one in Madrid, and one in California. They are kind of placed a 128 degrees longitude from each other so, that way, as they rotate, we always can have one or two stations communicating with the spacecraft, no matter where it is, in the solar system. And by that arrangement, you almost have two stations always continuously monitoring the spacecraft. And then the data comes from them to the mission operation center, at JPL, or the mission control center at JPL, which I'm very proud that when I retired, they named it the Charles Elachi Mission Control Center. But, also, in addition to our Deep Space Network, we have agreements with the European Space Agency, the Japanese Space Agency, and the Indian Space Agency that we all follow the same protocol to communicate with our spacecraft. So, that way, we can use some of these other antennas also because, every once in a while, there is a storm in Australia so that network, is limited, or snow in Madrid and, for some reason, there is some failure. So, we want to also have the same ability of communicating using other agencies' antenna, and vice versa, you know. Particularly in the early days, we were the only country that had a deep space network so they used to use our network to help track the Japanese or the European spacecraft. Now, the Europeans have three stations, the Japanese have one, and the Indians have one, and we all follow the same protocol. Similar to your cell phone, you land in Europe, and it works because there is agreement of having the same coding, same protocol: the same thing with the Deep Space Network. But it's absolutely essential. Without it, we could not communicate with our spacecraft. And it's like magic. I mean, even that I'm a technical guy, and I'm in electromagnetic waves and communication, I'm always amazed that we can communicate with Voyager, which is—usually, I figure it out in how many hours it takes for the signal to get here, and that signal takes two days. So, when I'm in the mission operation room, and I see the data from Voyager, that was sent two days ago at the speed of light. Then, I calculate how many seconds in two days, multiply by 300,000 kilometers pers second, and I think wow, that's amazing that we can still get that signal. And when you go and visit those stations, those antennas are amazing. It's like you take the Rose Bowl, almost—it's a little bit smaller than that—and you put it on a pedestal. That's effectively what these antennas look like. ZIERLER: Charles, in what ways were both rovers designed to handle all kinds of surprises in operating in the Martian environment, and in what ways were some of those surprises problematic in terms of how the rovers were able to operate? ELACHI: Yeah. I mean, there were challenges which we kind of knew about them, and surprises that we didn't know about. The one we knew about is clearly the temperature. We knew the range of temperature on Mars, which was many hundred degrees between the day and the night, and the electronics and the mechanics has to all work. That we knew about. We knew about storms on Mars because, from the orbiting spacecraft, we saw that, regularly, there are storms which come and almost cover the whole planet. And that's what led in the movie The Martian talking about the storm which blew away one of the astronauts, but a storm doesn't blow away an astronaut. They are not that strong. But they bring a lot of dust, on it, which limits our operation and our power. These were things which we knew about. The surprising things is about the traction that we have there. So, we know it was challenging. We drove very carefully. But, when we got to sand dunes, it turned out like here on Earth when you go in dune buggies on sand dunes. You have to drive very carefully, or you can get stuck, very carefully. One of the things that we prepared for—we didn't know the detail of it—is to have an identical rover here at JPL in a place we call the Mars Yard. So, it happened like Spirit, when we were driving it, we found out, even that we were very careful after the five years, it got stuck in a sand dune. The wheels were getting stuck in it. So, we came and tried to simulate that environment here on Earth, and somebody from analysis said, "it looks like the dunes are more like a talcum powder, kind of consistency." So, we sent everybody around the Los Angeles Basin buying every talcum powder that we can find. And you can imagine the reaction of the store as you check out with this huge bag of talcum powder. Somebody told me one cashier said, "How many kids do you have, you know? How many babies do you have?" [laugh] Anyway, we ended with hundreds of pounds of talcum powder, spread it, in our Mars Yard, and got the rover which we have on Earth to get stuck in it, and then figured out ways of how do you wiggle the wheels? How do you drive them to get out of it? So, this was a little bit of a surprise. The other surprise was on how sharp and damaging some rocks are on Mars. As we were driving, after a few years on Curiosity now, and we were driving long distances, we suddenly realized by taking a picture of the wheels that one of the wheels was getting cut. They are made of thin aluminum. That there was damage on the wheel, and it could be similar to when your tire blows up on the freeway, which happened to me two days ago, that the rubber, will get off, the wheel on this thing. It was not off it, but it was getting really seriously damaged. Then, we started realizing, by doing tests here, that these rocks on Mars are much sharper than we originally thought, and we need to avoid driving over some of these rocks. So, starting with that, we kind of drove more carefully, on the rocks, and that happened many years ago, so we are doing fine. I mean, Curiosity is still functioning properly. But it led us on Perseverance to build the wheels thicker, the aluminum to have thicker panels on it. So, we learned these were a couple of surprises that we didn't expect on the engineering side of the mission. ZIERLER: What were some of the biggest surprises for you personally in terms of dealing with NASA and all of the excitement around the rovers? ELACHI: [laugh] Well, in general, you mean? [laugh] Well, dealing with NASA itself, mostly the bureaucracy that comes with government agencies, and it's not really NASA itself but the government agencies, that they have to follow government rules. Because on the technical side, the fortunate thing is that most of the NASA leadership are engineers and scientists, and many of them were center directors before, or were project managers, so they fully understand the technical challenges that we face. But on the bureaucratic side, how much the rules of the government in contracting, how much it put limitation even on them. They get very frustrated, about it as much as we get frustrated. But they don't have a choice, you know. They have to follow the rules. As civil servant, they have to follow that rule. In our case, we have more flexibility. Being Caltech, we have more flexibility. Let me give you an example. During my tenure, some smart person, I guess at NASA or somewhere, came with the idea, well, instead of having each center having their own IT, we should have one contractor do the IT for all the centers together. And many of the center director resisted that because when you are in in control of your contract, you can basically—if the contractor is not doing a good job, you can come to them and say, "Hey, you guys better shape up or there will be a change." When it's done for the whole agency, if one center is having a problem, they cannot tell the contractor. They have to go to NASA, and have NASA IT go to the contractor, and you can imagine, all of a sudden, it's a long, a long process. So, they resisted but they did not succeed. This is the way the government wants to do things. And they tried to come and impose it on JPL, and I said, "Hey, wait a minute. We are Caltech [laugh], you know and, really, we have our own contractor. You have to trust us. We will follow the general rules, that NASA, particularly for security, but we want it through our own contract." So, we did our own competition, and we selected our own contractor, and that allowed us to be a lot more flexible. So, these are the things that I had to fight many times, dealing with the bureaucracy at Headquarters. And, to their credit, many of them saw the benefits and the disadvantages of the bureaucratic process, that the government has—not necessarily because of NASA's fault, but that's the government in general. And the other example is on issuing contracts. When NASA, any NASA center issue contracts, they follow the government's rules. It takes nine months to a year to have a contract approved. If the company which was not selected doesn't like it, they can appeal to the GAA or one of the government agencies. That'll take another several months. So, that slowed everything down a lot. At JPL, even though we follow the rules, we can issue a contract in less than three months. Industry cannot appeal it, because it's a Caltech contract—as long as we follow the rules, I mean, follow the process. And that's what my deputies, Gene Tattini, and, later, Larry James, were very savvy, at doing that from their Air Force days. It's really the imposition coming from the government rules which, usually, they have good intentions. But, usually, it's the accumulation of one employee of 100,000 makes a mistake, so there is a rule imposed on the 100,000. Another employee makes a mistake, it's imposed on the 100,000 or the million, employees. And that's unfortunate because I think that leads to a lot of bureaucracy, a lot of expense, and a lot of frustration, working with the government. At JPL, the rule I used to follow is every time we had a rule, I want to see three rules eliminated, taken out. And I used to have people track it because, I mean, that's a normal tendency—and that's why startups are much better than mature organizations in being much faster in doing things. At JPL, we're halfway in between. We do half bureaucracy. That's normal because we have to follow a certain rule, and we're using taxpayer money. But we are part of a university, so we have that continuous startup spirit that you would get at a university. ZIERLER: And, Charles, of course, from your initial listening tour when you were named director, and you went around talking to people at JPL, this was one of their chief concerns. ELACHI: Absolutely. That was one of their biggest, because that's what—I mean, technically, they are very smart. They know how to do—they don't need a director to tell them, "You use this transistor, or you use that material." But the bureaucracy, they have to follow it, and the rule, they have to follow that. I remember one of those, one employee, and he said—he brought a travel request, and he said, "Charles, look at this travel request for me to travel to"—I think it was an international travel. There were like nine signatures, and each one of them has to go to somebody, and it takes time to get the approval, and it takes the time of the person, to do that. So, when I became director, I called the travel group, and I told them, "OK, I want that form changed so there'll be no more than three signatures. If an employee was traveling, it would be the supervisor and the person in charge of the budget for that program, and that's it. I don't want to see more than three signatures on it." And, people did that, you know. And, then the other ones in—on, what does it take to hire an employee? So, we developed a process where I told them, "I want to have a system where if we go to a university, employees go to do interviews at the university, and they see somebody who's really good, they can make him or her an offer on the spot." Before, they had to fill in forms. It goes to our human resources. They do interviews. They do all kind of things. Anyway, so, that was one of the things that I really emphasized that we need to streamline, the things that we do, but being careful on not taking shortcuts, particularly when it comes to the risks that we are taking, and the quality control on the mission. ZIERLER: Charles, tell me about the origins of the Spitzer Space Telescope at JPL, and to what extent this meant new directions for JPL in space observation. ELACHI: Yeah, that's a very interesting situation because sometime in the '70s or the '80s, NASA decided on doing what they called the four great observatories, the Hubble being one of them. There was an X-ray mission, I think there was UV mission, and then what was called SIRTF. And the original intent with SIRTF would be done on the shuttle. That was Shuttle Imaging—sorry, Shuttle Infrared Telescope Facility. That would be flown on the shuttle, and it was assigned to the Ames Research Center. JPL had none of those four telescopes. I think two of them were done at Goddard, one at Marshall, and one at Ames Research Center. But there were instruments from JPL, like the main camera on the Hubble Telescope. In the meantime—and I don't know the history—NASA assigned to JPL a mission called IRAS, which was a small infrared telescope. That was the first astrophysics mission at JPL, and I think part of it was because of the strength of JPL in the campus in infrared instrument. There was Gerry Neugebauer on campus who was a leader in infrared. And that's what led to having, when we flew IRAS, that led to having IPAC, which was Infrared Processing Center, on campus. So, when IRAS was at the tail end of it, and SIRTF at Ames Research Center was getting more costly and more expensive and overrunning, NASA started thinking maybe we should move it to a center which built missions. Ames did not have that experience, so the contenders were Goddard and JPL, to do that. And then, at JPL, because IRAS was finished, there was the question of keeping capability for infrared astronomy, at JPL, the campus connection, so there were a number of factors which led to NASA assigning it to JPL, the SIRTF mission. And then as soon as it came to JPL, we also had the lead scientist on it. His name was Mike Werner, a Caltech graduate, who was at Ames. I met with him, and I told him, "Mike, it would be great if you can move to JPL with the mission. You have the history. You have the background." So, he decided to move, and continues as the lead person, on it here. And shortly after that, when—then people started saying, well, instead of the shuttle, maybe we can do an Earth orbiting mission, and that will have a longer lifetime. And that was the period where people were starting to get off the shuttle. And then shortly after that, while we were studying it, a JPL system engineer, who was a system engineer on the mission, kind of one day said, "Why are we putting this in Earth's orbit? Why don't we send it in deep space, because in Earth's orbit"—and we were doing all kind of fancy engineering and cooling because to do an infrared telescope, you have to cool the detector at very, very low temperatures. So, you have to put in a cryostat. But in Earth's orbit, they have the heat being emitted from the Earth, and you go in the shadow of the Earth, every time you go from one orbit to the next. So, you have all this change in temperature, which complicates the design of the spacecraft, and it was getting bigger and bigger and bigger with all these cryostats. So, somebody said, "Oh, that's an out-of-the-box idea." So, they looked at it, and we met with the science team, and they said, "Yeah, if you put it in deep space, or in what we call solar orbit, you can turn one side of the spacecraft toward the sun, and you paint it with—or put reflective material, and the other side is always in the shade, so it's cooling off all the time." So, it's like you carry an umbrella with you, and you keep it pointed at the sun, and you are in the shade. And, suddenly, the spacecraft got a lot smaller. The cryostat got a lot smaller, and the lifetime got a lot bigger, and the cost significantly went down. And NASA was delighted with that approach because the—with the increase in the cost, it was almost becoming risky or unlikely that it will happen. And all of a sudden, we brought it to a much lower cost. And Larry Simmons, who was the project manager on it—and all of that was happening before I became director, when I was in charge of the scientific instruments and astrophysics missions and future missions. And that's the same Larry Simmons who afterward became my deputy, you know. And that's how it came out. So, it really came, number one, because of the technological capability at JPL, the connection with the campus—even that was not the top factor because of the campus but it all helped—and then in the ingenuity of the people at JPL. Because, at JPL, we tend to think when we talk—think of a mission, we think deep space, you know. We are not wedded to Earth's orbiting, activity. Actually, it's an amazing story of how that—and I used to have a picture that I used to show as before putting it in deep space, and after we put it in deep space, and it's like half the size, the whole spacecraft. And that led to a much longer life. Matter of fact, it was supposed to be three years. I think it end up being like eight or nine years or ten years, mission because of the cooling that was done in deep space. Even when the cryostat was depleted, we were also in a much colder environment, so only one of the instruments had to be shut down. The other two instruments were still working fine. ZIERLER: Charles— ELACHI: And that's a good example of the ingenuity of JPL. ZIERLER: Charles, of course, the Thirty Meter Telescope is our minds right now because we're all waiting to see what the Decadal report says. I'm curious if in the planning for Spitzer or in its launch if you worked with people like Tom Soifer, and you saw Spitzer as a way for Caltech to maintain its excellence in astronomy but beyond land-based astronomy. ELACHI: Oh, absolutely. Now, the space activity is basically—it has to be [funded in an] evenhanded [way] because NASA is paying for it, not Caltech or a donor to Caltech, like the Keck organization or Gordon Moore. So, it has to be done evenly for all the science, all the scientific community. But, clearly, being at Caltech, and associated, it gives you a little bit of an advantage. And it was very important because after we launched SIRTF, and then there was discussion about how we are going to manage the time, on SIRTF, or get allocated what time, and we decided that the best way to do it is to do it from the campus from IPAC, the Infrared Processing and—Center, and Analysis Center. It was very critical that the team at IPAC which is going to be working on the operation, and how to allocate the time, and how to distribute the data, are evenhanded, even that they were managed by Caltech, you know. Tom Soifer was the lead scientist. The head of IPAC first was Chaz Beichman, who was here from Caltech and JPL, and now it's George Helou, who's from the campus. They had to lean backward to make sure they are evenhanded. So, they had committees which included outside scientists, and their process to make sure that everybody has equal access to it. But, no question, being here at Caltech, a faculty at Caltech or a student, you can just walk a couple hundred yards from my office, and you are in the place where the operation is actually happening, where the people are who the experts on the instruments, about the telescope. So, there is an advantage, and the broader science community realizes that. But, also, I think the broad community appreciate the evenhandedness of people like Tom Soifer and George Helou and Chaz Beichman and Gerry Neugebauer, because these people are highly respected by the community, so they know they are not going to play favorites, in doing that. ZIERLER: Charles, moving into 2004, were you involved at all with President Bush's announced vision for space exploration, and a new era of manned spaceflight? ELACHI: Yeah. No, I think because the way that thing happened, I mean, he asked NASA to develop that. I mean, he didn't sit down and think about it in the White House. And NASA involved all the different centers, in doing that because some elements of it were robotic elements, also, and some of it was human. So, clearly, NASA appreciated and relied on JPL to articulate what are the precursors that need to be done for the human missions. And then, also, at the same time, roughly at the same time as we were developing that, and that was after we landed Spirit and Opportunity, Sean O'Keefe was sitting next to me, literally next to me, sitting in the seat next to me when we were doing the lander mission operation. And he was delighted, ecstatic, like everybody, and he was really impressed by JPL, and how we handled things. There were a few issues after the landing. There was—I think on Spirit, there was some software issues which helped us communicate with it for like two days or three days, and we were all worried. But he observed firsthand the process that we followed to fix that, and how we ended up fixing that. So, after that, he asked me, he said, "Charles, would you be willing to come to Headquarters, and help the strategic planning at NASA for all of NASA?" And I told him, "Sean, no, I love JPL, and I really would rather not do that." He said, "Well, how about if you do it two days a week, and come to Headquarters, every other week, spend two days there, and do that, and I'll provide you with staff at Headquarters, people who would work with you full-time on doing that?" So, he talked me into it, and I love NASA the same way I love JPL, and I became really good working with Sean O'Keefe. I really enjoyed working with him. So, I did that for about a year, traveling to Washington every other week, and I had Mary Kicza, who was my alter ego, at Headquarters. We worked closely together, and we had a group of staff. The negative side, a few people at Headquarters were not happy about it, that here you have a non-civil servant, which was an issue, because for strategic planning because it involved budgeting not only the technical aspect but also the budgetary aspect. So, that was one thing where I relied heavily on Mary Kicza when it came to personnel and all that. But I learned a lot from it, and I tried to really be, kind of evenhanded between the robotic and the human mission, and the sequence of missions that we needed to do. I continued doing that all the way until Sean O'Keefe stepped down. And then at that time, I decided it's more appropriate to turn it over to a civil servant. So, yeah, JPL had some impact and, of course, I relied on a lot of people at JPL who were really good at doing strategic planning. And I brought, when we developed a plan, I brought a few people external to JPL. One of them was Kent Kresa—I had him come back. I think he was retired by that time from Northrop Grumman—as well as a number of other people, to review, does it make sense, the sequence of missions? So, yeah, I would say we had some impact on it, even that it didn't materialize exactly like it was originally planned to get humans to Mars. ZIERLER: Right [laugh], we're still talking about it. ELACHI: Yeah. [laugh] ZIERLER: Charles, what were some of the advances in computation or even artificial intelligence that allowed for the launch of the Autonomous Sciencecraft Experiment? ELACHI: Well, one of the technology programs that NASA had was how to infuse technology in scientific missions, as well in human missions. And always because we are relatively on the conservative side, project managers are very hesitant on including brand new technology in the mission. They want it to be tested for three, four years, preferably tested in space, for them to take those capabilities. And we were at a time where computing was expanding at an amazing rate, the capability, integrated circuit capability, which would be of great benefit, for the spacecraft, particularly with autonomy involved in it. So, there was this push of including technology but a little bit of hesitancy on it. So, I worked with Headquarters, and with the technology office on ways of incorporating that in different missions but also to do spacecraft purely to demonstrate technology. That was the example we talked before about electrical propulsion, was one example, on autonomous spacecraft. That was another example where really the focus was not on the science but on the technology, and to try to demonstrate the technology—we used to develop it in a way where if it works, and people get confident, it can be immediately translated, to doing, actual scientific mission. So, you look at the electric propulsion, people now don't even think twice about it. But in those days, 20, 25 years ago, there was a lot of resistance, to do it until it was demonstrated. The same thing with a lot of electronics, integrated circuits, computing, computers on board. Now, our computing capacity is at many orders of magnitude greater than what we had. Even when I became director, we had, a couple of orders of magnitude more capability, and we did the same thing on communication, you know. On communication, we did a different approach. What we did, we said, OK, we have the basic communication system with the Deep Space Network. But on every mission or every few missions, we put in additional communications links as an experiment. In the early days, we used to use one-gigahertz links, and we added a nine-gigahertz link as an experiment. Then, we shifted to the nine gigahertz and, as we go higher, we get more capacity, you know. The higher the frequency, the more bit rate, the more data we can get. And then when we were doing a number of missions, I remember on—I think it was on the Mars Odyssey or Mars Reconnaissance Orbiter, we were using the nine-gigahertz frequency. I told the project manager I want to add a 30-gigahertz frequency as an experiment. There was always a resistance. "Hey, look, that's more work. We don't have the money." And, usually, I used to have my saying, "Well, which part of what I told you did you not understand?" And then, immediately, they say, "Sure, we'll go and do it." [laugh] ZIERLER: [laugh] ELACHI: And, of course, my job was not only to tell them to do it, I had to go and get the money, to fund it. And now we're capable of many tens of megahertz from Mars. And, more recently, and just before I finished being director, then we started adding optical links on it. So, we don't jump to the new technology before we demonstrate it first because we are fatally dependent on it. So, now, we are going to fly on a mission coming up, an optical link in addition to the radio link, and I think that's going to be the mode in the future is having at least both of those being used. The optical link gives us a lot more capacity, but of course there is the cloudiness. So, I don't think we shift ever completely to optical, for deep space. But it could significantly enhance our capacity. ZIERLER: I'm curious, given in 2004 with all of the talk about manned spaceflight with a vision for space exploration, and now the reality of autonomous space missions, what deeper questions might that have posed for JPL about when to send people to space, and when robots could do this themselves? ELACHI: Well, that's also a very good question, and I used to get asked that question all the time, people expecting that as a director of a robotic place, I say, oh, I don't support humans. It's the reverse. I support both of them, and the logic is the following. I think for science purposes, robotics can do—it's the preferred way, and it can do almost all the scientific things we want to do. And the reason is not that it's smarter than a human—I mean, clearly, having a human walking around Mars would make much better judgments as a geologist—but a large part of Mars, a human cannot go to. It's not like Earth here where you can go almost to every spot, even go down the Grand Canyon, and look at all the different layers in the Grand Canyon, go to the top of a volcano, and look at the flows. On Mars, you are much, much, much more limited. So, really, the robots are a preferred way of exploring because we can send them anywhere. We can take the risk on them. And now that we are having helicopters, you can go and fly in the middle of the canyon on Mars. You have much more capability to be able—at an even lower cost or equivalent cost, you can explore the whole planet. And then there are places where you cannot send a human, like going to Europa and Io and all the satellite planets, or landing on Venus. So, for scientific purposes, I think, clearly, the robotic mission is the preferred way to do it. Where the human come to picture…and before I go to the human side, when we send the robot, it's actually, at the end, it's a human because they are the people in the mission operation room, making the judgments. ZIERLER: That's a very important point, yes. ELACHI: So, it's really like an extrapolation— ZIERLER: Yes. ELACHI: —of our arm, to the planet. So, it's effectively the same thing. Where the humans, sending a human had worked is the inspiration of being able—and being a country like a great country like the US to do great things, to really go and explore, and expand our range, and in the long term of having inhabitation, on Mars or on the moon. And the reason I say it's very important because I got inspired by the landing on the moon with Neil Armstrong and his team. That was really exciting, even though we had robotic mission. But as a human, I kind of associated with it directly as being in another place. And I saw how much young kids get excited at seeing an astronaut. When I was director, I used to get call from principals from all around the county in LA from principals that would say, "Can you, Charles, arrange for us to have an astronaut visit, here?" And I used to do it, and NASA used to be very supportive. Matter of fact, one of the roles of the astronauts is to go to the different centers and go and visit schools. And the kids used to love it, to having them with that blue suit that they wear. So, for me, it's worth every dime, we spend on it. I keep reminding people that the budget of NASA is only like 1 or 2% of the discretionary budget of the government, and that's discretionary. If I add social security and other, it's peanuts. It's minute. And look at inspiration that NASA provide to the public, and the astronauts provide to the public. So, that's why I think I support—I think we really need to play a leadership in both of them. And many times, I mean, I remember, one day, my grandson and granddaughter when they were 7, 8 years old, I took them one night, and Googled to see when is the space station flying over, where they live in San Francisco, and had them stay up, and we saw the station, moving by. And I said, "Imagine there are six people like you living on that station, humans." And for them, it was amazing, wow, that we have humans living in Earth's orbit. I mean, for us, it's kind of normal, you know. But for a young kid, that's really inspirational. ZIERLER: With the Tropospheric Emissions Spectrometer, what did we learn about the Earth's ozone, and were there any public policy responses with regard to that research, given the fact that we knew how harmful our activities could be to the ozone? ELACHI: Yeah. Well, that looked both at the ozone and the methane, so these were two things. For the ozone, the first primary one was what's called the Microwave Limb Sounder. And that was a sub-millimeter experiment that Joe Waters was the PI and flew, and it looked at the horizon of the Earth, and looking at the sunlight coming through that horizon to the instruments, seeing what's being emitted and what's being absorbed. And there was major concern about the depletion of the ozone layer, and what impact it will create on human here because that protect from the ultraviolet radiation. And, yes, there was major policy rules after that, about what gas we can emit, like the CFC from refrigerator, and that led to a lot of restriction on chlorofluorocarbons. There was international treaties resulted from it. So, I feel really good that, there, JPL played a major role on that part, and on the—I mean, JPL and NASA could play a major part on relating to protecting our planet. And that's why I said earlier, our top priority is to protect our planet before we think about inhabiting, other planets. I think that pays off a lot better. Then, we had a Tropospheric Emission Spectrometer, which was looking both at the ozone and about methane because the ozone is harmful even down in the troposphere, not only at the top of the atmosphere in the stratosphere but also down in the atmospheric. It could be very damaging, to your lungs if you get too much ozone. So, that was also an instrument which we developed at JPL. The PI was Reinhard Beer, and that was done jointly with the British because, as I said, we had a lot of collaboration with Oxford University where we had a number of our scientists who were graduates from Oxford University. And that was really for being to monitor the ozone, other gases, and also the methane because the methane is a greenhouse gas which is far more effective than carbon dioxide. There is less of it being emitted but it makes up by being much more efficient, in protecting the heat. And that was a very tough one to monitor, the methane, because the emission from it is very weak that we get from it. But we developed an instrument that was a very big instrument to do that, which was a challenge to fly on many experiments. And that's leading to now a lot more awareness of not only carbon dioxide but also methane. Now, in the last 10, 15 years, there have been a lot more advances in detectors and spectrometers. But now, you can build a pretty small instrument or a much smaller instrument, and much cheaper instrument, to monitor the methane. Matter of fact, as a result of that, a number of scientists who were involved in the Tropospheric Emission Spectrometer, recently, the Environmental Defense—the Environmental—EDL, Environmental Defense, a private company, which is a nonprofit organization, were able to raise private money, close to about$100 million to build a philanthropically funded orbiting satellite with the specific purpose to monitor methane. And the whole mission is less than 100 million, while TES, 30 years ago cost a couple hundred million. But technology has evolved, and understanding has evolved so much. And, here, I'm working myself, and a couple of faculty here at Caltech are—like Paul Wennberg, and Dan McCleese, who was the chief scientist at JPL when I was at the tail end of my directorship—are advising the philanthropic organization on building a what we call MethaneSAT, which will be launched next year.

