Louis Friedman, Engineer and Leader in Space Policy and Exploration

The triumph of space exploration in the modern era rests on the ideal combination of important science objectives, overcoming impossible engineering challenges, and mustering the sufficient administrative, budgetary, and political support to ensure mission success from proposal to orbit. Lou Friedman has worked in all of these realms, and his positive influence has touched many of the most significant space missions over the past half century.

Raised in the Bronx, Friedman pursued an applied mathematics degree at the University of Wisconsin at dawn of the space age, and he completed his dissertation at MIT in Aeronautics and Astronautics when the Cold War infused space exploration with a sense of existential urgency. Friedman worked as a guest at MIT's Lincoln Labs, and subsequently moved to the Jet Propulsion Laboratory's Advanced Projects Group, where he contributed to planning and execution of the Lab's flagship missions, including Voyager and Galileo, investigations for Venus, and the rendezvous with Halley's Comet.

Reading the tea leaves at the end of the 1970s, Friedman recognized that absent an infusion of political and budgetary support in Washington, the age of space and planetary exploration could wither as fast as it had grown. Along with JPL director Bruce Murray, and planetary scientist Carl Sagan, Friedman formed The Planetary Society to ensure an ongoing golden age in space science. As the founding executive director of the Society, Friedman lobbied Congress to increase funding and to expand NASA's purview and capabilities, and he helped lay the groundwork for JPL's Mars rover missions. His work on solar sails may one day open new possibilities in long-range space travel, and his advocacy for the importance of research on near-Earth objects has vastly improved the field of planetary defense.

In the discussions below, Friedman reflects on the unexpected twists and turns in his career, he addresses the Fermi paradox and the prospects for finding life beyond Earth, and he likens our age of space exploration to that of the discovery of the New World five hundred years ago. In retirement, Friedman has consulted around the world on a range of issues in space exploration, and he has authored three books on human spaceflight, the legacy of space cooperation and competition with the Soviet Union and Russia, and what may come of interstellar travel. Friedman is a fellow of the American Astronautical Society, and a fellow of the American Association for the Advancement of Science.

DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Thursday, August 25th, 2022. I am delighted to be here with Dr. Louis D. Friedman. Lou, it's so nice to be with you. Thank you for joining me today.

LOUIS D. FRIEDMAN: A pleasure.

ZIERLER: Lou, to start, would you please tell me your current or most recent title and institutional affiliation?

FRIEDMAN: [laugh] My current title is Emeritus. I am the retired Executive Director of The Planetary Society (and its co-founder). I left there in 2010. Since then, I've been consulting on a JPL-led study and have written three books. Can I call myself an author?

ZIERLER: That makes you an author.

FRIEDMAN: I guess I'm an author. That is a little bit daunting to realize, since I never thought of myself as that. I'm also on advisory committees with NAS and one with Breakthrough Initiatives.

ZIERLER: Lou, in what ways have you remained connected with The Planetary Society since you went emeritus?

FRIEDMAN: I haven't. I remain friends with a couple of board members, and a couple of staff and very generally keep up with them. Of course I am still pretty well known and identified with the organization.

ZIERLER: Lou, to the extent that you remain current with what The Planetary Society is doing, is it more or less staying true to its original mission, the ideas that you and others had in founding The Planetary Society?

FRIEDMAN: Yes and no, it is doing a great job remaining a viable and effective organization advocating NASA's planetary program. It is not as involved internationally or with innovation for planetary exploration as I would hope. On the other hand they are doing an excellent job in outreach and becoming more broadly involved with youth and education. Perhaps I think of it like a child who I helped grow up. nurture and love, and it's really turned out quite well and quite successful, and I'm very proud of that. It doesn't always do what I think it should or could , but it's doing what it wants to do, and that's OK. That is all right for my children too.

ZIERLER: [laugh] Lou, tell me about some of you consulting work. What are the kinds of things you're consulting on?

FRIEDMAN: Right after I retired I became a co-leader of a Keck Institute for Space Studies program here at Caltech. It was the Science and Technology of Exploring the Interstellar Medium, with co-leaders Ed Stone and Leon Alkali. At their workshop Slava Turyshev of JPL presented the concept of using the solar gravity lens, deep in the interstellar medium beginning at 550 AU from the sun, for high resolution imaging of exoplanets. I was excited about that – I am always attracted to new mission concepts that enable something that otherwise is impossible, in this case multi-pixel imaging of an exoplanet. I've been consulting with a JPL study for of this with Slava for more than five years or so on a far-out mission that would go deep out of the solar system to the solar gravity lens focus. The focus is in reality a focal line, a result of general relativity t that Einstein published in 1916 that light bends when it goes around a large gravitational object—in this case, the sun—and it bends to such a point that those light rays will come to a focus. If it's an extended object, it'll come to a line, a focal line. At that focal line, you get a hundred billion times magnification of whatever you're looking at. In our case, the idea is to look at an exoplanet, and be able to do multipixel imaging, which can't be reasonably done by anything else—not the James Webb space telescope; not even by the largest telescopes on Earth.. But you have to get out to the solar gravity lens focus, and that's out there beyond 550 AU, and the furthest we have ever gotten to is 140 AU- and that took Voyager over 40 years. That's one-fourth the distance. You have to go much faster, and that's what I've been working on: the mission analysis and design associated with something like that.

ZIERLER: Lou, what would this tell us about the universe that we don't already know?

FRIEDMAN: We don't know answer to the key question about the universe that drives space exploration: what is life. And we may never be able to if we can't compare the only life we know of (that of Earth) with other words. Whether or not there is extraterrestrials life or whatever it is, we need to understand the relationship of our life to the processes going on other planets – physical, chemical and maybe biologicals. That is the answer to your question – we hope to learn about what is life. And about the plethora, probably billions, of other worlds in our Universe.

Exoplanets and Life Beyond Earth

ZIERLER: Lou, to clarify, the idea that there are billions of exoplanets, right now, the count is somewhere above 5,000. Is billions—?

FRIEDMAN: No, it's approximately 5,000 discovered so far.

ZIERLER: Right. When we say "billions," is that an extrapolation? Is that a hypothesis? How do you understand the idea that there are billions of exoplanets?

FRIEDMAN: You're right, that's an inference. It's an inference based on kind of a principle of uniformity, that the Universe is pretty much uniform. We can see galaxies and stars, we can characterize them and observe their processes. And then what we have seen so far in many different star systems with the exoplanets we more or less expect to find everywhere with about the same distribution. So the billions of stars and billions of galaxies easily allows us to extrapolate or infer billions of exoplanets.

ZIERLER: Lou, what do we know so far about how ordinary or not our solar system is, and how might that influence the way this technology might develop in looking at these exoplanets?

FRIEDMAN: Reminding you again that I am not a planetary scientist – "only" an engineer, only a mechanician – albeit a celestial mechanician. [Smi0le.] We know pretty much our star is an ordinary star. The sun is a not so special star in a not so special location in a not so special galaxy. We don't know, to be sure, how unique or how typical our planetary system is. Observations of other solar systems, so far, seem to show lots of variety – at least as far as I can tell. Some giant planets close to their sun, some very far away, etc. In our olar system the so-called habitable zone is roughly 0.7-1.3 AU (although recall what I said about Europa and Enceladus and the moons of outer planets which some scientists consider habitable). In other solar systems with hotter or cooler stars or bigger or smaller ones, that zone will be different. It really is only a measure of temperature and the ability to sustain liquid water. In the new book I have coming out next year I use the habitable zone concept a lot, even while belittling its actual definition. I assert a lot of things about extraterrestrial life in the book – the nice thing is that no one can prove me wrong.

ZIERLER: That's right.

FRIEDMAN: No, actually that's not true. Life could be discovered on Mars tomorrow or some other discovery could be made to prove me wrong. We could even get a sign of extraterrestrial intelligence, which I conclude is not likely to exist at all. The fact that extraterrestrial life is a subject without subject matter is what me makes me so excited about the possibilities of seeing other worlds and making discoveries.

ZIERLER: [laugh]

ZIERLER: Lou, for all of this excitement over imaging these billions of exoplanets, are you more interested in technosignatures or biosignatures in determining whether there's life on these planets?

FRIEDMAN: The key word in your question was "interested." Of course, I would be more interested in technosignatures. I'm not made of wood. [laugh]

ZIERLER: [laugh]

FRIEDMAN: Of course, I'd be interested in technosignatures. I just think they are extremely unlikely to exist.

ZIERLER: Meaning technosignatures would suggest evidence of advanced life, not just organic life.

FRIEDMAN: Yeah, but I don't think there advanced life creating technology is very likely to exist anywhere else in our galaxy.

ZIERLER: Because your hunch is that we're truly alone in terms of being an advanced civilization?

FRIEDMAN: A little more than a hunch. That's my next book coming out. It's entitled Alone, But Not Lonely: Exploring for Extraterrestrial Life. The thesis behind it, or the reason behind that title is first the lack of any observational evidence despite myriads of observations and second the difficulty in transition from the simplest form of single celled life to complex life and then intelligent life. Thirdly, it seems from Earth's experience that intelligence in a species makes the species very short-lived. the likelihood of other intelligence species—by "intelligent," I mean evolved, complex life that have a technology that show themselves seems small no matter how you calculate it. This is probably rare, but for just simple life there are probably, billions of planets with life. Life got started on primitive Earth very quickly, in the first half-billion years. We don't know how – from the primordial elements and molecules or introduced here from interplanetary debris? But either way it is reasonable to assume that it is prevalent on planets everywhere.

But after life got started here, then nothing happened for half of our whole existence. Nothing happened for two billion years. It just was there. And the sequence of events in evolution after that seem beset with chances or even accidents of nature and planetary processes. Two more billion year and then finally in the last few hundred thousand, humans appear and then "intelligence," and then finally technology. That's such a blip of time that it is hard to assume it is a rule. It's 100,000–200,000 years humans have been around. Technology's been around for about 500 years, that is, the kind of technology that can show yourself to the universe, not counting fires in a field or something like that, and so really, tiny, insignificant times. Then, if you want to get into interesting questions, it's probably a pretty good prediction that humans won't be around another 100,000 years.

Whatever is your extinction hypothesis, whether you're a nuclear war worrier, whether you're a climate change worrier, or you're a pandemic worrier or, more importantly, you're an evolution worrier, the evolution of the human species, of our technology is moving at such a rate that it's hard to imagine that 1,00 years from now, we won't have some kind of different relationship with an evolved different species or the descendants of today's robots [laugh], whatever they are, and there'll be some kind of mixture of humans and robots. The whole span of humankind is probably less than 200,000 or 300,000 years out of this four and a half billion-year to date history of the planet and, ultimately, 10 billion years of the solar system. I think the notion of finding another species, quote, "like us" showing off technology is pretty remote.

[unrelated conversation]

ZIERLER: I wonder, Lou, if you wouldn't see the Fermi paradox as much of a paradox at all. It makes perfect sense why we haven't seen any other life, and never will.

FRIEDMAN: The Fermi paradox is only a paradox to those who assume there is other intelligent life in the universe. It's a good question. Where are they? Now, there could be robot probes. You can go into other theories which have been offered about this Bracewell probes or different kinds of probes that could be out there exploring the universe, but unobservable to us. We/. We might have the ability to make self-replicating robots that can go explore indefinitely, given enough time, to explore the universe and be everywhere. But Then the Fermi paradox still says, "Oh, if that's a possibility. Where are they?" You're right back where [laugh]—I think you get stuck on that too.

ZIERLER: Lou, tell me about this upcoming book that you're writing. What were the original ideas that led to it?

FRIEDMAN: It was motivated by becoming increasingly negative about interstellar flight even as I got involved with those studying and pursuing it. By the way, I am on the advisory committee for Breakthrough working on the goal of interstellar flight. . Do you know what Breakthrough is?

ZIERLER: Sure.

FRIEDMAN: I'm on their Starshot advisory committee. Because of my solar sail work, which we can get into in another context, I had always though that solar sails were a segue to laser sails, the only conceivable propulsion technology for flight to the stars. But it turns out that is not true. But I was involved in the subject. I'd go to these interstellar conferences, and they were full of same old ideas which hadn't changed much since the 1960s. They always had a mix of science-fiction writers and engineers with not yet quite real ideas for interstellar flight. Just life 60 years ago everyone is waiting for nuclear fusion powered spaceships or imagining harness theoretical ideas like traveling through wormholes or warp drive. That was discouraging. Then I got involved with Starshot, and they jumped on an idea for, possible, in principle, interstellar flight, adapted from work being done by Prof. Phil Lubin at UC Santa Barbara. It was to send a one-gram spacecraft at 20% the speed of light propelled by 500 gigawatts of laser, requiring hundreds of kilometers of arrays all working together. Then it gets to the nearest exoplanet in 25 years or so flies by it at a speed of about 140 AU per day – with its one gram payload! This is the nearest star; not the best star; not the best exoplanet; not the likeliest place; and it's one. That will be the best we can do. I said, "You've got to debunk this whole idea of we're going to go interstellar to explore the universe.". That led to the book, along with the positive work I was doing with Slava Turyshev on getting out to (only) 600+AU and using the solar gravity lens to really see exoplanets up close with tens of billions' times magnification.

As I got into the subject naturally, I had to consider the purpose of exploring exoplanets – discovering extraterrestrial life. So that led to me including a lot about the subject in the book. First I had to deal with and get rid thinking about the search for extraterrestrial intelligence (SETI), so that I could concentration the much more likely and realistic questions of life itself. At The Planetary Society, we funded SETI programs. We funded SETI research. We funded at Harvard University and at University of California at Berkeley. We funded a radio telescope project in Argentina as well. We funded SETI, and so everybody thought I was a SETI proponent, and I surely gave talks in which I said, "Send money. Help support SETI." I don't put down SETI – it is good research and technology. I just don't think it's going to come up with a positive result. But the two comments I have for myself there is, one, I could be wrong. Secondly, what you're doing is worthwhile because you're exploring the universe with good technology, you're advancing both technology and science along the way, and you're learning things. If it was all or nothing, life or no life, and if it was expensive, if it cost $10 billion to do SETI, I wouldn't be for it. But the kinds of projects we were supporting were hundreds of thousands of dollars. Even now with the stuff that Yuri Milner and the SETI Institute support, it's millions of dollars. It's not billions. That's worth it. I wouldn't be for it if it was billions. Or even hundreds of millions.

Space Policy and the Budget for Discovery

ZIERLER: Lou, based on that, just overall, where do you see the budgetary environment for space exploration right now? Where is the enthusiasm, both from the public, from industry, and from government sources?

FRIEDMAN: You asked two questions: what drives the budget, and what drives public interest. Remember, it was that dichotomy which led to the formation of The Planetary Society in 1979 – extraordinary public interest in Viking and Voyager exploring the planets and the political support drying up to the point of considering a cancellation of the planetary program. They have different as we see so many aspects of politics. I think public interest is driven by exploring the unknown. And, absent a major geopolitical purpose with Presidential backing, the budget is driven by special interests – mostly industry contracts in human space flight. The exploration of the unknown drives public interest – and that is manifested in the science program. And space science support in the Congress has been quite good. From a science point of view, the fundamental question I is about life on other worlds. The other science driver is about the big mysteries of the universe: how it started and how it works. The Webb Telescope, the Hubble Telescope proved that to you. The wonderful images captivate the public even when they are not understood, even when they are not even at ordinarily visible wavelengths but with infrared or X-ray. They get played up on the nightly news, and the news commentary is, "Oh, wow, that's terrific." News coverage is also enthusiastic about doing new things, things for the first time or what seems like the first time. It comes back to what I said earlier about exploration being the combination of discovery and adventure. That drives public interest. And that is what makes the search for and questions about extraterrestrial life of such high interest – it is an unknown, it affects us all, and the means to find out about it are high technology adventures. We don't know the answers.

ZIERLER: Lou, how do you deal with the challenge, the philosophical challenge of not being able to prove a negative? In other words, how do we know that these conclusions might simply be a limitation of our technology?

FRIEDMAN: That's why I can be arrogant, and assert anything [smile].

ZIERLER: [laugh]

FRIEDMAN: You cannot prove a negative. You can never prove there's not life on Mars. I keep reminding people in planetary science because that's a very important question you might ask. Can I digress?

ZIERLER: Absolutely.

FRIEDMAN: One of the big questions in the future of Mars exploration is planetary protection, keeping that planet pristine or not and keeping our planet safe. There might be a lot of debate about that, and NASA has guidelines, and there's international committees that have meetings on it, and there's all kinds of so-called rules. Of course, they have to be enforceable. But if humans go to Mars, they will contaminate the planet. We are not going sterilize the crew. You cannot wait until you prove there no life on Mars – that is unprovable. It can be considered highly unlikely or not, but not absolute. And the question is do you have to quarantine them when they return. Right now we are facing those questions on robotic sample return missions. You have to protect the spacecraft or at least the parts of it that come in contact with the surface. You also want to do this to protect the integrity of your science measurements.

Whatever you do on either human or robotic missions will have an element of risk. You can say we'll never send humans to Mars because we never want to contaminate that planet. You know that's not going to work. We'll take the risk because not doing so leads to not knowing. You may have other reasons for not sending humans to Mars, but either with humans or robots you are not keeping it a pristine park. As for the samples that come back from Mars there will be overdone protocols and a lot of expensive handling procedures but people will also ask, what about all the Mars material that has already come to Earth – it hasn't led to wiping out life on Earth, or anything else dangerous that we can detect.

ZIERLER: Is Mars sample return something that you're personally excited about?

FRIEDMAN: I led studies on Mars sample return back in the day when I was at JPL. I was the leader of the Mars program in the years right after Viking, so not in '76 and '77. I was an advocate and proponent of Mars sample return all the way up until the recent last few years. The recent last few years have me wondering if Mars sample return is the best approach now. It's budget and the somewhat fragile program and mission design put not just the mission but the planetary science program in jeopardy. And miniaturized in-situ instrumentation is rapidly improving. It has a very complex mission design that I think is programmatically fragile. You're caching samples now that some undefined mission of the future will go and pick up if Perseverance is still working eight years from now and can deliver the samples to new lander. As backup you are relying on helicopters in a new development to go out and pick up the samples. Then you have to put them in a rocket and take them to Mars orbit and transfer them to the European space agency orbiter for return to Earth. Europe obviously has a lot of budget pressures. China's doing a Mars sample return mission also, and theirs is likely to bring samples back earlier than ours (if it works). They have done veery well with their space program. If we had any sense, we'd all be working on this together because it's really complicated, and it really takes a lot of vehicles to do, so it's a big challenge. We should add resiliency and greater political motive to it, but by making it cooperative. If something goes wrong on our sample return, the only thing we can do is to hope to do it over at another very high cost and probably another lost decade. We could do a lot of rovers in that time, with a lot of good in-situ analysis. However, the Chinese presence looms both as a competitor and as an opportunity.

ZIERLER: Lou, what about the icy worlds, the ocean worlds around Jupiter?

FRIEDMAN: That's another kind of dichotomy to exoplanet scientists. If they found such worlds out there, they would say, "Oh, they're not in the habitable zone." [laugh] But now the astrobiology scientists, they actually rate places like Europa and Enceladus higher for astrobiology interest. At least some do. These are very important object to learn more about and they are fascinating—an underground ocean, water jets streaming into space, what else? And not just them but other moons out there. pe. I am excited about Europa Clipper -- there is much to discover there. Again, it's a long road to discovery of. Much of that exploration is guided by the principle, I credit Wes Huntress—I don't know if you've come across his name—of the '90s, who led space science at NASA, with this mantra, "Follow the water." The premise is that wherever there's water, there's a chance of life. That's what's driving it. Our exobiology program is to go where the water is. We've got this evidence of water in the Europa under ice and we've got the evidence of the stuff spewing out, both at Europa at Enceladus. This great mission that JPL's working on now, the Europa Clipper, is of course over budget and hence causes a lot of problems for the whole program. Whatever it discovers, it will be spectacular and unexpected. Nature will disappoint. We used to think that Mars was the only place for astrobiology. Now, we think there's lots of places, and even Pluto may have something. It's a stimulating topic. It is not that all these places are likely to actually have life – but that may have conditions to teach us something about the origin and conditions for life.

But I've got to come back to the question you asked, because I never answered it. This is all an aside. You asked what gets support for the budget. Public interest is one part – but only the minor part. The budget follows the special interests controlling Congress – industry, funding big contracts, employing people in districts and states. Most of this comes from the human spaceflight program, and so right now everything depends on the SLS launch, which is coming up in a couple of weeks. The politics of the budget, that is the funding levels, is driven by taking care of the space industry – the size, location and employment levels of contracts and work force. NASA. By the way, as an historian, you should go back, if you already haven't—you probably already have—to the recordings of Kennedy and James Webb—the James Webb; not the telescope; the man—having the talk. You know those tapes? [This is another aside]

ZIERLER: I do, yes.

FRIEDMAN: They're in the archives. Fascinating.

ZIERLER: They are.

FRIEDMAN: James Webb, the NASA Administrator and a politician, is telling President Kennedy that he needs to build a space agency and space program on a broad front of capability. Kennedy impatiently says ok, but pointedly reminds Webb his job isn't to build a space program – it is to beat the Russians to the Moon. Kennedy had no interest in space – Apollo was a tactical program in the Cold War contest with the Soviet Union. That is what generated the huge budget – never again achieved. The budget wasn't about space, it was about war – thankfully a cold war. That is what I meant by saying that a really big space goal needs a geopolitical rationale. Any president interested in science did nothing for space: Jimmy Carter, for example. Ronald Reagan and George W. Bush were all for the space program, but they did nothing to advance its budget or accomplishments. Clinton had no interest in space but he had to have a way to give the post-Soviet Union Russians some money after the Cold War to keep their aerospace industry is from selling out to bad actors. "Let's join with them in the Space Station, and we'll get that built." That was the way to do it and that got us the International Space Station, the only other human spaceflight initiative ever successfully initiated besides Apollo. The Shuttle was not an initiative – it was a weak compromise. It was Nixon's negative decision. That was him rejecting all the other proposals, and saying, "You can keep NASA, and let them do the vehicle but giving it no mission. Then he scaled that back the next year. It's only geopolitics that drives a big space budget, and that's a challenge.

ZIERLER: Lou, you mentioned the importance of geopolitics. Just looking at the headlines today, between tensions with Russia over Ukraine, and with China over Taiwan, what are you concerns about the future prospects of space exploration, given these problems?

FRIEDMAN: Sadly, Russia is now irrelevant for space considerations. They have allowed their space program to wither away – indeed we might say they are allowing their whole country to wither away. China – just the reverse. They are gilding a remarkable success story in space and a broad program of exploration, science, technical achievements and technology development. They are following in our footsteps going to send humans to the Moon, rovers to the Moon and Mars and robotic missions through the solar system. I am unsure if a space race with them will help our own program – why enter into another space race, one we might lose? We have little to gain from that. On the other hand, I think engaging China in space cooperation could be a meaningful way to build a positive relationship with our main competitor and geopolitical threat. And that wiped be good for our space program as well. I don't know if they see it as being good for theirs.

No American President is going to say, "We'll give up on human spaceflight. Let the Chinese do it or let the Koreans do it." That's not an American statement. The danger is that he or she will do as Nixon did, allow it to drift along without a real purpose or mission.

My concern is we will do it again. That we will continue to waste a lot of money on human spaceflight that lacks a sensible purpose or rationale. The Shuttle and Space Station were great technological achievements, but they don't do anything for science or space exploration, and even precious little for space development. I don't think that their wasting money is all bad because spending lots of money for great technological problems that employ people doing creative work with great achievements, and bringing out their best has merit in and of itself. It's good for education and it's good for the economy. It doesn't cause cancer. It has no bad side-effects. It's not bad for the environment. It's not bad for health. There's no negatives on space ventures except money. I don't oppose wasting money on human spaceflight, I'm just disappointed because we could do better and more purposeful for the whole world.

ZIERLER: Lou, in the grand sweep of history, and looking at the technology that will get us there, where do you see private industry? Where do you see companies like Blue Origin and SpaceX contributing to these accomplishments?

FRIEDMAN: I can't give you the grand sweep of history, especially in something as new and immature as private industry space development. It is too new. They're not doing much with human space flight, except maybe space tourism will develop – or maybe not. The two remarkable entrepreneurs – Musk and Bezos – leading this idea are driven by their ideologies, not the commercial possibilities. Their commercial ventures are means to their visionary ends – Musk on Mars, Bezos on Earth orbit. They have made private ventures – but their achievements require government funding and participation. I admire their innovation and brilliant cleverness – but I am not excreted about their goals. I focus more on science and exploration, and I am less interested in encouraging the tourism industry for billionaires and someday when it gets routine for millionaires. I know Elon, by the way. Elon was on the board of The Planetary Society for a number of years and helped us get our first solar sail project started. In (I think) 1999 when he was first getting interested in space, and in particular with doing a privately funded mission to Mars, he and an associate of his came to visit me at my house here in Pasadena and we spent the day brainstorming about developing a private mission to take a greenhouse experiment to the surface of Mars, possibly using Russian assets for launch vehicle and landing systems. I was of course was well connected with Russian robotic space developments and he was investigating using them. It didn't work out – the Russians negotiated in bad faith, and he decided he would have to guild his own launch vehicle. Hence SpaceX and the Falcon rockets. Bruce Murray played a big part in recruiting him on to our Board, with him and I going down to El Segundo to meet with him several times. I liked and appreciated Elon then, met with him every month or so. I can't say I have the same admiration for him now. In addition to the Russian connections Elon was attracted to us because The Planetary Society pioneered some private initiatives in space. We're the only ones still today who ever sent a privately funded payload to the surface of Mars. We did it twice. We did it on the Pathfinder mission in cooperation with JPL and we did it on a 2007 Phoenix mission cooperatively with the PI at the University of Arizona. That was a DVD anthology of science fiction literature about Mars developed jointly with Time-Warner. It is there on Mars as the first library awaiting future explorers. We also put a microphone on the surface of Mars as a piggyback on a Russian science instrument, but sadly that was on the ill-fated Mars Polar Lander which crashed on the surface. Anyway, Elon knew that we were innovative with being able to privately fund things, and he had this idea for wanting to fund or put a greenhouse on Mars. He' was considering the feasibility of privately fund the greenhouse on Mars. He and an associate of his came to my home and we spent several hours discussing it and the possibilities of using a Russian launch vehicle and engaging them for the entry and landing system. Jim Cantrell, who was working with us on the Cosmos 1 solar sail and had worked with us on the testing of Russian rovers was also here. He was working with Elon, too. We were positive about it. But doing business with the Russians was the key. Tso Elon followed up and went to Russia with Cantrell and several others to Russia to talk it through and see if they could do business. They went over to Russia, and the Russians tried flim-flam instead of doing business. They saw a rich guy with money. They didn't believe him. Elon was so disgusted, he came back, and he told everybody, "They're not going to be my rocket company. I'm going to have to make my own rocket company." That was the beginning of SpaceX. He joined our Board and kept his Mars goal but he got completely diverted into the commercial side of things and the rocket business.

ZIERLER: Lou, what about space tourism, sending the billionaires up on a rocket? Ultimately, do you think that will be good for the science?

FRIEDMAN: No. I think it's irrelevant. I certainly admire Elon and Bezos. And I envy (a little) those who pay millions to be tourists. But it is just exotic tourism –similar to those who pay on these Himalayan mountaineering trips. That's only open to people who can afford it or get really clever sponsorships and business out of it. What does that advance? It does not make space accessible "to all," and it does not advance science or commerce or much of everything else. Now, this is personal. Most space enthusiasts, which I've spent my life with, are enthusiastic about all space. They're enthusiastic about the rocket boys, and they're enthusiastic about the tourists and commercial ventures and the new ways of doing business. I don't object to those – but it's not my thing, no enthusiasm about it. I am interested in exploration and seeking new knowledge.

ZIERLER: Lou, I want to ask some questions specifically germane to your academic training as they relate to your career. Your educational trajectory, are you more an engineer or a scientist, at the end of the day?

FRIEDMAN: Engineer.

ZIERLER: What kind of engineer would you call yourself?

FRIEDMAN: [laugh] If we were at the cocktail party, and somebody said, "Oh, here's a scientist from JPL," I wouldn't object.

ZIERLER: [laugh]

FRIEDMAN: A scientist is much more prestigious. Bruce Murray was fond of saying, "Scientists do the work of God. Engineers do the work of man."

ZIERLER: I like that.

FRIEDMAN: But I think of myself of an engineer now. My educational trajectory was a back and forth path between, mathematics and engineering. I ended up with a Ph.D. in astronautics, which is a mathematical subject in engineering departments. In the late 19th and 20th centuries it was known as celestial mechanics. But I started out at the University of Wisconsin undergraduate in engineering. After one semester I transferred to the math department for a new degree course in Applied Math and Engineering Physics. Essentially a major in Math and minors in Physics and Electrical Engineering. In my first term, seeing how bad I was at mechanical drawing my engineering advisor said they wouldn't fail me if I transferred to math. Then I went to Cornell for my master' degree – in math, I thought. But there mat department was so "pure" (never solve an equation if we can avoid it), that they advised me to go to the Engineering Mechanics Department where they did applied math. That was a great move: it introduced me to Connie who was working in that department and it introduced me to space flight mechanics because of a serendipitous switch of advisors who was working on that subject. So I got my degree in Engineering Mechanics with a minor in (of all things) Astrophysics. Never even took an astronomy course. And then, at MIT, I debated about seeking my Ph.D. in math or astronautics. When I spoke to the Chair of the Math department and told him I was undecide, he said, "go to Engineering." I said, "why do you say that; you don't even know me?" and he said, "you will never make it in Math if you have doubt." The hell with him, I thought and went to the Aeronautics and Astronautics Department and got my Ph.D. there. I simply say now I am (or was) an aerospace engineer. But I loved math and celestial mechanics and astrodynamics and that was the path.

ZIERLER: But specifically, your thesis work, were you already focused on applying engineering into space science?

FRIEDMAN: You got that right. I did my Ph.D. course work at MIT while I was working at AVCO Space Systems on space flight mechanics. When it came time to focus on a thesis I talked to many faculty and eventually met Irwin Shapiro, then at Lincoln Labs (which was then part of MIT) and a Professor in the Physics Department. He had a group analyzing spacecraft data for testing General Relativity – using the data of the Marine planetary missions to Mars and Venus. Working with that group became my Ph.D. thesis: extracting scientific information out of spacecraft tracking data. The focus was testing General Relativity but many other parameters of scientific interest were involved, including the masses of the inner planets. When I started the work was centered at Lincoln Lab, on the Hanscom Air Force base about 20 miles from campus. But, MIT divested itself from Lincoln Lab, and the work moved down to the MIT campus itself. The divesture was part of the anti-war movement on college campuses. Irwin was a professor in the physics department and so I was in the Aero and Astro department with my thesis advisor in Physics. The other two on my thesis committee were Aero/Astro professors. They, and our department, were closely associated with Draper Laboratory many working on Apollo guidance and navigation. I was actually in the Experimental Astronomy Lab, part of Aero/Astro while I worked on my thesis. That's when I began talking to JPL people because they had the Mariner spacecraft data and were doing parallel studies. JPL sent us the data on magnetic tapes for us to incorporate in our program – do you know what magnetic tapes are or are you too young [smile].

ZIERLER: I've seen them, yes.

FRIEDMAN: [laugh] You certainly don't know what punch cards are. We used to have drawers and drawers and drawers of punch cards that we loaded up into the computer every night. Anyhow, they would send me the tapes of the data, and then I got to talking to JPL people. I made a lot of contact with JPL while I was working on my thesis and, in particular, with John Anderson in the orbit determination group, and Bill Melbourne, who had the navigation section. Later, as I began applying the work to future missions like Mariner-Venus-Mercury, I met Roger Bourke, who had the mission analysis and advanced projects group. That's what led me then to finish my thesis, and come to work at JPL.

ZIERLER: Lou, we'll cover all of that in subsequent discussions. Another overall question. When you were at JPL, what did you learn about the relationship between Caltech, NASA, and JPL? What worked well, and what didn't?

FRIEDMAN: That's a big topic, quite a switch. It is (or was) a hot topic too.

ZIERLER: [laugh]

FRIEDMAN: It is also a topic, if we are paying any attention to chronology here, way above my pay grade (as they say). I was hired in as an engineer (or scientist) on the technical staff and not involved in management or those global issues. I was aware, after all we were Caltech employees working at a government (NASA) facility, and I had a number of interactions with the campus. Sometime in the early 1970s (or was it mid-70s?) there was big attention paid to JPL-Campus relations, producing the famous "Orange" report. JPL was and is part of the Caltech family but I think back then it was a bit of an uneasy marriage. I think that is mostly in the past – but I really wasn't part of it and don't know that much. There is a cultural distinction -- TJPL is not a science institution. JPL's an engineering institution. Caltech is a science institution. Caltech is primarily a science institution, with some engineering; JPL is an engineering institution with some science.

Now, having said all that, my very first day at JPL, I was sent down to Caltech to go to a meeting. My boss wasn't actually there on lab. He was away on a trip. He said, "But there's a meeting down at Caltech. It's going to be about Mariner, Venus, Mercury. Go to there and talk to Bruce Murray." I've had nothing but good interactions with them over the years. Of course the marriage is more than a two way marriage, it is sort of a ménage à trois: Caltech and NASA – each fiercely defending their prerogatives while at the same mutually supporting the big goals and tasks they have undertaken. JPL is "mere" contractor to NASA and at the same time their (and the world's) lead center in Planetary Exploration. They are a national laboratory. In the recent past my impression is that JPL and Caltech have been very close and mutually supportive but that NASA, laboring under bureaucratic and political pressures, has been a bit stand-offish with the Lab.

JPL and the Special Connection Between Caltech and NASA

ZIERLER: What about NASA? What have been some of the key challenges in managing that complex relationship between JPL, NASA, and Caltech?

FRIEDMAN: NASA culture, management, resources, budget and workforce is dominated by human space flight. As I mentioned, not quite so with the public – science discoveries and the wonders of the Universe rate high with them. Thus, there is a tension between the politics and public interest which grates at NASA. The other tension is that all the other NASA Centers are civil service. JPL, albeit a Federally Funded Research and Development Center, is a contractor – subject to contract reviews and budget decisions, more so than the other Centers. JPL values its independence of civil service, NASA resents it. But that tension is relatively minor and even perhaps constructive, both NASA and JPL value their roles in planetary exploration and space science. But as in any business, or as in any family, the relationship has its ups and downs. It also, of course, depends on people – NASA is a bureaucracy: good bureaucrats make things happen and get the job done, bad bureaucrats get in the way of that.

ZIERLER: Lou, could you have been one of the founders of The Planetary Society had you not been at JPL first?

FRIEDMAN: Who knows? Probably not. I don't know. That's impossible to answer – there are too many variables. I can't imagine The Planetary Society getting founded without Bruce and Carl. They were really special in their own way. I don't know how much you know about either one of them, but they were well-known for intellectual disagreements in the late '60s, early '70s about interpretations of planetary data. But their differences were actually very minor, one would say about nuances of interpretation rather than fundamental. Many thought they were almost enemies, but that wasn't true at all, as the next decade was to amply prove. That's what really was so remarkable about them. They were two guys with strong views that could work together to come up with common views. But Bruce had no tolerance for speculating about pyramids on Mars. Carl was very full of the colorful language. He was very good at exciting people about that. [laugh] I guess they both, at the end of the day, really appreciated the roles they played, and made them synergistic and positive. They were both leaders in so many ways.

There hasn't been a leader in public engagement in space exploration like Carl, since or before. We miss him, in that regard. He's still in that category. There were lots of people who do very good jobs on interviews, but Carl was Carl. Bruce was very much a person who could lead and was an action guy. He also had no difficulty expressing his strong views. Now, he was controversial in many ways in his own time as JPL director, and at Caltech when he was there. He was intellectually honest – to a fault. I can't imagine successfully founding our organization without them. I was a target of opportunity only. If I had a different job, I probably don't know that They would have found me a target of opportunity. I can tell you that Carl took a lot of convincing by Bruce to first consider me because I wasn't a scientist. Carl had the view that he really wanted a scientist to lead The Planetary Society, and I'm not a scientist. Bruce kind of apologized for that, and said, "He's not stupid. Just talk to him." [laugh]

ZIERLER: [laugh]

FRIEDMAN: But Carl was open-minded – in many ways much more so than Bruce. (Bruce suffered fools badly, Carl just suffered them). Carl did come and talk to me, while I was in Washington, and somehow was convinced to say OK. It took about a year or two of working with Carl before he really got really comfortable and ultimately close with me.

ZIERLER: Lou, was the Voyager mission really central in terms of seizing upon the public interest in space exploration to get The Planetary Society started?

FRIEDMAN: The Voyager mission and the fact that nothing was happening after that. Voyager was big, and both it and the Viking landers on Mars had ignited public interest. But NASA was consumed by trying to get the Shuttle built, and planetary missions after Voyager were being postponed or cancelled. Within our first year, we helped organize public events for the Voyager mission. Yes – the Voyager mission helped put us on the map. But it was the dichotomy of huge public interest and huge political disinterest that drove us to create the Society. Voyager was on the front cover of Time magazine and the new NASA Administrator was planning to cancel the planetary program. Not just Time, but there were also a lot of science magazines around and other things that were covering it. Voyager was a very big deal; it was discovering whole new worlds with dynamic events [the Galilean moon and later the moons around Saturn] NASA had rejected the Grand Tour as a mission, but Voyager was on a Grand Tour.

It made these discoveries: volcano on Io – previously unimagined, a world that's spewing volcanoes, and an ice-covered surface of Europa – with an apparent ocean of liquid water underneath – also unimagined. This wasn't just new knowledge; it was a new paradigm – liquid water in the far reaches of the frigid outer solar system. It might change everything we think about the possibilities of life out there. And NASA wanted to cancel the planetary program! Carl and Bruce had an obligation to rally public opinion – and hence we formed The Planetary Society. They came to the idea that we had to form an organization. As I said, I was a target of opportunity because I was on leave as a Congressional Science Fellow back in Washington, and supposedly getting all this political insight. And I was observing the process of influence – and had begun thinking we need to form some kind of association to deal with planetary exploration – to influence the government decision process, i.e., to influence the politics. I saw associations being formed to influence commercial space policy for remote sensing and wondered, how can we do that for space science. Well, I was coming back to JPL without a job assignment. One political issue, and a mission design issue, was Halley's Comet – coming into the inner solar system in 1986, and despite enormous public and cultural interest – no American plan. I invented the idea of an International Halley Watch as a program to coordinate international interests and to pressure for an American reaction to define and approve a spacecraft to intercept and explore it. I was working on the Halley Comet thing, and that did continue but it wasn't a full-time activity. I come back, and I meet with Bruce. I was giving him a report on this idea, when he interrupts, in his usual fashion. He said, "I want to tell you about something. I've been discussing with Carl, and we have an idea." That's when, basically, they came and said we needed to form an organization – a public interest group. That was our start

ZIERLER: Lou, did you see that as a professional risk, leaving a secure job at JPL?

FRIEDMAN: Without a doubt, I saw it as a professional risk. First of all, we were creating something out of whole cloth – a brand new venture. Secondly, we were two scientists and an engineer; none of us ever in the business of business. Thirdly, it would take money (my salary, among other things) – we had no experience at fundraising and no obvious sources of money. Carl and Bruce said they knew people (an understatement) but it was not clear to me that they had any specific promises of funding. For a while I could juggle being part-time at JPL and part-time trying to initiate a new organization – but that had a built-in conflict of interests, both in the work and legally, since the organization we were building was going to lobby for government funding for NASA, among other things. But at least I had those first few months. But then I told Bruce and Carl, it had to change – I had to be full time to start the organization. It wasn't that easy, but they did raise a little money from people who chimed in early. But sustainable funding wasn't clear at all. I remember being Bruce and I driving from JPL down to his home near campus and him saying, " I think you're probably right. There's too many questions of you trying to serve both JPL and our new organization (still unnamed)." He says, "You can always come back. I'll take you back." [laugh] Of course, he left two years later.

ZIERLER: He joined you. [laugh]

FRIEDMAN: [laugh] Not quite, his leaving JPL had nothing to do with The Planetary Society. There was another factor which I spoke of earlier – nothing was going on in planetary exploration at NASA! Remember, they were trying to kill it and we were forming ourselves to prevent that. If I had stayed at JPL, it isn't clear I would have much interesting to do. I had started and was leading the International Halley Watch – but that wasn't a mission, and in fact it looked like we) the United States) weren't going to have a mission. So, I knew it was a risk because the funding wasn't clear, and we didn't have a business model yet. But we had Bruce and Carl – and those were powerful assets, they were great. And even if it was risky, would I ever turn down the opportunity to work with those two giants – no way. And it paid off – the did know people, and they knew people who knew people and they provided me with access to people who knew what we did not: non-profit business, fundraising, business model and contacts. They not only had contacts -- they had the insight as to how to use them. Not just contacts, but genuine leaders with their own brilliant experience which we could tap into. One of the first wad John Gardner. Do you know who John Gardner is?

ZIERLER: No.

FRIEDMAN: Really? He was Secretary of Health, Education and Welfare for Lyndon Johnson and then he was the founder of Common Cause – the political reform non-profit which had great influence in the 1970s and 80s. He was one I thought should have been President of the U.S. – but he never really was a politician. His experience with Common Cause was directly applicable to us – forming a non-profit, cause-related, public-interest, citizen-supported group. I didn't know that a priori, but I learned quickly. You've heard of Common Cause?

ZIERLER: Yes.

FRIEDMAN: Gardner was on the JPL advisory board. I don't know how Bruce first knew him – but Bruce got to know him well and introduced him to us. I got to know him then. That is an aspect of my working for The Planetary Society and with Carl and Bruce – I got to know and engage with great people. Gardner was knowledgeable about the nonprofit world, the business of nonprofit public interest organizations. That was the social activism in those days – cause-related public interest groups. That was the milieu in which you tried to form public advocacy. You formed a public interest organization, a nonprofit funded by citizen donations, and built a constituency. There were people who would fund constituency development – seeing it as an essential part of a democratic society. This is back in the '60s, '70s, that funded nonprofits just because it's good to have, in a democracy, constituencies that are advocating for positive public interest. Gardner introduced us to a hotel magnate here in LA, who was one of these kinds of people. He funded us with some early money, and told us he'd give us a donation if we could match it with other funds and would put all 50 into direct mail. He had no particular interest in space exploration – he wanted to help build our constituency. Of course he supported the focus on science.

ZIERLER: Wow.

FRIEDMAN: That changed everything. We learned a lot about how to form an organization based on that initial contact with Gardner and the people he brought to us to meet. That was really eye-opening; nothing I expected. And not what Carl or Bruce expected either. I had no background in business or organization development, and certainly not direct mail. Bruce Murray didn't even know what it was. Carl called it junk mail. Maybe it was – but it was the internet of its day reaching millions with promotion – and in retrospect, maybe not as junkie as the Internet.

ZIERLER: Lou, in subsequent conversations, we'll develop the story more fully. My last question for today is, between the unique business model and seizing on public interest for there to be more missions beyond Voyager, just a thought experiment: could The Planetary Society be formed today? Would that even be feasible?

FRIEDMAN: One note first – the business model wasn't unique; it was a whole industry of non-profit fundraising – it was unique to us space folks. Would the Society be feasible now – I think so, but it would be different. There are two reasons. When I retired from The Planetary Society, the internet was dramatically changing public outreach and organizational development, with new techniques and technologies and I increasingly saw that as a job for the next generation – I wasn't too interested in building another business model. The second was, surprisingly, I was getting older and I didn't want to be the long-time, old-guy Executive Director that everyone was waiting to replace – I wanted to sept out before others wanted me to do so. I did increasingly feel that things were different today, and I might not have been so enthusiastic about forming it in today's conditions. Of course, I don't know what Carl and Bruce would think now – they certainly were attuned to what were present conditions. For one thing, NASA's planetary program is quite well supported – there is no crisis in that regard. And planetary exploration is a worldwide endeavor with Europe, India, the UAE, Japan and China involved now and others maybe in the future. And many of the things we did to introduce citizen involvement in planetary missions, NASA now does and the role for private space ventures is growing. And public information is now much more widespread with the advent of the Internet and social media – it is no longer run through a filter of just a few magazines and newspapers.

Coming back to your first question about the Society today, they're doing effective lobbying. They've got a good Washington operation. They are, it seems to me, mostly focused on NASA advocacy, and they do a good job. They seem less motivated that we were in innovating and seeding new projects of exploration or taking on broad issues like the role of human spaceflight or international cooperation. That would be less interesting to me, and I think to Carl and Bruce. And that is another big difference – there is no Carl nor Bruce now, no leaders like them who I think could or would pick up the mantle. They attracted top flight people to help us get started. It is not the same now.

ZIERLER: Yeah, there you go. [laugh]

FRIEDMAN: I am not critical of the Society now, as I said earlier, they are doing well and I am proud of them. And I have to recognize my outlook's different as are the times. Maybe if I was 42 now, I'd see more clearly just how to form the organization in this Internet age of a million channels of information and advocacy. But I don't see their niche in our broader society the way I did in 1980. I think I should leave it to others to define their niche and value added in the current milieu.

ZIERLER: Lou, this has been a terrific conversation. In our next, we're going to go back to the old country, the Bronx, learn about your family background, and go from there.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Monday, September 19th, 2022. I am delighted to be back with Dr. Louis Friedman. Lou, once again, it's a great pleasure to be with you. Thanks for joining me.

FRIEDMAN: I'm glad to be here.

ZIERLER: Lou, in our first discussion, we took a terrific tour of your career, your approach to the research, the origins of The Planetary Society, so much else. Today what I want to do is let's go back to the old country, back to The Bronx. Let's go back even a little further than that. Let's start with your parents. Tell me a little bit about them.

FRIEDMAN: Both my parents were born in America. Well, that may not be true. There's some doubt about where my mother was born. She claimed and her birth certificate shows Paducah Kentucky. But there is some discrepancy about the year which could mean she was born while her mother was still in Nova Scotia, where the family was from. Her father got a job actually building Churchill Downs in Kentucky and moved the family down there in the early 1900s. In any case her early childhood was both in Kentucky and in Nova Scotia, when they returned there. My father was born in the United States, although, even in his case, there seems to be the possibility that his mother was pregnant when his family immigrated here from the old country. Before you ask me, "What is the old country?" he was never very clear on that because he claimed his family never knew what country they lived in. It was kind of either Russia or Belarus or Poland or Ukraine. It didn't matter (to them). He never talked at all about the old country. Of course, he didn't live there, but he didn't even encourage family history.

ZIERLER: Lou, where did your parents meet?

FRIEDMAN: New York City on a horse. Well, on two different horses.

ZIERLER: [laugh]

FRIEDMAN: They were horseback riding in Central Park.

ZIERLER: Do you know what year it was, roughly?

FRIEDMAN: 1932 plus or minus a year, I think. I think my father was more serious about riding. I remember he had the long riding boots and the riding outfit. I don't remember my mother having that, and I don't know how much she did of it.

ZIERLER: Lou, what education did your parents achieve?

FRIEDMAN: Neither went to college. My father went to high school in Vermont. My mother graduated high school, and then went to a nursing school. That's why she was in New York. She came to New York with her cousin, and they went to nursing school, and became nurses together.

ZIERLER: Lou, what kind of observance levels did your family come from, did your parents have? Did they have more Orthodox upbringings?

FRIEDMAN: No, my mother was not Jewish and my father was not particularly observant. However, we had a Jewish family household, which was reform observant. I doubt my father's family was Orthodox. Neither he nor my uncles and aunts were particularly observant. Actually, my mother did the pushing for observance, Hebrew school, etc.