ZIERLER: Charles, I wonder if you can convey just how daring a mission Deep Impact was, both in terms of the engineering to get it going, and how an impact itself could do something more than just destroy the instrument.

ELACHI: [laugh] Well, clearly, there was a lot of interesting comets over many, many decades, going to Halley. But there was a challenge to know, what is a comet made of? Because from ground observation, we only see the surface of the comet or the tail of the comet. So, people were intrigued of what's inside the comet? And the question was, yeah, maybe we can do a lander, and drill through it. But that's kind of expensive, to build a spacecraft to rendezvous with the comet, land on it, build a drill. Then somebody—I really don't recall who it was—said, "Why don't we go close to a comet, and shoot a bullet at it, and create a crater, and that crater is going to eject material from below the surface, and analyze that material?" And, of course, at the beginning, it sounded like a crazy idea because you need to be coming at very high speed, and impact the comet, and you need a second spacecraft, in a sense, watching what happens. And the speeds are amazing. I mean, the comet is moving at thousands of—tens of thousands of kilometers per hour, and the spacecraft is moving at that kind of speed, so it's like we shoot a bullet with a bullet.

But these things never stop JPL. So, we did propose to NASA a mission which was called Deep Impact, and the idea was to go and fly by a comet, and have the spacecraft have—basically, there is a regular spacecraft, but also then there was a bullet which was about 300 kilograms of copper. And then, basically, target direct at, if you want, that copper, that bullet toward the comet nucleus, and then move the spacecraft off trajectory so it doesn't hit the comet, and watch when that bullet hits the comet. And that was a big challenge because not only building it and rendezvousing with a comet—I shouldn't say "rendezvous"—flying by a comet, but also, I mean, the comet is a few tens of kilometers, and you really have to hit it, and you have to—you're pointing literally within a fraction of a millisecond so the bullet and the comet hit each other, because the comet is not just sitting there. So, it's maybe like two trains coming, and you want them to intersect, within only a fraction of a millisecond. You can miss it. So, we had to develop a lot of optical tracking technologies because we couldn't do it from the ground because it would take many tens of minutes for the signal to go there and come back, so you cannot joystick it.

So, we kind of navigated, and put it on the right trajectory, and then the spacecraft had a camera on it, and it kept moving to the center of the nucleus of the comet in the crosshair on the camera, and adjust the spacecraft to be that way, and just about a couple of hours before the intersection, drops a bullet, and move to avoid the impact, and watch it on doing that. So, it's exactly the kind of technology, you find in unmanned things like bombs that are sent by the military to home in on a specific, target, except here you can joystick it. Except in our case, we could not joystick it. It had to be completely autonomous. And we were sitting in the mission operation room with our fingers crossed [laugh], watching that nucleus from the camera to see—do we see a flash? And, yeah, of course, we saw a big flash, coming out, so we knew we hit it. And then from the emission which came from it, we had an instrument on the mother spacecraft, which measured the composition so clearly we did see water vapor, H2O. But we saw also a lot of organic material which came from it. So, that was our first example of actually hitting a bullet with a bullet, which was Deep Impact.

ZIERLER: Charles, I'm thinking about Hollywood right now. To what extent was this mission about figuring out ways of deflecting comets or asteroids that might be headed toward Earth?

ELACHI: Yeah. No, I'm glad you mentioned that because that was the second experiment, on it was to see how much deflection, we had of the actual nucleus of the comet. And we were able to measure that, by tracking from the ground, you know. So, we were triangulating between the spacecraft, the ground, and the picture of the comet, and people, by looking at the navigation, after—we tracked the comet before the impact, and then we tracked it after the impact.

And we saw a slight change in its orbit, and that was consistent with the strength of the impact because we can calculate the power in that 300-kilogram piece of copper, the speed of it, the speed of the comet. It's a fairly straightforward calculation of how much deflection do you use. So, that was kind of used as a model. And now, NASA is planning an even more specific mission purely to deflect an asteroid in this case. So, they are going to do something similar where they have an impactor based on the technologies that we developed, and develop an impactor to actually deflect an asteroid, and watch how much to do that. And that's kind of the thinking that, in the future, if we can detect an asteroid early enough, not just two days before its impact, but if we can detect it many, many months before it impacts, we can go and deflect it enough because the farther out it is, the less deflection you need, and then, it builds up. You can miss the Earth by a little, teeny deflection. So, the idea would be one of the techniques is to do exactly what we did in Deep Impact.

ZIERLER: When the results came in, you were quoted in the news as saying that "the success of the mission exceeded our expectations." So, what were the expectations, and how did the results exceed them?

ELACHI: Well, I mean, we were kind of expecting that we were going to deflect—I mean, to hit the nucleus, but we thought 70% chance that we will get it. The first thing was to hit it. But then it exceeded our expectation in the scientific payout because one of the things we also saw after the plume kind of went away, we were able to image the crater. We were not sure we can do that. We were able to see the crater, and were able to determine the size of the crater which was generated by that impact, and then the measurement of the deflection. So, these were kind of, if you want, icing on the cake, beyond actually hitting it and getting to see the plume.

ZIERLER: What do we know about comets as a result?

ELACHI: Well, now, we do know that comets are heavily water, made of ice, water ice; that there is a lot of dust in them. Matter of fact, on the surface, you have a lot more dust than you have inside the comet, again, because a lot of the surface—just imagine that it's made of a combination of dust and water vapor and organic material, and every time the comet comes by the sun, the water evaporates. That's what create the tail. So, you get more and more dust sitting on the surface of the comet. That's why we want to see what's inside of it. So, I think people now have a pretty good understanding of the composition inside the comet, and about the, the dust, and the percentage of dust versus water ice and organic material. But, still, the key thing is you always get better if you can take samples, and bring them back to Earth, and analyze them in much more sophisticated, instrument on Earth, like in the chemistry labs at Caltech. So, still, the kind of the goal is to be able to go to a comet, land, and actually bring pristine samples from below the surface—not from the surface only but from below the surface. So, that's one of the things that is one of the future missions that is being studied now.

ZIERLER: With the Mars Reconnaissance Orbiter, to what extent was this mission complementary to the Mars rovers, and to what extent was learning about Mars's atmosphere a mission in and of itself?

ELACHI: Yeah, it was really doing both. The mission in itself is a scientific mission, to look at the atmosphere, to look at the surface. And I think based on that mission, and on the Odyssey, which was another mission which is in orbit, also built at JPL, people say, no, we have better maps of Mars than we have of Earth because we have the vast majority of Mars, we are down to a resolution of a meter on the surface. And the higher resolution will give you better insight about the geology, about the erosion, which is happening. And it complements the rover.

The rover gives you in situ…now, you are talking, you can see centimeters. But the rover can cover only a limited area. So, usually, the idea is you take the images from the satellite, and you look at an area, and study it, and then the rover is your ground troop, you know. It tells you, and—so, it can be used in a sense as ground troop/calibration of the images you are taking, and then you extrapolate to the rest of Mars.

So, they are—so, the Mars Reconnaissance Orbiter and Odyssey are both key missions in their own right, and complementary with the rover. But, also, they bring the additional features of the communication, where, basically, it allows you to communicate with the rover at much higher capacity, and it will allow you to communicate when the rover many time is on the other side, of Mars which is not in direct view of Earth but is in view of the Orbiter, and then the Orbiter communicates with the Earth. So, it extends both in higher capacity but also more extensive coverage. And, finally, the orbiter images help us in determining where to send the rover, by looking both at the scientific, features, but also on the roughness, of the surface and the rock. So, really, it's hand-in-hand, they work together. I would say without the orbiter, the rover would be much, much less efficient in its capability.

ZIERLER: With CloudSat, to what extent did this research get you all the way back to the beginning of your work at JPL?

ELACHI: Well, that, clearly, that the Earth role that JPL has been playing expanded significantly over the last two decade. And particularly, matter of fact, when I was director, as soon as I became director at JPL, I changed the organization at JPL, and divided it. Before, we used to have instrument and flight, flight being the bus and the spacecraft, and then we had the instrument, and then we had the technology. When I became director, I cut it differently. I formed a directorate for planetary. I formed a directorate for Mars because Mars was a big focus. I formed a directorate for Earth science. And I formed a directorate for astrophysics. And each one of these directorates had in it the science, the instrument, the spacecraft, and the technology, and the operations.

So, it was more integrated relative to the scientific objective versus the engineering, which is bus, instrument, operation, and science. So, that created a big focus toward the Earth, observation in addition to the other one. And there, I put Diane Evans, who was a geologist, a relatively young geologist, was one of the first people appointed, who was younger than me, on doing that. And, so, she headed the Earth science, and she headed it almost continuously during my tenure. So, that created significantly more focus on Earth missions, not only Earth instruments, which we were already very good at. And it made us very competitive because we were very good at the instruments and very good at the science, so that made it easier for NASA to assign missions or to win competitive missions.

Coming back on the mission you mentioned, CloudSat, one of the key factors in global warming was to understand the clouds, their water content, because they are a key factor on how much sunlight gets reflected; how much get transmitted. And then we had developed technology at JPL for very high frequency radar instruments, which scatter from the cloud and from the rain, and allows us to measure the water content—that's what we needed to measure—and the thickness of the cloud. And that was—again—it was advances in technology which enabled that because we had to use—I don't remember now the frequency, but very high wavelengths, in the millimeter wavelengths, and the developing—development in building transmitters at that very high frequency was what enabled that mission to actually happen.

And that mission is still flying, you know. It was launched during my days. It's still flying, and it basically measures on a regular basis how much water content is in the cloud. And it's interesting, going back on the international aspect, that mission, I mean, it was done mostly in the US, but the principal investigator—his name is Graeme Stephens—was Australian but he was an immigrant who moved to the US after he graduated and is the principal investigator on it. And Deb Vane is one of the first female project managers to run a mission. So, she's also a lifelong employee at JPL, and she's still running that mission.

ZIERLER: Charles, given that the CloudSat mission looked at the connections between clouds and extreme weather events and climate change, of course, a year prior, Hurricane Katrina really made it apparent the deepening impact of climate change to these extreme weather events. I'm curious if Katrina was at all an inspiration or a source of the urgency behind the mission of CloudSat.

ELACHI: Well, not Katrina itself but all the hurricanes. I mean, Katrina made it dramatic because it hit, in a very inhabited area, and it caused a big damage. But slowly, people were realizing that these hurricanes are going to cause major damage, and that space activity could significantly help us in both understanding them and tracking them. So, it was a multi-mission kind of strategy. CloudSat was one element, you know. It gave us information. Matter of fact, in my latest textbook, I have pictures of CloudSat measuring across a hurricane, the water content in the hurricane. But, also, it helped on looking—and rain-mapping radar, which JPL was involved in, but Goddard Space Center was the lead to map the rain. It was a lower frequency radar which mapped the rain, not the clouds.

So, you need to measure the clouds. You need to measure the rain. You need to measure the wind, the updraft which is happening because before the hurricane formed—so, you had updraft which leads to the formation of the hurricane. You need to measure the temperature in the ocean, because hurricanes happen when there is warming of the ocean, and then the speed of how the hurricane moves depending on what the temperature of the ocean, and how much moisture is in the air, because that's a key driver into moving the energy from the ocean into the hurricane. So, it's a multiple kind of mission to do that. And then JPL was involved in some of these missions, and many of the instruments which led to that, so, for instance, measuring the wind at the surface. We look at it with what we call a scatterometer radar instrument, which measures the ocean roughness through the clouds of the hurricane and determines the wind pattern under the hurricane. We measured how much water there is the cloud. The rain-mapping radar measure how much rain actually is precipitating, and then how much updraft is happening, by measuring the doppler shift.

Infrared instruments measure the ocean temperature, which is on the surface. And a number of other microwave instruments will measure the amount of moisture in the eye of the hurricane in the atmosphere. So, by taking all of this data, the hurricane center in the US kind of needs to make predictions on the strength of the hurricane, and also about the track of the hurricane, where it will be going, which is critical for preparation and minimizing the damage that a hurricane does. So, it was really a collection of those, and Katrina was a very dramatic illustration of this. And I'm proud to say that JPL played a significant role in many of these hurricane studies in generating the data which goes to these mission—from these missions to the monitoring.

ZIERLER: Is part of this the importance of early detection, knowing where the hurricanes are headed?

ELACHI: Oh, yeah, a key factor. Now, detecting the hurricane is on the easy side because you can see it with visible imagery. We know most of the hurricanes happen off the west coast of Africa, so detecting the early state of the hurricane is relatively easy. The challenge is where would the hurricane go, and be able to predict many days ahead of time, and the strength of the hurricane because these are what cause the damage—because many hurricanes start and fade away, or many of them go in the ocean, and never hit land, so their damage is fairly limited.

I mean, they are helpful for tracking them for airplanes and navigation, and ships. But it's really learning more about the track, directing the track. I mean, we get to a stage where we are absolutely sure we know a week ahead of time where the hurricane goes. That has a major impact because every time you evacuate 100,000 people, that's a huge cost to do that. And then knowing the strength of the hurricane, is it going to be really damaging or not damaging? And, recently, over the last year, we are seeing more and more of these hurricanes, which are driven, we believe, because of the warming, that is happening in the atmosphere and in the ocean.

ZIERLER: Charles, we talked about the excitement possibly over searching for life on the red planet with the Mars rover missions. When the Phoenix mission was being conceived, to what extent was the rover mission providing further evidence that there might be life on Mars but the Phoenix mission was designed to look more closely, and to what extent was that unconnected from the Mars rover mission?

ELACHI: Well, usually, none of these missions are unconnected because each one contributes a new set of information. You learn a little bit more about it. The goal of the Phoenix mission, which was purely a lander, was to go to the polar region close to where the polar caps are, and actually dig below the surface, and see if we can get to the water ice. And it was successful, in doing that. So, we landed, we actually did some drilling—not drilling but scooping, and actually we scooped a little bit, we actually could see the white ice, which is just below the surface.

So, it verified that, actually, there is ice very close to the surface. It was a follow-up to the Mars Polar mission, the one which failed. That's why it was called Phoenix. It was an exact—almost an exact copy but, this time, we were a lot more careful, and we made sure we watched it as it was landing on the surface, and it was very successful. So, yeah, that was a very heavily—we capitalized on the polar lander which failed, but it was informed by the information that we got from the different rovers.

ZIERLER: So, how much closer are we now to understanding about whether there is or ever was life on Mars?

ELACHI: I would say we are closer, but we are not there [laugh] yet. That's a careful researcher response. I mean, we know water existed on Mars. We know there is ice below the surface on Mars. We know all the chemical components, all the ingredients to cook life on Mars, or to stew life on Mars—depending how you want to look at it—exist on Mars. We know there are organic, small organic molecules on Mars.

So, I would say we are maybe 80% there to say with confidence—and, again, we are careful with our words—that Mars is habitable. That means that life could have evolved on it, or we might find signature of life having evolved on it. So, I would say when we get samples back to Earth by the end of the decade, I would say we will get very close to 95% sure of the answer, one way or the other, about is Mars habitable; did life evolve on it; if evolved, to what level it was evolved? It didn't—if it didn't evolve, why not? Where did it stop, and what caused that? So, I would say by the end of this decade, we'll be very, very close to answering that question.

ZIERLER: Something to be excited for. Charles, last question for today, during your tenure as JPL director, JPL was recognized by the Space Foundation three times with the John L. Swigert, Jr. Award for Space Exploration. Being a third into your tenure at this point, to what extent was this and other honors a useful barometer for you about taking stock of where JPL was, and how you were performing as director?

ELACHI: I mean, no question, this is one of the measures, of doing that because it reflected the appreciation and the recognition by the broad community, be it scientific or be it engineering or being public, about recognizing the accomplishment of JPL in general. Matter of fact, interesting enough you ask that question. Literally last week, I was—we bought some new furniture, and I was moving all the different awards that I received, medals, newspaper recognition, and I was blown away.

I told my wife, "I'm amazed what we accomplished during those 15 years." I mean, literally, newspapers, I filled 12 boxes of articles from magazines to newspapers, articles, which were about JPL, about my recognition. And then I had—literally, I think, we counted like 60 or 70 medals that I received during that period, ranging all the way from the Bob Hope Medal, or award, which had nothing to do with space but it's recognizing about exploration, to a medal about science and art, by the Art Center, to purely technical recognition, like the National Academy of Engineering or the IEEE and so on.

ZIERLER: Charles, if I may, let me just add one more that might be very special to you, the Philip Habib Award, as a fellow Lebanese American.

ELACHI: That's right. That's right. So, that was that award also that I received, and the Order of the Cedar from the president of Lebanon. There were two of them. Chevaliers de la Légion d'Honneur from the French president. So, it was really uplifting, to see how much was accomplished. So, in a sense, when I give talk, I still talk about it as the golden age of space exploration. The only thing I feel sorry for is my daughter, dealing with all of this.

ZIERLER: [laugh]

ELACHI: What is she going to do with all that stuff?

ZIERLER: [laugh] Charles, that's a great place to pick up for next time.

[End of recording]

ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It's Friday, October 22nd, 2021. Once again, it's my great pleasure to be with Professor Charles Elachi. As always, Charles, it's great to see you.

ELACHI: Yeah, it's a pleasure to see you too.

ZIERLER: Charles, today, I'd like to start with a question that doesn't belong anywhere in particular in the chronology, but I only thought to ask it because of the research I was doing yesterday. So, I was in the Caltech archives, looking at the papers of William Dreyer, and I saw that he had a whole proposal about creating a JPL medical science laboratory, and the prospectus that he wrote was in 1973. Are you aware of this, of any research into medical health issues that JPL was involved in?

ELACHI: No, to be honest, I don't. I really don't know that. That's—yeah, no, I'm not aware of it. In 1973, I was at JPL but I was way down in the bottom of the organization doing my research. [laugh]

ZIERLER: No, of course—

ELACHI: I was not aware of that.

ZIERLER: —to fast-forward all the way to 2020, JPL did very important work on ventilators during the COVID crisis.

ELACHI: Yeah, that I'm aware of, because, I mean, that—the interesting thing at JPL, I mean, we have very imaginative engineers, and they love working on challenging problems, and because COVID was such a major impact, some people had some ideas. So, they went, and very quickly they developed these ventilators at much lower cost. And I think they have been used in a number of places.

ZIERLER: Was the ventilator project—did it have some existing orientation in JPL? In other words, is there a part of JPL that does work that's relevant to health sciences?

ELACHI: Well, we have a group at JPL or an activity at JPL to do innovative things. And, usually, what we do, well, part of our philosophy is that if people have interesting ideas, even if they are not 100% aligned with what we are doing, but they are engineering ideas or they can capitalize on the engineering technology we have, so we usually encourage them to go and do that because you can never tell what comes out of these things. I mean, many times, new inventions come out from nowhere if you are working in a completing different field, and something new comes out.

So, these—because of the capability of JPL in doing miniaturized things, electronic things, so a number of people—and I know the management at JPL encouraged them to do that because it was a national challenge. So, people come up with innovative ideas, and we let them go and work on it. And I wouldn't be surprised that something will come out of, that development which could benefit, some of the work we are doing at JPL for space missions.

ZIERLER: Charles, it's a theme we've talked about before, and it's one that you mentioned many times in your public lectures as JPL director, and that is the value of competition. I wonder if you can talk about that within the context of being an immigrant to the United States, and recognizing the way that the United States embraces free market capitalization for which competition is central.

ELACHI: Yeah. No, absolutely. I mean, I always say one of the biggest benefits that leads to the leadership, be it economical or scientific, is the fact that there is free competition in a constructive way, in doing that. And I remember at JPL, just before I became director, up to that time, almost all the mission were given to JPL. So, if it's a planetary mission, automatically, JPL gets it.

Then NASA decided in late 1990s that they want to run competitions on some of the planetary missions. And there was first the reaction, people had a negative reaction, I mean, the employees. "Gee, now, we have to compete to get these things." But I came from that background, even at JPL, where instruments, scientific instruments are always competed. They always were competed for the last 50 years. So, it was a natural for me that you have to compete to get something. So, I had a number of meetings with employees. I told them, "Look, guys, you should look at competition as a positive thing because it creates innovation and ideas." And I told them, "Look, if we don't win the competition, shame on us, you know. If we really think we are the best organization in planetary exploration, we should be able to win the majority of these things." And I always said, look—and then there was a question on should we share all our capability with other people, I mean, what we develop, and make it public.

And I told them, "Look, there is no way you can hide things, and if you hid them, it doesn't keep you at the leadership. The best way to stay a leader is to run faster than every…any…everybody else." So, that's—and I always give an example. I'm like, "Let's compare to the Soviet Union," because I went to Russia as the Soviet Union was opening a little bit, so I was invited to go to their space agency, and I visited their labs. What shocked me is that even that they were very good, one lab did not know what another lab is doing. Everybody was hiding their research. I mean, that was their system. While here, I go and give talks on everything we do everywhere, and people come up with new ideas, and I share my ideas, they share their ideas, and we get better by doing that. So, for me, that was a comparison of how openness and competition really allow you to play a leadership role, and really move things much faster than if you have a more autocratic system.

ZIERLER: Charles, of course, President Bush, the 43rd president, he made no secret of his love of space exploration, and his admiration specifically for JPL. What did that mean for you as director to have such a fan of space science in the Oval Office?

ELACHI: Well, oh, sure, it's very exciting [laugh], to do that because, you could imagine, I mean, he has probably hundreds of things every day that he has to worry about, and taking the time of actually watching—I think it was after the landing—

ZIERLER: The Mars landing, yes.

ELACHI: —to try and to sit down and watch the landing and watch the helicopter. It was very rewarding, to see that. And, the same thing with, every time we had a landing, the president called, the team at JPL. So, we had Bush 43, Obama, and now Biden. And in a sense, what almost all of them said is that by watching what you guys are doing really uplifts the spirit of the country because it shows that if we put our mind to do something, we can do things which seem impossible. So, that was the rewarding part about it, not only that they acknowledge what we are doing but the fact that they acknowledge that what we do is uplifting, and inspires young people. I mean, that's a big reward from what we get. And it reminded me of a story that when we landed Curiosity, and I had as guests the head of the French Space Agency and the deputy head of the Russian Space Agency. I invited them to come, and they were in the mission operation room. And after the landing, we went out to the entrance hall, and they came to me, and they said, "Congratulations, Charles. Only the US can do this." And I felt so proud, hearing that, from the French and from the Russians that it really makes…it gives a sense of reward for all of that hard work.

ZIERLER: When you're getting ready to talk to the president, when you're on the call when Sean O'Keefe is in the room, what are the protocols? What are the things that you have to keep in mind when talking to the president?

ELACHI: Well, I mean, they really didn't give us many guidance. We were sitting around the table, and it was on the speakerphone, and Sean O'Keefe was not with us. He was in Washington. The key thing we were told is just make sure you listen to him, not to interrupt him. And he was very gracious. I mean, it ended being a conversation, back and forth after he did the congratulations. And then at one moment, I told him, "Well, Mr. President, if you come and visit, we will like you—we will let you drive the rover."

ZIERLER: [laugh]

ELACHI: He said, "I'd love to do that but my Secret Service won't even let me drive my golfing cart."

ZIERLER: [laugh]

ELACHI: [laugh] He was very, very humorous, about it. And then when President Obama called, he was on Air Force One, so that was kind of interesting. It was in a different, setting. In that case, we put him on a speaker, for everybody to hear the conversation. So, everybody was lined up, and I was standing with the key members of the team because it was a videoconference. And the same thing…after the congratulatory notes, so it was a conversation going back and forth. And in the case of President Obama, he said, "Wow, I was watching the landing, and you guys, I didn't see any one of you wearing a tie," because he's accustomed, like at the Johnson Space Center, everybody's in white shirt and a—

ZIERLER: Right, right.

ELACHI: —and a tie. In our case, we had our blue shirts. So, they all had a sense of humor, a kind of personalized sense of humor.

ZIERLER: It was a wonderful transcript to read between you and President Bush. One very interesting thing you said when you invited him to come out, you invited him to discuss, of all things, string theory. What were you thinking?

ELACHI: [laugh]

ZIERLER: Why string theory, of all things, to discuss?

ELACHI: Well, because it's the one which always when we have young people, kids coming, they are always ask about string theory. They have no idea what it is. I have no idea what it is. [laugh]

ZIERLER: [laugh]

ELACHI: I have no idea to explain it but it's kind of fascinating. I think people who are outside the scientific field, as well as some people in the scientific field, get fascinated with these exotic things like string theory, Big Bang, all the gravitational waves, things which are kind of very hard, and you don't see them in your day-to-day life, and they are very fascinated about these things.

ZIERLER: A very interesting and funny question, after Deep Impact, whose idea was it to have the band The Comets play at JPL?

ELACHI: Oh [laugh], no, it was our public relation guys. They thought, that will be cool, to do that. And, so, we invited them, to come, and they were very gracious. They really agreed to come. Now, they were a hell of a lot older than what we remember, and they thought it was cool, because we were impacting a comet, and it was a great party. So, we had it, in the mall, outside JPL because we had kind of the tradition that when we have a landing, and things are successful, we have some kind of an event in front of the main building. And, usually, we have a band at JPL, and a number of people are musicians, so they usually play on that one. But on this one, our public relations guys said, "Let's invite the band, the real Comet band." And it was great, and people were dancing, and it was a great event.

ZIERLER: Charles, we talked in great detail during the time when you were selected to lead JPL, the way that works with Caltech leadership. In 2006, with the transition from David Baltimore to Jean-Lou Chameau, as vice president of Caltech, as JPL director, what role does JPL have institutionally, or the director specifically, in these decisions leading to who will become the president?

ELACHI: That is a very interesting question. Basically, what happened normally, the board of trustees form a board committee, but also they have a faculty committee, which basically is mostly faculty, and they do the first, if you want, to come up with a list, and do the first filtering before we do that. JPL normally is not involved in the decision to select the president. We have JPL employees involved in the selection of the director, of the search committee for the director. But for the president, it's all mostly faculty. But then, the chair of the faculty committee, they did interview me to ask about what are the challenges at Caltech. Do I have any suggestions? So, they did engage JPL. But in the case of Jean-Lou Chameau, it was really interesting because all of that is done very discreetly. But, one day, I get a call from Kent Kresa, who was the chairman of the board of Caltech, and he said, "Charles, we are at our final candidate. But when we talked with him about being the president, he said, ‘Well, I know JPL is a big part of the—of Caltech. I'd like to meet with the JPL director before I make my decision.'"

So, Kent Kresa was asking me, "Will you be willing to take him around JPL for a couple of hours?" And we decided to do it on a Saturday because we didn't want to let the cat out of the box, I mean, people seeing somebody coming, walking around. So, I went to pick him up from the Huntington Hotel, which is now called the Langham Hotel, and—

ZIERLER: Now, was it hello or was it bonjour?

ELACHI: [laugh] Well, he knew that I was educated in France, and I knew from his name as soon as they told me. I never met him before. I mean, I knew about him because he was at Georgia Tech as the provost. I drive there, and here he comes with Dave Stevenson, who was the chairman of the faculty committee. Dave just came to introduce us. We talked in French, and bonjour and so on, and Jean-Lou got in the car, and I told Jean-Lou, "Oh, I heard that your wife is here. Would she like to come?" He said, "Oh, will they allow her to go in?" I told him, "Jean-Lou, I'm the director."

ZIERLER: [laugh]

ELACHI: "I can take anybody in." [laugh]

ZIERLER: [laugh]

ELACHI: So, he went running back, brought Carol, with him. So, I drove both of them to JPL, and we chatted in French, and then I gave him more information about my background, where I went to school, and so on. And then we got to JPL, and we went—first, we spent about an hour in my office, and I told him about the relationship of JPL with Caltech, the campus, the history, our connection with NASA, what are the challenges that are coming up. Fortunately, everything was going very well, at that time. It was after the landing of Spirit and Opportunity, and we were getting ready for Curiosity. I took him to the museum, and then I took him to the High Bay where we were doing some assembly of our spacecraft. And he was delighted and, shortly after that, he accepted the offer of being at Caltech, and we had a great relationship. I mean, I used to meet with him every other week.

And one interesting thing I remember, when we were doing the landing on Curiosity, normally, the president of Caltech sits in the viewing area with the VIPs, because we had senators and Congressmen and so on. Jean-Lou being an engineer, he said, "Charles, is there a way I can be on the floor next to you in the mission operations?" So, I told him, "Well, that's not normal but, sure, we can arrange it for you." So, he was sitting there, he and I and the administrator of NASA. And him being an engineer, he was really engaged—

ZIERLER: Yeah.

ELACHI: —you know. He loved—he was a civil engineer. And I remember once we landed successfully, he and I hugged each other, and did a couple of steps of dance, together because—and he told me that, after, that that was probably the highlight of his stay at Caltech. Matter of fact, in his official picture, of Caltech, which is at the Athenaeum—we have a painting of each and every president—in his painting, he had a little rover, in the painting.

ZIERLER: Yeah. [laugh]

ELACHI: He wanted that, so it was great. And then when he left, he was always very generous with us. I remember he and his wife had a house in New Mexico, and then they sold the house, so they brought all the furniture back here. And my wife and I have a house which has a very southwest motif, and we collect southwest style carpets, furniture. So, they offered us their furniture, what they had, to put in our guesthouse. And, so, I gave him a check for it. He took the check, and he tore it up. He said, "No, that's a gift." So, my wife and I decided to give them as a gift a model of the rover, so we bought a—and he was ecstatic with it. And I remember he had it in his office, when he was in Saudi Arabia and then in France. He sent me pictures, of it. So, we had a great relationship.

ZIERLER: As an engineer, was there any particular value in having him as president of Caltech at that point?

ELACHI: Well, I mean, it's—Caltech kind of goes back and forth between engineers and scientists.

ZIERLER: Yeah.

ELACHI: So, Baltimore was a scientist. Jean-Lou was an engineer. Before Baltimore was an engineer, and then, after, we had Tom Rosenbaum. I mean, no, because at JPL, we're both engineering and science, and almost all the presidents I dealt with were very engaged with different activities at JPL because they are always very broadband. I mean, the presidents at Caltech, they have a very broad perspective. But Jean-Lou always asked, when we met a lot of—when there are issues and challenges, he was curious to know the engineering aspect, of it. And having that kind of experience, be it a scientist, Nobel Laureate, like in the case of David Baltimore or Jean-Lou as member of the academy, Tom Everhart before him, they carry a lot of clout with NASA, because NASA realized, I mean, because most of the people at NASA are also engineers or scientists. So, they connect with them versus having somebody purely administrative. So, yeah, there is a benefit, to doing that. It's usually the president at Caltech trusts the director of JPL to work the detail, or the engineering issues at JPL.

ZIERLER: Charles, that same year in 2006, you announced new policies on transparency at JPL. And I'm curious to what extent that was in coordination with NASA Administrator Mike Griffin's initiative on transparency, and to what extent that was a homegrown effort at JPL?

ELACHI: Well, at JPL, it was always a homegrown effort. I mean, transparency was a key factor. Matter of fact, when—usually when we have new employees hired at JPL, I used to go and meet with them. Usually, we used to give them a one-day entrance briefing, if you want, and it used to be on the first Monday of every month. I used to go for like 15 minutes or half hour, and welcome them, and I always used to emphasize that one of the key principles at JPL is openness and transparency.

And I used to give them a quote basically saying that "Look, don't try to hide things. Don't try to sugarcoat things. Just be completely transparent on things. If you don't know something, say, ‘I don't know it.' If something bothers you, say, ‘That bothers me, you know. We have an issue here.'" Because I told them, "It's a hell of a lot better to know about a problem before we launch a spacecraft than after we launch it. Sooner or later, we are going to have a mistake"—so, we really—it's—so, that's one of our core principle is openness and transparency. Now, Michael Griffin, emphasized that at NASA, and we emphasized it also at JPL, but it was something completely normal, for us.

And I think part of it comes from Caltech, the campus. I mean, the faculty will not hide anything [laugh], you know. They are completely transparent. They say what's on their mind. They don't care who does it bother or not bother. So, I think it's that culture of being part of Caltech, which created that kind of environment or atmosphere.

ZIERLER: Charles, in thinking about the Dawn mission that looked at protoplanets and dwarf planets, I'm curious if JPL worked with Mike Brown on the so-called Pluto-killing mission—

ELACHI: [laugh]

ZIERLER: —demoting Pluto from our nine-planet solar system.

ELACHI: I'm not aware of that, that there was any connection, in there. But, Mike, his office is across the hall from me. Clearly, what he did on Pluto, which I think was the right thing, I mean, he was just taking it in a very scientific approach of, gee, we've discovered a lot of objects which are even bigger than Pluto way out, so there is no reason why to call Pluto a planet. It could be a minor planet, but some people were offended that it was called minor planet versus a regular planet. But the Dawn mission was going to Ceres which was a pretty big asteroid. And I think in the early days, I mean, a couple of hundred years ago, astronomers thought that Ceres was a planet because, at that time, they just saw a dot on the thing. And then after, they found the size of it, so it became a minor planet or a large asteroid. So, I didn't think Mike was directly involved in that aspect. I'm sure scientifically, if he was interested, in it. But, yeah, no, what he did on Pluto was the proper thing. Now, some young kids didn't like it, and some astronomers didn't like, particularly, there was a mission going to Pluto. So, the people on that mission kind of felt left out. they fought it but the association which names these things agreed with Mike about that.

ZIERLER: Charles, you've talked many times about the importance of robotics in developing a permanent mission on Mars. Were there any particular advances in robotics happening at JPL or at Caltech that made you optimistic at this time to emphasize the importance of robotics?

ELACHI: Well, I mean, robotics, I mean, most of our works have been on—in robotics, particularly on spacecraft. But the key advance happened when we started developing rovers or develop the technological capability for rovers. We started with Pathfinder in the late '90s, and that became quickly apparent to us that having the ability to move and explore more areas, really makes a big difference. Because, when Viking landed, all what it had is an arm, which went about a few feet away, and you could see rocks in the horizon, which seemed to be very interesting. But there was no way you can get to them and analyze them.

So, after we did Pathfinder, and then we did Spirit and Opportunity, and then Curiosity, it became clearly apparent that being able to be mobile and to be able, to go and reach interesting areas, and take your instruments with you, and measure those, is going to open a whole new horizon. And that's kind of what led also for pushing, and for me to advocate to do the helicopter because then, for me, that was another major jump. I mean, the technology was developed on Earth, to do drones, but then we had to develop the capability which enabled it to fly in a Mars environment, which is very different than Earth's environment. The pressure was much lower. The temperature was much colder. So, we had to develop the technology for it. And it was very quickly apparent to me that this is going to be the next leap beyond rovers, where you can really send robots all the way, many tens, maybe hundreds, maybe thousands of kilometers, in the future. And Caltech had a road in the sand, so there was a lot of research on robots happening on the campus. There is a whole team which works on both moving robots, walking robots, hopping robots, drones. So, there was an interplay, between the campus and JPL on the technology in that area. And that's where I believe that robots would play probably the major role in the long-term exploration, of planets, particularly, in the case of Mars because humans have a limited capacity, particular in those harsh environments, how far you can go, because you have to be always suited and/or inside a capsule.

So, a human would be very limited even that they are smarter than the robot, but they are very limited in where they can go. And, also, there are many risky areas, edges of cliffs, that—canyons where the robots can go, and if, for some reason, they fail, it's not the end of the world. But astronauts would be very, very cautious. So, I really believe that the robots, both by themselves as well as an extension of astronauts, are really the way to do exploration, be it on Mars or places where human cannot go, like Titan, for instance.

ZIERLER: Now, this question will invariably get to a bit of science fiction because it comes at the intersection of robotics and humans, but does JPL think in the long-term, in the way that technology that's not feasible today, but if we want to talk about establishing a human presence outside of our solar system, far-flung concepts like uploading consciousness into a computer, or having a robot store human DNA for an embryonic creation at some point in the future, how wacky or far out does JPL get in thinking not just in the next 10 years but in the next century?

ELACHI: Well, these ideas are wacky, but we love wacky stuff [laugh] at JPL! Matter of fact, we always think the craziest ideas are more interesting, even if it's only one out of ten will materialize. It's always very, very hard to say, oh, we cannot do this, or that's impossible, particularly when we are talking about this century timescale. Because if we go back a century ago, let's say in the 1900, who would have thought that at any minute, I can walk down, get in a car, get to LAX, and fly to Paris, and I'll be there within 10, 12 hours? People would have said that was pretty wacky ideas, at that time, and probably science fiction people were talking about it. So, I think these things are possible, as long as they don't break the laws of physics, you know. I mean, it gets a little bit marginal when people say, oh, we can go faster than the speed of light. That, I would say, that's really wacky. I don't think I'll pay attention. But any of these other ideas, are possible.

I still think transporting human consciousness and intelligence is still a faraway kind of an idea because it is amazing what the human brain can do. And even today when you talk about artificial intelligence, and computer learning, and so on, I'm always a little bit skeptical about adding the word "intelligence," in it because it's really what it is and, from the beginning, I always thought it's really what the computer is doing. They enable it to handle a huge amount of data, in a very rapid way. But that doesn't make it intelligent. It makes a good processor. And, now, matter of fact, I see a lot of articles where people are saying, well, maybe we are exaggerating the statement "artificial intelligence," or the emphasis on the "intelligence" word because, basically, all what the computer can do so far is to execute what we tell it to execute. While as humans, we don't execute what our parents tell us to execute. We have an imagination. We can come up with something brand new based on what we have seen or what we have felt. I mean, you look at two 3-year-olds. Just by looking around them, they can become very conscientious of the world around them very quickly. Computers are not there yet. But, who knows, 10, 20, 30, 50 years from now, something new might happen.

ZIERLER: Are there groups at JPL that are specifically tasked with those questions way out into the future, or it's whoever wants to go there is welcome to?

ELACHI: Yeah. No, we encourage people to think way out of the box. We had, matter of fact, a group at JPL which was working on the origin of life, to figure out how did the first cells happen. Now, offhand, you could say, well, what does that have to do with what you do at JPL? But it does have to because one of the objectives is to send spacecraft to other planets to find out could they have life on them. So, a key thing is to be able to—ideally, we would like to know all the way [back], how did life start? What triggered that? To create a cell, and then the cell to create, life, is to see if we can see something similar, be it on Mars or on Titan or in the ocean of Europa. So, no, we have that philosophy which is from the campus. Basically, the way we put it on the campus when we are hiring faculty, we say, well, our goal is to hire the smartest people and let them loose. Let them go and think, whatever. Now, at JPL, we almost do that because we still have to build spacecraft, and launch them, and so on. But we do let people say, hey, we hire the best people, and if you have some ideas, we have discretionary money that we would provide them, to go and think about crazy ideas.

ZIERLER: Charles, I asked you a question about President Bush being a big fan of JPL. Maybe that was an easy question to answer. This might be a little harder, but I think it's very important for the historical record. There were reports during the presidential administration of Bush that he or Vice President Cheney or someone in the administration did not encourage NASA to pursue climate change research. And I looked through the record, and I couldn't find any statement from you one way or the other, and I wonder if you were taciturn because that was true but you were not in a position to complain about it, or if that's not true, and you never actually got any of that pushback from the administration.

ELACHI: No, I don't think—it's not true. No, I don't recall. I mean, people always ask questions, and that's normal. Every time there is a new administration, which comes in, they—or it's new people who are—I mean, at the presidential level, I don't think they get involved in that detail. But there are people under them. And, always, you have people across the spectrum, some people who love astrophysics, some people who love planetary, some people who love earth science, and always they ask questions about if we are spending the money the proper way.

But I don't recall ever at that time, with any of the administrations, of being negative about Earth observation. There were people on the Hill who were skeptical. I did encounter, talking with some people on the Hill, that they were skeptical in the sense of saying, well, why are we spending this money on this thing? Is it—because, in a sense, because a lot of scientists were saying this is human-impacted, some companies got threatened a little bit, oil companies, and of course they talk with their congressman. Their congressman is not very well informed, so they react the same way on, why are we doing this? I found almost all the time when I talk with people on the Hill who are skeptical, by showing them scientific data, actual data that we're acquiring with our satellite, many of them kind of start saying, well, maybe it is true. Maybe what you are telling us, it's true. Because we do show records from our satellite about the ocean rising, about carbon dioxide increasing in the atmosphere, about the warming of the ocean, because we have records which go over decades, from satellite, melting of the ice in Greenland.

And I remember one specific Congressman—we became very good friends—his name is John Culberson from Texas—and he was the chairman of the appropriation committee which oversees NASA. He was kind of skeptical a little bit about it, but he loved space. He loved planetary science, so he used to come often to JPL. And I remember from the time I met him—that was shortly after Spirit and Opportunity, or around that time, so that's 2004, it was the time I stepped down from JPL—he really changed from being kind of skeptical, to asking a lot of questions, to becoming a believer in that—that what we are doing is the right thing.

So, in general, the philosophy I use approach them is not to tell them the sky is falling because that looks like we are too alarmist. So, it was more to say, look, this is a major issue. Yes, there are some people who think it's human-made or not human-made. But that's irrelevant. The environment is warming. It's impacting our lives. We really need to do something about it. And even if the human contribution is 10% or 20% or 30%, we ought to reduce that, because, otherwise, it's going to make the problem or the situation even worse. So, by talking more of a logical way instead of an alarmist, way, I think many people kind of change their mind. But, going back to your original question, I don't recall ever being told by the administration that we shouldn't be doing Earth observation.

ZIERLER: OK, that's a very good point to clarify because there are some reports that suggest that that pressure was coming from the administration.

ELACHI: And, you can look at the budget. I mean, the budget of the Earth science, it went up and down a little bit. But it regularly continued to be growing. Now, clearly, at the present time, with the Biden administration, there is a positive urging because people are starting to appreciate that, really, climate change is a big issue.

ZIERLER: Yeah.

ELACHI: It's really impacting us, and we need—I mean, NASA is not going to solve it. What NASA does, it will be able to monitor what changes are happening, and, in the future, monitor any policies that are applied. How is that impacting the environmental change by cutting down carbon dioxide? Is the planet kind of stabilizing? So, that's where NASA comes into the picture.

ZIERLER: In 2008, it was an amazing milestone. It was the 50th anniversary of the Explorer 1. I'm curious what that get-together was like, and how it was meaningful for you.

ELACHI: Oh, no, we had a great party, to do it. We always have an excuse to have a party at JPL. [laugh]

ZIERLER: [laugh]

ELACHI: But it was a double thing, one, it was a—because there were still some employees at JPL who were involved in the Explorer 1, as well as we brought some of the retirees.

ZIERLER: Oh, that's great.

ZIERLER: Charles, was it also a moment of reflection in the ways that JPL had grown since 1958? In other words, in 1958, the name "jet propulsion" probably was a pretty good explanation for what the lab did. Fifty years later—

ELACHI: [laugh]

ZIERLER: —it's so much more. I wonder if that was an opportunity to reflect on that.

ELACHI: Well, sure, absolutely, because it is really—it was a different JPL, you know. I mean, we had the legacy and the tradition. But it was a very different JPL because, in 1958, we really were a jet propulsion lab. Almost 99% of our work was actually propulsion. And the biggest reason to do Explorer 1 was to demonstrate the propulsion; that we can put something in orbit. And there were some science aspects. There were some scientists at JPL to make measurements, with the satellite. But really, the major feat was the propulsion. And shortly after—and at that time, NASA did not exist. I mean, JPL existed but NASA did not—and we were basically a Caltech lab basically funded by the army because the US army was the main organization funding propulsion, for strategic missile and so on. So, shortly after that, when NASA was formed, they looked around, and which laboratories know how to say the word "space"? JPL was one of them, so NASA took over the facility from Caltech. But Caltech continued to manage JPL. And I'm told that there was a meeting, at NASA Headquarters. They were saying, "Oh, we really need to send spacecraft to other planets. Who would like to do that?" And Bill Pickering was sitting there, and he raised his arm. He said, "We would like to do that."

ZIERLER: [laugh]

ELACHI: And that transformed JPL completely from a jet propulsion place to a planetary, or robotics spacecraft, organization. And now we do very little jet propulsion, if any. We only do some work on electric propulsion, or on esoteric kinds of propulsion. But the traditional propulsion, we don't do it. But the name JPL stayed because of it has been known—

ZIERLER: Yeah.

ELACHI: —all over the world. Matter of fact, you reminded me of a little event which happened—I'm trying to remember. I think it was before I became director, so it was in the 1990s—where NASA—sorry, the government had tradition that when a well-known Congressman retires, they might name a building after that person. And I think, suddenly, one day, we found an announcement that the local Congressman—I think his last name was Smith—I never met him—that NASA decide to name JPL the Smith Lab. And everybody was taken, aback. What in the heck is—where did this come from? So, then, there was all kinds of dialogue back and forth. "No, we don't want that." And then they reversed it. But for a few weeks, we were called the Smith Research Lab, and it's like, the other places, the Kennedy Center, and the Johnson Space Center, and Glenn Space Center. So, no, we insisted that J…and I think our congressman at that time—even Smith, I think he kind of said, "No, JPL ought to stay called as the Jet Propulsion Lab because, historically, it's well-known that way." So, yeah, no, we like the Jet Propulsion Lab.

ZIERLER: That's right. [laugh] Charles, a broad thematic question that unites so many of the JPL missions in our solar system, and that is the search for water, and the resulting excitement because it possibly tells us that where there's water, there's life. So, let me frame the question in a way that might be a bit disturbing in light of the fact that through all of this discovery, all of this water that we're aware of, the life we—it's still an open question if it's there. So, maybe, water tells us nothing about life? Has JPL grappled with that difficult question in a systematic way?