ZIERLER: Now, did your mom convert, or she was just enthusiastic about Judaism?

FRIEDMAN: No, I don't think she ever converted. It was not a big deal, just as it was not a big deal for my wife who also was not Jewish. I know this, but conversion is not a big deal to people who are in Jewish families already. It's actually discouraged.

ZIERLER: Do you know from your parents' families if that caused any problems, the intermarriage?

FRIEDMAN: I never heard of it. Her sister also married a Jew also. Their children and me were close cousins and I spent many summers with them at their home in Massachusetts. Similarly I do not recall any issues on my father's side of the family about that – they had fights about everything else, but not religion.

ZIERLER: [laugh] Lou, for you, growing up, did your family gravitate toward one religion or the other? Was it Christmas and Chanukah, or one or the other?

FRIEDMAN: No, we were strictly Jewish, only Chanukah. I was Bar Mitzvahed. I went to a reform Temple. We observed the Jewish holidays. We lived in a primarily, but not completely, Jewish neighborhood, although the next block up was Irish Catholic.

ZIERLER: What was your father's profession?

FRIEDMAN: My dad had struggled with work. He was a salesman in the millinery business, basically, women's hats, and decorations on women's hats at a time when women's hats were going out of fashion, so he struggled. I think he was unemployed awhile, although he always went into work and did what he could to earn a living. I did not know details, but occasionally when to work with him in midtown Manhattan millenary district. He knew everyone, and they knew him there.

ZIERLER: Did your mom work outside—?

FRIEDMAN: The only foreign trip he ever took—I always think this is strange. Can you imagine where the only foreign trip he ever took out of the country—Haiti.

ZIERLER: Haiti?

FRIEDMAN: Haiti.

ZIERLER: Why Haiti?

FRIEDMAN: I guess they were buying some feathers for the women's hats or something. I don't know.

ZIERLER: [laugh] Lou, what about your mom? Did she work outside the home?

FRIEDMAN: Yeah, she was a full-time nurse for a rather prominent doctor on Fifth Avenue in New York. She worked there for many, many years. My parents did not have a lot of income between the two of them. She had to work and, my father's income was sporadic at best. We weren't poor, definitely post-was middle-class, comfortable but income was an issue.

ZIERLER: What neighborhood did you grow up in?

FRIEDMAN: In the Bronx on Jerome Avenue, 192nd Street. It is northwest in the Bronx between Fordham Road and Kingsbridge Avenue and just west of the Grand Concourse. At the time, Kingsbridge Avenue was primarily Jewish neighborhood. Although I had to walk one dangerous block through the Irish to get there (smile). I lived on Jerome Avenue with our window less than one hundred yards from the elevated subway trains which passed by every 5-10 minutes.

I lived across the street from St. James Park and St. James Church, The Bronx, like all of NY is a lot of ethnic neighborhoods. I went to public neighborhood schools. My high school, however, actually had a district which was neighborhood plus Harlem, so we had a a very mixed population. My track team was probably 80% Black that I was on.

Roots in the Bronx

ZIERLER: Now, your neighborhood, was it more high rises or single-family houses?

FRIEDMAN: Both. I was in a six-story apartment building as I said, by elevated subway on the same line that goes down the Yankee Stadium. Jerome Avenue was apartment buildings, but the next block up was all private homes. The next several blocks up were all private homes or two-family homes or something, so it was both.

ZIERLER: What schools did you go to? Let's start with elementary. Where did you go for primary school?

FRIEDMAN: PS 86.

ZIERLER: Was that a big school?

FRIEDMAN: It wasn't huge. It was five stories tall, I remember that. It was five stories tall, and occupied, a half a block, maybe.

ZIERLER: Was it more in middle school? When did you start to get interested in science and math?

FRIEDMAN: No, it was kindergarten. when I started – maybe. [laugh] I think I got interested in math and science in elementary school, probably by reading magazines and science fiction.

ZIERLER: [laugh]

FRIEDMAN: I don't know for sure. The only way I remember that is starting to go to the library, and reading science fiction and magazines like Popular Science somewhere around fourth or fifth grade.

ZIERLER: What about things like the Cold War and Sputnik and the Space Race? Did those things register with you? Was that important for you?

FRIEDMAN: Sure – somewhat aware, but not pervasively so. We had the bomb shelter drills under the desk and there was a lot of Communist paranoia and discussion. My parents were sensitive to it – worried about some friends who had dabbled in socialism or read the Daily Worker. But not to the point of fearing them or even avoiding them. My mother was right-leaning Republican, my father, a Democrat. I remember, because in 1948, she was for Dewey and he was for …who was it, Truman. Of course, Truman. He was for Truman, and he had an affinity for Truman, of course, too because he was a haberdasher as well as being a Democrat.

ZIERLER: [laugh]

FRIEDMAN: But my mother was for Dewey, and I remember that because we had Dewey buttons, and I think I was kind of helping wearing a Dewey button, I think, at the time. They were politically aware, but I think not particularly engaged. They were aware, of course, the Red Scare and the McCarthy business – and very opposed to him and that kind of demagoguery. They hated that kind of witch hunt thinking which touched on the lives of people they knew or knew will of. That was important for my high school, as you'll find out in a few minutes. We were aware of people's politics, and the politics that were going on. Then Eisenhower, everyone liked Ike although I don't know if my father was for Stevenson or not, and I even met him that year when I was 12 – sort of. I was up on the Grand Concourse. Do you know what the Grand Concourse is?

ZIERLER: I've heard of the Grand Concourse.

FRIEDMAN: It's the major thoroughfare in the Bronx. We told ourselves as kids that it was the widest street in America, but I don't think that's true.

ZIERLER: [laugh]

FRIEDMAN: We believed it. Eisenhower came down in a parade during the campaign, and I was standing in the front row with my camera, a little box camera. He swung out his hand to wave the crowd, and he hit my camera, and broke the viewfinder. But I still like Ike. I never held it against him. Years later I got to know his granddaughter. Susan, very well -- Susan Eisenhower. I told her that the family owes me a camera. [laugh] But, by that point, we were all digital, so she never paid.

ZIERLER: Lou, what options did you have for high school?

FRIEDMAN: Before then I went to junior high school. You're skipping that?

ZIERLER: I don't know. We got up to eighth grade. I thought high school was the next.

FRIEDMAN: No, Elementary school was 6. Junior High was 7-9 and then three years of high school.

ZIERLER: OK.

FRIEDMAN: I went to Creston Junior High School, PS 79. Did you ever see the movie Blackboard Jungle?

ZIERLER: Oh, sure.

FRIEDMAN: Creston was a little worse—

ZIERLER: [laugh]

FRIEDMAN: —and more dangerous. Gang fights, fights in the school. If I had gone to Creston for three years of junior high school, you'd be interviewing me in jail right now—

ZIERLER: Oh, boy. [laugh]

FRIEDMAN: But, fortunately, I made what New York called the SPs, the special progress classes. We got to do three years of junior high school in two. Even though I got into fights and got into trouble in junior high school, I only had to stay there two years. I even got kicked out of graduation, I got into so much trouble. But I graduated, of course, and did well academically. But the school was a tough school. There were a few good teachers. I remember taking an aptitude test there – this is important for your question. I took an aptitude test there, and the aptitude test came back, and said sales engineering was the preferred field.

ZIERLER: [laugh]

FRIEDMAN: Now, that may sound crazy, because I knew what it was. I still never really heard of the term, but it may be accurate. What one of my college professors told me years later – you are very good working at the interfaces, engineering interfaces with math, or in that area defining requirements vs. capabilities. I think sales engineering means being able to understand what the customer wants and being able to define the problems and solutions to satisfy tat. Part of what we now refer to as system engineering.

ZIERLER: Did that open up your options for high school?

FRIEDMAN: No. First of all, New York has special high schools, and I applied to two of them. One is Bronx High School of Science, and the High School of Music and Art, I should have easily made it into the former – but I did not. I screwed up the entrance exams. I didn't think I would really maker it into the latter – but I did. I was very good at the piano. I took piano lessons for a number of years. But music is not what I wanted to do, so I went to the regular public high school – which turned out to be great: DeWitt Clinton High School. I immediately got selected for Arista, the honors classes, and had outstanding teachers in science, math and other subjects, joined clubs, and was on the track and cross-country teams. High school was a great experience. It all worked.

ZIERLER: Now, did your high school have a strong math and science program?

FRIEDMAN: Yes, pretty much. Ph.D. teachers in both. Good physics class, and outstanding math classes. One math teacher, in particular, Dr. Julius Hlavaty—a Hungarian name—came to the math department during my senior year or the latter half of my junior year. He decided to form a math club. I got on the math club, and we started competing against schools throughout the city – and doing well. Hlavaty was a remarkable guy. He was a former professor at Columbia University who got fired in the McCarthy witch-hunt days because he was accused of being a member of the Communist Party in Hungary, or something like that. I don't know what the deal was. He was relegated to being a high school teacher [laugh], and that was so great. He gave me my love of mathematics. I can remember in class one day arguing with him. He was making some point about solid geometry interpretation. I said, "No, no, I read this in the book, and I think it was this." He said, "No, no, it really means this." I said, "No, I think I read this in the book, and it said this." Finally, one of the other students yelled, "Dummy, he wrote the book, remember?"

ZIERLER: On that point, Lou, I'm curious, did you have engineering classes or any good shop classes in high school?

FRIEDMAN: We had shop classes. We had woodworking and metal working, but I wouldn't call them engineering classes—

ZIERLER: Right. [laugh]

FRIEDMAN: —at least nobody else did. But we had to take shop, and it was required, and we had to take music and art also. I also started playing the cello in high school but only for high school. I never kept up with it afterwards.

ZIERLER: When it was time to start thinking about colleges, what was available to you? Where could you look?

FRIEDMAN: My parents either pushed me or agreed with me—one or the other—to realize that I shouldn't stay at home for school in New York. CCNY, City College of New York was free and very good, but it would have been like a continuation of high school. So we agreed on looking away. But we did not have a lot of money and could not afford the expensive private schools of the Ivy League or in the East—even with scholarships they were far too expensive. The Midwest had excellent engineering schools and were very low cost – so I applied there.

Purdue and Wisconsin and Michigan all excelled in engineering, and were affordable. Purdue was my first choice – and when I got a letter from them awarding me a scholarship, I thought that was it. Until a couple of days later when I got letter from the admissions department saying I wasn't admitted. A mix-up we could not resolve. Wisconsin did both – admission and scholarship and promise of more after one year. So that is where I went. Lucky choice – they also had an excellent math department.

ZIERLER: Now, you mentioned a connection between aerospace engineering to Sputnik. Is that to say that before Sputnik, there really was no discipline known as aerospace engineering?

FRIEDMAN: I don't think there was. There was aeronautics, of course, but universities didn't begin to have aerospace engineering departments until after Sputnik. At MIT it became the Department of Aeronautics and Astronautics. At other schools it may have started as aerospace engineering courses in (say) the mechanical engineering department until it became a department of its own. Celestial Mechanics or Astrodynamics could be part of the Math Department or an Applied Math department. Similarly in science, when Sputnik was launched in 1957, space science courses started up in various departments, often with the geosciences. I was very fortunate to be at Wisconsin because the first space science course in America was taught at the University of Wisconsin by Verner Suomi, an atmospheric scientist conducting experiments with sounding rockets and balloons and later on Earth orbiting satellites. This business of artificial satellites, and getting up to orbit, and then beginning to understand the whole field of celestial mechanics was very interesting to me—and that's mathematics.

That's where the great mathematicians of the 19th century in France and Europe came and did their work: Poincaré and Laplace and Tisserand. They were mathematicians, but they were applying it to the orbits of planets. That was the big field. Space is basically a laboratory for all the sciences that we learn, mathematics and physics and maybe someday biology—not yet, though. [laugh] I began an interest in space science, but I was attracted to celestial mechanics.

I'm in the engineering school, 1957, my freshman year, and I'm taking mechanical drawing and some other electrical engineering introductory course. The mechanical drawing course is just not my thing – I am lousy at it, I don't like it, and it is at 7:30 am at the opposite end of the campus that I have to walk through when it is -20 degrees Fahrenheit. The instructor agrees not to fail me if I will transfer out of engineering – which now I want to do anyway, to the Math Department. So the next term, I transferred over to a new interdisciplinary degree program they set up in the math department called applied math and engineering physics. Essentially it was a major in mat and minors in physics and electrical engineering (which included computers). It was excellent – and either I was tailored for it, or it for me.

ZIERLER: Lou, what year did you get to Madison?

FRIEDMAN: 1957.

ZIERLER: 1957? Were you there?

FRIEDMAN: Started in September '57. Sputnik was launched in October '57.

ZIERLER: Oh, my goodness. Do you remember the day, what that was?

FRIEDMAN: I remember the event. I don't remember what the day was. I'm not going to make up some story about, "Yeah, I was staring into the"—most people who tell you they went out, and saw Sputnik, didn't. It was very, very hard to see with the naked eye.

ZIERLER: Was it a major news story? Did you remember people talking about it?

FRIEDMAN: Yes, it was a major news story, a huge story – in the newspapers, radio and tv. The political reaction was huge. And the beep-beep from it had a popular and psychological reaction. There were all kinds of fretting that it was end of America as a country of leadership, that it was now proof that the communist technology works, and that the future belongs to communism. Of course, that was all overblown. But there was a national call to "arms" which benefitted all of us going in to that field. President Eisenhower did his best to minimize that point of view, but then he got criticized for it, accused of not understanding the significance. But Eisenhower had it just right. He knew exactly what the threat was. It had nothing to do with space science. It had to do with rockets, and missiles, and remote sensing. He knew where the threat was, and it wasn't about space. It was about rocketry. And the U.S. was actually in pretty good shape on the military side, even if we didn't have the first big space achievements.

To deal with that he, and the Congress, created NASA. He set it up as a civilian space agency. He wanted to differentiate it with how the Soviets integrated space with their military. But the country also passed the National Defense and Education Act – which enabled us students to get a lot more financial support. The second launch, which was, I think, that's the one I think with the monkeys in it. That was a big story, with no political correctness. Few cared if the monkeys died in space. They were monkeys.

ZIERLER: [laugh]

FRIEDMAN: But it was an achievement. They went up there, and they lived (briefly) to tell the tale. No, the Soviet news media told it for them. Then, of course, that ultimately led to the first manned spaceflight, and the space race was on. That was '61 by that point. I was graduating. Kennedy had given his speech about racing the Soviets to the moon. A whole bunch of ironies here – Kennedy beat Nixon in the 1960 election largely on the basis of invoking the non-existent "missile gap." (And looking much better than Nixon on TV). Kennedy launching the space race to beat the Soviets. Would Nixon have done that? I was too young to vote, but in those years I was for Nixon.

ZIERLER: Really?

FRIEDMAN: I was a Republican in college. I wrote for the student conservative journal about bomb shelters. But being a Republican in the '50s and 60s —even up until Barry Goldwater—was something you could be proud of. It was a party of really smart, liberal people with progressive ideas, who believed in good government. It wasn't like being a Republican now. Even Nixon would have been a good President, if he wasn't such a sleaze. I have moved politically. I started out active in a conservative student club in college. I am proud to say that every five years, I have moved further to the left, to this day.

ZIERLER: [laugh]

FRIEDMAN: I keep moving to the left.

ZIERLER: Lou, tell me about moving over to math. How was that good for you?

FRIEDMAN: That was interesting. First of all, I was good at it and I liked it very much. I got straight A's in calculus. But when I got into differential equations, things were different. The professor comes in. His name was Beck. He comes in, and he says, "I'm Beck. The book is Buck." (The book was written by a Professor Buck). Then he began writing on the blackboard from one side of the room to the other, finishing just as the bell sounded at the bottom of the last blackboard. Every class! At the six-week mid-semester time, I was floundering – had a D on my exam! So I began rewriting everything that was on the blackboard and by the end of the semester I had my A again, and I was back to loving math. If you recall, I switched into math from engineering – it turns out that was the story of my whole academic experience: switching between math and engineering. After my undergraduate degree, I went to Cornell for my Master's in math – and quickly found out the department there was all about pure math, nothing applied. One professor bragged he was going to get through the whole year without solving an equation. He didn't – needed to solve one for some abstract theorem he was trying to prove. But I wanted applied math, and that, it turns out, was in the engineering school: in the Engineering Mechanics Department. So I switched at Cornell to Engineering Mechanics. As an aside, let me tell you what my undergrad advisor at Wisconsin told me when I was applying to grad schools. I asked him about applying to Caltech. He says to me, "Are you Jewish?" I said, "Yes." He said, "That's religion enough. Don't apply to Caltech."

ZIERLER: [laugh]

ZIERLER: Wow. Obviously, Caltech had that reputation?

FRIEDMAN: Oh, yeah, Caltech is a religion. Caltech's a small school, and it's all intense. He didn't say I couldn't make it there. He said, "You won't like it there."

ZIERLER: Did that dissuade you? Did you end up not applying?

FRIEDMAN: I ended up not applying. I took his word for it. Besides that, I was going for maximum financial support – scholarships, etc., and I didn't think Caltech was a likely choice for that. /And my goal was math – not physics. I ended up narrowing my final two choices down to Ohio State and Cornell – both with excellent math departments. My parents looked at me like, "What the hell? Are you crazy? You can go to Cornell, and you're thinking of some other school?" "Mom, you're a New Yorker. You think Cornell's a dream, the place." "No, all my friends tell me." "They're all New Yorkers too," I said. [laugh]

ZIERLER: [laugh]

FRIEDMAN: But, at the end of the day, I chose Cornell. It was a good scholarship. But as I said, it resulted in another switch – this time from math, back to engineering as I explained. It was a good switch to Engineering Mechanics – a life changing switch. Connie was working there as the technical typist (a profession before computers when equations had to be typed on typewriters). She and I met – and next 58 years was all about us. For my studies I had intended to work with a professor who was a specialist in applied differential equations. But he was going on sabbatical so he sent me down the hall to meet Prof. Mitchell who was interested in space flight mechanics -- astrodynamics. And that is how I got into my career choice.

ZIERLER: Who was that professor that you ended up working with?

FRIEDMAN: Thomas Mitchell. He ended up at UC Santa Barbara, specializing in acoustics. I did a Master's thesis with him – it was supposed to be about rendezvous at Earth from a Mars return trajectory, but it morphed into a whole trajectory analysis of the Mars to Earth trajectory – the orbital mechanics of interplanetary flight.

ZIERLER: Lou, tell me about orbital mechanics. What kinds of things was Mitchell working on?

FRIEDMAN: He was working on the optimization of trajectories, where you try to compute how to go from one place to the other in gravitational fields by minimizing some function. You put all the equations in, and you could minimize anything. You could minimize time, energy, velocity of particular maneuvers, etc. Velocity translates into fuel, which is practical for engineering of the spacecraft. You minimize velocity, you minimize the expenditure of fuel. But you have to take into account constraints – e.g., the velocity supplied by the launch vehicle, or time of flight requirements, etc. It is a non-linear differential equation problem with boundary conditions. You can make approximations to solve it analytically, but for really space flight you have to do a full-scale numerical simulation. For the analytical part, you basically use Kepler's laws of motion, which describe orbits. Those are simplified because they're only basically two-body laws: sun and Earth. If you want to start taking into account other motions, like Jupiter and the moon and other planets, and you want to start taking into account other effects, like solar radiation pressure, then the equations become complicated, and you've got to start integrating them. You learn how to do numerical integration and computation and stuff like that.

ZIERLER: Now, was this a terminal master's degree? Did you not decide yet if you were going to stay on for the PhD?

FRIEDMAN: It was a terminal master's degree at Cornell. The goal was eventually to get a PhD. The summer between my two years at Cornell, I worked at AVCO Space Systems Division, and while there I was offered a permanent job after I completed my Masters with the benefit that they would allow me time off and pay my tuition to work on my Ph.D. at MIT. So, that was my plan – and it really worked out well because during that second year at Cornell, I met Connie and we got married after I completed the Master's. Then we moved to Massachusetts for the AVCO job and MIT. We moved to Lowell, Mass., on the top of Christian Hill. [laugh]

ZIERLER: [laugh]

FRIEDMAN: After one year in Lowell we moved to bigger house in Andover, Mass. That's where I stayed for five years, going to school at MIT, working at AVCO, and bringing up our children.

ZIERLER: Now, were you part-time at MIT? How did you find enough hours in the day?

FRIEDMAN: AVCO gave me the time off for two courses per semester. And quite fortuitously my work at AVCO was directly related to my course work and studies at MIT. At the end of my coursework, MIT had a requirement for me to be full-time student and so I left AVCO and began full-time work on my thesis and qualifying exams.

ZIERLER: Now, tell me about the job at AVCO. What was it like?

FRIEDMAN: The job at AVCO?

FRIEDMAN: Well, can I start with MIT first – it is related?

ZIERLER: Sure.

FRIEDMAN: I go to MIT applying for admission into the Ph.D. program. I had not decided (once again!) about engineering vs. math. In this case – aerospace engineering, which is in the Department of Aeronautics and Astronautics. I go to the math department and explain my interests and uncertainty and the head of the department there says to me, "go to engineering, you are not suited here." I got kind of angry pointing out he didn't know anything about me. To which he replied, "If you are not certain about us, you don't belong here." Well, I respect arrogance and agreed with him and went to Aero/Astro. It was great – they are working deep in the Apollo program, strongly connected with the (then called) Instrumentation Lab under the legendary Doc Draper (who the Lab is now named after), and also having a couple of their professors working with AVCO on the optimization and control algorithms for space flight. And, as I noted earlier the celestial mechanics of space flight is a mathematical subject. This was MIT. And while I appreciated the arrogance there, it was nothing compared to that at Caltech, where I think they have a required freshman course, Arrogance 101.

ZIERLER: [laugh]

FRIEDMAN: Then I started with courses in optimization, calculus of variations, and basic astrodynamics. The professors were great – especially Wally Vander Velde, who did the optimization courses, and Dick Battin, who authored a canonical textbook on astrodynamics. Vander Velde also consulted at AVCO and so there was some excellent cross-fertilization between my academic study at MIT and the work I was doing at AVCO. Battin's course was directly applicable – in fact I was programming, using his book, at AVCO for interplanetary trajectory work we were doing. We (and others) were breaking new ground in solving for interplanetary transfers between planets –a presage of the work on gravity assist which was about to become so important in planetary science. I became very good friends and a close colleague of Dick Battin as I matured into my professional life at JPL working on mission analysis and navigation. But when it became time to find a thesis topic, instead of finding one in the Aero/Astro department with this subject, I was introduced to Irwin Shapiro, in physics, who led a group at MIT Lincoln Lab analyzing planetary ephemerides and spacecraft tracking data to test General Relativity. Lincoln Lab was located at Hanscom Air Force Base in Lincoln, Massachusetts, just outside the Beltway from Boston, maybe 20 miles. It was primarily a defense contractor, but Irwin's group all the planetary ephemerides, an outgrowth of their work analyzing planetary radar observations, like those take at the Arecibo Radio Telescope. They had a huge program – a cabinet of punched cards over ten feet high analyzing orbits to more than twelve decimal places (one part in a trillion – or smaller). Comparing models of the solar system gravity fields (and other forces) with observation data and using the residuals to estimate parameters in general relativity, masses of solar system objects, the solar wind and more.

I hooked up with Irwin at Lincoln, and Irwin had a thesis topic for me, basically using the new Mariner data from JPL, Mariners 4 and 5. 4 went to Mars, and 5 went to Venus to extract scientific information in physics – especially general relativity, but also the masses and gravity parameters of Mars and Venus and Mercury in the inner solar system. So Irwin became my thesis advisor – with Vander Velde and another professor from the Aero/Astro department at additional members. I was still in that Department, but Irwin was at Lincoln Lab. But this was during the Vietnam War and the issue of Universities having Defense Contractor Labs became a hot potato, leading to divesture – Berkeley with Los Alamos and Livermore, MIT with Lincoln Labs and later the Instrumentation Lab. Irwin had to move his group down to campus – to the physics department, where he was a professor. I moved with Irwin down although I was still in Aeronautics and Astronautics. Anyhow, that's where I began my thesis, and did optimization, and did trajectory work, and analyzed the Mariner 4 and 5 data, which got me to know the people at JPL because I had to talk to them about getting the data from them. It's a long answer to whatever your question was.

ZIERLER: [laugh] Lou, was there any crossover value between your graduate studies and your work? Were they relevant to each other at all?

FRIEDMAN: My work at AVCO—?

ZIERLER: Yeah.

FRIEDMAN: —or my work later?

ZIERLER: No, your work at AVCO.

FRIEDMAN: Yeah, that was your original question about half hour ago when I said I wanted to deal with MIT first. I explained they were related, at least some of the time I was at AVCO, especially when doing interplanetary trajectory work and I mentioned the close connections with Dick Battin and Wally Vander Velde. And MIT had a strong emphasis on Guidance and Control, and I was in the G&C section at AVCO. That all said, I had other jobs and tasks at AVCO, some even not so much related to space missions, but more to defense systems.

I took the best trips I ever took in my life. They sent me to Ent Air Force Base in Colorado to run trajectories that were so complicated, it took the Air Force computer to run them. AVCO didn't have anything like this. I would submit the run at six o'clock in the morning, and get back the results after six o'clock at night. So I had the whole day free each day for a week – to explore Colorado Springs, go up Pike's Peak, go to a Dude Ranch, etc. In the evening I worked for a couple of hours to go over results and submitted a new run for the next day. I also had a brief stint doing secret, limited-access work in a locked room at AVCO.

ZIERLER: Lou, I wonder if you can talk about the budgetary environment, post-Sputnik. Was your sense that between your work and at MIT, was the federal government just throwing money hand over fist into this research?

FRIEDMAN: That's why AVCO had a space systems division. AVCO had no expertise in this subject whatsoever. They were known for magnetohydrodynamics work and theoretical physics and doing real propulsion kind of things, and for reentry systems for the heat shields on missiles. They had a lot of military contracts for heat shields on missiles. They had no expertise in this area at all. But there were so many contracts, it was easy to get them. Yes, there was a lot of money. A lot of missions were being studied. The most important phrase from my career in Kennedy's speech that launched the space program was not, "We go to the moon not because it's easy but because it's hard." It's, "We go to the moon and do these other things."

ZIERLER: Yes.

FRIEDMAN: My career is always about these other things. That's when built NASA, and that's what gave NASA the right to try to study all missions to comets, missions to asteroids, to Mars. That was no interest to Kennedy on any of that stuff, but that's what built up the NASA thing. Yes, there was a lot of money around and even as Apollo ended a lot of companies were betting on doing "other things." But that started to end with the Vietnam War. President Johnson was trying to do "guns and butter," building up a big war in Vietnam and building a Great Society in America. Civil space was minor, and budgets began to shrink. In fact, in a few years, AVCO gave up space systems entirely. I mentioned that I worked on classified stuff at AVCO because the planet space science stuff was small budget. Military stuff was a huge budget. I ended up in a locked room with a combination to my door inside another room, which had a doubled key system to get in, with top secret clearance, documents and all of this, working on guidance equations for missiles and reentry systems. One project became so significant, but they couldn't tell you what it was for. It was just, "Here's the equations. Program them and solve them and use them and figure out the error, and things like that." I had classified documents I had to doubly lock up every night. I remember once they told me to take it up to New Hampshire for some meeting up there, and I had this classified document. Instead of coming right back, I stopped at a Target or something, and they put out an all-points bulletin on me because I wasn't back on time. [laugh]

ZIERLER: [laugh]

FRIEDMAN: When I got back, "You can't stop anywhere when you're holding classified." "I had it in my possession all the time." "No, you can't do that." But they wouldn't tell you what the application of the project…there's a point to the story, by the way. I am not just rambling. I found out after I left AVCO, years later maybe, that the application of the project was smart bombs in Vietnam which were killing civilian populations. I was so opposed to the war, and so opposed to the bombings. I that I really felt sick at that and made up my mind to never again work on a project that I don't know its application – defense or civil. After I left AVCO, I never again worked on a classified project.

Lincoln Labs and National Security

ZIERLER: Lou, were you aware more generally of those tensions between campus and what was happening at Lincoln Lab during Vietnam?

FRIEDMAN: Oh, yes, very much so. First of all, I was at MIT and Lincoln Lab, both, so I knew about the issues on campuses about divesture – getting rid of defense labs. Secondly, the Vietnam War was a total influence on our life. The 1960s were extraordinary, and no year in American history was more extraordinary than 1968 – the year I went full time on my thesis work. Vietnam, or should I say anti-war, was huge. Bit even huger (sic!) was civil rights. And it all came to a head in 1968: the assassinations of Robert Kennedy and then of Martin Luther King; the urban riots, the civil rights struggle; the killings of children and civil rights workers in the South; the desegregation issue; the Vietnam War protests; Lyndon Johnson saying, "I will not run as your president again." He always had this parental way of speaking. The Soviet invasion of Czechoslovakia was that year; and then the Chicago riots at the Democratic Convention. We stayed up all night with some friends. We drank one bottle of whiskey each, watching those Chicago riots. While the kids slept upstairs. Yes, 1968 was the worst year in American history except for the Civil War years.

During the 60s, I moved from right to left. I was active in Republican politics up until 1964, when they nominated Goldwater. We feared he would continue the Vietnam War and so we voted for Johnson – and instead, he did. I was a campaign local chair for both Ed Brooke for Senator and Nelson Rockefeller for President – both with fine political views. The Republicans had some terrific people in those years. But the Civil Rights struggle and the Vietnam War pushed me to the left. I was a wee bit active in both social causes.

ZIERLER: What was it like working with Shapiro? What was his style as an advisor?

FRIEDMAN: He's an extremely personable guy; terrific. Quite brilliant and exacting. He could demanding but was always positive and constructive. He would call you up, and he'd say, "I read your paper on this sort of thing. Come see me. It's got lots of errors. So I would worry about it for a day or two until we could met and when we went over it – the errors were some sloppy phrasing or typos, not fundamental. But he, appropriately, wanted it not just right, but sensible. He was very accommodating – I had three kids, commuted about 20 miles daily, had to adapt to first Lincoln Lab, then the move to campus, maintain my Aero/Astro work, and fight the problem of large computer programming and runs to get residuals down to one part in a trillion. That latter took a lot of frustrating time. He was also a bit competitive – in a good way, he wanted his work to be the best. It was cutting edge: testing general relativity and examining unknown or un-modeled forces at play in the solar system. There was a bit of a competition, as well as cooperation with JPL's for accuracy, and JPL had people doing some of the same work as I was doing. We had friendly relations with them, but we were competitive with them too. Then we were competitive with the people testing general relativity, as well as some real disagreements among theorists about various aspects of it.

ZIERLER: The Shapiro Delay, right?

FRIEDMAN: That was a measurement from planetary radar data – before my time with him. I mentioned that our work with spacecraft tracking data was a n outgrowth of his work with planetary radar measurements deducing the ephemerides of the planets. He did come up with a lot of good stuff and played a principal role in radio science experiments with spacecraft as well as in physics.

ZIERLER: I talked to him, and he told me with the Shapiro Delay, wouldn't it be great if he proved Einstein wrong? He'd be a lot more famous if he did.

FRIEDMAN: [laugh] None of us expected to prove Einstein wrong. But you are looking for refinements and effects beyond the first order. There's something subtle in that. Did Einstein prove Newton wrong? Yes, but that doesn't detract from Newton. [laugh] It doesn't. Like you still have to learn Newtonian mechanics before tackling Einstein. [laugh] General relativity is certainly proved but even to this day, people think they're testing relativity. They're not really testing relativity. They're looking for other effects that might be at work in the universe that won't prove general relativity wrong. It may prove that general relativity didn't have all the answers to all the questions, and that's why they search for unified theories and things.' It's really exciting trying to discover things –even way out in the fifteenth decimal place.

ZIERLER: Lou, did you ever travel to JPL as a graduate student, or was it all over the phone?

FRIEDMAN: Hmmm – I am not sure – I can't remember exactly. I did a paper and presentation on the upcoming Mariner Venus-Mercury mission and using it for relativity testing, and I think that may have been at JPL. MVM was the first mission to use gravity assist purposely to target spacecraft encounters. It was something I was studying in my course work –early work on it was being done at MIT as well as JPL. I got involved in the mission studies and development first in grad school and then at JPL. I know I presented work on this, and I know I was interacting with folks at JPL, but I can't exactly remember if I came out to JPL then. I think so.

ZIERLER: What did you see as your contributions to the field with this thesis?

FRIEDMAN: There are two answers to this – one is part of a group, one is individual. The first is that I was part of the group that developed the use of orbit tracking to extract scientific information about our universe, specifically about the solar system. This has turned out to be very significant and a part of every interplanetary spacecraft mission. Included in that scientific information is general relativity, the masses of the planets, the gravitational shapes of the Sun and the planets, the solar wind, the distribution of mass in the asteroid belt and even aspects of the geophysics of celestial bodies. My individual contribution was of course a tiny part of this – I did get (I think) the first definitive determination of the mass of Mercury from the spacecraft tracking data I was analyzing – Mariners 4 and 5. I did not succeed in getting a definitive determination of the general relativity parameters – that came later with additional spacecraft data. And I did advance the programs of determining the planetary ephemerides – modeling the solar system. But, only as part of the larger group of people working on that.

Jumping ahead, I should mention that the end of my thesis work and my beginning at JPL was almost seamless. My very first day at JPL, I began working on the MVM mission and I became the experiment representative to the radio science team (which included Irwin). And then veery soon I became involved with the trajectory development of gravity assist for the mission and was fortunate to be in the early days contributing to that important aspect of celestial mechanics and mission design. But I am guessing we will get to JPL later.

ZIERLER: Lou, before the Mariner mission, how well developed, even at a conceptual level, was the idea of gravity assist? Were people talking about this even before the space age?

FRIEDMAN: Well, the effect of gravity bending orbits on a close flyby was known for a long time, mostly from the observations of comets. I believe it was studied by Tisserand in the late 19th century for analyzing the perturbations of comets as they go around Jupiter and other celestial bodies. The basic mathematics was known. Whet was new in the space age was to use that effect on spacecraft trajectories to target the velocity vector, and hence the orbit direction, after a close flyby. Mariner Venus-Mercury was the first mission to fly an orbit using gravity assist, but it was not the first mission on which gravity assist was studied. That would have been the Grand Tour – on which trajectory work was being done in the mid-60s. That is when it took the work on the seminal discovery by Gary Flandro, Utah, of the opportunity for a spacecraft to go to Jupiter, swing by, and then go to Saturn, and then swing by and go to Uranus, and then swing by and go to Neptune, called the Grand Tour. That's something that happens. The alignment of the planets is such that you can only do that once every 176 years with any reasonable trajectory without super large rockets the size of which have never been built to compensate for the fuel.

If you do it ballistically, you have to take advantage of the swing bys of the planets. Flandro discovered this Grand Tour opportunity, and began computing that. He did the seminal work on that, and then JPL began following up on it. Michael Minovitch at JPL did a lot of the early work on it too, along with others. JPL, by the way, and Caltech have been sued by Minovitch because he claims to be the inventor of these trajectories and had done the early work. He was an iconoclast in the highest regard, with a lot of personality problems. I was his group supervisor at JPL in 1972 and '73, so I was engaged in all this. But I didn't get involved in the lawsuit, which came later. But that's part of Caltech history, so you might run into him somewhere else. The subject exploded in the 70s, not just with the interplanetary missions but with designing multi-satellite encounters for the Jupiter Orbiter using gravity assist from the four Galilean moons. With this I was very involved. The other breakthrough that happened with the MVM mission occurred right in my group at JPL when visiting scientist Bepi Colombo (visiting from Italy and from the Harvard-Smithsonian Center for Astrophysics) looked at a plot of the MVM trajectory and asked would it possible to target the Mercury flyby for a repeated flyby of Mercury on a subsequent orbit. We poo-pooed it at first as an improbable likelihood, but then realized the gravity assist enabled us to do almost anything – including that. So the Mariner 10 mission made repeated flybys of Mercury. Colombo, by the way, was a remarkable, brilliant and delightful person – and he became a close friend of me and my family (even my kids. I was honored to speak at a memorial service for him at the University of Padua at the very lectern used by Galileo).

ZIERLER: Lou, what was most exciting to you about the Mariner program?

FRIEDMAN: I guess, to me, the Mariner Venus-Mercury was extremely exciting because (a) it was the first gravity assist mission. It was also the first visit to Mercury. It truly gave me a sense of exploration – adventure plus discovery. Going new places, doing new things – and directly applying all what I had studied – astrodynamics, guidance and control, and mission design balancing the science and engineering. I got a chance to work at the science-engineering interface that I like so much. It also introduced me to some outstanding people who I became greatly involved with for the rest of my career – notably Bruce Murray, Gene Giberson and John Casani. But, after MVM (when it became a flight project and us advanced projects folks transitioned off) I began working with the navigation section on the Grand Tour, which became the Mariner Jupiter Saturn mission and later, Voyager.

The task was to take the statistical uncertainties in the trajectory and calculate how much fuel should be carried aboard the spacecraft to provide trajectory correction capability. You want to carry enough so that you have contingency for at least 99% of any expected errors, but not so much as to add too much weight to the spacecraft. This was very interesting, and clearly important. I knew a lot of theory, but this was my first experience with a real spacecraft design activity – I learned a lot from Bob Mitchell (who later became the Cassini project manager) and Ed McKinley. From that task I was asked to participate in a groundbreaking development – the use of imaging for optical navigation. Prior to Voyager, all navigation used radio measurements only, measuring range and doppler shift (to get velocity). But the development of on-board cameras permitted using celestial navigation with star positions and incorporating optical navigation became a major effort. It also became a turf battle between the Guidance and Control Division and our Mission Analysis Division. They formed a committee called the Approach Guidance – Science Instrument Committee (the issue being the use of cameras for both guidance measurements and science observations). We (mission analysis) won the turf battle – which was probably helpful to my career [laugh]. I soon became the Group Supervisor, when Roger Bourke went on to Civil Systems (which JPL was getting into). The navigation work on Voyage was picked up by the project team as soon as it got formed and then I reverted to working on newer advanced projects – a Venus Radar Mapper (which became Venus Orbital Imaging Radar which became Magellan) and Jupiter Orbiter Probe (which became Galileo).

The work on Galileo was exciting and interesting – and ground-breaking. I already mentioned it was using gravity assist to provide multi-moon targeting in Jupiter orbit and to simultaneously move the orbit's orientation though the planet's whole magnetosphere. That got both the planetary scientists like Murray and Sagan excited, and the fields and particles scientists like James Van Allen excited. And it made us mission designer heroes. That was fascinating work, and I would bring the computer home at night. Finally, we had portable computers we could bring home, and chug out printouts, and I would do that. Then somewhere in the middle of all of that, we learned about this guy at Battelle Memorial Institute who had computed a trajectory that said it was possible to rendezvous with Halley's Comet. I am running on here, rapidly through time – Do you want me to go off on that—

ZIERLER: I would love to.

FRIEDMAN: —or do you want me to stop?

ZIERLER: No, no, please.

FRIEDMAN: Rendezvousing with Halley's Comet is really hard to achieve – it was considered totally impractical. Intercepting it is much easier, but rendezvous requires you to match not just position with it, but also velocity. Since the comet orbits backwards in the solar system, that is in the opposite direction of Earth' around the Sun. it is equivalent to "stop the world, I want to get off." An intercept produces a very fast flyby; a rendezvous would permit detailed science observations over a long period of time. But it would require enormous energy, far more than can be supplied by launch vehicle we have ever had. Someone in my group (for which I was the supervisor at this point) barges into my office saying "Jerry Wright has computed a way you can do a rendezvous with Halley's Comet with continuous solar sail low-thrust. My initial reaction was to say, "that's impossible." Bu then I am given a paper to read and sure enough there is the analysis. Solar sails, like solar electric propulsion, produce a low-thrust derived from solar power that is small but continuous. Over time, large energy or velocity can be added. But unlike solar electric (which requires converting the solar input to electrical power and then to heat up a propellant), the solar sail requires no propellant, no mechanisms, only a very light-weight solar sail. Well—getting to Halley's Comet was something everyone wanted to do. It is the most famous celestial visitor in history, and the composition and processes of comets are crucial to understanding the solar system. So, the notion that we could actually rendezvous (fly up to and in formation with) it was tremendously exciting and appealing – definitely something to work on. We were the advanced projects group with a motto "Anybody, anytime." We had on t-shirts. I still have the t-shirt." Clearly, we had to investigate this challenge – new as it was. Solar sailing was only a theoretical idea, there was no NASA program for it, so we had to start from scratch. Jerry Wright's at Battelle. I immediately said, "hire him," We make him an offer he can't refuse. He comes to JPL, and so now he's in my group, and we're all working on this. That led JPL to make a mighty effort to create a mission to Halley's Comet, and led me to a whole history of solar sail projects and activity. It's all in my first book, Starsailing: Solar Sails and Interstellar Travel.

ZIERLER: Lou, let's go back to Cambridge. Besides Shapiro, who else was on your thesis committee?

FRIEDMAN: Wally Vander Velde and I am a little unsure of who the third was – perhaps, Jim Potter – I would have to go back and check. In addition to my thesis work I was of course specializing in astrodynamics in the Aero/Astro department and minoring in Optimal Control which was both in that department and electrical engineering. The thesis work was, as I said, centered on a huge numerical integration program modeling everything gravitational and many things non-gravitational in the solar system. And we were trying to solve for every parameter we did not know and which might be revealed in the spacecraft tracking data. The computer was at Lincoln Lab. It is a big computer. It takes up as much room as the social hall in the temple. But as I said, we had to move our group out of Lincoln Lab and we had to move our program to a different computer. Just a couple blocks down the street from the Aero/Astro department at MIT is the short-lived NASA Electronics Research Center. We somehow made arrangements to be able to use that computer. ERC was created in the mid-60s, but it lasted only a short time. In fact it closed, just about 1970 as I was leaving MIT and it's computer – by total coincidence – came to JPL the same time I did. So, in Cambridge I have my office in the Experimental Astronomy Lab, part of the Aero/Astro Department, I am working on the computer at NASA ERC down the street, and across campus is my thesis advisor Irwin Shapiro in the physics department. But I was also close with the folks at Draper Lab working on the Apollo program, with Vander Velde and other faculty members were. I was close with Jim Potter also for some of the work. I knew Dr. Draper because I took a small seminar with him. But I wasn't in the Draper lab. I was in something called the instrumentation lab—no, the experimental astronomy lab. Instrumentation lab is what Draper lab is now called. My degree title actually is "Instrumentation" – even though I had almost nothing to do with instruments. The Draper lab did a lot of military work too, I think. I think, again, it was part of that split.

Toward the end of 1969 I was (a) simultaneously making good progress with the thesis but not quite getting closure with the results, and (b) coping with another loss of facility as the NASA ERC was closing down and the computer going to JPL, and (c) running out of money with a family of three kids to support. Job interviews led to the conclusion that I wanted JPL and they wanted me. So the obvious solution was for me to go to JPL, start my job there, and finish up my thesis in Pasadena with access to the computer, the planetary ephemerides and all the support I needed. So I came here in January 1970 and did just that. They were moving the computer from Cambridge to JPL, I moved more or less with it.

From Cambridge to Pasadena

ZIERLER: Aha.

FRIEDMAN: JPL is going to get that computer, and do that kind of work. I'm looking for a job. I could go to work at JPL. I literally was in the Electronics Research Center the last day they used that computer in Cambridge, and I was literally at JPL the first day that they turned it on to use it at JPL. [laugh]

ZIERLER: Lou, do you have a story, an understanding of how JPL got this?

FRIEDMAN: No – facilities and equipment transfers were not something I knew anything about until they happened.

ZIERLER: Now, did they have to create a position for you? Did you apply to an open job? How did that work?

FRIEDMAN: No, I applied to JPL, and I had been working with John Anderson and the people doing orbit determination with those kinds of same things. But I also had begun talking to Roger Bourke, who had the advanced projects group where they were called on to create new missions and work that process, I like so much of balancing science requirements with technical engineering capabilities. Mission design is very creative. I talked to both groups. I interviewed Bill Melbourne, who was the section manager, and John Anderson, who was the group supervisor of the orbit determination people, and also Roger Bourke, who was this group supervisor of the advance projects group. Ultimately, JPL gave me offers in both groups. I could choose. Either was I was going to work on aspects of the upcoming Mariner-Venus-Mercury mission, and probably the Grand Tour. The decision was what kind of work I was going to do – mission design or orbit determination. I chose the former and selected the Advanced Projects Group. I might have been influenced by the interviews I had with each group – the one with Anderson and Melbourne somewhat conventional in their building located off Lab in La Cañada and the one with Roger in his airplane as he flew me over the area to familiarize me with LA, Pasadena, etc. Roger and I had met some months earlier and talked several times, so when I showed up to JPL he thought it would be more productive to fly me around – and I agreed. [laugh]

ZIERLER: [laugh] Now, that's a way to do it.

FRIEDMAN: I called Connie at the hotel. I say, "Roger says he's going to take me out on a flight in his plane. Do you want to come?" She says, "Hell, no."

ZIERLER: [laugh]

FRIEDMAN: She said, "I don't even want you to go."

ZIERLER: [laugh]

FRIEDMAN: I said, "I better go with him," so we did, and the rest is history. I joined his group. But the first assignment I got was to work with John Anderson and Doug O'Hanley on the Mariner Venus-Mercury radio science data. I was basically working again on the interface as the experiment representative to the science team from the mission analysis group. It comes back to that sales engineering thing in junior high school. Always work at the interfaces. I'm good at that. Still I'm good at that (he said modestly).

ZIERLER: In what year, Lou, what year was this? Was this 1970 when you joined?

FRIEDMAN: 1970, yeah. My first day at JPL, I went down to Caltech to an MVM meeting chaired by Bruce Murray. And then I got assigned to the experimental job on the radio science team so I was, again, immediately working with Melbourne's section, and also with the radio science team which included Irwin, and John Anderson and Von Eshleman – but I was working for Roger Bourke, and doing both, which was great. That's how I got to meet so many really good people. But then it gradually moved away from the radio science, gradually more into the mission analysis and design. Then (a year or two later) when Roger left the group, I was the next group supervisor.

ZIERLER: Now, in 1970, Gary Flandro had already made his calculations. Was anybody thinking about what eventually would become Voyager? Was the next mission—?

FRIEDMAN: Oh yes, it was before '70. The Grand Tour sturdies began in the late 1960s and by 1970 (I think) JPL was working on a spacecraft development called TOPS, Thermoelectric Outer Planet Spacecraft. They were designing a spacecraft that could do the Grand Tour, which involved unprecedented flight times and mission operations over many years. It was to be autonomous (as much as possible for that time) and of course nuclear powered. The people working Voyager trajectories were there before me. I told you earlier I got assigned to work the navigation requirements for the pre-project development of what ultimately became Voyager. Specifically estimating the delta-vs, that is the velocity for trajectory corrections to account for navigation uncertainties. That was in1970 or perhaps early ‘71. Flandro had left JPL by then (I think he was only a summer or temporary hire while a Professor at Utah). Although he continued to come back and work with us. Others working on the trajectories then included Mike Minovitch, Vic Clarke (I think), Phil Roberts and Roger Bourke in our group and soon afterwards, Paul Penzo. Others too.

ZIERLER: Did you have any initial contact with Caltech? Was that relevant for you at all?