ELACHI: Well, it's interesting. I know for sure my wife has grappled with it. My wife is an artist and she used to be a movie producer of animation movies. And, always, when I was telling her we were searching for water to look for life, she said, "Why water?" And I say, "Well, because that's what we are accustomed to here. Life on Earth evolved in water." And she said, "you ought to be thinking out of the box. Maybe life on other planets is very different. Maybe it's not based on water. Maybe it's based on something else, so keep an open mind." So, usually, yeah, we do keep an open mind. I mean, I have to listen to my wife, and I always listen to her. And at JPL, many people do think a little bit, and that's why I was saying there was somebody, a researcher at JPL working on the origin of life, because by understanding the origin of life, the way we know it, it might shed light on how is it different life that could happen [elsewhere]. So, yeah, people think about that. But, as of now, the only life we know about, or we have experience with, is the life which has evolved through water, organic material, and energy, which is the life here on our planet. So, we tend to look at something similar.

Matter of fact, in the 2000, the Mars program was called "follow the water," and that's why we're searching for water. And now we are saying the program is search for habitability. That means look at the organic material or environment which could be habitable. But they are still based on our understanding of what life is, based on carbon. So, we look for carbon, organic, molecules, and we look for water, and we look for a source of energy.

But your point is legitimate. I mean, life could be very different. I mean, there is no reason why it should be identical to the life here. And, so, it becomes a philosophical issue. What is consciousness? What is life? How does it evolve, and so on? So, yeah, who knows? It might be very different.

ZIERLER: In all of JPL's discovery, all of the data, all of the image, all of the analysis, is there a moment that sticks out in your memory when JPL got tantalizingly the closest to thinking that maybe they discovered life on one of the planets or satellites?

ELACHI: Well, I think the—probably the most exciting part was when Curiosity found molecules which are carbon-based. That mean it was a chain of molecules. They were very short, because that was kind of what we were looking for. Are there any chains of carbon molecules? And it did find short carbon molecules. So, that kind of became exciting, and tantalizing. Is this the beginning of building longer chains which could become, the kind of life that—the other tantalizing time was when the discovery of phosphene in the atmosphere of Venus. But then it became apparent that it was a very, very weak signal. We are not really sure, that that—another tantalizing time, again, was the detection of methane on Mars. First, it was detected from the ground, but also it was very weak.

And then when we landed on some of the landers, we did detect a very, very faint signal of methane, which was variable because, also, people believe that maybe it's generated by some organic chemical activity. So, yeah, there were some tantalizing times, but it still fell short of really strong proof that will allow us to say, yeah, we know life exists. So, we are still at the stage where we can say, yeah, there are a number of places which are potentially habitable, but we don't have the absolute proof that actually life exists on them or existed in the past.

ZIERLER: Because, of course, it's impossible to prove a negative, JPL has not proved that life doesn't exist—

ELACHI: That's right!

ZIERLER: —in the solar system. Where is there opportunity to go back and look closer in those areas where there is the most excitement?

ELACHI: Well, clearly, Mars is one of them, and I think when we bring samples back to Earth, that's going to go a long way on us really understanding the composition of those samples, and about the organic material in them or the environment in them. But, also, the possibility of life on Europa…on the oceans of Europa below the ice, again, there, it's also very logical. If you have liquid water, that means you have the right temperature. We see organic material both on the surface and on the plume of Enceladus. So, both Europa and Enceladus, we believe that there are oceans below the surface which are liquid, and they are made of H2O, and they have organic material. So, it has all the ingredients to cook life, if you want, or generate. So, these are the ones which are getting a lot of focus. And possibly Titan, on Titan, there, it's kind of the reverse. We have a lot of organic material based on carbon, the whole land—the surface of the planet is made of organic material.

But it's so cold that the…the water is all frozen. But there could be life in a frozen environment. So, here, we have a number of tantalizing satellites and planets, which have all the ingredients of what led to life on Earth. The question is, did evolution kick off, and lead to life on those planets? And I think those would be answered, I would say, within the next decade to two decades. I think we'll have proof, one way or the other, from those areas.

ZIERLER: Charles, a fun question, whose idea was it to beam The Beatles song "Across the Universe" in February 2008?

ELACHI: Well, I don't recall whose idea it was. But I thought it was a cool idea—

ZIERLER: Yeah.

ELACHI: It was really cool. No, I think we have a number of people at JPL who are very much into music and so on. So, in the case of Spirit and Opportunity, somebody on the operation team—because in there, in the case of those missions, we had every day to kind of send command to tell them what to do the following day. So, we used to have the rovers sleep during the Mars nights—sleep meaning not operate. And then in the morning on Mars time, we used to wake them up. So, somebody come with the idea, oh, why don't we send a piece of music to them to wake them on music, you know? So, every day, we were sending, music, different kinds of music. And the people had fun about choosing different kind of music. And then in 2008, somebody came with the idea of sending The Beatles song, Across the Universe. And, these things, I mean, they were fun—it kind of humanized the whole process—but also the media loves it.

ZIERLER: Sure.

ELACHI: And young people love it, that. So, it kind of brings space down to Earth, in a sense, and it give a personal connection, and it makes us scientists viewed more as "normal people." Because I remember, we had a band at JPL, and we have a choir. And the choir was invited once to one of the events in Pasadena at the Arboretum where they used to have concerts. So, they brought the JPL choir. And I was sitting at a table, and there were a bunch of other tables. I remember, after the JPL choir sang, one guy said, "Wow, I didn't realize that engineers can sing, you know." So, it kind of came to me. I heard them at the table next to me. So, I told him, "Oh, yeah, no, we are human like you are." [laugh] So, it kind of humanized when people see that, instead of the idea that we sit in a lab with white coats, and we are nerds, and so on, when we do things like this, people say, "Yeah, these people are like…normal people." [laugh]

ZIERLER: I wonder, technically, if you can explain how does one go about beaming a song across the universe?

ELACHI: Oh, we just transmit it on our—because we send signals, like radio signals like the way you receive the songs, on your radio. That's exactly the communication that we send to our spacecraft. It's the same concept. So, we actually record it, and code it, and send it from the Deep Space Network, the antenna we have around the world. So, if somebody living on another planet, the nearest star to us, which is five light-years away, so when we sent that in 2008, by 2013, that signal would have reached, a neighboring planet, so if there are advanced humans on those, they would have received the music of The Beatles.

ZIERLER: Was there hope or is there hope that in sending out these signals that they'll be received, and that we can get confirmation of receipt?

ELACHI: Yeah, that's possible, perfectly possible because, radio signals propagate across the universe. So, if there are other planets where there are civilization with advanced technologies, that meant that they can detect these kinds of signals, because they would be very, very weak, and they have to be evolved at least to the same technological level as we are, here to be able to receive radio signals, so that means having radio receivers. Yeah, it's perfectly possible, and that's one of the techniques that people are using to look if there is life on other planets is by looking at radio signals coming from other stars, using big antennas.

And, matter of fact, now that we have a number of observatories, both on the ground and in space, which will tell us which stars actually have planets similar to Earth, the radio telescopes are going to zoom in on those planets or those locations and see if we receive any signals from them. Now, the likelihood is not very, very high, but it's not zero either because not only you need life to have evolved on those planets, but you need life to have evolved technologically advanced enough that they have developed radio transmitters. We have to remember we only developed them 100 years ago or 120 years ago, here. So, our whole lifetime, of life on our planet, it's only very recently that we evolved to the technological stage to send signals. So, yeah, if there are other planets where there are human or life which has evolved to our stage of technology, they may be transmitting signals, or we might be able to receive their TV programs. [laugh]

ZIERLER: [laugh] Is JPL involved on an institutional level with organizations like SETI that are dedicated to this research?

ELACHI: Well, yes, we work both scientifically—we have scientists who work with them. We have engineers. It's not a major effort at JPL, that we are involved in. But we do support them. Sometimes, people have used our deep space antennas, except our antennas are very busy communicating with spacecraft, but because they are very big and very sensitive. So, yeah, we do exchange information about technology. But that's not a major focus, at JPL.

ZIERLER: Charles, when President Obama came in, along the same lines of what I was asking you about President Bush and climate change, where the media might tend to overplay these distinctions, President Obama cast himself as a very pro-science president. And, of course, I think he very much was. In light of that, did that change anything for you and JPL when he came into the White House?

ELACHI: Well, it always helped when you have an administration which is scientifically—how to say?—inclined or supportive, of science across the board. I mean, it does impact NASA, in a certain way. And, yes, when the Obama administration came in, they put more emphasis on the robotic missions because it's driven by scientific objective, versus the human program. Again, this didn't cancel the human program, but it's an emphasis of where you put the emphasis…because, in general, NASA budget is kind of stable. It grows by inflation. But then within that budget, you have pieces which are for science, pieces for technology, pieces for humans. So, depending on who—what is the philosophy of the administration, you have a change in emphasis, a little bit of it—not dramatic. It's not suddenly that we got a flood of money. But it was more sympathetic, with the request, for doing robotic missions. So, yeah, it does happen. And then with the Trump administration, there was more an emphasis back on humans. Now, with the Biden administration, there is again more emphasis on planetary and Earth science. So, that's common but, in general, it's not a drastic change of, of emphasis.

ZIERLER: Were you able to develop a relationship with science advisor John Holdren at all?

ELACHI: Yes, we did develop that. Matter of fact, he came to the landing of Curiosity, and he was a keynote speaker after the landing. And he was very gracious and very, very articulate, in emphasizing the amazing things that American technology can achieve, and the advances that it can achieve. I remember after the landing, and he was in the mission operation room in the viewing area.

After the landing, he came down and congratulated all the team. And then when we had the press conference in von Kármán, which is the major auditorium, with the media, I introduced him. So, he gave the first talk, and then Charlie Bolden gave a second talk, and I gave the next talk, congratulating the team, and saying how exciting, it is. So, yeah, no, he got pretty engaged during that, particularly during that landing. And it's the same. Like I mentioned earlier, the emphasis is not only on the advance itself but on how inspirational it is and how much it illustrates that leadership in science and technology enables our country to do great things—not only in space but also economically, or medically or, whatever, the technology can be applied to. So, that's what I kept emphasizing to people. It's not only because of space. I mean, space is one element.

It advances our whole capability, and creates an environment of innovation in the country, that if we are—if we develop these things, it creates a spirit of innovation, like what I call "dare mighty things," it creates this across the board, be it in music, in art, in all kinds of economic factor. And space is a good way of doing it because it's highly visible. I mean, people see events in space that we develop much more than, well, a new chip that was developed. The new chip might have more impact on our lives, like what Carver Mead did, but when you land on Mars, everybody's paying attention to it versus, oh, a new chip was developed. So, it's really the high visibility of space which lead to that inspiration.

ZIERLER: Charles, in what was I'm sure one of your most difficult moments in your tenure as director at JPL, tell me about the station fire in the summer of 2009.

ELACHI: Oh, wow. Yeah, that was really a scary situation because that fire just started a few miles behind JPL, but it came all the way literally to our fence, you know. At JPL, we have antennas on the hill, and I was in my office. I mean, we closed the lab for a couple of reasons, one, because of the fire risk but also because of the smoke, and the risk for the employees. So, we shut down the lab for a couple of days. But we were very concerned about that. But, fortunately, the fire department—there is a fire station immediate—well, there is one at JPL, for local impacts, as well as a city fire station next to us. So, they were great. I mean, they all went up to the top of the hill, with all their trucks, to protect that, and then they called in a number of airplanes, to come in and drop fire retardant, in our area. So, yeah, I remember being in my office, watching the airplane coming and dumping all of that. It was scary, and we have pictures of it. And, matter of fact, I'm trying to remember, I think on our—because every year, for the holidays, we have a card that we send from the director's office to all the employees and all the friends of JPL. I think for that year, we had a picture of the fire [laugh], saying we survived, [laugh], we survived the fire. [laugh]

ZIERLER: Given the sensitivity of JPL's instruments, with all of the heat and the smoke, was anything damaged in the fire?

ELACHI: No, there was nothing. That was also a big concern, you know. We made sure, because I think we were—I don't remember which spacecraft we were assembling. And we were concerned that despite all the filtering that we do in our chamber, that that could create some damage. So, we did do extra precaution, covered the spacecraft, but there was no real damage because of it.

ZIERLER: I wonder, given all of the work that JPL does in climate change, if this hit a little too close to home in that regard.

ELACHI: [laugh] Yeah. No, it did come [laugh] kind of close to home, and, I mean, we didn't need that to convince us. But this did come close to home. And, also, the other aspect of it, also, which was kind of interesting is we deployed a number of our instrument—not only for that one but for other fires also—using infrared instruments to help the firefighters, because, with the smoke, it was very hard for the planes to see where the fire is active. So, by using infrared instruments that we developed at JPL—and now, they are becoming common—actually, they were able to see through the clouds, I mean, through the smoke, actually, where the fire was active, and be able to home in on where to do drop the retardants.

ZIERLER: Charles, I know you love talking to children about space. That's very important for you. And, of course, many times—I know, from experience, I'm a father—when children talk about space, they express a sense of wonderment for which clergy and philosophers have as much authority in some degree as space scientists. So, when asking those existential questions about who created the universe, or does the universe have an end, or what does it all mean, as an educator, as somebody who wants to teach children, what do you see as your role in terms of what science can answer and what it cannot answer?

ELACHI: Well, I think, particularly with the children, I mean, it's—all of us, when we were kids, we were always very curious. We were always exploring, trying different things. And, somehow, as we get older, maybe because of the experience of life, we tend to become—most of us tend to become more conservative, so we lose a little bit that curiosity, which is essential. Particularly for scientists and researchers, curiosity is absolutely at the heart of what we do. That's why I always find it fascinating about talking with children, to see the excitement in their eyes, and they always ask amazing questions. I mean, always, I mean, usually, at JPL, we always bring students from high school, from middle school, even from elementary school to tour JPL. Every year, we have like 20,000 children who come and visit JPL with their teachers. I mean, we organize it. And every once in a while, I used to go and join them, for the fun of it. And, always, they had these questions like what you said. How did life start? What's—what was before the Big Bang? How did the Big Bang happen? What's string theory? I mean, things which are—and one of the most interesting ones, I remember, it was a daughter of a friend of ours. I was giving them a tour. She was like maybe 9 or 10 years old, and she asked a question that I never thought of. She said, "Oh, we have a planet named after the god Venus, Jupiter. Why is Earth called Earth?" And to be honest with you, I never thought about that question [laugh], so I said, "I really don't know." I went and Googled it, and it turned out it's related to some German name, which means dirt. So, I learned from them [laugh] something that I didn't—it never crossed my mind to think about it. So, always, children make you not only wonder, but sometimes they bring things that you don't think about. [laugh]

ZIERLER: Why was it important for having children be involved in a naming contest for a major JPL mission?

ELACHI: Oh, I thought that was great because, I mean, this started to engage high schools, and middle schools. Someone at JPL—again, I don't remember who. I mean, usually, people come to me with these ideas. "Wow, this is cool. Let's go and do it." It's like, sending the music of The Beatles, or bringing The Comets, the band, to JPL. So, that's what I love about JPL. We have a lot of imaginative people who are always thinking. So, that started, and, again, our public relations said, "You know"—because that's where we have our education office—"that will be a great way of engaging schools and children." And, so, we started the concept. It started with Spirit and Opportunity where we had—that was I think the first time that was done by NASA and by JPL where we engaged schools to name, and not only to suggest names but also the student had to write an essay, a one-page essay about why they would suggest that naming. And I remember the—in the case of Spirit and Opportunity—the winning—that was the winning name. It was a middle school girl who was born in Russia who was adopted by American parents. And in her essay, she said, "That's what the United States represents for me: spirit and opportunity." And that was, I mean, it was very touching. That's probably why she won, the competition to do that. And as a reward for it, she came to JPL. We gave her a tour. We had her scribble her name on the rover, so her name is on Mars, and then we took her to the launch. And then it became a tradition after that. So, the same thing we did on later mission, NASA is doing it more commonly now. And the same thing happened with—that we had people—we started by when people visit JPL to watch, let's say, when we were assembling a rover or a spacecraft, to have them sign their name.

And then somebody came with the idea, "Gee, why don't we scan all these pages, put it on a chip, and put it on the spacecraft which is flying, so people can say, well, we have our name on Mars?" And that's how we started, and now it's becoming very common. A lot of people put logs or names, on spacecraft, I mean, with certain protocols. So, it's always these ideas which come from innovative, people, and it's a way of engaging the public. I mean, I'm a member of a club in San Francisco, and one time we invited a number of those members of the club in—when we were doing Spirit and Opportunity, and I had them sign their name, and put it on the chip on this. Even now, 16 years later when I see those people, they say, "Wow, I tell everybody even now that I have my name on Mars." [laugh] And these people are not scientists, you know. They are completely—they are investors. These things have impact, on the public.

ZIERLER: Charles, can you talk about JPL's role within the larger international collaboration to monitor potential asteroid impact threats to planet Earth?

ELACHI: Yeah. No, that is a—now, JPL is—in almost every program we have or every mission we have, we have international collaborations, on this thing for the simple reason that, there are smart people all across the globe. The more eyes who are—that are watching for asteroids, the more likely that you'll be able to do the survey, and [utilize] more telescopes. The Europeans have major telescopes, particularly in the southern hemisphere in Chile, in addition to the telescopes we have in the US. And JPL has—there is a center, by the way, which is called—I don't remember the exact name but something like asteroid survey center, where anybody who detects asteroid can contact that center so they can distribute it to other places, so they can watch those asteroids. And at JPL, we have a center, a group of people which do the navigation, the tracking. So, if they get information about the track of an asteroid, they can project in the future using traditional celestial mechanics. For the next 50 years or 100 years, where would that asteroid be, and is there likelihood for it to impact Earth, or how close it will come to Earth?

That's a team at JPL, so they are—we are very engaged with the international community, and they do that very quickly because, I mean, it could be a telescope in Chile which detects an asteroid, and they want to have that center at JPL which can project where it will be a couple of weeks later, so a telescope, let's say, in Hawaii can look at it, and track it. And that's distributed now easily on the internet, so it's done very, very quickly. So, yeah, no, we are very involved in the whole international program about surveying asteroid, tracking them, and particularly projecting, in the future.

And now, JPL is putting together a mission, which will actually—because one of the challenges about the asteroid is you can detect them at night. So, during the day, it's much harder to detect them, or if they are coming from the sun side, they are very hard to detect early enough. So, we are working on a mission, which would be launched, I think a couple of years from now, with the University of Arizona or Arizona State University to put a spacecraft, in deep space, which will enable it then to detect asteroids, and survey asteroids coming from any direction. So, that will add basically to our network in addition to the ground telescope. And the hope is that we'll be able over the next decade to basically know about 99.9% of the asteroids that are around, particularly the ones which come close to Earth in the future, and projecting over many years. Because if we know that, and if we detect them early enough, then it's much easier to deflect them. So, if we know an asteroid is heading toward Earth potentially five years from now, or in one, it's very easy to deflect by a little bit, and avoid it hitting Earth. If we don't see it until two days before it hits Earth [laugh], it's a lot harder, you know. Then we duck down [laugh] and pray. [laugh]

ZIERLER: It gives a whole new meaning to the idea that early detection saves lives.

ELACHI: That's right, absolutely. [laugh]

ZIERLER: [laugh] So, Charles, heaven forbid, if there was an asteroid that threatened Earth, threatened civilization, what role would JPL play specifically in deflecting it or even blowing it up?

ELACHI: Now, clearly, we would play a major role for a couple of reasons. I mean, we don't have a program today to do that, but we are doing activity and research to really understand how you deflect an asteroid. For example, Deep Impact, so that was—we demonstrated the technology that, yes, if we detect an asteroid early enough, we can send a spacecraft, and be able to impact it and deflect it. So, in a sense, we were at—we have developed the technology and the capability, to do that. So, yes, if there are—if we detect asteroids which could be of risk to Earth, I think JPL would be playing a major role. I mean, overall, NASA and the government would be playing a role. But JPL would be playing a major role, both in navigating spacecraft toward an asteroid, impacting them, or the technology to impact them.

Now, I could imagine the Air Force would play also a major role if the decision is to blow up an asteroid, which I'm not sure it's the best solution because if you break it in pieces, they still might come and hit Earth. There might be some pieces which are big enough. I think people are thinking about, depending on the size of the asteroid, and the time it's detected, how early it is detected, there are a number of techniques which can be deployed. And NASA has a program, related to the whole activity of both detecting asteroids but also how do you avoid them hitting the Earth. The mission which will be launched I think next year jointly with the Europeans, which will also be able to go and have a spacecraft rendezvous with an asteroid, and another one impacting it, to refine our technology of how much it can deflect it.

ZIERLER: Because you love movies so much, I'm curious if you saw the Bruce Willis movie, Armageddon, where they were oil-drillers sent to drill and blow up an asteroid.

ELACHI: Oh, yeah. [laugh]

ZIERLER: Is that pure Hollywood? Is that a feasible solution? Can you land on an asteroid, and drill into it?

ELACHI: Well, yes, you can land on an asteroid, and you can drill, into it. Now, I mean, all of these dramatized things, to make them a really attractive movie, but, no, the—what happened in that movie is very logical, very reasonable, on doing it. Yeah, you can land. You can—matter of fact, landing on asteroid is a hell lot easier than landing on Mars because, in effect, because asteroids have very little gravity because they are not very big, really. When you say landing, you are really rendezvousing it. You come very gently close to them, and you touch them, and you land it, on them. Now, for people, to be walking around and so on, it is a challenge because you have almost no gravity, so you really are almost like huge hopping. Every time you kick yourself a little bit, you go hundreds of meters, away. So, there is a little bit of science, a little bit of exaggeration there of being able to walk on them. But, no, but that technology is perfectly feasible.

ZIERLER: Charles, as prelude to questions about the Kepler exoplanet mission, and in light of the fact that exoplanet research is so incredibly exciting right now, how far back in your tenure, either as director or just working at JPL, were exoplanets something that, first of all, we knew about, and, second, when we had instrumentation where we could do legitimate research on them?

ELACHI: Yeah. No, I was very heavily involved in that because I remember in 19…in the late '80s, Lew Allen was the director at JPL, and I was the division manager of the science division. And one of our scientists, who was an astronomer, comes to my office one day, and he said, "Look what I've seen." he had a picture taken with a telescope of Beta Pictoris, which is a fairly close star, and it showed what looked like a haze around it, like rings around it. And he said, "That star might have rings. And if it has rings, it might have planets around it." I remember going to the director at, Lew Allen, at that time, and showed him that picture. And I told him, "Maybe we need to start thinking about some program about exoplanets, what we need to do." So, of course, we sent that picture to NASA Headquarters. The head of science at NASA, his name was Wes Huntress, at that time, he was a scientist who used to be at JPL, in the same division that I was in. He said, "Charles, why don't you chair a group to look at techniques to detect planets?"

So, I actually formed a group with another colleague by the name of Chaz Byshman, and we invited a bunch of astronomers to come and spend a couple of days of brainstorming. Some astronomers turned us down. They said, "Oh, that's too esoteric. We don't think that's worth our time." Some astronomers actually came. So, we had a three-day meeting at—on campus, matter of fact, and we generated a report talking about the different techniques which could be used for—and they ranged from, looking at the motion of a star, which became very—that's how the first planet was detected, to—from the ground, but also to look at techniques from space. Also, there was a technique about being able to look at the brightness of the star, and when a planet moves in front of it, it blocks part of that star, so by looking at the intensity of the star, which is what led to the Kepler mission. Another technique was to use interferometers, which will allow basically to block the light from the star itself so we can see the planet, and a technique which is called a coronagraph which does the same thing as interferometers but using a different technique.

So, we actually wrote that report. And, at the beginning, it was not—I mean, people took it as another report. But, very quickly after that, as more and more stars were being detected from the ground, then that report became more serious, and then people started to propose missions, for doing detections of stars. And Kepler was the first NASA mission, to fly in space. And that idea was from a gentleman or a scientist at Ames Research Center, so he was a key advocate for it. And that technique was pushing the limit of sensitivity of detection because when a planet comes in front of a star, it dims its brightness by like a fraction of a part per million in brightness. So, you need to have sensitive detectors, and you need an array of detectors so you can look at many stars at the same time. And that was about the time when the CCD arrays were becoming more capable, building very large arrays. So, it was a combination of an idea, which scientists were advocating, and the technology. So, they submitted it at Ames. We worked a little bit with them, but Ames submitted the idea to NASA, and it was selected.