FRIEDMAN: Yes, but not so much with Grand Tour or Voyager. I already mentioned my first day at JPL: I went into my assigned office, and there's a note on my desk from Roger Bourke, who was my group supervisor. "I'm away this week …go down to Caltech. There's a meeting going on the Mariner Venus-Mercury mission. It's an all-week meeting or three-day meeting. Go to the whole thing. Introduce yourself to a guy who's in charge, Bruce Murray. Tell him I sent you down there to learn, because you're going to be working on either the trajectories or the navigation for the mission." The first day, I get in my car, and I go, "Where's Caltech?"

ZIERLER: [laugh]

FRIEDMAN: I go down to Caltech, and go down and meet Bruce, briefly. I spent that week on campus – it was a good introduction, not just to the campus, but to people too. Some I knew or had met in connection with the studies I had done on MVM radio scheme for my thesis. Another Caltech early interaction was related to my thesis work – there was a conference on testing general relativity in connection with spacecraft tracking data and I was told to give a talk there about the studies related to the MVM mission. So, I put a talk together and go to the conference – organized by Kip Thorne and when I get there I find there are 3 or 4 Nobel Laureates there (not to mention Kip, a future Nobel Laureate) plus many physicists from around the world, and campus. It was daunting.

ZIERLER: Right, right.

FRIEDMAN: I'm going, "Feynman, Jesus Christ, what did I"—

ZIERLER: [laugh]

FRIEDMAN: "I can't talk here."

ZIERLER: [laugh]

FRIEDMAN: I give my talk.

ZIERLER: Lou, how did the talk go?

FRIEDMAN: The talk went OK. I didn't make a fool of myself, since Kip and I have remained friends ever since. And also with Feynman, too, who was there – he and I remained casual friends. But I emphasize, I am not in that league of physics – I'm just an engineer, not a scientist. I was very interested in what was being discussed – looking for tiny perturbations in experimental results which reveal new physics. They were looking at the 14th, 15th 16th decimal place in the data. We became friends, and colleagues even though they were doing physics just beyond the limit of my real understanding – but I was doing the application of space flight results to it – and I think that was appreciated. I worked with that, and even I saw Kip a few weeks ago. Our paths intersected again with Steven Hawking, when The Planetary Society gave Stephen Hawking a medal, and Kip helped with Liasson with Stephen's people in England. Then I went over and met with Stephen Hawking. But that was a different story; related to the Planetary Society and nothing to do with 1970. I had good interactions because of the radio science team, for MVM. Dewey Muhleman for example was on the team. Is that a name you know?

ZIERLER: Sure.

FRIEDMAN: Dewey Muhleman was [laugh] a competitor to Irwin and our group at MIT – although a friendly and cooperative one. They were colleagues in the same field. But when went to JPL and was part of the Caltech team it felt like I had been traded to the Red Sox from the Yankees.

ZIERLER: [laugh]

FRIEDMAN: [laugh] I'm trying to play with the Red Sox and, really, my heart's in the other place. But, everyone here was a terrific ballplayer.

Voyager and the Planetary Grand Tour

ZIERLER: Now, were you exclusively focused on Mariner during the early years at JPL?

FRIEDMAN: No, Mariner Jupiter-Saturn came on Voyager, like I told you. I think my work on Voyager navigation started in '71, maybe even late '70. Then in 1973 or so, I was asked to take over the leadership of the Venus radar mapper study which was going on at NASA-Ames and some industry contractors. But JPL was brought into it and I became the study leader. It became VOIR, and much later became Magellan in the evolution of things. No, I worked on the the Mariner Mars missions -- 6 or 7 or 8 or 9. I worked on 10 and then on MJS which became Voyagers, so my early work was on Voyagers, and the VOIR.

ZIERLER: Lou, it's a great place to pick up for next time. We'll get into your involvement with Voyager. The last topic we'll cover today is really that transition from missions. From all of your work on Mariner, how did that inform Voyager? How was that really the foundation or the intellectual stepping stone to the Grand Tour of the outer planets?

FRIEDMAN: There are better people than me to answer that question, or more accurately, those questions. It is not a straight-line transition. Initially, the spacecraft development for the Grand Tour was entirely new – I mentioned TOPS: nuclear powered and semi-autonomous, both beyond the development of the Mariners at that time. My job, way down in the weeds, was on the navigation requirements – sizing the fuel for trajectory correction maneuvers to compensate for orbit determination and performance uncertainties. But the Grand Tour/TOPS broke the budget that NASA had, and the mission was cancelled – or about to be. In fact, I gave a presentation of my AIAA paper on the navigation at a meeting in San Diego in January 1971 on the very day it was announced that the effort was to be cancelled.

ZIERLER: Oh.

FRIEDMAN: Congress cancels the Grand Tour in January of '71. I go to the conference and I begin. I say, "I'm giving you a lecture at a horse and buggy conference the day automobile's invented."

ZIERLER: [laugh]

FRIEDMAN: I thought we're done. But when I came back from that meeting I find my group, under the direction of Roger Bourke spent a furious weekend working on a backup plan – a scaled down mission to go only to Jupiter and Saturn. And to do it with a simpler spacecraft – a Mariner. It was called Mariner Jupiter-Saturn. Roger led a tiger team to come up with trajectories and mission design while spacecraft folks scaled down the requirements for long flight times with lower mass and power. For the spacecraft story of TOPS to Mariner, I was a more distant observer and there are others you would need to ask. I would start with John Casani, although other players from that time are probably also around – maybe Ron Draper and Tom Gavin would know. I went to work under the direction of Bob Mitchell for detailed calculations to produce lower propellant requirements. They salvaged from the Grand Tour and ultimately MJS became Voyager and actually carried out the Grand Tour by lasting way longer than its requirements. That seems to be a JPL way, being ingenious. That's when Voyager is born, that weekend of intense work in January.

FRIEDMAN: That group that was working on it also began looking into other mission possibilities. There was a Mariner-Jupiter-Uranus effort (MJU), and of course even those working the baseline MJS knew there were at least mathematical possibilities after Saturn – depending on the way we flew around Saturn. It was an extremely creative time for gravity assist development as the real ability of fulfilling our group's "Any Body Any Time" motto began to be understood. But JPL management sold NASA, and NASA sold Congress on the scaled down MJS mission and soon a project team was formed. Bud Schurmeier the project manager and Ed Stone the project scientist. I became close friends with them, especially Bud, and used to enjoy kidding them that I was on Voyager before they were. Albeit in the pre-project study phase. I was close the mission design as I said, but not to the spacecraft and I think the story of how that "scaled-down" backup idea became a spacecraft that is still working after 45 years outside the solar system environment and made so many discoveries on the way out there would be a good one for Caltech heritage.

ZIERLER: The rest is Voyager history. Lou, on that note, let's pick up really on the origins of Voyager for next time.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Wednesday, October 12th, 2022. It's great to be back with Dr. Louis Friedman. Lou, once again, it's great to be with you. Thank you so much.

FRIEDMAN: Glad to be here and glad to be talking to you.

ZIERLER: Lou, today we are going to pick up developing the origin story of, of course, the Voyager Mission. We left, last time, you explained some of the technical developments at JPL that made it possible. My first question for today is, how closely was NASA tracking these developments? In other words, when JPL felt like it had something ready for NASA to support, was NASA prepared for this?

FRIEDMAN: Yeah, NASA and JPL are very close, without a doubt. In a way, it couldn't have been closer if they were in the next room instead of across the country. It was very close. Of course, when a person is in the next room and you're here, you may be doing something that he or she doesn't know, or you don't want him or her to see right away. There was always a little of that going on. But NASA and JPL were very close. I'm sure there are times, like any other working relationship, "Oh, gee, they're looking over my shoulder every minute or, gee, now, I wish they'd pay a little more attention to me." All those things came up, but it was normal and it was close.

ZIERLER: Who at JPL really led the efforts to explain these developments to NASA, the feasibility of what would become Voyager?

FRIEDMAN: That is a hard question for somebody who's basically chitchatting in an oral history as opposed to going back and really getting every name right. There are many people involved, and I have to emphasize as strongly as I can that these are team efforts. But there is also an organizational structure with a chain of command and for major communications with NASA that was pretty structured through the study or project management. I was pretty low on the totem pole in those days – but on studies I was leading (for example with VOIR) I talked to mid-level managers at NASA and went there to present. But on projects like MVM and the Voyager, where I was just one of many on the team, things bubbled up to the project manager who synthesized all the inputs and was responsible for interface and customer discussions. And if it was a big policy issue, it went to the Director. On MVM, the manager was Gene Giberson, on Voyager it was Bud Schurmeier. For science issues, things flowed through the Project Scientist, like Ed Stone on Voyager. Prior to the formal project organization these discussions with NASA would have probably been handled at the Program level – Assistant Lab Director like Bob Parks or Jack James I would guess. I think John Casani was involved early, but I am not sure when – you can check with him. Ron Draper at JPL led the spacecraft development, I think; maybe Ray Heacock too. My own personal involvement ended before the official start of the Voyager project – I think it was still MJS when I was with it.

ZIERLER: Lou, on a more general level, is your sense that NASA needed to be convinced by JPL to support Voyager, or were they on board from the get-go?

FRIEDMAN: NASA was on board from the get-go as far as I know. Again, I'm pretty low level at this point and really did not have insight into the politics. But they got the budget constraint forcing them to cancel it. And what people need to understand is when you say NASA takes an action like canceling Voyager or canceling Grand Tour, it sounds like a pejorative statement about stupid old NASA. They canceled the Grand Tour. [laugh] They're part of the government. They have to obey the law, and the Congress had canceled the mission. They had to issue a stop work order on the Grand Tour. But NASA was very open to the idea of resurrecting it, as far as I know, anyway. The other thing to understand is that NASA is an organization, not a person – it had all kinds of dynamics with some people helping and some not so much. A bureaucrat is someone who gets something done – a bad one get the action blocked, the good one moves is forward. We aways had both.

ZIERLER: Lou, was it simply a name change from Mariner Jupiter-Saturn to Voyager, or was there something more substantive? Was it a new program that went along with the new name, Voyager?

FRIEDMAN: Yes and no. It was pretty much not a substantive change in the technical details. The substantive change came with the end of TOPS and the cancellation of Grand Tour. But when the MJS work came in with the backup plan, that development led to Voyager, and ultimately I think the name change from MJS to Voyager was more cosmetic. But again, I emphasize, I don't know – I wasn't involved in that level of politics or policy. If you had all the paperwork or computer printouts in front of you for Mariner Jupiter-Saturn and then for Voyager, pretty much the same. But a program name gets a different connotation. For reasons again I'm not part of, they wanted to give it a new name. Now, the history of names is pretty complicated because, originally, the Viking mission, with Mars orbiters and landers, was proposed to fly on a Saturn rocket, the same one that launched Apollo, as a much heavier spacecraft, and its name was Voyager. It got canceled because it was too expensive, too big, and no Saturn rockets.

The people at that time—and this is before my time—recast it on a smaller launch vehicle—still a giant launch vehicle; the biggest one we had at the time—and renamed it Viking. It wasn't Voyager; it was Viking. Probably you should talk to Casani and Stone – they undoubtedly know more about the re-casting of MJS as Voyager. I presume you are interviewing them.

ZIERLER: Yes. Lou, do you have insight on why Ed Stone was chosen to be project scientist for Voyager?

FRIEDMAN: [laugh] Above my pay grade, I guess.

ZIERLER: [laugh]

FRIEDMAN: Certainly at that time, it's above my pay grade. Now, nothing's above my pay grade. I'm not going to justify Ed. He's great. He was a brilliant scientist. He did a great job. Whoever did it did the right thing.

ZIERLER: Sure. He was the obvious choice?

FRIEDMAN: I don't even know who did it. I wonder if it was Pickering. Who makes that appointment? I don't know if NASA did it. Probably NASA did it.

ZIERLER: Your sense is that Ed came on once Voyager was official?

FRIEDMAN: You'll have to ask him exactly when he came on. Yes, I think so. When the project gets approved, in those days, it was a very clean day a project started. The project was a new start, and it was a certain day. Whether he was already on in the pre-project lead up to that, or whether he was doing things, and then got named, I don't remember, I don't.

ZIERLER: Lou, the idea to have two identical spacecraft, Voyager 1 and Voyager 2, was that baked into the project from the beginning, or that developed after the project got started?

FRIEDMAN: I don't really know. As I explained last time, I was pretty far down from those considering the project formulation strategy. I know we worked on several options of the mission design including the MJS and I mentioned an MJU. The Mariner line of development favored two spacecraft – we had Mariners 3 and 4, and then 6 and 7, and then 8 an 9 all for Mars. And going to deeper to Jupiter and Saturn with longer flight times was certainly riskier – I am sure that the led to the two spacecraft decision, especially as it was a scale-back from the more ambitious autonomy development for the TOPS spacecraft. But I was not part of that deliberation and planning.

ZIERLER: Lou, for you, what were your responsibilities at this point in the development stage for Voyager?

FRIEDMAN: I was in the pre-project development, before it was even called Voyager. We did mission analysis and design: trajectories and navigation. I mentioned that I was working on the delta-v requirements in order to estimate the amount of propellant that had to be carried on the spacecraft. That will contribute to the determination of the spacecraft mass which in turn defines what size rocket is needed for the launch vehicle. We also did the design of planetary encounters – where to aim the trajectory to meet science requirements and deal with engineering constraints. Included in that is the multi-planet targeting. When you could go? What size vehicle? What was the launch energy? What was the encounter speeds? Could you encounter Jupiter and then Saturn, that kind of thing? My initial assignment was to work on the fuel requirements, which is a a statistical study. You estimate the amount of uncertainty in the orbit, and the trajectory, you calculate how much delta-v is required to make those corrections. Then that translates into a fuel allotment. Then you calculate how much residual error you have, and then you do all kinds of statistical analyses on them. You come up with an estimate, and then you do a 1 sigma estimate, 2 sigma, 3 sigma, meaning, how much uncertainty you have on the estimate. Then you estimate it to be 99% probable, which is 3 sigma. This work brought me in contact with the orbit determination and radio tracking people, and those who were beginning to think about using optical navigation for estimating the spacecraft position.

ZIERLER: Lou, the idea that it would need to be launched, otherwise we're not going to be able to do it again for another 176 years, did that impart a sense of urgency in the five or so years before launch? Did people feel like, "We've really got to get it now or it's never going to happen in our lifetimes"?

FRIEDMAN: Yes and No. We're a little smarter than that—

ZIERLER: [laugh]

FRIEDMAN: — there is no question that the 176-year period of the alignment was a huge motivating factor. It was the impetus for trying to make that mission happen. But quickly it was realized there were many ways to skin the cat – that is to accomplish the multiple planet visits. I already mentioned other gravity assist studies – Jupiter-Saturn, Jupiter-Uranus, Jupiter-
Saturn-Pluto, Jupiter-Uranus-Neptune and these opportunities spread out over several years. In fact, every time you go to Jupiter (every year) you can swing-by and go somewhere else. So the "rare" alignment was a driver, but it didn't necessarily drive the mission design – if that makes sense. Seizing the opportunity of the Grand Tour alignment drove our efforts to define a mission, but the power of gravity assist as we began to study it gave us flexibility with that design – as I told you about the group motto (emblazoned on T-shirts), "Any Body, Any Time."

ZIERLER: [laugh] Lou, I wonder if you can explain in a little more detail just what the gravitational assist made capable since, as you said, there was some wiggle room there. Let's say Voyager hit that four-planet mark. What would it have been able to accomplish? Let's say it only hit one of the planets. How much more limited would Voyager have been as a result?

FRIEDMAN: Well, it did accomplish the Grand Tour. We got to all the outer planets, and we did the swing-bys and the gravitational assists. And we did more – went through the Saturn rings, and went on into the interstellar medium. If you missed the targeting for one reason or another, it clearly would have been a big loss – maybe miss a discovery at a Saturn or Uranus moon, but it would not have been a catastrophe – because as I said, the mission design was flexible as long as your spacecraft was working. I mentioned targeting possibilities for Uranus after Jupiter and for Pluto after Saturn, and others. The myriad of Voyager discoveries were enabled by the planetary alignment and by the cleverness of the mission designers and operations team navigating the spacecraft to target the spacecraft and point its instruments. If you had try to meet all those science objectives and do those missions without gravity assist – it would take a very long time and very large rockets to give you the energy you were otherwise getting from the planetary swing-bys. And, as we got experience with gravity assist, we developed many kinds of missions – in the inner solar system between Venus and Earth and Mercury, and around Jupiter and Saturn using the gravity of their moons in orbital tours.

ZIERLER: Lou, so I understand correctly, the value of the gravity assist is in speed; not necessarily power. In other words, the power source of the spacecraft, that's not being affected. It's just how long it's going to take for the spacecraft to get to their ultimate destination?

FRIEDMAN: You're using the word "power" as we would measure in electricity and watts. Is that right?

ZIERLER: Yeah, just the power source of the spacecraft.

FRIEDMAN: You're not using the word "power" in the more general sense of the energy of the motion of the spacecraft?

ZIERLER: Correct. Just like the idea—

FRIEDMAN: OK.

ZIERLER: —now we understand the—

FRIEDMAN: Right. Then you're correct. The power for interplanetary spacecraft comes either from the Sun (with solar cells converting it to electricity) or from an on-board nuclear source, from the decay of radioactive material generating heat which is converted to electricity. In either case, it is not from the motion of the spacecraft.

Interstellar Travel and Gravity Assist

ZIERLER: Now, is getting to interstellar space only possible because of gravity assist?

FRIEDMAN: No. It is only possible ballistically with gravity assist. You know what I mean by "ballistically"?

ZIERLER: No.

FRIEDMAN: Basically, "ballistically" means you launch the spacecraft, and you send it on its way. Its only source of speed is its launch energy, and that determines where it's going and how long it will take. Ballistic means flying only under the influence of gravity. Up until 1980, that's the way we launched all spacecraft into the solar system, including Voyager. The only way you can get to interstellar would be to have the gravity assist, like the Voyager and Pioneers going out. The gravity assist provides the extra energy. But what got invented in the 1980s was electric propulsion and low thrust. That gives you an ability to continually thrust while you're going along. You're not limited to just your launch energy. Now, you have your launch energy plus whatever propulsion you can carry along in the form of fuel for electric propulsion. That's, of course, still limited. I am not aware of any practical solar electric mission studies for reaching beyond the solar system. Nuclear electric yes, and I am working now on solar sail missions into the interstellar medium. But interstellar flight is tp another star system, in my opinion, a bridge too far. Impossible with any existing or known propulsion system. If you mean getting into the interstellar medium, like Voyager, yes a nuclear electric, and maybe a solar electric can do it, and so can solar sails.

ZIERLER: Without gravity assist?

FRIEDMAN: Without gravity assist? The answer is yes, in the same way that the solar sail, which I'm working on now, gravity assist would give only minor improvement because of the we are already achieving vey high speeds. That is achieved by flying in very close to the sun – a sort of gravity assist from the Sun. I didn't know we were going to get into this much technical detail. Do you want to get into that?

ZIERLER: Sure!

FRIEDMAN: First there is a question of what you mean by interstellar flight. If you mean going to another star system, I already indicated that is impossible with any practical system. If you mean going into the interstellar medium, where the environment is dominated by interstellar particles (like where Voyager is now) that can be done without gravity assist, even faster than Voyager. You can even do it ballistically, although solar sails or nuclear electric will be faster. You can take your orbit launch not to the outer planets but launch in toward the sun. You launch down to a low perihelion around the sun, and then apply a big rocket motor to boost yourself out, to give you an extra delta-v. The question is, can you carry a big enough rocket motor? The answer is yes, if you get close enough to the sun because, at that point, you're doing what's called an Oberth maneuver, after the well-known German rocket pioneer Hermann Oberth. It's a maneuver that's done at perihelion. Just picture an ellipse, and now picture putting a lot of energy into the ellipse at its perihelion. That will open up aphelion to a much larger distance. You'll go much further. If you put enough energy in, it'll open it up to infinity, which becomes a hyperbola, which goes out of the solar system. You can do that. Now, you have to get fairly close to the sun, a few solar radii, and you have to have a big shield to protect you, and so it's a very hard job. I don't think it's practical, personally. That's why I was kind of dismissive at the beginning, saying that you can't do it ballistically—but you can. In fact, JPL had a proposal, which I didn't consider too good, for doing it that way. You can also do it with low thrust, and there you can apply the delta-v continuously, and you can apply more of it so you don't have to get quite as dangerously close to the sun, and you can get yourself enough speed. You can do it with a solar sail with no propulsion on board by just using solar sunlight as the propulsive force. Then you can still apply, and you get, of course, a lot of solar power, solar energy close to the sun. You're getting one source of increase, and you're getting the Oberth maneuver, which is you're applying it at perihelion, so you really do get a high-efficiency increase in the velocity, and you can get to interstellar speeds.

ZIERLER: Lou, go to back to my question about speed, could we get to interstellar space as fast as we did without planetary assist? We got there in 2012. Was it only because of the gravity assist that we got there as fast as we did?

FRIEDMAN: Yes. Again I assume you mean the interstellar medium.

ZIERLER: How long would it have taken if you could just do some rough calculations without gravity assist? What would it take to get there?

FRIEDMAN: The answer to your question is, it's the wrong question. [laugh] I'm sorry. I'm on the stand here, and I tell a lawyer, "No, I'm sorry. That's the wrong question."

ZIERLER: [laugh] Tell me what the right question is.

FRIEDMAN: The judge is going to intervene, and say, "But that's the question he asked you. Answer it, sir."

ZIERLER: [laugh]

FRIEDMAN: The right question is, how big a rocket would it have taken to get off of Earth at interstellar speeds with the weight of the Voyager spacecraft? And what assumptions do you make about the spacecraft. I mentioned to you a few minutes ago about going close to the Sun and doing an Oberth maneuver. That could take you out faster than Voyager. If you are trying to compare the Voyager gravity assist with just a straight ballistic launch from Earth with the same size spacecraft, I am not sure any rocket could do it. If we had to do it that way it would have to be with a much lighter spacecraft. I don't think the Saturn V would've done it. If the Saturn V launched a CubeSat, it would certainly get up to interstellar speed. The answer is, somewhere in between [laugh]. Suffice it to say that gravity assist and the planetary alignment enabled the Voyager mission. Gravity assist has enabled other missions like Galileo and Cassini as well.

ZIERLER: Now, to go back to the original question, going into interstellar space, was that central to the mission of Voyager?

FRIEDMAN: No, it wasn't even thought of. It wasn't any part of it.

ZIERLER: Because it wasn't technically feasible? Why not?

FRIEDMAN: Voyager was designed to go to Jupiter and Saturn. A few smart guys at JPL, maybe even one or two at NASA [laugh], but a few smart guys said, "After Saturn, maybe we can target it to Uranus or Neptune or something like that." Post-Saturn mission targeting was considered, but only as an option "if all is going well." But even that thinking was pretty much limited to the planets: Uranus, Neptune, Pluto. In general, the spacecraft was designed to be robust and not with any lifetime limit, but still I think the expectation was that 20 years would be very lucky. I recall people saying it would be on an escape trajectory that could go to interstellar space, but I do not think there was much thinking of it functioning and doing a science mission there – at least not in the early days of the mission.

ZIERLER: Nowadays, Voyager 1 and 2 are still going. They're in interstellar space. It seems to me like someone needed to plan for them to be as long-lived as they have been. I wonder if you can explain that.

FRIEDMAN: What we've learned, pretty much, is that, on the one hand, space is a very hostile environment, faulting [laugh], and you can't fix things up there easily. But what we've also learned is that if you do it right, it is a benign environment, and spacecraft that work continue to tend to work. You usually don't design it with limits. I told you that consumables, like fuel, is limited – but how much you plan for is a matter of statistics. If things go well, you have lots of margin and can last a long time. Engineering design has a lot of that – engineers are conservative and they design for all the bad cases with workarounds – and then if things go well, they have a very robust and resilient spacecraft. If things go badly, they can recover. So, the reason they lasted so long was a combination of things going well with a terrific resilient design.

Spacecraft design is a very conservative philosophy at JPL against failure that puts in lots and lots of redundancy, lots and lots of the best parts that cost a lot of money, because they want it to work. There's conservatism at every step of the design. I gave you the specific example of the fuel requirements. You don't just estimate how much fuel you'll need, and fill up your tank, and say, "Let's go." You estimate. I'll give you the example of a car trip. If you estimate how much gas you need to get from here to Vegas, you say, "OK, I can make it, and I don't have to stop at the gas station." If there's no gas station along the way, or they're closed, you're don't have to worry because it's only 300 miles. Your tank range is 400, so you're OK. But you're not planning for contingencies of a rainstorm and a flood, and you're going to be washed out, and there's going to be a general strike on all gas stations in the western United States, and no oil deliveries. You might be stuck in the desert with all of these things that would happen to you. And if things go well, you might make it a lot further or feel free to take some interesting side trips. When you're designing a spacecraft, they actually consider all those contingencies, and they design for all the worst cases. In fact, there's a phrase. Not just the worst cases but the sum of all the negative tolerances is put into the mission design. Everything we can think of, we add. We don't just say statistically what's probable, and then try to get the mean average of them. We take all the negative tolerances, and add them up. You get a very, quote, "over-designed" spacecraft. The value of that is it can do lots of things once it's up there, including going on to further planets, and lasting a lot longer. That's number one. Number two is that you also program the spacecraft with a lot of, "If this happens, that happens, this and this and that. We'll do a test on that." It can take corrective actions in its own programming. Very often, sometimes the ground is involved with that; sometimes not. But there's a lot of that that goes into it as well.

ZIERLER: Lou, what about the—?

FRIEDMAN: Redundancy and conservatism is in there.

ZIERLER: What about the enlarging or the arraying of the Deep Space Network? I was under the impression that it needed to be improved because people were thinking about how far out, including to interstellar space, the Voyager spacecraft were going to go. But it sounds like what you're saying is that's not necessarily the case.

FRIEDMAN: As far as I know the DSN improvements were driven by having to serve more missions and having to reach deeper into the solar system. Nothing I came in contact with said that interstellar space requirements were driving it. The Deep Space Network was enlarged in a lot of dimensions; one in the number of antennas. A lot of that was just due to traffic. There's a lot of things up there, so you needed more antennas to do the coverage. Increasing the data rate capacity was also a factor. That had an enlargement that had to do with frequency. When I started, we were working at L band, which is UHF, roughly. Then they went up to S band communications. Then while I was working on Venus-Mercury, they wanted to experiment with X band, a higher frequency, so you could get higher data rates from further distances. Now, they're up to K band and Kᵤ band, I guess. You keep improving the electronics and the frequency thing so that you can get more data from further distances. We could not get Voyager data if we were limited to the DSN that did the Mariner Mars missions in the 1960s. We're now using X band communications on those. Servicing spacecraft at greater distances was important, but I don't think interstellar distances were considered.

ZIERLER: Lou, let's move on now to the different trajectories and different launch dates of Voyager 1 and Voyager 2. What was the decision-making on that? Why Voyager 2 first, and why would one be faster than the other?

FRIEDMAN: I'm not good on that. I wasn't part of that, and I don't remember. Sorry.

ZIERLER: That's OK.

FRIEDMAN: I'm not even sure I was involved enough in it to have fully known even, so I'm not sure if it's a failed memory. [laugh] or that I just wasn't involved. Remember, I got off the mission development before it became a project, and before it got its Voyager name.

ZIERLER: As you joked before, some things were above—

FRIEDMAN: I know the launch dates, of course, were dictated by the celestial mechanics. But you're asking me about—and I did hear an explanation of the Voyager 2, Voyager 1 naming— I think Voyager 1 got the designation because it got to Jupiter first. Even though it launched second. , Voyager 1 gets to Jupiter—

ZIERLER: Voyager 2—

FRIEDMAN: I have to go back and look. It has something to do with their arrival times as opposed to their departure times—I think.

ZIERLER: Now, as you joked before, there were certain things that were above your pay grade. Where were you? In other words, how many levels were between you and Ed Stone, as project scientist?

FRIEDMAN: An infinite number because he was in another world. I wasn't on the science team, I was in the mission development. Furthermore, I don't think Ed was on board, while we were working the pre-project development. I was in a group known as the Advanced Projects Group, which means we didn't work on any projects. We only worked on things that were going to become projects. We were in a mission and system analysis division. JPL is a matrix organization with technical divisions and people in various disciplines, which were then pulled out to work on projects and programs. While doing the pre-project development, in addition to my group and section, I worked for the study or program leader, and they in turn worked for Assistant Directors. There was a chain, but it was only 3,4 or 6 levels or so. Remember I told you I went to work on the fuel requirements for the navigation for Voyager?

ZIERLER: Yeah.

FRIEDMAN: That was an ad hoc assignment. It wasn't my group's responsibility. That was actually with the project (study) team, and I had to go work for people in another section who were doing the mission analysis, because they were working on the project. That is what you do in a matrix organization – work both in a line management of technical specialties and on a project or study team with program organization.

ZIERLER: Lou, what do you think the value was? Obviously, it worked, so there must have been a value in Ed's role sort of separate from all of this matrix structure coming from Caltech. How did that work so well?

FRIEDMAN: It's tremendous value, but it's a value that goes along—it's always about people. You can talk about reorganization and organizations all you want. It's the people and their working relationships that are the key. The function of organization is to allow those relationships to be productive. Ed was a great project scientist working with some great people both in other science disciplines and most importantly with the engineering teams designing and building the mission. In all of these other positions, and they worked well together. If they had appointed some jerk as a project scientist, which I can't imagine, or he had somebody who was just stupid to work with, it might not have worked out so well, but that wasn't the case. I do sing the praises of both Ed and the science teams, and Bud Schurmeier. John Casani, Charlie Kohlhase and the engineering teams. The management was excellent and of course there are thousands of people supporting all aspects of the project – technical, scientific, administrative, communications, etc.

ZIERLER: It's really because Ed is such a phenomenal person that made it work?

FRIEDMAN: Yeah, that's right but not Ed alone. Bud Schurmeier was a phenomenal person. He is the one who made the mission happen – he and his teams: spacecraft and mission. Ed without Bud wouldn't have done anything, and Bud without Ed wouldn't have [laugh] achieved the great results. But either of them without the support of the rest of the teams would also have not been able to do it alone. Voyager has many heroes. None, more than Bud Schurmeier.

ZIERLER: As you emphasized at the beginning of today's conversation, it's a team effort?

FRIEDMAN: Right.

ZIERLER: Lou, for you, during these years, was Voyager your exclusive work? Were you doing other things at JPL?

FRIEDMAN: Oh my yes – as I explained I was in advanced projects, always doing new things. I was a temporary assignment to Voyager, remember? First of all, I'm in the advanced projects group. Within six months, I think, it becomes a project or gets the go-ahead, and we're not involved anymore. I'm still on this temporary assignment doing fuel calculations, but it's not my main thing. Then what happened, I get an assignment. The division manager calls me in, and he says, "Voyager's going to have something new that we've never done on the spacecraft before called optical navigation." Typically, we determine the orbit by radio, getting doppler and ranging data from the spacecraft, and tracking it with the DSN. The data is processed and the orbit determined. For deep-space, this might be less precise as distances get larger. And spacecraft imaging was now getting good, so that imaging the planets against a star background could give another precise measurement of position. This optical navigation data had to be incorporated.

Whose job was that – that was both a technical question and an organizational one. A committee was formed to deal with that question - the Approach Guidance Science Imaging Committee with representatives from the different technical division. I was asked to represent our division – the mission analysis division with the objective of winning the argument – that is to place us as the lead in optical navigation. This is a long answer to your question – I am working on the Voyager project – actually the pre-project development – but I am working for my line management, and Ed Stone is not yet on the scene – at least this little part of it. And then, I started on other advanced mission development concepts. In particular, I was asked by Roger Bourke to take over (from him) working on the Venus Radar mapper mission study. It was actually managed by NASA-Ames Research Center, with two industry contractors. Ames asked us to take charge of the contract monitoring – which I did. That was a silly mistake by Ames – because it put JPL basically in charge of running the mission studies, and within a year we took over the project development entirely. I became the study lead, working closely with the radar group at JPL – Walt Brown, Rolando Jordan and Tommy Homson. So you see I am completely reassigned away from outer planets to Venus and to a whole new science idea. The idea of using a radar technique known as synthetic aperture to actually create images of planetary bodies was new, and it was controversial – not all scientists bought into the idea of interpreting such images for scientific data. So JPL hires this guy, a scientist, and he is assigned to work for me on the radar mapping study as our study scientist. Charles and I sign up for a course at UCLA on synthetic radar imaging and we took it together. He understood it, I pretended to. But being a good study leader, I renamed the project Venus Orbital Imaging Radar (VOIR) with the double entendre of the acronym and French verb "to see". Or perhaps triple entendre, since it was pronounced voyeur.

ZIERLER: [laugh]

FRIEDMAN: There were two issues that I think dominated our study – one science, on engineering. The science issue was the interpretability of radar data as images. The military was doing things like that, but it was classified and the NASA community had no insight as to whether geology was really being studied with radar imaging. Gerry Wasserburg, here at Caltech, headed one of the chief science advisory committees and he was very skeptical. I remember us presenting to him – with difficulty. The other issue was the circular orbit requirement. That took a lot of energy for orbit insertion and made the spacecraft bigger (more propellant). But I held firm to that because the science interpretability would (we were told) be harder with an elliptical orbit, with varying distances orbiting the planet.

ZIERLER: What was the outcome of that work? What were some of the lasting legacies?

FRIEDMAN: A complete success – all battles won – until the war was lost. VOIR moved ahead in its development and became a NASA project proposed for a new start in the GY81 or 82 budget. Then in the 1980 election happened. —what year did Jimmy Carter win? 1976.

ZIERLER: He won in '76; started in 77.

FRIEDMAN: It was in the '76 run-up to the '76 election. No, it is when he was running for re-election against Ronald Reagan. Campaigning during a stop at the Burbank airport, Carter promises the new start for VOIR. But Carter lost, and the Reagan administration not only cancelled it – but threatened to cancel planetary exploration altogether. This is what led to The Planetary Society, a story for later. So JPL did what they had done on Viking, on Voyager, and on Galileo – when the program is about to be cancelled because of money, the Lab comes up with a lower cost option. In this case it was the smaller spacecraft doing the elliptical orbit. Hats off to Charles Elachi – by this time there was much more confidence and demonstration of the value of the synthetic aperture radar data and its interpretability for real geology. The project was re-cast as Magellan, a very successful and productive mission which flew later in the 1980s.

ZIERLER: Lou, let's go back to Voyager. Where were you for launch? What was that day like for you?

FRIEDMAN: I surely wasn't there, '77. I was involved with other things at that point, so I was a spectator like everyone else. Remember I had moved off Voyager studies around 1972 or so, had done the Venus radar study, had developed orbit tours for what became the Galileo mission and had begun the Halley Comet solar sail study. So I was distant from it.

ZIERLER: It wasn't a really big deal to you, either the first launch or the second launch?

FRIEDMAN: No, I was interested of course, and it was exciting – it was a big deal historically but not in my daily routine. For that I was a spectator. It wasn't my project. I didn't have any ownership to it. I'm very proud of the little bit of contribution I made in the early days. Its significance was not lost on me. And over the years I have had a lot to do with the encounters and results of the mission. If they have a party of the 50th anniversary or something, I'll show up, and say, "Yeah, I was a part of it." But it's not my project, a small part. Galileo, Magellan and Mars Pathfinder after Voyager were projects I felt more a part of and whose launches did emotionally sir me. The launch of the Magellan mission, I did, because I was a leader of its development, and I remember that launch. I remember standing down at the Cape, and having an emotional feeling about that launch because I helped make this mission happen. I did feel that on the Magellan mission. Galileo similarly.

ZIERLER: What years were you most involved with Magellan?

FRIEDMAN: But I was not involved with Magellan. [laugh] I was only involved with the pre-project to it when it was VOIR. Right. But that was the early to mid-1970s. But, back to your question, I had already been so involved in the pre-project for Galileo Jupiter Orbiter Probe. I was much more involved with that than I was with Voyager. I did a lot of the orbiter work on that. Much more involved with Galileo. It was called Jupiter Orbiter Probe in those days. In fact, I think it was called Mariner Jupiter Orbiter briefly too. I was heavily involved with that in the '74, '75 timeframe. Then I became involved with Halley Comet solar sailing. I jumped around, which is what you do in an advanced projects group. You made a big deal about my involvement in Voyager, but I don't want to overstate it. It was just what I said it was. On Jupiter Orbiter, I was much more deeply involved, both in coming up with the orbit designs to encounter the different moons and to move the orientation around. I also was more involved in other gravity assist studies – swinging by the inner planets for targeting future encounters. The Jupiter orbit tour work (which became Galileo) was particularly exciting because it brought possibilities to the science team that they had not thought possible. Jim Van Allen in particular named our mission design option the flower orbit because he liked the idea of the petals going in all four quadrants of the heliosphere of Jupiter. I was very involved with him and the science team on the Jupiter orbiter design, much more so than I was in Voyager.

Exploring Jupiter

ZIERLER: Now, the Jupiter Orbiter design, how much was it influenced by what was assumed Voyager would do? Was it looked at as redundant? Was it looked at as in partnership? How did that work?

FRIEDMAN: Neither – it was a follow on, Voyager was a reconnaissance, Galileo went back to explore in more depth. This is true throughout planetary exploration – first we had flybys of Mars and Venus and then followed them up with orbiters. Same with Mercury, and later with Saturn. And, in the case of Mars and Titan, even with landers.

Voyager' flew by the Jupiter and Saturn systems in five days – quick passes by the planets and their moons. The Jupiter Orbiter spent months and months with lots of observations doing lots and lots of things in a lot more detail. It's a horse of a different color. It's a spacecraft of a different generation. It was a technique. Everything about it was a different generation. I go back to the Mariner example, the first flybys of Mars. Those are interesting, but they didn't really reveal much. It was the orbiters that started to reveal, say, Jupiter. Voyager was wonderful. It did reveal some things. But it was the Jupiter Orbiter mission, the Galileo, which did it in depth.

ZIERLER: So I'm connecting all the lines correctly, Jupiter Orbiter ultimately becomes Galileo, or Galileo subsumes Jupiter Orbiter?

FRIEDMAN: It was called the Jupiter Orbiter Probe mission. It was going to be an orbiter of Jupiter, and deploy a probe into the Jupiter atmosphere. The orbiter of Jupiter would visit the moons of Jupiter. That became the Galileo project. Galileo was what the Jupiter Orbiter Probe was named. NASA made a lot of crazy compromises with the Jupiter Orbiter Probe. Again, first of all, why would you have the orbiter and the probe on the same spacecraft? Why wouldn't you have a probe mission and an orbiter mission? Money. Do as much as you can because you'll get the opportunity to do it just once. You don't get the opportunity to do it every year or every five years. Also, Jupiter Orbiter itself had to be designed to be a high-resolution imaging of Jupiter atmosphere and the moons, and it had to be particles and fields measurements of the whole environment around Jupiter and the magnetic field and the large heliosphere and all of that. Different spacecraft requirements; totally different spacecraft requirements. The camera wants to be pointed precisely at the fields and particles. It wants to look all over the place. What did NASA decide? JPL didn't like this decision. "OK, we'll do both. [laugh] We'll have an inner part that looks, and another part that spins." There was a lot of give and take on those kinds of decisions, but they did it, and it worked.

ZIERLER: Lou, in the early days, what were the science objectives for Jupiter Orbiter? What were the most important things for it to learn?

FRIEDMAN: Again, you have a science team composed of a few dozen people, each with different objectives and disciplines. There are the fields and particles folks who think plasma physics is the most fundamental thing to study in the Jovian environment. And there are the planetary geologists who want to look at all these new worlds and see what surface and interior processes might be going on there. And there are spectroscopists who want to measure the composition. Each thinks theirs is the most important, and each is right. At Mars you have the life question as the most fundamental. But at the outer planets and their moons you have many objectives, and it was up to Ed Stone to balance them and up to Bud Schurmeier and the mission team to figure out just how many of them they could accomplish. Scientists would argue, sometimes violently (figuratively!) until as Bruce Murray liked to say, they were in violent agreement. You asked what was the principal objective – discovery! Everyone expected that we would discover new things, the moons were new worlds, the heliosphere was huge, the interaction of the fields and particles with the moons affected everything. Discovery was the objective, and it was fulfilled. Voyager transformed those bodies from names that were nothing more than dots that people knew because they looked at them with Earth-based telescopes, to actual worlds that had dynamics on them—a volcano on Io; an ice field on Europa, covering up a heated ocean; ice and craters on Ganymede—all these things that were different, and different interior processes that are changing these worlds, and changing our view of planetary evolution. That became a very high objective for Galileo – study of the moons. The repeated encounters with the outer planet moons was a very high priority. Now, here's where my field comes into play, and I feel some pride in this. Those repeated encounters, if you just said the mission objective is to go to Io, Europa, and Ganymede three times, two times, and do this over the course of a year, we can design a trajectory that does that. But that trajectory also changes the orientation of the orbit every time it does those things, so you control that too. Now, that gives you a two-fer, you satisfy the heliophysics and you satisfy the geologists. That is good for the specialists, but of course, everybody cared about everything. The mission design process was very exciting.

ZIERLER: Lou, just looking at the timeline, you're working in Jupiter Orbiter in the mid-1970s. Galileo doesn't launch until 1989. Why the delay? What took so long?

FRIEDMAN: Ask Ronald Reagan.

ZIERLER: [laugh]

FRIEDMAN: The delay is all political and launch vehicle related. Reagan's the guy that came in, and said, "Let's cancel the planetary program, and put all our money into building the Shuttle." To be fair, I doubt Reagan really said or even thought that – his people did, including his science advisor and the NASA top management. Galileo intended for a Titan launch vehicle had to wait for a shuttle readiness because the U.S. decided to put all eggs in the not-yet-built-but-cost-overrunning shuttle. And the shuttle readiness, once scheduled for 1981 was delayed and delayed. And, by the way, every time there was a launch vehicle shift it had an effect on the spacecraft, so that had to be accommodated. The shuttle delays and the huge cost overruns demanding more from the NASA budget were why during the 1980s there were no new planetary missions started and why the only launches were the two missions left over from the 1970s.

ZIERLER: Absent these budgetary challenges, how soon could Galileo have launched? When would it have been ready?

FRIEDMAN: I think we intended it for launch and it was on track to launch in '84, I think. Maybe even earlier.

ZIERLER: By the time you left JPL, you were confident it was on that trajectory to launch in '84?

FRIEDMAN: No, remember, I left JPL because we saw the looming crisis in planetary, so I wasn't confident of anything. We were working on that.

ZIERLER: Do you think the delay was beneficial at all for Galileo? Were there any technological developments that made it a more successful mission in the delay?

FRIEDMAN: I don't know that. No, I don't know. I doubt it.

ZIERLER: Lou, let's go back to the Venus—

FRIEDMAN: I never heard that.

ZIERLER: Let's go back to the Venus Orbiting Imaging Radar. I asked about science objectives for Jupiter. What were the science objectives for Venus at that point?

FRIEDMAN: Oh, that's very interesting, no question about it. First, look at the surface of Venus. Nobody's ever seen the surface of Venus. It is cloud shrouded. Every telescope picture from Earth shows nothing but clouds. The idea was to see the surface of Venus. You can't do it optically because any camera will only see clouds.

ZIERLER: This is true for Mariner, obviously?

FRIEDMAN: Huh?

ZIERLER: This is true for Mariner? Mariner didn't get through at all?

FRIEDMAN: Mariner 5 had no camera at all – it would have been useless. Mariner 10 had a camera, but it was for Mercury. It did photograph Venus and did see the clouds shrouding the planet. Pioneers sent atmospheric probes through the atmosphere to get pressure, temperature and composition information – no pictures. Now, the Russians were beginning to get pictures of the surface, and that's another whole story. But, the Russians (actually the Soviets) did get images on the Venus surface with their Venera landers, and they even had an imaging radar before we did. This was a surprise. But you didn't ask me that. You asked me the purpose of the Venus Orbiting Imaging Radar. It was to image the surface with the synthetic radar aperture orbiting the planet. Now, radar imaging was not a technique that was known, but primarily to the military for all-weather ground imaging. It had not been used in scientific studies for geology. It was not straightforward to produce an interpretable image. There were disagreements about whether radar imaging would be interpretable. There was no purpose to the mission if it was not.

ZIERLER: How do you do that without actually doing it?

FRIEDMAN: A lot of simulations, and some access to the military experience imaging Earth. Then, of course, there was some classified data around. There were companies – there was knowledge in the industry. I mentioned this company in Michigan that was doing Defense Department work on radar imaging, and they had information and data and some results they could share. Charles and I visited them. Gradually, you got enough research behind it that scientists were convinced.

ZIERLER: Lou, what kinds of radar were considered for Venus? What are the options available?

FRIEDMAN: That's a good discussion to have with Elachi, not me. He was the scientist. As I told you, synthetic aperture radar, that was it. That was the technique. The synthetic aperture is created by the relative motion of the spacecraft over the surface. The big tradeoff was circular vs. elliptical orbit – the latter less of a demand on the mission, but since in the elliptical orbit the altitude varies while you are creating the synthetic aperture it is a harder computation problem for the instrument. We wanted circular – but when the mission was in danger of being cancelled because of being too costly, the scientists figured out how to accommodate the elliptical orbit therefore lowered the mission cost. That was Magellan – and as you know, it gave terrific results.

ZIERLER: Lou, you mentioned that there's a Russian aspect to the story about Venus exploration. What was it?

FRIEDMAN: At that time Russia was the leader in Venus exploration. Venus was Russia's planet, and Mars was the American planet. The Russians had never succeeded with a mission to Mars, and the American missions to Venus were smaller than what Russia was doing. As we had landed on Mars, they were landing on Venus. The radar mapping was something we thought would give us a major step forward in Venus exploration (first mapping of the surface) and we did not expect the Russians had the sophisticated electronics to do that. But they did. They too adapted their military radar satellite experience to produce synthetic aperture radar missions in before us. I think their mission launched in 1983 – Venera 15. It was a surprise. I had a personal experience. Venera 15, their radar mapper, was due to go into orbit in October 1983. I was at an International astronautical Congress meeting, where the head of their mission and head of the Institute doing the mission, Vladimir Kotelnikov, was to present a paper about the mission. One of the translators comes up to me, and says, "Mr. Kotelnikov is embarrassed by his very poor English. He can read the papers written in English, but he doesn't want to deliver it because he's embarrassed by the way he speaks." I said, "OK, you can do it." He said, "He is asking you to do it because you understand the technical material. He knows you've been doing the Venus Radar Project." I thought that was interesting. I'm still young at this point, and he's the head of the institute. He also knew I had been to Russia at that point. I say, "Sure, I'll read his paper. Why not?" So, I go up to him, and we shake hands. Then, casually, I say to him, "Your spacecraft is going into orbit tomorrow," because we knew this. We have trajectory calculations. It's all determined by celestial mechanics. There was no mystery to it. But the Russians at that point never would give the dates of their spacecraft until after they had occurred. This was Soviet times, all very closed. I said, "How is the spacecraft doing? Is it ready to go into orbit?" He says to me, "I don't know anything about that." I said, "You don't know the spacecraft's going into orbit tomorrow." He says, "No, I didn't know that." He's lying, of course. [laugh] He's the head of the institute whose spacecraft is going into orbit around Venus the next day. But, at that time, they wouldn't say anything. But, no, they did, and they had a surprisingly good result. The Venera mission's radar data wasn't equivalent, it wasn't as good as our ultimate Magellan data, but it was many years before that. It did produce some basic radar images. They saw the surface of Venus. This was, by the way, the last such Soviet planetary mission in the closed society. The next one was their VEGA Halley Comet mission under the direction of Roald Sagdeev who was opening up the Russian space program just as Gorbachev was opening up Soviet society.