But then NASA said, "Ames Research Center doesn't have a lot of experience in building, instruments and spacecraft. Maybe we should look at a center which has experience to build that mission." So, they asked both JPL and Goddard to submit proposals to NASA about who—how we would approach building it. And, to make a long story short, NASA ended selecting JPL. But the principal investigator continued to be the person, from Ames Research Center, and that's how Kepler came about. And then out of that mission, we found that literally thousands and thousands of stars actually have planets, and that mission looked at a very small part of the sky, using that technique. And as a result of that, then there was a number of missions after which were proposed which had broader coverage, and the technology had evolved by that time. So, we had more sensitive detectors. Now, there is a mission from Goddard, there's a mission from JPL, and there is a mission from Europe. So, this becoming now a common technique.

If you go back to when we wrote that report, which was in the early '90s, it was very esoteric. I mean, we knew it's feasible, but the technology was kind of not ready yet, to do that. And NASA invested a lot of money in developing the technologies, both for the coronagraph as well as for the interferometers, as well as for the arrays of sensitivity. And, now, both on the Jim Webb, there will be some capability of a coronagraph to look at planets. There is a mission called the Roman mission, R-O-M-A-N, named after a person who used to be at NASA a long time ago. And that mission has a full-up coronagraph being built at JPL to actually look specifically at planets by blocking the light from a star, and looking at, at possibly the light from a planet. And in the latest Decadal survey, which is happening as we speak, they haven't yet made it public, one of the missions which is proposed—we don't know if—also by JPL, it's called HabEx, which is a mission which is even a bigger telescope which will use a coronagraph actually dedicated to look for planets, kind of Earth-size planets to Uranus-size planets. So, that whole field, I think, I would trace it back both to—credit goes to the scientists at JPL which did Beta Pictoris, but also on the—to the scientists in Switzerland who won a Nobel Prize [Didier Queloz and Michel Mayor] who were the first people who actually detected a planet around a star.

ZIERLER: You talked about the earliest proposals in the 1990s. So, fast-forwarding to 2009, what were some of the key technological developments that made Kepler possible after these 20 years?

ELACHI: It was clearly the focal plane, the detector, so that, I mean, the telescope was fairly straightforward, there was no challenge, and the spacecraft was straightforward. But it's having a very large focal plane of CCDs, like your camera but much, much larger, and very, very sensitive. That means we can detect a very small, reduction in the bright star. And that technology was heavily based on Defense Department technology because the Defense Department was interested in doing these things so they can monitor, like, when launches are happening, see the plumes of launches from space, so building—so, clearly, a lot of the technology that was developed by industry for the Defense Department, we actually used for our purpose. JPL's technological capability was calibrating those detectors. We have a lab at JPL, which is called the Microdevices Lab, which has basically capitalized on technology developed in industry, but we calibrate because, for industry, calibration is not critical.

If you are looking for a plume of a rocket, all what you want to do is extract the plume. You don't care if it's accurate to one part per billion, how bright is that plume. But, for our purpose, it is critical to look at the changes which are happening to parts per billion, and we want to make sure it's not noise; that it's actually a planet which is blocking the light of the star. That calibration was happening at JPL, so that was the JPL contribution, other than building the instrument and the spacecraft, and the DOD technology, which was in industry, which enabled those kinds of detectors to be available.

ZIERLER: And is this advance with the detectors, is the thing that's most important with exoplanets being so far away, is it—how do you even seen them? How are they not blinded by whatever star they're orbiting?

ELACHI: Well, because as it orbits its star, so, when the planet is in front of the star, it blocks the light of the star. So, we are actually measuring the light from the star, and we see is there a dip in that light, and will the dip repeat itself, you know? So, if you see a dip, and then you never it again, then it's most likely noise or something else. But if the planet is in orbit around a star, so let's say it's in orbit of two days around the star, so then you look at the signal, and if you see a dip every two days, and it keep repeating, then it's most likely something which is orbiting that planet. And then by looking of how deep that dip is, that will tell you how big the planet is. If the planet is bigger, it will block more of the light of the star. So, that's how we determine both the presence of a planet, the size of the planet, and then the orbit's repetition, or, if you want, the period around the stars by doing that. So, it has to repeat multiple times before we can say, yeah, that's a proven planet.

ZIERLER: Charles, it's as much a philosophical question as anything else. But best-case scenario, with exoplanet research, we detect a biosignature. We detect a technosignature. What then?

ELACHI: [laugh] Well, it depends what you get on the biosignatures because, now, I mean, with the focus that people are doing—and we started doing it with some of our infrared telescopes like the Spitzer telescope—is when you look at the spectrum coming from a star, if you have a planet which comes in front of it, you add to the spectrum of the star the spectrum of the planet, I mean, the light coming from the planet. And then when the planet goes behind the star, you only see the star's spectrum. So, by taking the difference, you can extract the weak signal of what's coming from the planet itself. When it's in front, you have the sun. When it's in the back, you have only the star. So, by taking the difference, then you can extract the light from it. And we do see some information about the chemistry in the atmosphere of the planet. But as we get more sensitive, then we can get more information about the composition of the atmosphere. Does it change?

That means that there are clouds. And, particularly, one would be able to use a coronagraph to block the light from the star, and get the light from the planet by itself, clearly, without doing the differences and so on. So, then, you know for sure it's all coming from the planet. So, by looking at both the time change and the composition, you can learn a lot. Then, the next step, I mean, if you see—let me think—methane, for instance, then you know methane tends to be most likely from organic or volcanic, activity. So, there is an organic possibility. It might be coming from cows, which are [laugh], on those planets because that's how we get a lot of the methane here. Or if you detect CFCs, which is what we use as coolant in our refrigerator, CFCs do not exist in nature. It's a molecule which was invented in our industrial age. So, that will say, well, maybe there is industrial activity going on. So, you can logically start progressing toward potential industry or life on it. Then, the next best step would be to have these radio telescopes, we talked about earlier, focusing on that star or that planet, and see do we detect any radio signals, not—I mean, human-made or not natural radio signal, like a radio signal which has a code in it, or repeats, or it has certain sequences in it which are not generated, by natural kind of phenomena. So, there is a step wise process which could take us closer and closer on potentially, could these planets be inhabited?

ZIERLER: In what way, Charles, either with Kepler or with subsequent projects, does this also possibly yield insight on turning the camera back at us? In other words, in looking at these exoplanets, are we also looking for evidence that we're not just the ones watching others; but others might be watching us?

ELACHI: Yeah, no question. I mean, if we detect signals from them, radio signals, that means they are evolved enough that they can detect our signal. There is no question that they have the technology and the capability to detect any signal coming from Earth. So, as of now, that's the best way, I mean, short of UFOs, which I still don't think they have happened. But, yeah, if we detect radio signals from other planets, or laser signals, I mean, that's the same thing as radio except at higher frequencies, then, most likely, that planet or that part of the solar system is evolved enough that they can detect what we are doing. Even if we are not transmitting toward them, because, if they are capable enough, they can detect just regular TV transmission or regular radio transmission. I don't know if you want them to watch our TV programs but [laugh], yeah, they would be evolved enough to be able to detect our signals.

ZIERLER: Charles, I'll go there because you already laid your cards on the table that you don't think UFOs have come here. It's a joke of a question, but I can't help but ask. So, as JPL director, they never took you down to Area 51, and showed you all the good stuff?

ELACHI: [laugh] Yeah. No, and I did—when I was JPL director, I got many emails or inquiries of people saying, "Oh, we saw these things. What do you think about it, these things?" "No," and I say, "look, I mean, it's not that UFOs are impossible. But we really don't have any—you can explain a lot of them by natural phenomena." Like, I was just reading in the news today that some people in the Midwest, they saw flashes of light, in our atmosphere, and it turned out that it was a Russian satellite, which was decaying, and actually entered our atmosphere. So, I think the likelihood of other UFOs coming here is remote, because the nearest star to us is light-years away. So, the UFOs need to have traveled literally many tens of thousands of years before they get here. Now, having said that, it's possible that other civilizations have developed the capability to move at almost the speed of light, and they can get here in 5, 10, 20 years. But that's remote at this stage. Then, my next question is why don't we see them? Why didn't they land, and interact with us? If they took all that effort to come here, then they must want to interact with us. And we haven't seen that, so I'm skeptical. Even that I'm a kind of out-of-the-box thinker, there is a limit of how much far out-of-the-box. I enjoy those things, and I enjoy the science fiction, and I enjoy the email I used to get, and I used to respond to all of them, on doing that. But I think—still, I don't think we have gotten UFOs here yet.

ZIERLER: And, just for a sense of scale, when Kepler or subsequent missions are looking at exoplanets, how far away are they? Are we talking about the Milky Way, Andromeda, beyond? Where are these exoplanets?

ELACHI: No, they are mostly in the Milky Way, and even in the near part of the Milky Way because, again, I mean, most of the observations now, particularly the technique of using a coronagraph to be able to see the planet, because the farther the star is, the harder it is to separate that planet from it. Now, the measurement where we look at the wobbling of the star, that we can look even if we have very far away stars. But the focus at this stage is our Milky Way. But, also, remember, if we detect something in the Milky Way, they could be as far away as hundreds of thousands of light-years. So, we are talking, I mean, just in our Milky Way, we are talking of huge distances, and there are literally billions of stars. So, if we find planets similar to our planet in our galaxy, then, most likely, they are common in other galaxies also.

ZIERLER: What do we know so far about Earth being a common type of planet, a Goldilocks planet? Do we know already from exoplanet research that there are Earth-like planets out there?

ELACHI: Well, let me—I'll be careful, being a scientist, a little bit on doing that. We know that there are planets which are in the Goldilocks environment, that they are not too close to their star to be too hot, or too far away, to be too cold. We know there are planets roughly the size of Earth. We know there are planets which have solid surfaces like the Earth has. Matter of fact, around one star—I don't recall the name now—where we see, like, six or seven planets around it, three or four of them are in the Goldilocks region. So, I could say that we now know that, literally, there are hundreds, which have been detected, if not thousands of planets which are very similar, which are in an environment similar to Earth. Now, are they exactly like Earth? Do they have oceans like we have here? How much ocean? That's still to be determined.

But I think with the Jim Webb telescope, and the Roman telescope coronagraph, again, which we will be getting data over the next decade, and with larger ground telescopes, which will have coronagraph on them, within the next decade, we will be able to take images of planets which are about the size of Earth, roughly speaking, and if they are in the Goldilocks region, we'll be able to determine if they have clouds, if there are changes which are happening in their atmosphere. So, we can answer much more precisely that, yeah, we have planets which are similar to Earth. Now, does that mean there is life on them? That's the next leap that we have to take.

ZIERLER: That gets to the water question from earlier.

ELACHI: That's right.

ZIERLER: Were people talking in the early 1990s both about biosignatures and technosignatures?

ELACHI: Yeah. No, I think the idea of detection—or let me call it technosignature or detection of signal—goes back a long time, I mean, long time, many decades, where astronomers, radio astronomers, actually, they did do calculations on what's the likelihood that life existed. And they did the calculation by taking, how many stars, what's the likelihood of planets around stars? Then, from that, what's the likelihood of looking at evolution on our planet, I mean, over two billion years. We have developed technology in the last 150 years to communicate. So, you can take that ratio, and you can multiply all of these, and they came up with positive numbers that, yeah, there is likelihood that some planets exist around some stars which are at the same level of technological evolution. Therefore, there is the likelihood of technosignatures.

The question is, how far those planets are, and when will that signal reach us? I mean, if a planet is 60,000 light-years away, it will take 60,000 years for the signal to get here. So, yeah, no, the technosignatures people, I would say, many, many decades ago, people thought of that. And the biosignature, I mean, people like Carl Sagan conducted experiments, on how could life have started, by kind of zapping mixture of organic material, and be able to generate organic molecules. I think, well, that could happen on that other planet. There is no reason why only Earth. And then there are the people who are philosophers who think, look, why would it only evolve here, you know? I mean, it's everywhere. I remember—I don't remember now his name. It's a priest who was in Rome in the 1600s who wrote articles about talking about life on other planet that could exist, and he was, he was burnt on the stake because it was heresy, then. So, people go back all the way to then where they thought, well, maybe life exists somewhere else. There is no reason why it exists only here. And, again, I mean, here, we follow, and maybe I'm going a little bit off-script here, where people say, well, but life exists only here because God created it here. And I say, yeah, it could be. I mean, independent of your religious belief, it's very possible that God created life here. But why wouldn't he create it everywhere, you know? I mean, God is in charge of the whole universe. He could have created Adam and Eve on every planet in our galaxy and other galaxies. So, there is no reason why he picked this galaxy and this little planet. [laugh]

ZIERLER: It's a lesson in humility. Maybe we're not that special.

ELACHI: [laugh] Yeah, that is true. That is true. [laugh]

ZIERLER: When talking about technosignatures—and this goes back to your wife's very wise observation that we should expand our notion of what life looks like—in thinking about technosignatures, does that include thinking about life not in cellular form but as electronic or computational beings?

ELACHI: Yeah, that could be. That could be. I mean, we, for people who are—have a really broad imagination, I mean, it could be that it has evolved to that stage where it's technological.

The more likely is that it evolved biologically, in the natural evolution, and could have evolved, like you were asking earlier, on robots which became so smart, that they kind of overtook the planet from the biological life, let's call it, and became a techno life. Well, these are possible. I mean, you can make a good movie out of that. [laugh]

ZIERLER: That same year, of course, I'm curious, the Planck telescope, in what ways did JPL partner with the European Space Agency on this mission?

ELACHI: Yeah, we worked very close with ESA on it, and particularly, I mean, clearly, it's a European mission, the Planck telescope. And where JPL played a major role, again, is in the detectors. And that's an area when we collaborate with our European partners as well as other partners on it, and this advances that we have in the US in detectors. And the Europeans rely very heavily on us for many decades. Now, they are developing their own capability. But they rely a lot on the US investment in detectors. So, Planck, we are very closely involved in it because of the detectors. Matter of fact, one of the lead scientists on it is—his name is Jason Rhodes. He's a scientist at JPL, and he's one of the lead scientists on the Planck mission. And there is agreement between NASA and the Europeans that the Planck data will be—actually, there is a—at the IPAC or the Infrared Processing Facility, there will be an archive for that data for utilization by American scientists. So, that's a perfect example of the close collaboration between Europe and the US in space exploration.

ZIERLER: What was the value in collaborating with the Europeans on this, making it a worldwide or at least an international effort?

ELACHI: Yeah, well, I mean, the Europeans have their own program, you know. They want to do research the way we do research here. And by doing the collaboration, which goes both ways—they participate on some of our mission; we participate on some of their mission—it enabled American astronomers to have access to that telescope, instead of only European astronomers. And that's common in the scientific world. There is a lot of very close collaboration. There is not—you see very little national-type, "Hey, this is my telescope, and we don't want to give it to our colleagues in Europe." There is a lot of interplay. And I don't know how you'd track it back in history, but maybe part of it is on that we are a nation of immigrants. We have people who come from all over the world, you know. As I mentioned to you, many of the scientists at JPL came from all around the world, particularly from Europe but also from other locations around the world. So, I think in the science community, there is that spirit of working together, with collaboration or collaborators from all over the world.

ZIERLER: Charles, tell me about the construction of the new visitor center, and why that was so important to you?

ELACHI: Well, again, it was an issue. And, unfortunately, we were not able to—we didn't get the funding to actually do what we really wanted to do. It was really the outreach aspect, that—and NASA was sympathetic, for these things, that it's important to have—to reach to the public, and to get the public to really know about what we do. We do have a small museum at JPL that people can visit, and it's a very exciting museum. I mean, during my tenure, we renovated it. We moved spacecraft in it. But it's not at the scale of the museum like what you have down in LA. We wanted to have a place where we can really highlight even more than what we have now. I think our museum now, I'm guessing, it's probably about 2,000 square feet, and we jam it with a lot of things. And we get a lot of visitors who come to JPL. I mean, normally per year, as I mentioned earlier, we have like 20,000 students, and we get maybe 30-40,000, people who come and visit at JPL, and we take them around on tours. So, that's why it was very important for the outreach. But I was able to achieve a lot of things. But every once in a while, I was not able to get the funding [laugh], to develop the museum, I mean, the visitor center. But, alternatively, what we ended up doing is to have an open house. We started having at least once a year, sometimes twice a year, where we bring a lot of our spacecraft to the mall, and we open a lot of our lab, and we open it to the public, and just in those—for a weekend—and just in those two days, we used to get 40-50,000 people coming, to the point where the neighbors start complaining about the parking, where people were parking miles away, coming in.

And I remember one year, we really felt bad because it happened on that weekend, it hit like 100 degrees, it was really tough. I mean, we had people coming in wheelchairs, and people who were in their—elderly people, young people, people who came from other states, you know. So, then, we established a process of having people have to go online and get a ticket—not to limit the number but to spread them because we had no idea when people would show up. Sometimes, we got a huge number of people during one day, and fewer in the second day. I'm told now that once we—I mean, before the pandemic—once we put them online, within five minutes, they are all taken. [laugh]

And JPL really has a very positive image in the public, and that's why we wanted to have a visitor center or a museum, if you want, to do that. But we found alternative ways, and, matter of fact, today, with the internet, we do almost the equivalent of a visitor center because it's not only pictures, but we can get the public to see videos. We walk them around. They take a tour of JPL, you know. On the videos we have, with a lot of the visualization technique, we can reach a much broader population, all around the world. Matter of fact, there is one program which we call Eyes on Earth, which was developed at JPL, where you can actually get on your iPhone all our data, images, of temperature across the globe, precipitation, on your iPhone, almost in real time, I mean, literally within hours of what we have there. And that's becoming international. Matter of fact, recently, we were recently, literally a couple of days ago, we were on a video conference working with colleagues in Saudi Arabia where they took that program, translated it into Arabic, and they were showing it at a museum in Saudi Arabia. So, here, you have kids in Riyadh in Saudi Arabia looking at the data that JPL is getting from our Earth-orbiting satellite, literally that same day worldwide. So, online visualization is kind of taking a fair chunk of the outreach capability that a visitor center would have done.

ZIERLER: Charles, of course, outreach is good in and of itself, but it's also fuzzy in terms of measuring how do all of these outreach efforts come back and help JPL? So, in all of your efforts to do outreach, to spark the curiosity of all of the people who are interested in JPL, what are some moments that stand out for you, either in an interaction with an individual, or with talking to people, that you said to yourself, "This is all worth it. It's so important"?

ELACHI: Man, you hit on a very good and personal one. And let me tell you a story, considering that you want the history. I met my wife on a blind date. Her name is Valerie, and she was producing animation movies, and that was in the '70s. And at that time, they used to do them by hand. So, on the first blind date, I took her out for dinner, and then took her to Caltech, of course, to impress her.

ZIERLER: [laugh]

ELACHI: And on the second date, I took her to JPL. And I took her to a lab run by a guy called Jim Blinn, and he was doing the first work of using computer visualization, on animation and so on, and he was doing that to be able to visualize as our spacecraft are flying by, in that case, for Voyager. He was doing it specifically to ask, "How do you see the planet? How do you visualize different angle?" You rotate the spacecraft. It was very elementary. And she looked at it, and said, "Charles, this is going to put the animation industry out of business."

ZIERLER: Oh, wow.

ELACHI: "In a couple of—in a few decades, it's going to be done all by computer." Because, at that time, they were still doing it all by hand—

ZIERLER: Yeah.

ELACHI: —and doing that. So, that hit me at that time, and look what happened. Jim Blinn, after many years, he developed, and he left, and I think he went and worked at Pixar and worked at Disney Imagineering. And now, very few people do it by hand. Almost nobody does it by hand, anymore. So, that was an event which really hit me about how visualization, computer visualization is going to change completely our way of visualizing things. And now, you see the movies, you think they are real but, in actuality, they are done by some of the technology that Jim Blinn developed at JPL. So, that's another example. When people ask me about the benefit of space technology, I'm sure Jim Blinn was not thinking about doing animation movies at that time. He was focusing on visualization of our spacecraft. And JPL became a lead center about visualization as a result of that. Then, more people were doing that, and that's what we did this Eye on Earth program, and we have a program called Eyes on the Planet, and so on. And now, we don't think about it. It's a common industry. But I remember, and my wife regularly reminds me of what she told me, on that date 45 years ago. [laugh]

ZIERLER: That makes me think, of course, that if your wife had that amazing observation, she was able to extrapolate into the future, just think what all of the people, the tens of thousands of visitors and the millions of visitors online, their exposure to what's happening at JPL, just think where their imagination is taking them.

ELACHI: No, absolutely, I mean, and the other example also that I give, which kind of relates to what you are saying, is on the camera, in your iPhone. The focal plane of that camera basically was developed, the technology was developed at JPL for our telescope because we wanted to get very lightweight, very low power, focal planes. We never thought about them to be in iPhones. And some entrepreneur must have seen it or read about it, and they developed it. And, fortunately, Caltech has a license for it, so, now, every time, I say, every time somebody buys an iPhone, Caltech maybe get half a cent from that. [laugh] And it led to many tens of millions of dollars that came to Caltech, because of that development, and it benefited all of us. I mean, now, nobody thinks twice taking hundreds of pictures, with their iPhone. So, that's another example where—I don't know if it was somebody who visited JPL or read about it, which led to applications that's not what we were thinking about, ourselves. And I'm sure there are many examples like that.

ZIERLER: Charles, back to the missions, in thinking about the Large Binocular Telescope interferometer, it's interesting, when does JPL decide to get involved in ground-based astronomy?

ELACHI: Well, our involvement in ground-based was mostly for testing our technology and working with the campus. Really, the focus on the campus is for ground telescopes. And, for us, the focus on participating in radio astronomy, the ground telescope, is to go and test our technology and our instruments, before we develop them for space activity. So, it's a great synergistic relationship between us and the campus.

Every time we develop a new focal plane, we work with some faculty on the campus to put it in cameras and go and test it at Mount Palomar so we understand its properties. Or, for instance, another example kind of stretching it a little bit is like for laser communication. We wanted to develop technology for using lasers for communication to expand our capacity, and we started using Palomar as a receiving telescope because you need a big aperture. So, it's basically demonstrating capability and technology before we deploy them in space. But, also, they benefit the ground astronomy community because they get those detectors, and then it allows them to do better capability on it, be it spectral capability or, sensitivity or resolution. So, we work very closely with the radio astronomy community, like the Keck telescope where we were demonstrating the interferometer, technology. We were thinking about space, but we want to demonstrate, can we do this? Can we really demonstrate, combining, optical signals? So, we were very heavily involved. Some of our scientists were working very closely with the Keck telescope project to do the interferometric capability.

ZIERLER: Charles, you mentioned the Decadal survey, which now is coming out very soon. And with Keck, I'm curious, when the Thirty Meter Telescope was being developed, did JPL play an advisory role? Were people talking with JPL at all in thinking about the TMT?

ELACHI: Yes. No, there was a very close relationship. Matter of fact, at one time, one of the JPL project managers was hired by, I mean, hired—was moved to the campus to work on that project. And the other capability is we were doing a lot of work at JPL on mirrors with adaptive optics—what we call adaptive optics. That means you have a flexible surface, and then you have actuators behind the surface to control the accuracy of the surface, you know. And the reason it's important for us, for space is that when you launch a telescope, you live in a very different thermal environment in space, so it could distort the optics. And, here, we are talking a fraction of microns. So, it benefits us to be able to have adaptive surfaces that, after you launch, you can then adjust them so you can get a perfect, a perfect surface. The story of the original case of the Hubble Telescope where they had the wrong mirror, so if we had a flexible mirror there with an actuator behind it, we could have fixed it immediately. So, we moved to an era where, on future telescopes, we wanted to have the mirrors be adaptable. And as we moved to bigger and bigger mirrors, we started talking about combinations of elements. So, you have smaller elements that you adjust. And that's the technology being used in the Thirty Meter Telescope. So, there was a lot of interplay, you know. We learned from them, and they learned from us, on how do you develop arrays of mirrors that you put together, and then you have actuators which adjust them to make it a perfect mirror. So, yes, there was very close collaboration, and still there is close collaboration, with them.