ZIERLER: Lou, more generally, did you feel the Cold War at JPL? Was that in the air?

FRIEDMAN: Yeah, I guess, sure. The Soviet-American competition in space was in the air, for sure, and some of that's Cold War, I mean, it is Cold War. I think the answer would be yes. JPL had people who were working on Cold War aspects, secret projects to understand what the Soviets were doing, and so it was there, sure. But it was also normal scientific competition – everyone wants to be first and best, whether competing with enemies or competing with friends.

ZIERLER: Without getting into any sensitive details, were you involved in—?

FRIEDMAN: I can't because I really wasn't involved with sensitive information – at least from a national security perspective.

ZIERLER: But were you aware that JPL had military clients beyond NASA?

FRIEDMAN: I knew of the so-called secret group that was monitoring Soviet stuff, but I didn't know much about them. I knew some of the people, but I didn't know what their work was. Vaguely, I knew what their work was, but I didn't have any interface with them or anything like that. My Cold War involvement preceded JPL (at AVCO) and followed it (when I got involved with Russian space program stuff at The Planetary Society).

ZIERLER: Lou, we've talked about the solar sail concept but not chronologically. When does this begin? When do people, including you, seriously get to thinking about it?

FRIEDMAN: We are chronologically at it now – after my work with Jupiter and Venus orbiters and after I left the technical division, Advanced Projects Group, and moved up to the Advanced Programs office. I do jump around in my memory a little, but bear with me while I try to get these things right.

ZIERLER: Sure.

FRIEDMAN: I told the story of how the Halley Comet Rendezvous opportunity was identified by Jerry Wright and how it became a subject of study in our Advanced Projects Group. This is in 1974 or 5. I moved up to the Program Officer, and Bruce Murray moved in as Director. By the way I tell the story of our JPL solar sail program in my first book, Starsailing: Solar Sails and Interstellar Travel. Which undoubtedly you have read. [laugh] Things come together in strange ways technically and socially or programmatically or whatever you want to call it. We got this technical idea that comes out of the blue here, with an obscure engineer in Ohio, and then we have another cultural phenomenon that comes in named Bruce Murray, and he's the director of JPL. He's yelling at his management, "Everything you're doing is nothing but a bunch of gray mice. What we need around here is purple pigeons."

ZIERLER: [laugh]

FRIEDMAN: They all go away, and say, "What did he say? What did he mean? Purple pigeons are things that you notice that really make a difference, that look attractive, that are exciting. Gray mice are dull and uninteresting, you don't even want to see them. He was trying to tell us this. The management runs around, and forms a purple pigeon committee. [laugh] I think they must have called it something else. They get people to lead various studies of exciting new ideas that are out of the box, like a mission that can orbit Saturn, and send a probe into the atmosphere at the same time, and land—and that became Cassini. Then there was a mission, I think. I think maybe one of the outer planet missions came up in this category too. I don't remember them all. Oh, Mars sample return was there; a Mars sample return with a rover on the planet at the same time. We haven't done that yet, but we keep working on it. But that was another one. He hired somebody in the art department that drew beautiful pictures of these things. The purple pigeon art is around.

I was in the middle of this – I was an Advanced Programs Leader and we were figuring ways to make these purple pigeons fly. And of course I had one of my own -- this Halley Comet solar sail. Somehow, I was made in charge of these purple pigeons, and that purple pigeon became my purple pigeon. We began working on it with a significant spacecraft development team. It was a significant effort, with a lot to learn – the whole of solar sailing was new: the sail, the dynamics, the spacecraft, and its control. We had dozens of people on our team and we brought in outside experts who had studied various aspects. And of course we began marketing it to NASA. This is 1975, maybe '76 too, I think. Yeah, I think it was.

ZIERLER: Lou, were people talking about the solar sail concept before the realization that Halley's Comet was coming into the solar system?

FRIEDMAN: The people who were talking about it were not anywhere within NASA or JPL. It was an idea, and there was some literature on it. The idea goes back to the 1920s to two Russian scientists Friedrich Zander and Konstantin Tsiolkovsky. They are the first to think of it as a propulsive force for space flight. Even before them in celestial mechanics the effect of light pressure on celestial objects was known and calculated. Then in the late '40s and early '50s, a couple of American engineers did papers on them, the first one being published shed in Analog Science Fiction magazine because they project was so way out, [laugh], even though it was a technical paper. Then in the late '50s, it got up to the level of academic papers, research papers. But in the space program, it took the idea that you could deploy things in space before it started getting any study in NASA.

ZIERLER: What does solar sail accomplish that other kinds of propulsion cannot?

FRIEDMAN: The chief attribute is it doesn't require propellent, so you don't have to carry any expendable mass. No propellant, no fuel, no motor - like a sailboat. What's the advantage of a sailboat over a powerboat? It doesn't have to have a motor. It doesn't have to have gas, and it's beautiful. It's romantic. But that's not enough for a space mission, but it is nice. It does attract attention. But it basically doesn't require propellant. It uses only external free fuel, the Sun.

ZIERLER: Is this the same kind of technology we would see in solar panels on our roof?

FRIEDMAN: No. Solar panels on our roof, and solar electric propulsion is converting light to electricity through a thermoelectric power converter of some kind. And then you have to use that energy to run motors or heat water or heat propellant – a lot more complicated. The solar sail uses the sunlight directly, the momentum of the photons of the light itself; the transfer of momentum. Light has momentum. Not obvious to everybody because it's made up of photons, which are zero mass particles. But light has momentum, and we don't feel that momentum here on Earth because we have too many other forces around us. It is hard to demonstrate on Earth. But light in a vacuum will push something. Laser can obviously push something. Sunlight can push something. But, in the absence of gravity, it'll just push it outward. Solar sailing is done by the reflection of light off a mirror or a very thin mirror that pushes the object along, and that's how it gets its propulsion. Solar electric converts that sunlight in solar cells to electricity, which then runs an engine or lights a propellant or does whatever it does. On your roof, it will convert it into electricity, which runs the grid in your house.

Comets and Solar Sails

ZIERLER: Why Halley's Comet? Why would Halley's Comet be so relevant for solar sail technology?

FRIEDMAN: This is an accident of history. Comet Halley is the most famous celestial visitor of all human history – literature, art, science…. And its coming "now"; that is, in the 1980s just as we are learning to explore the solar system. For the first time in human history we don't have to be mere observers, we can go exploring. But it comes into the solar system backwards – going around the Sun in the opposite direction as Earth's and all the planets' motion. It is beyond the reach of conventional propulsion (rockets and motors) but with the solar sail having an unlimited energy source we can slowly stop our positive orbital direction and match that of the comet and go rendezvous with it. It takes an impossible idea, and makes it an engineering project. While solar sailing can do lots of other things, everything it can do in the solar system, more or less, can be done with rockets and propulsion. The Comet Halley rendezvous was unique – solar sail was, we felt, uniquely enabling. And, as I mentioned earlier, the comet is a most interesting celestial object – a once in a lifetime visitor and opportunity for exploration. It looms in our literature since the Middle Ages. It's on the Bayeux Tapestry hanging in some church in Europe, in Bayeux. It was the prediction of doomsday to people, even before then. Mark Twain wrote about it in famous books. Everybody knows Halley's Comet. It's the biggest celestial event of a person's life. And now for the first time we can explore it -- Everyone expected there would be space missions to the comet, but here we had a chance to rendezvous with it. This very purple pigeon became a high priority for Bruce Murray.

ZIERLER: [laugh]

FRIEDMAN: This is the purplest of purple pigeons. That lit up Bruce Murray, every part of his body, and he said, "That's the one." He put a lot of emotional and organizational energy into that. He got into it personally.

ZIERLER: Why? Why is the rendezvous so enticing?

FRIEDMAN: Comets are primordial remnants of solar system formation. Studying them up close is a way to explore the very origin and evolution of the solar system – a key problem for astronomers and planetary scientists. A rendezvous gives an opportunity for serious study, much more than a fast flyby with only minutes of close-up observations. In addition by flying with the comet it is possible to study its dynamical behavior and the composition of the materials that are blown off of it as it comes closer to the Sun. And as I mentioned the sail unique trajectory inward toward the Sun then going around the Sun multiple times to raise the orbital inclination and flip the plane of the orbit over to allow the spacecraft to match Halley's orbit going backward through the solar system enabled the rendezvous previously thought impossible. But reality overtook the promise. As I mentioned, Bruce Murray, the Lab director, got very involved personally in presenting this to NASA – and he and I both went to Johnson Space Center to meet with their director, and then to NASA HQ to meet with the Associate Administrators for Space Science. They loved it, and then we got what Bruce aptly named the "kiss of death." NASA had a huge Solar Electric Propulsion program and their management was furious at this new idea coming in and saying we could do something they couldn't. They demanded equal time, and so NASA, while telling us to go forward with the sail, set up a parallel study with Solar Electric Propulsion and arranged for us to come back within a year for a "shoot-out." Sounds fair – but in fact it was a way for the bureaucracy to bury us. The huge investment in SEP was going to dominate – anything they designed would be unprecedentedly large, massive, with giant engines and power converters – everything they already liked building. Now, not only were we trying to make a new mission happen – the Comet Halley Rendezvous, but we had two huge technology efforts battling, one with a constituency and us from "not invented here." I came back and told my team – if they win, Halley's Comet will lose. And that is what happened. They won, and within a few months the whole project was terminated. Now, let me admit the real truth – we were too audacious for our time. Everything about it was way beyond anything we could do, even now. It was a solar sail that was equivalent to a half-mile on a side. It was an enormous solar sail. [laugh] Then we came up with this design called the helio-gyro, which was even larger. But even that did not matter – we needed a shuttle launch in 1980 or 81, and the shuttle was not ready.

ZIERLER: [laugh]

FRIEDMAN: My friend Ken Atkins. Who you may recall was appointed by me to be the Group Supervisor when I left our Group, was the head of the solar electric propulsion comet rendezvous mission. Pete Lyman, a very good guy, was appointed the project manager of the Halley Comet effort, over both Ken and me. When we get together, Ken loves to reminisce with me about it – he won of course, but as I always remind myself, I had said right at the beginning, "Ken, if solar electric wins, everybody loses because it'll never happen." And that was right.

ZIERLER: You saw that?

FRIEDMAN: I did. He goes, "Argh."

ZIERLER: [laugh]

FRIEDMAN: We would have those kinds of discussions. To this day, the bottom line is solar electric won, and everybody lost. To this day, I keep reminding him of that quote. The reality though is that the solar electric program won, and has been incorporated into many missions now at NASA – none anywhere the size of the Halley Comet system which was huge. And solar sailing emerged hated by the bureaucracy for being an upstart and causing waves. Getting its consideration back in NASA has taken decades. And worst of all, the U.S. never did a Halley Comet mission – that is another story.

ZIERLER: Lou, if the engineering was feasible, where else could we see solar sail technology applied beyond Halley's Comet?

FRIEDMAN: That's a good question. The Halley solar sail was really way before its time. The solar electric program was too. Both designs were far too audacious and could not ultimately have been carried out at that time. Besides, as I said, the shuttle wasn't available then anyway. Solar sail propulsion depends on the area of the sail and the mass of the spacecraft. The thrust is proportional to the area divided by mass. It's engineering feasibility will depend on having low mass spacecraft – possible in principle since it does not have to carry propellant or engines. So, where else could solar sailing be used? I used to say that the only thing that made solar sailing special was the fact that it was a low-cost way to achieve interstellar speeds – and the precursor to the only possible way of doing interstellar flight. I think I explained this about two hours ago.

ZIERLER: [laugh]

FRIEDMAN: Now I don't think that interstellar flight is really feasible, but getting through and out of the solar system fast with solar sails is. That we that we could get to the outer planets, and go out at these fast speeds with solar sailing leads to some innovative fast flyby low-cost mission possibilities. I am working on this right now. We also think it is the most practical, affordable way to reach the solar gravity lens focus, a distance beyond 600 AU, and enable using the lens to get high resolution images of exoplanets. The only way to get multi-pixel images. Whereas I used to think it was the pathway to the stars – I'd say it in every talk I gave – I now have gone more deeply into the subject and really conclude there is no pathway to the stars. As I say in my forthcoming book, flying to the stars (and their exoplanets) is a bridge too far. Solar sailing can do other things. In fact, as I mentioned, we're working on a number of missions to do that. There's a lot of mission concepts it can be used for. It could be used for an Earth orbit as a pole-sitter to sit in a particular location and study the polar region of the Earth. A solar sail can hold its orbital position steady offsetting the effects of gravity; not being reduced to having to follow the orbital path. It can go to different points in interplanetary space, and do monitoring missions, again, by holding its position. Solar weather monitoring and heliophysics of the Sun are science objectives. It can also do these fast missions to flyby planets very fast. It's a great way of modifying the inclination of orbits so that you could do a solar polar orbiter much more efficiently than you can any other way. The solar polar obiter is important for mapping and studying the Sun. These are things we haven't done yet. I think there is a solar sailing future now for solar system missions as well.

ZIERLER: Meaning it's feasible now or at some point in the future?

FRIEDMAN: Some now are feasible and the more ambitious ones need technology development. The Planetary Society flew LightSail – so it proved feasibility of a small solar sail. It's still flying up there. The Japanese flew a solar sail, all the way to Venus. Solar sailing is now ready for next steps in development – materials and size of the sail. What wasn't feasible was the Halley Comet design. It was too big; too audacious for its time. Ultimately, it may be, but it was way too audacious; a technological leap that we asserted at the time, and I think it's too big, to take in one step anyway. I think we could do cislunar and even the solar polar orbiter with today's technology. The fast sails to the outer planets should have material that can go closer to the Sun and bigger areas.

ZIERLER: Lou, your work on the Mars program while you were at JPL, could you see a trajectory that made the rover missions in the late '90s and early 2000s? Was the trajectory already there, do you think?

FRIEDMAN: What happened? There are really two stories you asked for here – one is my story while I was the post-Viking Mars leader at JPL and then another story in the 1990s while of course I was at The Planetary Society. You're talking about me and my part in it, right?.

ZIERLER: Of course.

FRIEDMAN: [laugh] OK. [laugh] Let me bring it back to me.

ZIERLER: But your work, I'm saying, your work on the Mars program.

FRIEDMAN: What happened is that the solar sail project ended, as I said. I was still in the Advanced Programs Office under the direction of Jack James and Norm Haynes. and This was 1977, I think—yes—and Viking has landed on Mars. I. What's next? NASA had no idea. Then the NASA administrator James Fletcher is called by the president of the United States, who was Gerry Ford and congratulated, the President says, "Great success with Viking. Congratulations. That was Viking 1 and Viking 2. We admire what NASA does. What are you going to do for Viking 3?" James Fletcher goes, "Oh, uh, mmm, we don't know, I will get back to you on that." It was a great embarrassment. No answer to the president who wanted to know what he can do next. [laugh] Of course, everybody in the bureaucracy is scrambling around. "We got to have answers. We got to do more."

They started a study of a Mars sample return, and they had it done at Johnson Space Center, which is in charge of lunar samples, but not experienced in planetary missions or Mars. NS Johnson Space Center doesn't do robotic missions at all, so they didn't do a very good study. So BASA decides ti do a combined JPL-JSC study, not just of sample return but of many mission candidates that could be the next Mars mission. Orbiter, penetrator, rovers, even a Mars airplane and a novel idea promoted by Jacques Blamont of the French space agency – an inflatable rolling ball to explore the Martian surface. And, then Mars Sample Return. They ask me to lead the whole program. I am told to consider everything. The first thing I do is I get on a plane, and go down to Houston, and I get someone to be deputy manager, and then build a working relationship for a JPL-JSC study team: coordinated, eschewing the internecine warfare. JSC participation was mostly on the sample return science. I then formed different teams for each of the competing mission concepts and appointed team leaders for each. And so, we studied Mars Orbiters, Mars landers/penetrators, the Rolling Ball I mentioned, a Mars airplane and the Mars Sample Return. The airplane was the high flyer [laugh] – a predecessor to today's drones. We had a mini-rover, an adaptation of a CIA spy device, and we even built some prototypes of it and of the airplane. The idea was that we would bring all these studies together and then recommend a menu or options to NASA. And then a little more than halfway through these studies, I get a phone call from NASA – the Associate Administrator for Space Science. He says, "How much of your budget have you got left?" I tell him. He says, "Spend it all quick because you're not going to get any follow-on money afterwards. It's over. We will stop studying future Mars missions. Period." He was right. NASA didn't put any money into Mars for the next half a dozen years. That was the beginning of the dark period, that I mentioned. All money went to shuttle; no money for planetary missions. This was the situation toward the end of 1978 – the future of planetary exploration was in doubt. The Mars program would end as soon as our report went in. (One of the Vikings continued working until, I think, 1981). That was the last job I had at JPL before I took my leave of absence and went as a Congressional Science Fellow to Washington.

ZIERLER: Lou, that's the last topic I wanted to touch on today. Did you look at that time in Washington as your exit strategy? Were you thinking along those lines about policy advocacy, or you thought you would be going back to JPL?

FRIEDMAN: I was pretty sure that I was going to stay at JPL or at least in the space program. But I was casting about. I knew nothing was going to happen in planetary for a while, and I was casting about, well, where's the right place to try to make something happen? Would it be in policy, a political or programmatic area, rather than in technical projects and mission development? Would it be in other kinds of missions? We're all beginning to think about what else was going to be done. But my intention was to come back. For one thing, I had a family here, and I had a good job here. I didn't see myself as a policy wonk, and staying in Washington. Now, everybody who goes to Washington thinks they're going there temporarily, and then some do, but many, many stay on. They get the Potomac Fever, as it's called, and they just stay there. There were probably moments when I thought maybe I'd get Potomac Fever, but I didn't. There was never any doubt in my mind, Then, of course, in the middle or two-thirds of the way of that year is when Sagan and Murray came to me about forming a group and doing things. I was pretty firmly rooted in staying here.

ZIERLER: What did you learn from your time in Washington?

FRIEDMAN: It was a huge broadening lesson – in two dimensions. I learned about space programs I knew nothing about – mostly in Earth orbit, remote sensing especially. I learned a lot about the position of the space program in the national political agenda and public interest. It was important, but it was minor. I tended to think in my small world—and many things to many people. I learned a lot of different aspects of it. Among the things I learned were that space is highly regarded. Space is all good—civil space, anyway. I'm not going to get into the kooky stuff, the Space Force thing. But, civil space, it's all good. There are no negatives with it – it doesn't cause cancer, it doesn't harm the environment, it deals with science and innovation. The only negative might be, for some people, is that it wastes money, it is expensive. But even that isn't all bad, because the money is spent on science and technology and innovation – good people doing good jobs. And stimulating education and creativity. And that is even true when the project itself might be a little misguided or poorly conceived. Space is a positive, and in the political world I learned it was considered positive – Congress people liked to take credit to be willing to fund such esoteric projects. But in the political world, and in popular culture, it may be good, but it isn't important. It does not rise to national issues very often. I can illustrate this with a couple of stories: We were trying to convince a few more congressmen that this is important. One replied: "Are you kidding? If my constituents knew that I supported a $15 billion NASA budget for looking for what Mars and Jupiter are made of, they would vote me out of office. I'm doing that because I'm so smart, and I realize the value of these things. I'm ahead of my contingency. You don't have to convince me. You have to convince the public." That's what I learned is that you have to convince the public (although likely that Congressman was being disingenuous – they are always telling you to get them more support). The other story is that I was once with a colleague arguing what I thought was a strong, rational argument in favor of some planetary mission and the only question the Congressman asked us was, "where are you from?." The point was that no matter how smart or logical we were, we were arguing a special interest – our own projects. I learned to recognize special interest arguments. And like I said earlier, I also learned about many parts of the space program I had never worked in or knew the players involved.

ZIERLER: Lou, as you alluded to earlier, and it'll serve as my last question for today, when you went to Washington, did you gain a deeper appreciation? Did you become more pessimistic about the prospects of planetary science, or that was separate?

FRIEDMAN: I got very negative on it, but that's because I knew what was coming. We already knew there was nothing going on in terms of new missions. While I was there, the Shuttle had the big cost overruns, and was sucking up all the budget. Jimmy Carter doubled down on the Shuttle, making it America's only civil space launch vehicle, and declared there would be no more new "high challenge engineering initiatives." Ronald Reagan's folks were even worse – they were planning to shut down planetary exploration. JPL was being urged to find military work. So I was pessimistic. I was coming back to JPL where my next job was not at all obvious. Now, at this point, I was keeping in good contact with the director Bruce Murray. I would come back on trips, and I would go into his office, and we'd talk, and we'd talk about the political situation with regards to planetary programs. I wasn't worried about starving in the street. But, on the other hand, I didn't know what my job was going to be. There wasn't anything obvious what I was coming back to. During that year, I got the idea in discussions with some other scientists of creating something I called the Halley Watch. Again, Comet Halley was looming. Bruce Murray was making a big political effort to now do a Halley flyby mission, and get JPL at least to do that much. That was his undoing as director of JPL. That's another whole Caltech story for you, which I don't know if you'll get into or not.

ZIERLER: [laugh]

FRIEDMAN: You'll have to interview Murph Goldberger. Is Murph Goldberger still alive?

ZIERLER: Unfortunately, no.

FRIEDMAN: Oh, I guess they're all dead. I'm the only one alive that knows the story. No, that's not true. I know people who know the story. But that whole Halley Comet brouhaha, Bruce was pushing on that. I got the idea of an international Halley Watch, which I thought would be something we could use to promote a US Halley's Comet mission. That's ended up being the job that I figured out for myself. When I came back to JPL, I became leader of this new program called the International Halley Watch. Are you going to get into that whole Halley Comet story?

ZIERLER: Sure.

FRIEDMAN: With who?

ZIERLER: As much as I can get from you, and I'll learn more about it from others. I'll have to see.

FRIEDMAN: OK, yeah, because it's interesting. The idea I had was to coordinate the space agencies who were doing Halley Comet missions – Japan, Europe, Russia. And promote the idea that the U.S. should also be one – not left behind. And to bring to bear the vast amateur and professional astronomy communities who would be observing the Comet from Earth-based telescopes. And to use all this coordination to improve the knowledge and tracking of the comet, to help the Europeans and Russians navigate to their close encounters. My discipline of celestial navigation made me see the advantages of coordinating observations and navigation information. So, I came back to JPL and started the International Halley Watch – with comet scientists. Ray Newburn at JPL, Jurgen Rahe in Germany—who later came to NASA. As to the politics of getting a Comet Halley intercept mission, remember, now that I'm left JPL in 1980, and a lot of that Halley political action on it was in the '82, '83 timeframe, so you have to get people who were around during then at JPL and Caltech. I was involved in Halley politics with The Planetary Society, but not inside JPL – and Bruce and I were quite rigorous about not mixing the two – not letting The Planetary Society be a JPL arm. There were some crazy politics in connection with the Halley mission and the Reagan administration saying "let the private sector do it," but the inside stuff in NASA and JPL you haver to get from others.

ZIERLER: Lou, in our next conversation, we'll pick up where we've left off in our first conversation, the origin story of The Planetary Society, and that interesting conversation you had with Bruce Murray.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Thursday, October 27th, 2022. It is great to be back with Dr. Louis Friedman. Lou, once again, it's great to be with you. Thanks for joining me.

FRIEDMAN: Thank you. Glad to be here.

The Origins of the Planetary Society

ZIERLER: Lou, today we're going to pick up right where we left off last time, the origins of The Planetary Society. If we could zoom out, it's something we touched on in our earliest conversation but I think it bears a little more explanation here, and that is if you can explain how after all of the excitement and success of Voyager, really capturing not just the American public's imagination but the world's imagination, how is it possible that following that success, NASA was not at the ready with a string of new missions to build on planetary science in the solar system? How could that be the case?