ZIERLER: While we're on the topic of TMT, of course, it's not your area, but with all of your perspective and connections to Caltech, the TMT is incredibly important to Caltech, and there's concern that the project might not go through, depending on what the Decadal says. How do you reflect on what this might mean for Caltech, and what does it mean more broadly for astronomy, given all of the political problems that we've seen in Hawaii?

ELACHI: Well, that is a challenge. Matter of fact, I, from the beginning, I expressed, not concern but to tell the people on the campus that this could become a problem, because before we did—sorry, after the Keck telescope was developed. The Keck telescope was just two telescopes. We came up with the idea of maybe we can add four, five smaller telescopes which will combine with the Keck telescope, so we get even a larger area.

And Ed Stone was the director still at that time. That was in the late '90s. And Headquarters was convinced, so they funded us to build four smaller telescopes to be able to put them in Hawaii. And we built the telescope. We were ready to deploy them, and then there was a big issue of the Natives in Hawaii saying, oh, we are adding more telescopes, and so on. And it went through a whole process of doing that, and it ended up that we had to cancel those telescopes because we couldn't get the approval in convincing them. So, when the Thirty Meter was being, started, and there was a pushback from the local community, I kind of reminded Ed Stone, "Remember, what we tried to do, and we were not able to do it." And he was aware of it. And I think Ed and Caltech and UC have done—gone through a long effort to minimize the impact, including that the University of Hawaii was prepared to take off some of the telescope which are already there, to make up back for it.

They funded an education center. So, I don't know how this is going to evolve. I mean, it would be a shame if it cannot be built, in there, I mean, for two reasons. One, it's scientifically very important in itself, but, also, in keeping the leadership of the United States because the Europeans are building an equally large telescope in Chile, and Chile welcomed them with open arms. So, I do respect the Hawaiian tradition. But I think in this case, there is room for some compromise, of working there because I think it has huge benefit not only for the US but also for Hawaii, for educating, the Native and the local Hawaiians, and educating them about science, and enhancing their educational, capabilities.

ZIERLER: In what ways is the Decadal survey and its recommendations important for JPL and its missions that get funded or not?

ELACHI: Oh, no question about it. It's very critical because NASA follows—religiously, they follow what the Decadal recommends. And, by the way, just for the benefit of people listening, there is a Decadal for each discipline. So, there is an astronomy Decadal, which is going to come out shortly. There is a Decadal for planetary, a Decadal for Earth science, and a Decadal for heliophysics. And NASA follows very religiously, and Congress follows very religiously, what the Decadal recommends.

ZIERLER: So, what is JPL specifically looking for the Decadal to say when it comes out in early November?

ELACHI: [laugh] That's interesting. I mean, I know—again, I'm not—now, I've been away from JPL for five years. But I know what the priorities are. The one I'm aware of—there are two telescope missions—one which is called LUVOIR, which is advocated by Goddard. And it's a telescope even bigger than the Hubble—sorry, bigger than the Jim Webb telescope, which would be great. But I think the experience of the Jim Webb, the cost experience, that it ended up costing $10 billion—started with$1 billion, ended up being $10 billion—I don't know. If I was on that committee, I'll be a little bit worried about even a bigger telescope. Despite what people would say, that could be a—there is another one which is called HabEx, which is advocated by JPL. I think that one makes more sense because it's affordable—affordable meaning a few billion dollars. But, also, its focus is on the question of exoplanets, I mean, that's the main purpose of that mission. So, I would say, at least for me—I'm not an astronomer, so I can say my opinion—I would say the HabEx would be, as a general scientist, a lot more exciting because of the habitability question, and the affordability. So, we'll see what the Decadal will come out with. [laugh] ZIERLER: Charles, back to 2011, was JPL involved in the aftermath of the Fukushima disaster at all? ELACHI: Yes, in actuality, we did offer robots because some of the robots that JPL developed—and it was a program—I think we were working with DARPA, at that time—where you can actually send robots in high hazardous areas. I don't know if they actually used a JPL robot or it was based on some of the companies we were working with provided robots to go in high hazardous area. And that's another benefit of the space technology where you can use robots to go in places where it would be a big risk for humans. ZIERLER: What about in terms of detecting tsunamis? ELACHI: Well, it's—on the detection of tsunamis, at that time, we still were not at that stage. But, now, we have the capability from satellites, if we are at the right place at the right location, being able to detect the wave of a tsunami. The challenge is you need to have the satellite at the right location. Now, in the future, we are talking of a network of hundreds of satellites monitoring our planet. Then, you'll be able to see every point on the planet every time. So, I think in the future, we'll be able to do that, by—with a space capability. Now, it has to be done from the ground, but it is projected that actually it will happen. ZIERLER: What would space-based telescopes be looking for in detecting tsunamis? ELACHI: Well, in the case of tsunamis, it would be—it's not a telescope in the traditional sense. We probably would be using a system to measure the ocean height, so we can see if a wave is moving, on the ocean. So, we'd use probably a laser or radar altimeter. That would be probably the more appropriate way of detecting it. ZIERLER: Would this be related at all to earthquake detection? ELACHI: Yes, I mean, we are developing techniques there where we can measure surface changes, which can happen. What we know now, we can measure the effect of an earthquake. So, if an earthquake happens, and the surface moves, we can measure motion of a few centimeters. Research is going on, heavily, on the campus, but also at JPL and in other places, where we can look at the stress around a fault, the bending and the motion happening along a fault. So, it could become an indicator of areas of high risk of earthquakes happening. I don't know if we'll get to a stage where we will say, well, an earthquake is going to happen behind our house on April 19, 2025. I'm not sure we'll get to that kind of level of accuracy. But we'll be getting, I think, pretty soon—now, we are saying which areas are potential high-risk areas, because we see a lot of motion and a lot of stress which is happening in those areas. And we are developing a mission called NISAR, which will be launched two years from now, which will be doing that worldwide. It will be mapping the whole globe every week, and we'll be able to measure the surface displacement every week, down to centimeters, not only for an area of high hazard for earthquake but also, like volcanoes tend to inflate just before eruptions happen. So, we'll be able to do that, and we are doing it now from airplanes or from some satellite in certain locations from satellites. We'll be able to measure the surface subsistence resulting from water pumping from the water table, you know. It's being used now in the Central Valley, so the technique is available. We have demonstrated that from satellite. But it's not operational in the sense that the satellite does the coverage every week. So, this mission called NISAR, which is run by JPL, and where a lot of the processing will be done on the campus, will allow us to do it on a weekly and regular basis. ZIERLER: That same year with the Aquarius mission, two questions. First, how can space telescopes measure ocean salinity, and why is ocean salinity important for understanding climate change? ELACHI: Well, that Aquarius has an interesting history, so I'm going to expand on your question— ZIERLER: Please. ELACHI: —because it shows also the international/political factor. Aquarius was done jointly with the Argentinian Space Agency, where they developed the bus. We use a radio telescope, not an optical telescope but a radio telescope. First, the technique. The technique is we look at the microwave emission from the ocean. And as you add salt to it, you get a slight change in the amount of microwave being emitted. So, that's how we measure the salinity. The same way when we look at land, if there is soil moisture, we see a different microwave emission than from dry areas. So, we can monitor the amount of salt in the ocean. Now, the next question you ask—and then I'll go back to the politics—the next question is, why does that have to do with climate change? Well, depending on how much salt you have in the ocean, that's how much you have heat exchange between the atmosphere and the ocean. It turned out that the amount of heat exchange happens depends on the temperature of the ocean and the salinity of the ocean. So, clearly, how much heat is being absorbed or extracted from the ocean, the salinity has a factor in it. In addition, is the life in the ocean, the fish life, the salinity has a factor in it. So, that was the scientific reason for doing that mission. We looked at microwave emissions, and then it's getting to a model about the heat exchange. Now, you'd say, how did Argentina get into the picture, in here? Well, during the Reagan administration, there was concern about the—there were a lot of German scientists who left Germany after World War II or during World War II, went to Argentina, and they were meddling a lot in nuclear energy. And there was a concern about nuclear bombs, of Argentina developing a nuclear capability. So, the Reagan administration worked with them, and negotiated that "Hey, if you stop doing your nuclear work, we will help employing the scientists in Argentina to work in space. And to demonstrate the goodwill, we will be glad to work on a joint program to help you develop your space capability." So, that's how the Aquarius came about. JPL was encouraged to work, I mean, NASA and then JPL were encouraged to work with the Argentinians on space mission, and Aquarius was one idea which came about. And, later, it became using also synthetic aperture radar, so there were a number of missions which we collaborated with them. And on a personal note, it gave me the opportunity to travel every year, to go down to Argentina, which is a beautiful country. I loved Argentina. I was there half a dozen times, visited different parts of Argentina. And one of the most exciting parts of Argentina is we actually—three times, I drove across the Andes, both in the southern part of Argentina, in the central part, and in the northern part of Argentina with friends of ours and my wife. So, it's interesting how these things evolve from trying to encourage German scientists in Argentina to get out of nuclear research, to me enjoying the great—a great country and the great people and great steaks. [laugh] ZIERLER: [laugh] Charles, to go back to the political context, and the way that you clarified quite importantly that the Bush administration did not stymie climate change research. To flip that around, did the Obama administration specifically encourage climate change research for NASA and JPL? ELACHI: Yeah, it tended—no, they did encourage that, and the message is very easy. Usually, I used to say, "Show me the money," in addition to the speech, "Will you walk the talk?" So, it shows up in the budget, at NASA specifically for Earth. And, yes, in the Obama administration, they did increase, I mean, not dramatically—they didn't double it—but they did increase the funding in the Earth observation. Same thing what's happening now in the Biden administration, there is an appreciable—particularly in Congress—there is an appreciable increase in—like 10 or 20%, above inflation—in the Earth's observation. And going back on the Bush administration, they were the main ones which encouraged, which led to the NISAR mission I was just mentioning earlier, which would allow us to monitor changes in the surface. It's one of the global changes. Maybe it's not the atmospheric change, but it allows us to monitor the melting of the ice in Greenland, the dynamic of the ice. So, it's directly relevant to climate change. And that mission was encouraged and supported or started by the Bush II administration. Now, their interest partially was they wanted to encourage collaboration with India. Matter of fact, the "I" in NISAR, it stands for NASA India Synthetic Aperture Radar. So, it's a joint mission which is done with the Indian Space Agency, and that was part of the political factor. But, also, it had an Earth observation global change factor which came in it. So, it was during that administration where that mission got—I mean, we have been advocating for it for many decade. But it's that administration which got it started. ZIERLER: Charles, you mentioned Dave Stevenson when he was chair of the committee leading to Jean-Lou Chameau's selection as president. With the mission to Jupiter, the Juno mission, did you interact at all with Dave, because I know this was so important for his research? ELACHI: Oh, sure. No, I interacted with Dave regularly, not only on that mission but regularly, because, I mean, he's highly respected. He's a super smart planetary scientist, so I always appreciate his opinion about things. So, I used to do regularly—when I was director, and before, when I was on the executive council in charge of many of the scientific activities, I used to regularly come and interact with people on the campus. I mean, one of my goals, when I was director, and I know during Ed Stone's also, was to build more relationships between the faculty on the campus and JPL. And that's why we establish a joint appointment program where we had a number of people from JPL actually lecturing on the campus or doing research part-time. So, I regularly used to come and talk with different faculty, on the campus about their perspective, particularly in the planetary and the astrophysics work. Mmatter of fact, my first chief scientist at JPL after I became director was Tom Prince, who was a professor of astronomy. And then my second chief technologist was Jonas Zmuidzinas, who was also in the astronomy division at Caltech, very focused on instruments and detector. My first chief technologist was Paul Dimotakis, who was in the aeronautics department. So, I followed kind—in general, not always—but the tradition of having a faculty being the chief scientist or chief technologist as a mechanism—one of the mechanisms to build more relationships with the faculty at Caltech. ZIERLER: What was the earliest planning that ultimately would become the Juno spacecraft? ELACHI: Well, the Juno mission was one of the competitive missions. It was selected competitively. And the principal investigator on it was a JPL scientist, so he came to me, and he told me that he has this idea of using microwave emissions, for looking at the internal structure of Jupiter. And, so, I supported him. He formed a team, at JPL, and he brought scientists from around the world. Also, he has international scientists. And the main instrument was being built at JPL for it. And, competitively, we won that competition, I mean, we, JPL, and the team. And then after that, the PI ended up moving to Southwest Research Institute for personal reasons. He wanted to go back to Texas. But JPL continued the development of the mission, with the same team. And, even now, I have one postdoc working with me who was actually working on that mission. I personally was not involved in the mission as a scientist. I mean, I was involved as the director of JPL. And that mission turned out to exceed everybody's expectation. I mean, scientifically, the main purpose was looking at the internal structure of Jupiter, looking at microwave emissions. But, also, for educational purposes, they put a camera, and that camera is generating amazing images, of Jupiter and the dynamic of Jupiter. And Dave Stevenson is involved in the analysis, as well as a couple of other faculty members, like Andy Ingersoll, who is another colleague, who is heavily involved in that mission. And, as I said, one of my postdocs is involved in the analysis of that data. Now, I'm going to get involved in it in the future because it turned out that that mission, it has been extended, you know. It was supposed to be for three years. I think they extended it for six years. Now, it's being extended for 10 years. It's going to be able to fly by Europa. And with that instrument, they are going to be looking at the emission from Europa, microwave emission, which might allow us to know a little bit about the subsurface structure of Europa. Now, where I get involved, I'm directly involved in a mission which is called the Europa Clipper, where we have a radar instrument which will be sounding that ice, and I'm part of the team which is designing that instrument. So, getting any early information about the subsurface structure could benefit us in the future interpreting the radar sound of data. So, it's amazing how things come back that you never think about, that will be able to directly benefit. And, matter of fact, my postdoc is going to be working on modeling the emissions from Europa, and how does it benefit the sounding that we'll be doing later, later in the decade, with the radar instrument. ZIERLER: Charles, a technical question, without landing physically on Jupiter, how was Juno able to see through Jupiter's cloud cover to see what the planet looked like? ELACHI: Well, let me make sure it's clear, it's not landing. It's orbiting. ZIERLER: Right. ELACHI: It's orbiting Jupiter. We look at the emissions. Now, you say, how could you see through the cloud? A perfect example: look at your radio signal. When it's cloudy, you still hear your radio work, so microwave actually go through clouds. It's, I mean, it's a little sensitive to it, but it can see through clouds. So, in effect, what's happening on this mission is you have whatever features you have way down in the cloud, many thousands of kilometers, because they are not absolute zero, because they are warm, they will emit microwave, and that microwave will go through the cloud. And the lower frequency you are, that means the longer wavelengths, the deeper you can probe, you know. For instance, you can look on, let's say, when it's raining. If you use radio, you can receive it very well. But if you go to the TV, the old-fashioned TV, you see a lot of static behind it because of the rain because it's operating at a higher frequency. So, the same thing on Jupiter. The high frequency comes from clouds which are close to the top of Jupiter, and the lower frequency come from clouds which are way deep, deeper, or whatever material is deep on Jupiter. So, by using… think they are using seven or eight different frequencies. So, by using multiple frequencies at different levels, we are seeing deeper and deeper and deeper into the atmosphere of Jupiter. So, in a sense, you are seeing in 3D, looking at emissions happening from the molecules which are deep in Jupiter. That's how Juno actually works. ZIERLER: To go back to outreach, of course, when it comes to Jupiter, the public really wants to know about the Great Red Spot. What does Juno— ELACHI: [laugh] ZIERLER: —tell us about the Great Red Spot? ELACHI: Well, it's showing that it's much more complicated and dynamic. And what's interesting, it's showing that, OK, we have a big red spot, but there are lots of similar spots which are not as big. But it's effectively a huge hurricane, which is happening on Jupiter, and we see the dynamic of the clouds. We are seeing that there are dozens and dozens of these hurricanes all over Jupiter. So, people like Andy Ingersoll, really—who is a planetary atmospheric scientist—are working on understanding the dynamic of these red spots and hurricanes and shedding light on the dynamics of hurricane here on Earth. People like Dave Stevenson, he's looking at the deep structure of Jupiter, and how did it form. How did it come about? So, yeah, no, we are learning a lot. And the benefit of something like Juno, which is in orbit is we can monitor it on a regular basis, you know. So, you can see the dynamic of this red spot, and the other part, of Jupiter, and looking at the composition from the color, looking at the atmospheric composition of these activities. ZIERLER: As the largest planet in our solar system, to what extent does the Juno mission have an extrapolative effect? In other words, how what we learn about Jupiter tells us broader things about the solar system in its entirety. ELACHI: Well, sure, because, I mean, Jupiter is, I mean, in a sense, is like when you go in a lab, and you do an experiment in the lab, and you learn the fundamentals, and then you can extrapolate it to other—because now you understand the physics and the chemistry. By looking at Jupiter, you are understanding the physics of how did Jupiter form, the dynamic of it, and that could extrapolate to other things, like Saturn, but also to potentially other exoplanets on what's the dynamic and the property. So, really, by studying the different planets, and by modeling how did they happen, how did they come about, it tells us about how did our solar system form and—because we can go to them and visit them and understand them. And by learning that, we can extrapolate about how other solar systems form, and vice versa. So, when we look at other solar systems, the planets are very different in their structure and the number. The first reaction is, oh, we will be seeing big planets far away from the star, and small rocky planets next to the star. That's how our solar system is. We have Mercury, Venus, Earth, and Mars as rocky planets. And then at the outside, we have Jupiter, Saturn, Uranus, and Neptune. We're finding that other stars have different kinds of distribution. There might be a big, big, rocky planet far out; smaller planet far out; bigger planet close by. We are finding that other solar systems are not necessarily a Xerox copy of our solar system. So, that makes it exciting because now, you see the diversity of how these happen. And then people like Dave Stevenson and other people working on formation of solar systems have to explain how these other solar systems [evolve] so differently. So, that's what makes the scientific aspect very exciting. ZIERLER: Around this same time, JPL worked on a moon mission to study the gravity of the moon. It's funny to think because, really, since the Apollo mission, not so much interest was paid to the moon. So, I wonder what the origins of a broadscale study of the moon were at this period. ELACHI: No, I mean, there're scientists interested in the gravity of the moon. And, here, it was interesting because the technique for doing that was developed for Earth observation. We wanted to learn more about the gravity field of our planet. So, some people at JPL and other outside scientists came up with this, what I thought was a very innovative idea where you fly two spacecraft following each other in orbit, and you measure the distance between them. As the first spacecraft comes to an area where there is a slight increase in the gravity field, it would speed up because it gets attracted, so the distance gets a little bit larger. And then when the second spacecraft reaches the same area, it catches up with the first one. So, by measuring the distance between the two spacecraft very accurately, I mean, down to the centimeter, we can determine the gravity of the planet. It's kind of counterintuitive. But for scientists, that kind of makes sense instead of using a pendulum, which is what we would normally use to measure the gravity. So, that led to a lot of applications for the gravity field of our planet. Then a scientist at MIT by the name of Maria Zuber who has been working with JPL—she's a planetary scientist; one of the leaders in the field—she said, "Why? Why don't we apply this technique for the moon, and be able to measure much more accurately the gravity field of the moon?" So, she came to JPL. We worked with her. We developed the concept, and we proposed it competitively, for a program called Discovery, and she won the competition, and that's how it came about. So, it was here a technology developed for Earth which then we take and we apply it, for—in this case—for the moon. And now, people are thinking about similar kinds of techniques for satellites and other planets for being able to use a similar kind of approach to measure very accurately the gravity field. And the reason the gravity field is important, it's not only a curiosity, but it tells us about the internal structure of the planet because, basically, you are measuring all the different masses, the core and the mantle, and both their mass and their size. So, by measuring the gravity field very accurately, we can learn a lot about the internal structure of the planet. And that's very critical for when you want to do very accurate orbiter missions and very accurate landers because they are—their dynamic is driven by the gravity field, of that planet or that satellite. ZIERLER: Charles, many, many questions to ask about Curiosity. But let's start right at the basic level. The name Mars Science Laboratory, who came up with it, and what does that name convey or connote? ELACHI: Well, I think the reason we called it—that was named at JPL. We didn't think it's very imaginative, but it was descriptive because, in a sense, it—that was the first time we have a rover which literally have almost the majority of instruments you would find in a chemistry lab at a university. So, it had a spectrometer. It had an oven, and you can put samples in the oven and heat them. It had gamma ray spectrometer. It had an X-ray spectrometer, so almost the majority of things that you have in a chemistry lab or a science lab. So, for, I mean, we always like to give some name other than rover number this, or rover number that, so we called it Mars Science Lab. But, then, as you discussed earlier, then we changed it to become Curiosity as a result of the competition. But we always need to have a name, to do that. The same thing with Mars 2020, which became Perseverance. Now, here, it was a different reason. We called it Mars 2020 because we wanted to put the pressure to fly it in 2020, so we thought we'll give it a date, and then that will put kind of an additional incentive to get it funded so we can launch it in 2020. ZIERLER: The name Curiosity, how was it selected? ELACHI: Same process that we did Spirit and Opportunity, that it was a competition, done at at middle schools. And, by then, after Spirit and Opportunity, the program became, I mean, we had—I don't know—I think somebody told me—hundreds of thousands of inputs. I think with Perseverance, we almost got to the many, many hundreds of thousands of inputs. And then, basically, what happened, student were asked to write an essay, and we usually advertise it by sending emails to the teachers at schools. And we have what we call ambassadors, JPL ambassadors. These are people who are volunteers, and we send them materials, and they give talks at local schools, to get young kids excited about space. And it's based on those write-ups, you know. Then, the word Curiosity, it was selected, to do that. And I thought it was very, very appropriate. I mean, when you think about them, Spirit and Opportunity, because it was in the early development. Curiosity, it's a perfect reflection of what we do in space, and what we do in science, and what we do at JPL is about being curious. And then, after that, Perseverance, that one we didn't predict. But, then with the pandemic, the team at JPL, I mean, it was a challenge to be able to get it ready to launch earlier this year, because it hit just as the final integration of the rover was happening. And, here, suddenly, people couldn't come to the lab except under very special circumstances. So, the team persevered. I mean, they took that literally. They persevered and worked hard, and still launched it on schedule and on time. So, we didn't expect that but it really was reflective of the team spirit. ZIERLER: Charles, does the Curiosity's intellectual origins go back before Spirit and Opportunity, before 2004, or could it only be contextualized and conceived once we have this initial Mars mission? ELACHI: Yes and no. Basically, we tend to think as a program, about multiple things that we do because, sometimes, many of these missions require decades of planning. From the time you think about them until you launch them, you need a decade. So, you don't wait until a mission is done before you start thinking about the second one. Otherwise, you get one mission every 10 years. So, in the program, we thought about, what are the different steps we want to do? And, of course, the farther out, the more ambitious we are because technology will enable us to do that. So, no, we were thinking about what became Curiosity even before Spirit and Opportunity. But Spirit and Opportunity enlightened us about, what experiment to do because we learned a lot from it. But, also, it enlightened us technologically, about how do we operate the rover. It was a big challenge to operate Spirit and Opportunity because we had sent commands every day. By the end of Spirit and Opportunity, and by Curiosity, we became so knowledgeable of how to operate that that we gave a lot of autonomy to the rover. And now, with Perseverance, we have even more autonomy, and a capability on board, to do things. So, no, we tend to think about this multiple times. I mean, let me take an example, the sample return mission, which is Perseverance, the first step. We thought about that in the '90s. Matter of fact, I chaired a committee at that time to define an architecture. That's before even I was director. Again, it was Wes Huntress who was the head of science at NASA, and Dan Goldin was the NASA administrator. So, in the mid-90s, there was a lot of discussion about collaboration with the French Space Agency about Mars exploration. They asked me and my equivalent in France, who was kind of the director of the space center in France, to chair a committee, and lay out an architecture for Mars sample return. Now, it happened that we were studying that at JPL. Since the 1970s and '80s, people were thinking about how you do sample returns. And we laid out a program in an architecture, for it. But, at that time, it turned out the funding was not amenable to move immediately on a sample return mission. So, that's how we ended up doing first rovers, what became Spirit and Opportunity rover. Then, we end up doing Curiosity, which was more sophisticated. And then when we were thinking about Perseverance, or what we called Mars 2020, that was the first step into the Mars sample return architecture because the architecture we had at that point, we needed to go first collect samples, put them in a certain location. Then, send a second mission to land, grab that package, put it in the nose of a rocket, put it in orbit around Mars, and then send a third spacecraft to grab that container and bring it back to Earth. So, we laid out a three-step process, all part of what we call the Mars sample return. Now, there were some advocates saying, well, why not launch it and bring it back straight to Earth, and build a bigger rocket on Mars? But technologically, we felt that that was too risky. So, we ended up recommending the three-step program. That's what led to a—so, that's from two decades ago, almost—what led to Perseverance and now about the Mars sample return, the next step which is scheduled for 2026, 2028, depending on the funding. And it's being done jointly with the Europeans, not only the French. The original idea was to do it with the French because it happened, at that time, the minister for science in France was a planetary scientist who did his postdoc at Caltech— ZIERLER: Aha. ELACHI: —Gerry Wasserburg, and he was all excited about bringing sample return. So, we advocated in the government there of funding jointly with the US. But then he moved on, and then it kind of went on the back burner for a few decades. ZIERLER: Charles, some engineering 101. In thinking about Curiosity as coming after Spirit and Opportunity, in what ways is bigger better for a rover, and what are some of the challenges in having a bigger rover, and making sure that it doesn't break down; that it does what it's supposed to do? ELACHI: Sure. No, in this case, bigger was better because we needed to put more sophisticated instrument. So, in order to accommodate the half-dozen instrument on Curiosity, we couldn't have done that, on Spirit or Opportunity size-wise. I mean, Spirit and Opportunity, they're about the size of a desk, while Curiosity's about the size of a car. You can put a lot more instruments, in a car than in the drawers of a desk. And the other aspect of it, we wanted to be able to use nuclear power so it can survive for a long time and provide somewhat more power. That requires more mass. So, clearly, we needed a bigger rover to do that. Now, the implication, for it, now, we are landing a bigger mass, on the surface of Mars. So, the technique we used for Spirit and Opportunity—which was we enter the atmosphere, we use a heat shield, and use a parachute to slow us down, then retrorocket. And just before we hit the surface, we inflate airbags, and let the airbags kind of bounce on the surface. And when we stop, we deflate the airbags, and then we open, and the rover comes out. That technique was not possible with Curiosity, which was a much bigger rover. So, that's why we came with the idea of a Skycrane, to do that. And that required a lot of development, to be able to both develop and demonstrate that capability. And then we needed bigger retrorockets. We needed a bigger parachute. We needed a bigger heat shield to do that. So, there were a lot of technological pushes that we needed to do between Spirit and Opportunity and Curiosity because of the mass of it. Now, the driving, we just needed more power. I mean, that was not a huge step forward. We did find that the autonomy—that's being able to operate the rover the way we did Spirit and Opportunity in the early days—was just too stressful, so we needed a lot more autonomy. So, we developed that capability. We needed to make sure we land more accurately, on the surface, so we needed to develop that capability. And that also led to more advances when we did Perseverance. So, in the case of Perseverance, we actually controlled very accurately where we wanted to land, I mean, not to the meter level but within a few hundred meters kind of capability on doing that. So, it was really a step-by-step that we learned from one mission to the next on both the autonomy, the landing capability, the accuracy of the landing. Now, Perseverance and Curiosity, from a landing point of view, except for the accuracy of that, they were very similar. So, the parachute, the heat shield, the retrorocket, the Skycrane, they were very similar. And the weight was roughly very similar. Perseverance is a little bit heavier. But it fit within the same heat shield and the same technology. We had to develop the more accurate landing parameters, and the challenge on Perseverance was on being able to drill, be able to pull samples, put them in a container. So, that's where a lot of the technological advances, were focused. And the public outreach was in putting a lot of cameras on it so we can watch the parachute deploying. We can watch the Skycrane coming down. We had only a couple of cameras on Curiosity. On Perseverance, I think we had like 18 cameras, operating all the time. So, it made from public outreach as well from engineering to see how the parachute deploys, and how well the engineering things work, and it allowed us to do that. And that was because now, you can buy a camera, and put it here in your hip pocket, and so that allowed that capability. ZIERLER: Given the sheer size of Curiosity, during the landing, were there any hold-your-breath, dramatic moments? ELACHI: Oh, are you kidding? ZIERLER: [laugh] ELACHI: We were holding our breaths for minutes. ZIERLER: [laugh] ELACHI: [laugh] Yeah, no, because a couple of things. I mean, one, it was the largest parachute we have ever deployed, and we were deploying it as a supersonic parachute. The Skycrane, it was the first time we are doing Skycrane. Even that we tested it in pieces, but we couldn't test it completely, here on Earth ahead of time because the environment on Mars is different than on Earth. So, yeah, every time you do a landing, or entering in orbit, you hold your breath. But that one was pretty dramatic because we were making a major leap, from Spirit and Opportunity to Curiosity. That was a huge leap in the technology and the capability. And people ask me when—what worries me the most? When was my heartbeat going the highest? And I tell them it's when the parachute opened because if the parachute doesn't open, we are just a projectile coming in at high speed. And that parachute was folded and packed two years earlier, and we never tested the parachute itself. We tested equivalent parachute. So, all what it needs is whoever was sewing that parachute or folding it, if there was the slightest error, we are in deep trouble. So, I was watching very carefully to get a signal, what we call the Doppler shift, which tells us the speed at which we are entering. And when the parachute opened, we were supposed to suddenly see a reduction in the speed, of it. So, I was watching that signal to see are we going to see a sudden, disruption in the speed or slowing down. Once that was done, I told the NASA administrator next, oh, we are 90% of the way there. We still could have a problem, but this was my biggest worry [laugh], for this thing. And the same with Perseverance, when I was watching it on, on my computer because it was during the pandemic, so I was looking exactly for that feature. And the person reported, in real time, that was the key thing they were looking for. ZIERLER: Now, 3,200 Sols and counting, did anybody think back in 2011, 2012 that it would be going for this long? ELACHI: No [laugh], nobody would have thought. I mean, we knew that the power system would survive for a long time because it was a nuclear power system. But, at the end, it's a mechanical machine, like your car. It's built by humans, the electronics. We did plan on three years because we felt that we can do most of the science in three years. So, we tested it for six years, you know. We always test for twice maybe sometimes three times these things. So, yeah, people had—we were highly confident on the three years, reasonably confident about six years, but coming to 10 years, that was a stretch. [laugh] But people at JPL, we are very thoughtful, careful how we build our spacecraft, and, yeah, they—and we're very careful on how we operate them, so, and they keep doing great science. So, we are delighted that they are surviving, that long. And one thing I told the team, I'm keeping my fingers crossed that it will survive until we land Perseverance. And when we did Spirit and Opportunity, I said, I hope we will get them to survive until we land Curiosity. ZIERLER: Yeah. ELACHI: Now, we could say that since 2004, our country has had a permanent presence on the surface of Mars, you know. For the last 17 years, we had continuously been on the surface of another planet, I mean, roving, I should say. We have landers roving on other planets. ZIERLER: Now, has Curiosity had any mechanical problems? Has it been able to repair itself if so? ELACHI: Well, usually, it's hard to repair mechanical problems. You can easily repair software problem. You can kind of not repair but get around electrical problem because you have—we have redundancy. The mechanical structures are hard to build redundancy in them, so we build them pretty resiliently. But it did have problems, even in that. We found that, after like three or four years—I remember, I was still JPL director, and I got—one day, the project manager came to me to show me a picture of the wheels. And he showed me one of the wheels, that it was actually cracked, and it was kind of peeling off, because they are made of thin—not thin, but a reasonably thin aluminum layer on a skeleton, which is harder, you know. That's how we build them to be light. The skin was peeling off where it could get serious damage after a while. And then we found out that the reason that was happening, we underestimated how sharp are some of the rocks on Mars. So, as we were driving even over small rocks, they were so sharp that they were kind of damaging that, if you want, that skin that we are putting on the skeleton. That led us to do some tests on the ground because we had wheels at JPL. So, we took some of the wheels, and we drove them and drove them and drove them, for 24 hours a day, 7 days a week for many months, and we did see the similar kind of damage. So, we did two things. One is we started driving more carefully so we still have [the ability] to operate it. The other one is we started to develop back-up options. What if one wheel completely falls off, and is completely damaged, and how do we run with the other five wheels? And, matter of fact, we can go around with four wheels, even possibly with three wheels. We will not be able to drive as fast or as more flexible, but we still can drive. So, yeah, so we learned from that, and we made the skin, thicker, for Perseverance. And as we are driving it, we're becoming smarter in how we drive that. Same way as you do with your car, if you go and drive off-track, on unpaved areas, you become more careful. If you get a flat, you say, oh, next time, I'm not going to drive over these big rocks [laugh], you know. So, so it's exactly the same experience. [laugh] ZIERLER: I've asked some engineering questions. Now, on the science side, what was most important, before you realized that you had 10 years and counting to rove on Mars, in those initial three years, what was most important for Curiosity to look at? ELACHI: Yeah, so, the geologist in that mission, the chief scientist was John Grotzinger, another of my colleagues at Caltech. He's now the chair of the Geological and Planetary Science division. And he came from an experience of going and exploring things in the field and learning about the history of the area by looking at different kinds of rocks, coming from different layers. Matter of fact, he had some background in looking at areas for petroleum exploration and learning by not only looking but examining the composition of different layers and different rocks, learning about the history of that area. So, he translated that experience into where we go, and where do we drive, and what kind of rocks we analyze. And based on that, and working with the engineering team, and extrapolating how fast we can drive the rover, and which area we can go to, kind of laid out a scenario, and felt that, based on that scenario, three years will allow us to measure a certain number of rocks. I don't remember how many kinds of rocks. And that will allow us to learn about the history of that area, particularly about the potential presence of water in the past. So, that was a heavy focus on looking at rocks which would have formed in a water environment or having been modified by a water environment. So, John Grotzinger, working with the science team, was the key guy who basically laid this out, based on his experience in the field. And in the same way on Perseverance, which is going to collect rocks, you would ask, well, we wanted to collect about something like 24 or 32 samples, how long—how did you come up with three years, that you would be able to go and collect those samples? So, again, here, we had a geochemist by the name of Ken Farley, again, from the campus, one of our colleagues there, who has done a lot of work on sample analysis and sample extraction. And working with a team, they laid out—and the engineering team of how fast you can drive, how long it takes you to drill. So, they laid out a scenario of how long it would take to drive, drill…well, first, to drive, decide to drill, and collect the samples, seal them, go to the next area, and collect, about 24 or 32 more samples. And that's how they came up with the lifetime, for the mission. So, it's all based on our experience on Earth doing something similar. ZIERLER: Of course, Mars is a big planet. Why Gale crater? Why was that chosen as the landing site? ELACHI: Well, because based on satellite images, high-resolution sites and satellite images, it looked like an area which used to be a lake, a big, kind of a lake in a crater, and also alluvial fans where you see on one side of it what looked like a dry river, and then a big fan, alluvial fan. So, really, the logic there is that, clearly, this area had water in it, which had dried up. It's not there now. It might have been, or it might be below the surface. And this is most likely where there was a potential of life that could have evolved. And they used an example like the Nile Delta. If you go and look at the sediments as the Nile Delta formed that a lot of things which came not only from that location but all along the Nile River, all the way from Central Africa where a lot of that material came. So, here, you have a collection of material and rocks which came from very large area, which came and got fanned, if you want, put in that area. So, that [site offered the] highest likelihood of getting a diversity of samples. ZIERLER: Where the rover is able to drill, which is in and of itself an amazing engineering feat, I wonder if you could explain. Obviously, we're not FedExing these samples back to Earth. How is the rover analyzing, and sending back what it's learning to JPL? ELACHI: Well, on Curiosity, you are right, we are not planning to bring them. On Perseverance, we are planning to bring them. In the case of Curiosity, the main approach was you actually drill through a rock, and that was a challenge in itself. Just think of yourself when you are sitting down, I mean, when you are drilling on a piece of wood, you have to hold it and hold the drill. When you are drilling in a rock, you really have to hold it. There, you have this rover, and this arm that has a drill at the end of it. So, we created a system where around the drill, we have legs which comes on the surface and they kind of anchor themselves so when the drill turns, the whole rover doesn't turn, or the arm doesn't break. So, it was a challenge to do that. And then as we drill, basically, it vaporizes, you know. It makes it into in little, like sandy material. And then we scoop that material and put it into an oven in the rover. So, imagine the arms. It drills, scoops some of that material, bring it on the top of the rover. We open a container, drop the sample or the powder, if you want, and then we heat it, and then not only heat it but we put a sample in some location. We have X-ray and gamma ray spectrometer; X-ray similar to what your dentist actually uses to see what's inside your tooth, except a lot more expensive here because it's [laugh] more accurate. And we get the data from it, like images like what your dentist gets, and we transmit that to Earth. And then you put it in an oven, and you heat the oven, and you look what gases are being emitted from it. We have a spectrometer which measures that composition and transmits that data to Earth. So, it's, in effect, it's similar to what you do in a lab on Earth, except here instead of the scientists being next door to the instrument, you have a radio link. So, it's detected and measured in the instrument. We transfer it to our communication system, and send it, back to here. Same thing like now when your—if you have a medical record at your home town, and your doctor here wants to contact the doctor at your home town to get your medical record and pictures, it's basically sent through a link to here. It's exactly the same, except the link here is many hundreds of millions of miles away. [laugh] ZIERLER: Charles, last question for today, were there a range of power sources that JPL could choose from, or did it have to be the radioisotope power generator supplied by the DOE? ELACHI: No, it's pretty limited. I mean, the only option we have is either solar power, but we needed—we were concerned about the dust, and so on, on the solar panel, or to use the nuclear source or what we call a plutonium or RTG for radioisotope—radio thermal isotope generator. So, no, the choices are pretty limited. When you go out in the solar system, you havea limited number of options of sources. The same thing for Voyager and Galileo that we use radioisotope, so it's the same thing. And because it has nuclear material, it has to be developed and under the control of the Department of Energy. So, we don't do the—we developed the thermocouples. These are the devices which take the heat and generate electricity. We developed those kinds of things at JPL. But the building of the device, and the nuclear material, is done by DOE. Matter of fact, we—it's built by DOE, tested, they take out—they take the radioisotope, the container out. We take a model of it, we put it on the rover, and we put the nuclear part of it literally at the last minute at the cape after we are on the top of the rocket, and then we have special devices to come and plug it into the rover. And the reason is you don't want nuclear material floating around, in our test lab, in our assembly, in our transportation. So, there is a whole methodology of how you do that and keep things safe. ZIERLER: And then do we know theoretically at least how long Curiosity will have power? ELACHI: Yeah, because, basically, the plutonium has what we call half-life time—that mean it decays—of like 80 years. That means the amount of power will drop by about 50% in 80 years. So, we know, as far as the source itself, it will be living for a long time. Now, would the rover itself survive for that long? Who knows? I mean, look at Voyager. It had been operating since 1976, so that's 45 years, you know. And we still have enough power—not as much as before—but enough power that we can communicate, with it, and operate it. ZIERLER: Charles, more questions on Curiosity and so much more for next time. [End of recording] ZIERLER: OK, this is David Zierler, director of the Caltech Heritage Project. It is Wednesday, October 27th, 2021. Once again, it's my great pleasure to be with Professor Charles Elachi. Charles, as always, wonderful to be with you. ELACHI: The same here, wonderful to talk to you too. ZIERLER: OK. Charles, today, we're going to pick back up on Mars 2012. Tell me about the decision to bring Leonardo da Vinci to Mars. ELACHI: Well [laugh], it was kind of an interesting story because after Spirit and Opportunity, it happened I was in Italy, and I was giving a lecture in Milan. And a colleague of mine that I—that she interviewed me. She's a reporter, Italian reporter. She interviewed me a number of times. She said, "Well, the Royal Library in Turin would like to invite you, and you will be able to see Leonardo's Codex of Flight. So, I said, "Oh, that sounds like something interesting." So, I went to Turin, and I—we went to the museum, talked to the museum director, and he took me to the vault where they have the Codex. And, of course, there were guards, and it was really very secure because they had more than the Codex. They had a lot of things about Leonardo. And then he handed me these gloves, so I was wondering why are they doing that? So, I put the gloves on. They pulled Leonardo Codex, and he said, "Well, you can leaf through it." I mean, I was taken aback, by that time. I thought they were just going to show me the thing. So, I sat down, leafed through it, and it was kind of amazing because, I mean, Leonardo is one of the most amazing scientists and artists, in world history. So, it was very touching. And then, at the end, he said, "Well, if we scan his Codex, is there a possibility to put it on Ingenuity?" And I said, "Wow, that will be cool, to do that." So, we actually did. So, they scanned it, and sent it to us at JPL. We put it on a chip, and it made it to Mars. And, as Leonardo, other than being a great scientist, he was also one of the early people who came up with the concept of a helicopter. And there were a number of drawings which were amazing. They were not necessarily for space, but he had one drawing which was for a military kind of tank, if you want, which was kind of shielding fighters, you know. And it looked almost exactly like the lander, like Ingenuity lander. It was conical shaped, and it had wheels at the bottom. So, it was eerily very similar to what Ingenuity looked like when it was packaged inside the heat shield and the back shell. We had a series of his images that we then put next to the Curiosity images. On the floor were—we were doing the Curiosity operation, and everybody who looked at them were absolutely amazed with the similarity between the two. I mean, it was probably a chance similarity, but it was an amazing similarity. ZIERLER: I've heard it said that da Vinci was really more of a scientist, and he used art to get at the scientific curiosity that he had. ELACHI: Oh, absolutely. I mean, he was a great scientist. He came with all kinds of concepts about flying, about helicopters. So, yeah, he was an amazing renaissance man, both a scientist and, as you said, used his art to reflect on the science. But, also, he was an artist in his own right, in addition to the science. ZIERLER: Charles of all of the engineering brilliance that went into Curiosity, what stands out in your memory as most impressive or most difficult to achieve in the end? ELACHI: Well, I would put it in two ways. I mean, one, clearly, the descent, the Skycrane. That was, number one, very novel, I mean, for a planetary mission. I mean, on Earth, it's done when a helicopter deploys, loads or even deploys tanks. But for a planetary mission, it was very novel, and it was very challenging because it was very hard to test in an Earth environment to simulate the Mars environment. We could test a few pieces of it, but we couldn't test exactly, flying Skycrane. So, I would say that was probably one of the biggest challenges. And, also, the other challenge was the instrument. Like always, instruments are always challenging because it's not only doing the capability that we want in those instruments. You can do that in a chemistry lab. But you have to shrink them, basically by a factor of five to an order of magnitude, to reduce their size and power, and to be operated remotely. So, always instruments have been a challenge. And the last one which was kind of a challenge, but it might sound normal to people, which is the parachute. And on every mission that was always a challenge because we are coming at extremely high speeds, and we are deploying very large parachutes because the pressure on Mars is very low. So, in order to get enough drag, you needed to do a very large parachute, and deploy it at supersonic speeds. So, I would say those three were kind of, in that order, the biggest challenges. ZIERLER: To step back from history to some extent, 2012 is really right in the middle between 2004 and Mars 2020. So, where do you put it in terms of what we learned in 2004 going forward, and what could be planned forward from 2012? ELACHI: Well, basically, let me put it in both the technical aspect and the scientific aspect. On the technical aspect, Curiosity in 2012 was a significant advance relative to Spirit and Opportunity. It was much larger, more complex. The landing was different. So, that was a quantum jump, from a technological capability…because the parachute had to be bigger because we were coming with more energy on it. Then from Curiosity to Perseverance, there was not a big advance in the landing system and the rover system. They are very similar. The advance was more into the drilling and how to preserve the samples that Perseverance is capturing, as we speak. So, most of the challenge was really in the payload which is held on the arm to actually make measurements. Now, on the scientific case, again, it was when we moved to Curiosity, there was a much more sophisticated instrument than what we had on Spirit and Opportunity, including drilling—not taking—not preserving samples but actually drilling, scooping some of the—what comes from the drill, and putting them in an oven, and doing an analysis, on them. So, there was a significant step forward on the chemical analysis of the material, on Mars. And that's what gave us a first, handle potential organic material, very short organic molecules, that we found on Curiosity. And the other interesting thing, up to that time, we were thinking that Mars, its—the surface is very rusty. That's why Mars look red. And we thought that rust would be fairly deep, and therefore there is unlikely to have any potential life, close to the surface. But when we did the drilling on Curiosity, we found that within literally a centimeter from the surface, we started seeing a gray powder coming out, which gave an indication that the rusting was not too deep on the surface. So, that kind of prepared for Perseverance, that the sample that we will get most likely would be able to get through that rust because rust is not very amenable. It's very oxygen-rich, so it's not very amenable, for preserving life on a surface. So, yeah, there was a—I would say there was a quantum jump between Spirit and Opportunity to Curiosity, and then Curiosity really prepared the groundwork, for Perseverance both technically and scientifically. ZIERLER: Charles, an organizational question, because Curiosity was so complex, because there were so many principal investigators who had their own piece of Curiosity, right, in what ways was the rover really many projects literally rolled into one, and to what extent was it a unitary project that had these different aspects to it? ELACHI: Well, that's interesting. Yeah, it was a multiplicity of instruments, and you have different PIs who wanted to do, advocating for their instrument. But that's where a leaders like John Grotzinger, one my colleagues and division chair, comes in. He was the project scientist, so he had to herd all these cats. And John was absolutely superb. I mean, John put as the highest priority: what is the top-level scientific objective, of the mission? He brought a united kind of vision. And with his background as a field geologist, he really understood what would it take to go and analyze rocks, and analyze, different surface layers so we learn about the history. And he kind of corralled the scientists who were on the individual instrument to work in a team effort, and it worked superbly well. So, I give a lot of credit on the scientific side to John and his experience. On the technical side, we had Pete Theisinger, who was a very experienced project manager, and he was a, he worked on Spirit and Opportunity also as the project manager. He really brought the team together and balanced the needs of the scientific community and the engineering community. Because, at the end, yes, we want to do the science, but we want to make sure we land safely, you know. Otherwise [laugh], we won't get any of the science. So, I would say the leadership that came from John Grotzinger and Pete Theisinger really was a very critical factor in the success. ZIERLER: Charles, was Curiosity engineered to be a multitasker? In other words, could it be running its various components at the same time, or were certain days or periods of time specifically devoted to one project that the rover could do? ELACHI: No, it had the ability to do multiple instruments. Like, when we were doing things in the oven, we were still using the arm to do other capabilities. So, it was a multitasking kind of mission. Of course, we are always very careful because you have a limited amount of power. So, the challenge was—because, we were getting the power from the nuclear generator, but then we were using it also fill a battery, and then running with the battery. So, there was a balancing act between the engineering and the scientific measurements. And the operations team, that's one of the key things they do is how you balance all of these things so you can capitalize…I mean, use all the power you have but not more than what [laugh] you actually got. ZIERLER: You mentioned that President Obama contacted the team from Air Force One. What was that like? ELACHI: Oh, it was really amazing because, I mean, number one, the president calling was really a highlight for the team. But, also, calling from Air Force One, that was the first time. Before that, when President Bush called, he called from the White House. That was exciting, also. But, we were told about roughly when it will be, so we had the whole team in the mission operation room. We had everybody sitting down there, and they had the speaker in there, and then the leadership of the project was standing behind me. We had video communication with them. And, yeah, at the right time—I guess the president's scheduler is very good—just at the right time, he comes on the phone. And he first started by congratulating. He said, "I'm President Obama, you know. I'm calling to congratulate you." And then he said, "Who am I talking to?" So, I was going to say, "I'm President Charles Elachi," but I thought I had better— ZIERLER: [laugh] ELACHI: —I had better be more proper. So, I said, "This is Charles Elachi, the director of JPL." ZIERLER: [laugh] ELACHI: "And, Mr. President, we have the whole the team here listening to you." And then we went through a conversation. He talked about the mission, what are we trying to do? And then he talked about how inspiring it is, what we had accomplished—I mean, clearly, he was briefed by his science advisor, John Holdren, because Holdren was at JPL during the landing. ZIERLER: Yeah. ELACHI: So, he had a first-hand experience of actually the excitement and the accomplishment that was done. So, I'm assuming that Holdren briefed the president. So, the president was very articulate about the inspirational aspect, and what the United States can do when people work together on even achieving amazing things that seem almost impossible. And then he made a funny comment because, we had the team, all of us, dressed, with our blue T-shirts with the insignia which said Curiosity on it. That's a tradition at JPL. Each project actually has a T-shirt with our favorite color, with the insignia. He said, "Wow, you guys look different. I'm accustomed to seeing people in white shirt and ties." ZIERLER: Yeah. ELACHI: I think he was referring to people at the Johnson Space Center. So, I told him, "No, Mr. President, here, we focus on accomplishing the mission." ZIERLER: [laugh] ELACHI: "That's our focus." [laugh] ZIERLER: [laugh] Charles, in what ways after everyone could take a deep breath after Curiosity landed, you have the initial amount of time where you think that you're going to be able to get all of this data. At what point did you realize that Curiosity could be renewed, and that the mission would be ongoing, and would continue learning things about Mars? ELACHI: Well, I mean, it was kind of in our plan, you know. The Curiosity mission, we were planning for like two years. And John Grotzinger and the science team working with the project at JPL actually laid out a plan. I mean, it was a flexible plan. But they laid out roughly where they want to drive based on satellite images, what are what looks like interesting areas, and they had a mechanism to keep updating and adjusting it based on what measurements they get, and then what new information they get, and on the exact landing location…because we landed within a few kilometers from the target that they picked for that. So, there was a plan for roughly two years. Now, of course, it ended up being much longer. It's still running here, now, five, six years later, and probably it will run for many years to come. And based on new information we get both from satellites and from Curiosity itself, the science team readjusts where they are going. And based on what they see on the ground, from the cameras on the rover itself, deciding which area to go and investigate with the scientific instrument. So, I would say, the first few weeks to months are defined pretty solidly because a fair amount of it is really learning how to drive the rover, learning how to use the instruments, checking that everything is working well. But after that, there is a fair amount of flexibility, based on the scientific results that we get. ZIERLER: Looking ahead, do you see additional rover programs for Mars? ELACHI: Well, yes, because, we had a long-term program from the beginning, even from the days of Spirit and Opportunity, and even before that. we laid out kind of a long-term almost like a 15- to 20-years program, leading to a sample return. I mean, that was our golden target that we want. And, matter of fact, that was planned almost in the '90s, you know. Before I became director at JPL, I was asked by NASA and by Ed Stone, who was the director at that time, to chair a working group which brought a number of people, both internal and external and international, to kind of lay out, if you want, the architecture—the top-level architecture of what a long-term program require because the—in order to get to a sample return, you just don't fly, land, get samples, and come back. You really need to lay the groundwork both for developing the engineering capability of roving, and the drilling, and then you need to develop the capability of communicating with the ground so to have a network of satellites in orbit around Mars to be able to communicate back to Earth. So, we laid out the plan of Spirit and Opportunity, which were some of the first significant rovers after Pathfinder. Then, we took the next step, being Curiosity, which is to learn more about the science, learn more about the drilling, and learn more about roving on Mars with a relatively high capability rover. And that laid out the groundwork for Mars 2020 or what's called now Perseverance. In the meantime, we were also putting orbiters around Mars, both to get very high-resolution mapping as well as for communication. We use them for relays. So, we kind of planned almost 15 years ahead of time, and almost 20 years ahead of time. And it's interesting enough that the architecture we laid out in the mid-90s, the committee that I chaired with a colleague from France, Michel Courtois, is almost exactly what's being done, both collecting the samples and then later to land, grab the sample, and launch them in orbit around Mars, and bring them back to earth for intensive analysis. So, it's almost exactly, what we had before. Now, of course, the technology has evolved, over that timeframe, so there is more capability and better technology, particularly for accurate landing, for rendezvousing, in orbit between the capsule, which have the sample, and the spacecraft that is bringing them back. But the core architecture is almost exactly what we identified in the '90s. ZIERLER: Charles, to be clear, the only thing at this point that would stop Curiosity is simply running out of power. ELACHI: Yeah, well, in actuality, the power is not the issue because it's using what we call an RTG, a radioisotope system. And it uses plutonium. The half-life of the plutonium is like about 80 years, so there'll be enough power for many, many decades. I would say it will be more either a mechanical failure in it. After all, running a rover is like running your car. You have to take it to repair shop every year or every couple of years. Here, we cannot bring it to the repair shop [laugh], to fix things. And there have been some issues with the wheels, but we are being very careful now on how to drive. So, I think the likelihood of it surviving many years to come, I think, is highly likely. I mean, I'm knocking on wood as I'm saying that. And there is always the risk. It's being operated by humans so there is always the risk of some error, which could happen. Again, we have a lot of checks and balances to make sure that doesn't happen, and we have a very experienced, operations team which has learned from Spirit and Opportunity, and so far on Curiosity. So, I think it's fairly likely that it will survive for many decades to come. ZIERLER: If, heaven forbid, let's say, Curiosity breaks down tomorrow, is it more feasible and even possible to send some kind of a robotic repair crew, or does it make more sense to just start all over again, and send a new rover? ELACHI: Well, David, maybe we should hire you at JPL. I like your out-of-the-box thinking. ZIERLER: [laugh] ELACHI: In principle, it's possible. But, probably, it's a more cost-effective way to send another one. Now, as of now, we don't see the need of another rover like Curiosity. I think the focus now is on bringing the samples back. Now, based on what we find with the samples, I'm pretty sure there will be a push to lay out a more ambitious exploration of Mars, to go to different areas. And that's where the helicopter plays a major role, the helicopter we are demonstrating on Perseverance, because the helicopter—the rovers allowed us to reach out to many kilometers relative to a lander, maybe many tens of kilometers, depending how long they survive. The helicopter, in the future, will be able to go many hundreds of kilometers, if not farther than that. So, I could envision that come in the 2030s, based on the results of what we get from the samples, that there will be a push for a much more, if you want, spatially ambitious program that means going to many areas around Mars, interesting areas, maybe dozens of areas, and really explore the whole planet. And, depending on how things evolve, there might be potentially a human endeavor and a human station on Mars. And even with the humans, I think rovers and helicopters are going to be very critical scientifically because humans are going to be very limited in how far they can go, and what area they can explore because of the risks of those area. So, I could envision not much after—maybe even before we bring the samples back that the science community and NASA will sit down, form another architecture committee, sit down and say, "OK, now, with all that we know about Mars, what should we be doing in the 2030s and the '40s to explore that planet? ZIERLER: Charles, moving beyond Mars, and into the solar system at large, given all that we've learned about rovers' capabilities on Mars, do you see any possibility for rover landings on other planets? ELACHI: Oh, sure, you know. I mean, let me go through some of them. I mean, one of the biggest challenges is Venus. Now, Venus is challenging because the surface temperature is extremely high, and it melts lead effectively. So, as of now, there have been only one lander on Venus which survived only for a few minutes. It was done by the Russians. But there is research going on that explores: can you operate and build devices which can operate in extremely high temperatures? And I could envision over the next decade there will be technology which will enable us to do that, and then we would be able to possibly rove on Venus. I think a trigger could be—there is a mission now which is planned that was just recently approved by NASA, which will be to put a very high-resolution radar that will be put in orbit around Venus. And we'll be doing something similar to what we've done on Magellan except much more—at much higher resolution, and then doing 3D topography with it. And based on what we see, I'm sure we're going to see some very exciting things that people say, "Wow, maybe we should look at a way of putting a rover to go and rove in those areas and do in situ measurements." And that's how science operates. You make a major leap, and you find some new exciting things, and you push for the next jump, and then you find exciting things. So, I could envision, again, in the 2030s and the '40s to talk about rovers on Venus. The other place which is just natural for rovers would be on Titan. That's a planet which, I mean, a satellite of Saturn, which is basically bigger than our moon. And it has an atmosphere, so landing on it will be somewhat similar almost to landing on Earth because it has a heavy atmosphere similar to Earth. It's very cold but, we have the technology or we can develop the technology…to put rovers on it. Matter of fact, NASA recently approved a mission which would put a drone, which will fly over Titan. So, it's kind of leapfrogging the rover step to go all the way to a drone, to a drone step, which will allow more extensive coverage. And then I can see on Europa, for instance, there we have an interesting concept that we believe that Europa is made of a shell of ice. And we're having a mission called Clipper, which is going to basically sound that ice to see how deep it is. We believe there is an ocean below that ice, a liquid ocean which has H2O, and it has organic material. Ultimately, what we would like to do is to drill, get down to that ocean, and put a submarine, in that ocean. And one approach is to put a submarine which has wheels, so it floats up to the bottom of the ice, and drive upside down, if you want. And we are testing exactly a similar—let me call it a rover submarine. We are testing that in the frozen lakes in Alaska where people—a team—where they actually put an upside-down rover, if you want, in those frozen lakes—and the bottom of the lakes are liquid, and it has a layer of ice—and, actually, driving, and we're controlling that from JPL. So, yeah, no, I can see rovers in many locations in the solar system where you really want to reach the different areas. ZIERLER: Charles, in space astronomy, the NuSTAR and WISE space telescopes, tell me about their development, and some of the things that they were set out to learn. ELACHI: Well, NuSTAR was a gamma ray instrument, and Fiona Harrison at Caltech is the principal investigator. And she developed a new technique, of how to, if you want, have a gamma ray or X-ray—I think it's an X-ray, sorry—an X-ray telescope by having a boom, and having a kind of a focusing element at the end of the boom. So, you have a long focal plane. And that led to a lot of interest in that technique and doing X-ray astronomy. So, Fiona was really a trailblazer in that technique. I mean, it was developed at JPL. And now there are missions which are even closer to taking the next step in doing that. On the large telescope, that's a generic name, I mean. There are a number of ideas of building larger telescopes. But beyond Jim Webb, I mean, there are ideas about using that kind of technology for building a larger telescope. The challenge there is going to be how do you deploy them? Already, Jim Webb is a challenge of how to deploy it. If you want to do something bigger, it's going to be even more challenging. Or even doing something—I mean, now, with the talk of, what's called the SLS, which is a new launch vehicle which has the capacity of a bigger shield at the top of the rocket so you can put bigger telescopes on it without needing to deploy them. So, you can probably go up six to eight meters. The same thing with the SpaceX Falcon Heavy satellite. So, there are a number of approaches of being able to put larger telescopes in space. And that always, it's very straightforward. That's what you get with the resolution. Similar to your camera, the bigger lens you have, the more acuity or resolution that you get. And, therefore, that's why there is a strive toward building larger optical and UV telescopes. ZIERLER: Charles, one of the markers of your tenure as JPL director was the importance of diversifying JPL's research agenda and delving even further into Earth sciences and astrophysics. So, first, I'd like you to talk a little bit about why diversifying JPL was so important during this time? ELACHI: Yeah. Well, JPL's focus was, at the beginning, mostly in—after the jet propulsion—was mostly on planetary mission, and that was great because that was exploring new frontiers. I lived through all of that, in my career at JPL. But, also, I saw how things come and go, funding wise, and I lived through periods where JPL had to lay off a number of employees because of funding [shortfalls] in planetary science. It was going down, particularly after Viking. So, there was a significant, layoff which had happened. But, also, because of my background in instruments, and particularly looking at the Earth, so, when I became director, I really had two reasons why I pushed for—and even before I became director when I was director for the science. Number one is that if you really want to have stability in our activity, we really need to have a broader portfolio where if an administration favors Earth science, we can do good, if it favors astrophysics or favor planetary. The other one, it became the—realizing that the Earth is really an important…Earth observation is a very important national goal because the beginning of seeing the climate change, the ozone hole, etc. It became that scientifically, it was very important for JPL—and publicly—for JPL to play a significant role also in Earth's observation because we foresaw that that's going to be a major policy issue, and, to some extent, a survivability issue in the long-term. And the third one, which kind of was a third leg, was because of my instrument experience, it was evident to me that the technologies are the same, that instruments are almost the same, if you are using them for Earth observation or for planetary. Matter of fact, the reason JPL became so good in Earth science is because many instrument scientists came to JPL to do planetary. And then they found that the opportunities are not as frequent as they would have liked, so they turned their attention to use the same instruments for Earth observation. So, looking at all these factors, it was evident to me that getting more heavily involved, particularly in Earth science but also in astrophysics, was very important for JPL. And then the connection with the campus, I mean, the campus has a very powerful team, particularly in addition to planetary and astrophysics and astronomy. At that time, there was not very much Earth science activity at JPL. There was some but not as much. Now, it's much bigger, the activity in Earth observation, particularly monitoring the Earth's atmosphere, the dynamic tectonics, and the dynamics of plates. So, I would say now, if I look at the campus and JPL, I think we have a world leadership role not only in planetary but also in Earth science as well as in astrophysics. And the two elements of Caltech, the campus and JPL, really complement each other in that leadership. ZIERLER: Charles, you provided the vision for why diversification was so important at JPL. But how did you go about implementing it in terms of the scientists, in terms of the funding, in terms of the institutional connections? ELACHI: Well, first off, I mean, our reputation on the instruments helped tremendously because we had a lot of instruments which were flying on Goddard Space Center satellites. So, that helped significantly because—and then the argument kind of I made at NASA Headquarters that, look, there is room with the expansion in Earth observation. There is room for two centers. And at JPL, because particularly the one which we used was our expertise in radar instruments both for imaging radar as well as for altimetry and scatterometry, I mean, there was no question JPL was the leader in that field. Everybody, even our competition, acknowledged that JPL is the leader. And these are instruments which are very demanding on the spacecraft. So, my argument to NASA was, "Hey, look, really, these Earth missions, which was radar, are the instruments with a little spacecraft attached to them. So, it makes a lot of sense for JPL to play the leadership role in having those missions, and to manage them." So, it started first by doing the altimetry mission, TOPEX/Poseidon and Jason, which was done jointly with the French Space Agency. So, JPL had the leadership for it. And then it moved to doing scatterometry, and we had a couple of missions on doing that, and then the radar because we had all the shuttles, SIR-A, SIR-B, all the shuttle missions. Then, we convinced NASA to do a free-flying program called NISAR for NASA India Synthetic Aperture Radar, which will be launched in 2023, which probably will be the ultimate of what we can do in this decade, where we'll be literally mapping the whole planet every other week at resolutions in the few tens of meters, a few meters, and monitoring the change which is happening, planet-wide, for a variety of applications, be it tectonics, water resources, vegetation, polar ice, glaciers, volcanic activity, human hazards like explosions—and the natural, like earthquake. So, really, JPL established itself over the last two decade as a leader in Earth science because of the instrument capability. ZIERLER: Charles, to clarify though, does JPL's process of diversification need to happen within the context of NASA's process of diversification, or are there missions or areas of research where there's opportunity for partnership with other government agencies like the National Science Foundation or the Department of Energy? ELACHI: Well, no, it was mostly through NASA. However, you are correct. There were some opportunities, outside of NASA, for example, NOAA, you know. So, we had a number—particularly instrument. We didn't do missions for NOAA, but we provided instruments, capability, and data access. So, we capitalized a little bit on that. But, also, we did technology work for the Air Force where, there, the technologies are very similar, particularly on telescopes, and instruments. So, even that we did not do missions for the Air Force, we did a lot of work on technology advances, which benefit both the Air Force and NASA missions. So, I would say today, I think JPL between NASA and NOAA and DOE—but at DOE, it was not mission-oriented. It was really more working on power systems, like the nuclear system. It's about maybe 15% of JPL is non-NASA activity. And that's healthy, because, again, particularly the Defense Department, they have much a bigger investment in technology. So, my thinking was, if we want to stay leaders at NASA in our technology, in our mission, you need to be a leader in the technology, and the Defense Department was the best source for funding some of these technology activities. And the Defense Department funds a lot of activity at Caltech…on campus, also in advances in technology…be it DARPA or the Air Force or the Office of Naval Research. So, the investment that DOD does in technology is significantly higher than NASA because DOD is a bigger agency. So, they invest a lot more in technology. So, it was a win-win situation where we capitalized on our experience in space to developed new technology for DOD, but also we capitalized on the investment that DOD did for us to play a leadership role in the NASA mission. ZIERLER: To stay on the funding question, when Caltech receives these enormous gifts from people like the Brens or the Moores or the Resnicks, how does that work in terms of areas of research or overlap for which JPL is a player? Does JPL see any part of those funds? ELACHI: We don't see the funds but we participate in the definition of these activities. And the reason is simple. I mean, JPL has a budget which is four times the budget of the campus. So, it's not that JPL is in big need, particularly of philanthropic money. So, we don't want to compete with the university, and definitely don't want to compete with the campus, on the funding. To give you an idea, I mean, JPL budget now is about$2 billion, a year. The campus is about \$600 million. Now, a lot of our activity is for building spacecraft. However, in a number of these activities that the philanthropists are interested in, there is a lot of technology at JPL which could benefit the campus, or joint effort, and people can experience that benefit.

For instance, looking at the gift related to solar power, the idea was to develop technologies that the Brens funded recently was to develop technologies which basically allow you to put old solar cells which acquire power, and transmitters to transmit the energy to the ground on single sheets. And that's the kind of thing that JPL, is working on, so there was a lot of joint effort with the campus, both on the architecture but also on the technology. JPL brought its own money, to do that. The same thing with the Resnicks. One key element of that initiative of, the environment and—in space monitoring to see what's happening to the environment. As part of the team that is working on the Resnick activity on campus, there is a team working on the remote sensing element of it in addition to the development of sustainable, environment and energy projects. And Mark Simons, a colleague of mine, who's also in a division here, who is also the chief scientist at JPL, is a leader in that area. And he's capitalizing on the missions that JPL are developing like, for instance, the NISAR mission that could benefit a lot, for monitoring what's happening on our planet, and particularly the changes due to global warming, as well as the tectonics. So, there is a natural interchange, even if there is very little money which comes from the campus, to JPL. Usually, it's more the JPL funding activity, at the campus than the other way. But intellectually, there is a lot of synergy and a lot of interchange which happens in those areas.

ZIERLER: Charles, in early 2013, it was a time of transition when both Caltech President Jean-Lou Chameau and deputy director at JPL, Gene Tattini, announced that they were going to step down. What did this mean for you and for JPL?

ELACHI: Well, these are expected things, I mean, the same way when I retired from JPL. But, it was superb working with David Baltimore. When he decided to step down, you kind of think about what kind of a new person is going to be. Will that new president be engaged with JPL? Will they put high priority on JPL as part of the Caltech family? Now, in the case of Gene Tattini, he and I built a very—a superb relationship, because, basically, he was my deputy almost a month after I became the director. So, we kind of lived together. But, we were always aware that, sooner or later, people are going to retire. And one high priority I had at JPL is to make sure we have a good succession plan, to be thinking about who are both internal and external for all the positions at JPL.

Matter of fact, we used to have—once a year, I used to sit down with all the members of the executive council, and we used to discuss for each member of the executive council who are the potential replacements if they decide to retire, and how are we preparing those people to build that experience and talent and so on. Now, for my deputy, Gene and I used to sit down by the two of us, and a couple of times with Jean-Lou, about who would be a good replacement. And, again, because of—we found that having somebody with an Air Force background, Air Force in space background, this really works well, because of their experience, and discipline of how they do things, and the philosophy that in the space program, in the Air Force, it's not done for profit. It's being done for the national interest. The same way at NASA, we don't do our missions for profit. We do it for national, interest. So, the thinking is a little bit different than in industry. So, we had our eyes on Larry James, who became the deputy director, and he was basically the commander of Bundaberg. So, we had interaction with him, for launches because we did a number of launches from Bundaberg.

Larry was also an astronaut. He never flew but he was an Air Force astronaut, so he was very heavily involved in space. And, matter of fact, without telling him that, because he was down here at the Air Force base in Los Angeles, we invited—my wife and I invited him and his wife. We told him, "Hey, we are doing a float for the Rose Parade, you know. Would you be interested in coming and helping us put flowers on it, because the JPL employees volunteer to put flowers on the float?" And he loved it. So, that was kind of we got to know him a little bit in a non-business kind of an environment. And then when Gene decided on retiring, it happened. It's interesting because it happened as I was dealing with the people in the Pentagon. And one of the leading people there told me during a meeting, "Hey," he took me aside, he said, "Larry James has just decided he's planning to retire," because I told him that we have our eye on him. And I was asked…so, I immediately called Gene Tattini, and I told him, "Hey, Gene, before anybody comes and calls Larry James, can you call him, and tell him we are interested in him?"

ZIERLER: [laugh]

ELACHI: [laugh] So, Gene did do that, and Larry James loved it because he knew about JPL, and we have interacted with him. So, it was a very—and then Caltech formed a committee, interviewed Larry James, and it was a perfect match, you know. And Larry was absolutely delightful to work with. I would say I was fortunate to have both Gene Tattini and Larry James as my deputy. Both of them were absolutely great.

ZIERLER: Charles, as you—

ELACHI: And Larry James, because he lived down the street from us, every once in a while, I see him even now. And I tell him, "Well, Larry, what—how are things going?" He said, "Charles, the best thing you have done is selecting me as the deputy director. I'm absolutely loving it. Now, I can go around and tell all my friends and family what I do. [laugh] I was not able to do that"—

ZIERLER: [laugh]

ELACHI: —"when I was in the Air Force." And you can see that he's really loving, doing that job.

ZIERLER: Charles, as you well know, Tom Rosenbaum has said many times that JPL is a jewel of American science. I wonder how that translated when he became president of Caltech.

ELACHI: Well, you are right. The key thing, I mean, JPL is no question a jewel, for the nation in NASA, even that some other NASA center might be a little bit envious.

ZIERLER: [laugh]

ELACHI: But I keep saying, well, every once in a while, we kind of get told, "Oh, you guys are very arrogant." I say, "Yeah, but we deserve to be arrogant—" [laugh]

ZIERLER: [laugh]

ELACHI: —"for how good we are!" And, no, it's very appreciated that people like Tom Rosenbaum and Jean-Lou and, before them, David Baltimore, and effectively, I would say, almost all the presidents of Caltech looked at JPL as a jewel. And it's kind of a trust that the nation and NASA has given to Caltech in a trusteeship thing of really overseeing and managing the leading organization. And you go—even when I go around the world, I would say, even internationally, I would say, JPL's reputation is even higher than when you talk with people in the US. I mean, in the US, people also think of JPL, very, very highly. So, it is really a unique institution, and not because only of its accomplishment but the arrangement that was done between a small private university and the government to manage an institution like JPL.

So, usually, when I describe that to my colleagues in Europe, they are amazed, how is that done, because they know about the success of JPL. How is that arrangement being done? Matter of fact, a couple of times, the head of the French Space Agency and European Space Agency came and spent a couple of days here talking with me—and I think at that time it was Jean-Lou who was president—to really understand how the setup works, because they were thinking, well, could we do something similar in France? Now, of course, the arrangement that we have between JPL and NASA is a historic arrangement. It probably will be much more complicated to do it now if somebody was starting from scratch. But historically, JPL was founded by Caltech, and then NASA came into the picture. So, it's really because of that history that we do that. And, yes, it is a jewel, in NASA. And I have to tell you all the people in Congress that I interact with see it the same way, you know. That, what I remember Congressman Culberson saying it's a—he always says what a jewel JPL, is, and it's a special, really special place.

ZIERLER: I want to return to some wacky ideas that we talked about last time, but these are specifically on the basis of turning wacky ideas into testable propositions. So, was there anybody at JPL or the way that JPL interacts with the theoretical physics community that one day might make testable the notion of the multiverse or the notion that our universe is the child from a parent universe? What way in the future, or even thinking about it now, might JPL play in making these wacky questions into testable propositions?

ELACHI: Now, you are taking a huge leap in the wackiness—

ZIERLER: [laugh]

ELACHI: —in going there. But, yes, we do have people at JPL—matter of fact, we have a team—which really takes wacky ideas, and says, "How can we do that?" Now, the multiverse is a big leap forward, so I'm not aware of anything specifically on that. But we are looking at what technology is needed to go to a neighboring star. I mean, that requires like really a huge leap into the technology, basically, being able to get to speeds almost at the speed of light, which has not been achieved in a large, large structure.

So, yeah, we do have people who sit down, and they think about solar sails. They look at laser-powered sails. We look at matter-antimatter, propulsion systems, nuclear systems. And we do fund that from our internal funding because, in general, the g