FRIEDMAN: How could it be? [laugh] That was basically the topic that Bruce Murray and Carl Sagan would talk about when they were s meeting while Carl was on here with the Voyager imaging team and working on Cosmos. But first let me more precise – the comment I made earlier about NASA not being ready to discuss future missions was in the specific context of President Ford's congratulatory phone call toe NASA Administrator Fletcher. It was "only" that he wasn't prepared to talk about a future Mars missions, since Viking had just landed and no results were yet known. After Voyager, the scientists both in and out of NASA knew what they wanted to do – and were working on what became Galileo and Magellan, and other missions were being studied. But the Administrations of Presidents Carter and Reagan we intent on building the shuttle and funding little else in NASA – so the budget decisions were being made to cut planetary. It wasn't that they didn't know what to do – it was the politics of the budget. And Sagan and Murray were discussing that – which is what eventually led to forming a public interest organization. Sagan had moved to Pasadena – temporarily while working on Voyager at JPL and Cosmos at KCET in Hollywood. He and Bruce would meet quite frequently, and that's the question they posed. Here's Voyager, and here's Viking, and such interest in Mars and the outer planets, and NASA's is being told to cut back or even stop planetary missions. There's a subtle factor at play. Viking didn't discover life and, in the minds of some, that was a disappointment. We know better now. We know better [laugh] than, "Oh, gosh, there's no giraffes walking around, so that must have been a lousy mission."

ZIERLER: [laugh]

FRIEDMAN: But that was the mindset on the part of some of the, shall we say, more simple-minded political thinking of the day. There was strong evidence of popular support in the media, but stronger evidence of little political support. That is one dichotomy. Then there's another disconnect, which is the NASA interest and the science interest. NASA has been highly dominated by human spaceflight, and it was formed because of human spaceflight. The current program has no objective, just to spend money. But the public perception of NASA is its greatest achievement – ten years in the past then, 50 years now. It was human spaceflight – Apollo. The way to break through these dichotomies, to build up public interest, and to get out the message that NASA is exploring new worlds is to form a public interest group. That is what Bruce and Carl concluded, and that is what led to me and ultimately The Planetary society. Until us, the space program version of public interest was industry lobbying for big hardware contracts – the shuttle, engines, rockets, and the space station. There was some scientist lobbying for science funding, but that too was self-interest. We wanted to represent the public interest, the interest that dover media and public fascination with space – discoveries and adventure. By 1979. The Carter Administration had doubled down on the cost-overrunning shuttle, putting all U.S. civil launches on this brand-new launch vehicle. Then Carter loses to Reagan and it gets worse. His budget director is Stockman—I forgot his first name—David Stockman. Hans Mark becomes NASA deputy administrator. I think he's come up in our discussions. Hans, a brilliant guy, refugee from Nazi Germany. He became secretary of Air Force, and was a center director of NASA Ames. He was on Bruce Murray's Advisory Council to JPL. His last job was chancellor of the University of Texas system. But, he was a hawk. He advised Bruce Murray his first day on the job, practically, as the new deputy administrator of NASA, "Don't count on any more science missions. You go find some work over in DOD." You imagine how that went over at JPL. [laugh]

ZIERLER: Right.

FRIEDMAN: That was his advice. He and Fletcher, the re-named NASA administrator, made the decision to cancel the planetary program, together with Stockman at OMB. Their comment to us was, "Don't worry about it. The Shuttle will get built, and then we'll be able to fly to every planet every year. You'll have so many missions, you won't know what to do it." Oh, yeah, thank you. Future money is always cheap, near money is dear. They were going to cancel the Venus Orbiting Imaging Radar, which Jimmy Carter had supported during the presidential campaign. That led to—and I think we talked about this in connection with Voyager, and Galileo, a scaled-down, lower cost mission, Magellan. The Galileo mission was under attack too. It had been approved in the '70s, but was being buffeted by changing launch vehicles, budget constraints and shuttle uncertainty. The program was a mess caused by the politics. That is where we were then. No new missions. Is this too long an answer to your question?

ZIERLER: It's OK. No, it's great.

FRIEDMAN: [laugh] But then that led Bruce and Carl to have these discussions about what to do. The answer was, form a public interest group, a well-established means of advocacy in a democracy. Like Sierra Club, and environmental organizations. Like Common Cause and non-partisan political causes.. Cause-related nonprofits were a well-established way for citizen advocacy and for democracy. They were supported both for the cause and for the very process of citizen-involvement. Two things happened to Bruce and Carl that were fortunate. I say fortunate because these were two brilliant people, way oversubscribed with responsibilities and activities. Carl's TV show, and Voyager imaging, and Bruce running JPL. Two things happen, one is me—

ZIERLER: [laugh]

FRIEDMAN: —he said modestly. [laugh] Bruce says to Carl, "This guy Lou Friedman is back in Washington getting a lot of experience in the political world, and he's kind of got nothing to do when he gets back here. He's available. Let's talk to him. Maybe he'll have some ideas." But he really meant is maybe I will be available to work on their ideas. Carl's initial reaction was, "Oh, yeah, I met him. know him. He's very good, but he's an engineer. He's not a scientist." [laugh] Carl's right. That's OK. I get it. [laugh] But Bruce convinced him to just talk with me and then form a judgement. Carl did that. He came to see me when he was in Washington and we had a good hour plus chat where my office was in one of the Senate annex buildings. Our discussion went well – I had been thinking about the issue of advocacy and was going around town talking to people about their views on organizing. I was struck by how the remote sensing industry organized – of course they were promoting a business from which the goal was profit, but it was still part of the space program and had a public interest component. Albeit for commercial ventures. The second fortunate thing was John Gardner. John was on the JPL advisory board and he and Bruce had a good rapport, John was a founder of Common Cause and therefore knew all about non-profits, public interest, advocacy and the associated industry of fundraising for non-profits. He had been a Cabinet Secretary under Lyndon Johnson, and briefly had even had his name mentioned as a possible Presidential candidate. I admired him, and as I got to know him, I admired him more. Do you know Common Cause?

ZIERLER: Sure.

FRIEDMAN: They were big then. They were really tackling political reform, and it became a large and effective organization built on citizen support. We got a lot of advice from John about how to form a public interest group. In addition, he knew people. He knew that constituency building was done through direct mail and he introduced us to some very excellent people who did that. Direct mail was the Internet of that time. No websites, but letters, flyers and brochures in the mail. Now, they say you have to get a TikTok page or something—

ZIERLER: [laugh]

FRIEDMAN: —an Instagram account or maybe something else. There's always some advice about how to reach and influence people. In that day, it was direct mail. Direct Mail is still relevant and still ubiquitous – but it is one of many ways of direct communication as opposed to the way it was then, I'm sure you see it in your mailbox.

ZIERLER: Of course.

FRIEDMAN: He put us in touch with a firm that did direct mail, and they in turn introduced us to all the other necessities of building a membership organization. John also introduced us to some major players in non-profit causes. In particular he introduced us to one who provided a significant donation on the condition we use it for direct mail organization building. We did just that, and soon became the fastest growing membership organization in the country of any kind. It was not just the mechanics of Direct Mail which made us so successful, it was the outstanding people who contributed to it. In addition to Gardner, we had Harry Ashmore was a Pulitzer Prizewinning author in Little Rock, Arkansas, writing about civil rights in the '60s. He then affiliated with Gardner and Common Cause. He became an advisor to us in this whole business of direct mail, and a wonderful guy. Peter Tagger was the knew all the details of managing the effort. We also had outstanding copy writers who created our message into mail copy, using wonderful pictures of the planets which we provided. It was in meetings that Carl, Bruce, me and Charlene Anderson, who became editor, had with Harry and Peter, that we came up with the decision for a high-quality magazine for our members. Charlene Anderson was part of it, by that time, she was the second employee of The Planetary Society. There was some debate about the magazine. Bruce Murray had this notion of a well-written but low-budget newsletter chock full of information and latest science results. Harry and Peter looked at our images of planet pictures and thought that it would be crazy not to present them – in color on glassy paper, a high quality looking magazine, along with articles by scientists about the results. Carl took no convincing – of course. That led us to create The Planetary Report, instead of a mimeographed newsletter. Charlene, who had been editor at The Cousteau Society Magazine, came over to us as our editor. When she first came over, I was looking for an assistant because it was getting busy. But then she became the editor because that's her skill, as the editor of The Planetary Report. It was a perfect match. The Planetary Report was molded by her and by Carl. Bruce and I contributed content – but they set the tone and guided it. Remember this was before the Internet – we became the public access to planetary exploration.

ZIERLER: [laugh] I want to go back to that formative conversation with Bruce Murray, and your feelings about it. Were you ready at that point for a career transition?

FRIEDMAN: Certainly. I was certainly ready because, first of all, I was on leave doing this thing in Washington and coming back was, by definition, a transition. The danger was not was I ready? The question was, was I going to get Potomac Fever; try to get her to stay in Washington? I think I told you, no, that wasn't going to be my plan. I had family back here, and I was definitely coming back. But as I also told you, JPL didn't have any missions, and the future was bleak. Especially since my work was in creating new missions. The bleak situation is why we're creating The Planetary Society. The Congressional experience had given me a broad outlook, and the political situation had given me a gloomy one. So working with Carl and Bruce on both of those factors not only made me ready for a transition – it created one. My whole work goal is always to make a difference, and this is what we were trying to do. And, on a practical note, I didn't have that much to come back to at JPL – there were no new starts, no new mission developments. I was working developing the International Halley Watch – but that was mostly a ground-based coordination program because the U.S. wasn't going to do a mission. My transition time was ½ on the International Halley Watch as a JPL employee and half-time starting a new organization outside of JPL --forming this new organization that we don't have a name yet for to work with Bruce and Carl.

ZIERLER: Lou, what was funding source for each?

FRIEDMAN: It wasn't too clear – either then, or even now in the sense I really don't recall it exactly. Carl and Bruce had major contacts who they thought would help start us up. I wasn't so sure, but we did get some initial funding from some including money that the authors of the Voyager Record book had earned and had earmarked for the advancement of SETI. I went half-time, given our limited funds, and also given that I was getting the International Halley Watch started in NASA and JPL. And trying to help some Halley Comet mission development. But is soon became apparent that it was too hard to bifurcate myself into JPL mission advocacy and development of a non-governmental, independent organization. And, I told them, "I got a family. I can't work free." So they and we asked more people for support. They actually did successfully raise some money from some key donors, including Paul Newman, the famous actor before your time, I realize.

ZIERLER: I know him. I know him.

FRIEDMAN: A kid like you doesn't know him—

ZIERLER: [laugh]

FRIEDMAN: But a lot of people did know him at that time.

ZIERLER: [laugh]

FRIEDMAN: Can I tell you an aside funny story, a Caltech story?

ZIERLER: Absolutely.

FRIEDMAN: One day, I'm in my office at the Society (this is years later) and I get a phone call from the President's office at Caltech. They wanted to contact Newman and Bruce had told them I probably had the contact information. Seems they wanted to invite him to Campus for some major happening. She asks me, "We want to get in touch with Paul Newman. Do you know how to do that?" I said, "Of course." She says, "Could you help?" I said, "Wait a minute. He's sitting right here in my office. Let me have you talk to him yourself." [laugh]." You could imagine what she was thinking for the next 30 seconds while I had her on hold. [laugh] I said, "Oh, he had to leave. I'm sorry."

ZIERLER: [laugh]

FRIEDMAN: I was all being a wise ass.

ZIERLER: [laugh] That's great.

FRIEDMAN: But I did give her the address and phone number for the contact.

ZIERLER: Phone number, right.

FRIEDMAN: He had a phone number. He had a thing called The No Such Foundation. Cute name.

ZIERLER: That is cute.

FRIEDMAN: Anyway, they raised some money, tens of thousands of dollars, enough to pay my salary for a few months and some expenses. I was working out of my home, to my wife's chagrin but with her support. We did a mailing to our science colleagues using a secretarial service and that raised some more start up money. Then we were going to bootstrap through the direct mail, using the seed funding from that donor I mentioned – brought to us through John Gardner and Harry Ashmore. That's how we got started with the money – it was an edgy time. Especially when I severed employment with JPL. I remember saying to Bruce, "It's a big step for me because we don't know where this is going to go. But I'm going to have to make a commitment, and it's not possible to juggle JPL, and halftime new organization." He says, "Oh, I don't worry about it. You can always come back to JPL." Of course, then he left in three years. [laugh] It was a risk, but I was working on big things with big people and presumably was still employable in case it all crashed. [laugh] I definitely wanted to do it. It was a dream job – working for only two people, Bruce Murray and Carl Sagan, working closely with them, starting a new venture, breaking totally new ground and all in pursuit of making space exploration happen when it otherwise might not. That's pretty good.

ZIERLER: Yeah.

FRIEDMAN: On the one hand, it's difficult because they're not at my beck and call.. They were hard to get, and I frequently had to wing it. On the other hand, they were great individuals and they insisted on working with great individuals – they always went for the best. The history of our Board of Directors and Advisors reflected that. Think of the fine people they brought to our Board and who I got to know and work with – for example, Michael Collins, Tom Paine, Norm Augustine, Laurel Wilkening, Gen. Don Kutyna, Shirley Hufstedler, John Bryson, Kathy Sullivan, Laurie Leshin and later Elon Musk to name a few. That, as much as anything, differentiates The Planetary Society of Murray and Sagan, with the Society of today. Working for and with these people was not only an honor, but it was exciting, interesting and rewarding. And working with great people like that wasn't confined to the Board – we had many great colleagues in planetary science and in the arts who I also got to work with.

ZIERLER: I want to start first—

FRIEDMAN: Of course, not all of these were evident at first, but the attitude was. That was why it a no-brainer decision for me. I remember talking to Connie, my wife, and saying, "I don't know what this is. They don't know what they're doing either. They've never done anything like this. They're scientists. They're hard to get, and they're not easy to work with. But what's going to be better [laugh] than working with them in a new venture on a new idea to do something that I really care about, planetary exploration?"

ZIERLER: Lou, this triumvirate, I want to start first with Bruce Murray. Were there any conflicts of interest, given where he was at JPL, in terms of this not being fully independent from JPL?

FRIEDMAN: My first idea was to have an office on Caltech campus – some nonprofit organizations did that. But the powers that be decided that was a conflict of interest. The idea of JPL lobbying through Caltech is a hugely sensitive subject with NASA, and a perception of JPL or Caltech setting us up as a lobby would have been self-defeating. I took pains to separate myself from JPL – both formally with employment as explained earlier, and also by even little things like using a copier there or logistical arrangements. Others, however, probably perceived a conflict but we were rigorous in avoiding it.

Bruce, as director of JPL, never mixed anything financial or otherwise with the Society. In later years, NASA people were not permitted or were strongly discouraged from being on our Board because of ever-increasing perceived conflict of interest concerns. JPL's current director Laurie Leshin was on our Board when she was at the University of Arizona, but she had to quit when she went to NASA. As rigorous as we were to not have any conflict of interest, there was obviously a confluence of interest. And others, especially those who might have resented the independence and promotion of the Society generally or of Carl and Bruce particularly, might have perceived conflict-of-interest. On the legal and financial fronts we were rigorous – perhaps to an extreme. For example, use of a copier, getting a picture from the photo lab at JPL, getting something printed – we did that with our funds, never using Lab or NASA funds. Bruce used Society funds at Caltech for any correspondence related to the Society. Carl and Bruce worked for the Society with no financial compensation, but we did pay some relatively minor office expenses where appropriate.

But on the more substantive part, NASA did resent the role of the Society as an independent voice for planetary exploration – and even complained to JPL about it from time to time, only to be told that JPL didn't have any control over the Society. Early on we added to our board a lawyer and the treasurer of Caltech, Henry Tanner. Bruce knew him. He said we needed a financial guy. Henry was that. Joe Ryan was a partner at a major Los Angeles law firm, O'Melveny & Myers. He was a running buddy of mine. He and I used to run every morning together, and run marathons together. We were friends, and he managed to bring us into his big name corporate law firm, pro bono. He took care of our incorporation, tax exemption status, etc. He also had strong community connections.

Working with Carl Sagan

ZIERLER: Lou, at this point, how well developed was Carl Sagan's celebrity?

FRIEDMAN: Pretty good. He had been on Johnny Carson. He was prominent enough to already get the Cosmos TV gig, and that's big. That was huge, the largest PBS show ever made, I think, in some measure. He was very well-known in the late '70s. It was probably his appearances on Johnny Carson that got him the most well-known in terms of the public, but he was a frequent commenter, and he was in the news. The Viking mission also made him well-known. And he was controversial -- I think he had already been—he was turned down by the National Academy of Science for being too popular – that is because of some scientists' jealousy. Then by '81, he was really well known because now Cosmos was beginning to be shown on PBS, so it was everywhere.

ZIERLER: Do you think his profile was central to The Planetary Society's success?

FRIEDMAN: Yes. Essential? Probably. Valuable? Absolutely. [laugh] Important? Absolutely. Both substantively with his broad intellect and perspectives, and promotionally as being instantaneously recognizable. Certainly, it opened the initial doors, not just in the public mind, which gave us good support, but also with people like Paul Newman, Johnny Carson, and political figures – senators, representatives, and even the president. And, perhaps, most important, the media. He attracted people to our Board and he attracted donors to our cause. But I want to emphasize the substantive too. He understood communications and public interest. His judgement on those matters was terrific and guided us. The dynamic of his working with Bruce Murray (and me) was wonderful – true solid discourse. He also very much guided the development of The Planetary Report. I don't know if anybody else could write so well. ZIERLER: How involved was he on a day-to-day basis? You said sometimes it was difficult to get a hold of him. What would you need him for? What kinds of things?

FRIEDMAN: Usually, it was a policy question. I wanted to talk to somebody about doing something—it's hard to remember your individual things—it could be an article that was going in The Planetary Report [laugh] that he was late on [laugh], or a direct mail piece he was in. It could be a scientific or planetary exploration issue, it could be a political contact, it could be a deep question like our approach to international cooperation or nuclear energy in space. He was very involved, but that said he was often hard to get – no way at my beck and call. It was a normal relationship, especially given his celebrity status. There are times I felt ignored, and times I felt why is he bothering me on some small point. He wouldn't sign his name to anything he didn't write or, at least, read carefully. Like most people in the direct mail that you get, you see it signed by all kinds of prominent people. They don't ever read it. They allow their name to go there. Carl didn't, so he had to read over, and edit everything that was written for him by a copywriter. And he was completely involved in policy – he, Bruce and I would hammer out every policy statement, political action, congressional testimony, and high-level contacts.

ZIERLER: Lou, when did the member dues become an important part of The Planetary Society's funding structure?

FRIEDMAN: Absolutely, from the get-go. We had donors, some notable, but still after we got the membership going, the dues and member donations were the financial base. Donations from the direct-mail was the thing that surprised us the most – we didn't know there would be such a thing. But the consultants explained, that now you got members, you need to give them something to do – and that something was to support us in things we were doing. Dues and special appeal donations were our financial base. We did slowly develop some higher level of donations from higher net-worth folks. We also got a couple of external donations from foundations – but it was not a major part of our funding.

ZIERLER: You mentioned that The Society member dues were central to the funding structure right from the beginning.

FRIEDMAN: We did a mailing. The first mailing we did was to an organization called the Division for Planetary Sciences of the American Astronomical Society, our colleagues in planetary science. They had been also politically upset and concerned about the program being canceled, and so they were urging Bruce Murray and Carl Sagan individually. "Do something, can't you?" We wrote to them saying we were doing something and that they should join us as founding members. We got a very good response and from then on we were a membership organization primarily reliant on dues and individual donations from members. Then we bootstrapped that into the direct mail campaign that I told you about, with the professional consultant help and the seed donation from the person who John Gardner introduced us to. The first mailing led to another and then another, and we grew rapidly. Members were very important at the beginning. We got a few big donations here including an ordinary looking couple who dropped in without any introduction and talked to me for about ½ hour. As they left they handed me an envelope – it contained a $35,000 check. I raced the six blocks to get it into the bank. [laugh]

ZIERLER: Wow.

FRIEDMAN: Things like that happened, and they were important. But member dues and donations were the principal, both financially and politically. It made us a citizen's organization. And soon it was the most important programmatically – in that it led to the creation of our projects, which really made us special, and which were so exciting to me personally. That came about when Peter Tagger, who I mentioned to you, at a meeting we were having at Carl's home asked us what we planned to ask the members for. We had not thought of that – and he introduced to the concept of special appeals, asking for donations to specific programs and projects that we would undertake with the funding. We had vaguely thought of raising money to fund SETI and lobby for planetary missions, but we had not specifically thought about the special appeals to members to get them engaged in such projects. We even thought we could seed some research or experiment development for planetary missions, but we never imagined we would carry out our own space mission or actually develop flight qualified payloads to go to Mars. What Peter taught us was that asking for money was they way to keep members involved, to make them feel a sense of ownership in the projects and the organization.

ZIERLER: Lou, what was the game plan in terms of the things to focus on first? In other words, there's the search for alien life. There's planetary science. There's dealing with near-Earth objects. How did you and The Planetary Society prioritize where you would put your emphasis?

FRIEDMAN: The first thing was the mission statement, which ended up being "To explore new worlds and seek other life through science, education and public involvement." The first projects were largely opportunity driven – they came to us, of course within the boundaries of our mission statement and interests. SETI funding was cancelled by the Congress, and American SETI scientists could not attend an international meeting. We jumped in, got a foundation grant, appealed to our members and funded scientists to go. We of course immediately reacted to the negative U.S. budget proposals and engaged our members in writing to Congress for planetary support. Galileo and Magellan were immediate topics. Soon after we were formed, one of our advisors, Jacques Blamont, the Chief Scientist of the French Space Agency, introduced us to an idea for Mars exploration by balloon. They were studying it, and through their cooperation with the Soviet Union were hoping to fly it in the future. This was an outgrowth of the Venera balloon which they had worked with them. Bruce was taken with it and organized a student program at Caltech to develop it, along with others – a colleague from JPL, and students at Utah State University. This all led to a hugely successful special appeal by the Society, and a novel program to design, develop and test Mars balloon concepts. Another early project was introduced to us by Carl – an innovative SETI receiver being built by a brilliant Harvard physicist that we could fund and make happen. That eventually led to Steven Spielberg contributing and joining our Board of Directors. Private funding was the only funding for SETI now that NASA had to stop their program. We didn't do this as a "plan" or in a bureaucratic structure – we seized opportunities to advance our mission and created exciting new projects.

ZIERLER: Lou, what was the scientific basis for the excitement for searching for alien life forms, and why wasn't NASA doing this itself?

FRIEDMAN: As you might expect there are differences of opinion about that and different interpretations of what little we knew, and know, on the subject. Extraterrestrial life is a subject without subject matter. Astronomers tend to argue that the billions of probably habitable planets we now know to exist make the odds in favor of such life being on at least a few, if not many, of them. Biologists argue it may be unlikely given that intelligence has only evolved once among millions and millions of species here on Earth, and that even microbial life took two billion years to evolved into much of anything. And we don't know how. So, personally, I think the scientific basis is flimsy. But the means of investigating it and the questions it poses are scientific and good things happen when you conduct sound science and explore – so it is supported in a lot of the scientific community. NASA twice tried to start a SETI program and twice got it shut down by political forces who found it non-credible. Just after The Planetary Society was formed then Senator Proxmire from Wisconsin gave it the "Golden Fleece" Award. "Looking for aliens? That's not what we do with government money." Golden fleece, meaning it was fleecing the public. That led to our first special appeal and political action – we raised money for SETI scientists and we went to Washington to lobby for the program. Carl met with Senator Proxmire and he relented and a program was again started later in the 1980s. Another NASA program got started, and had perhaps a year of observations in the early 90s and then another senator, Senator Bryan from Nevada, did something of the same sort to kill the program ridiculing it in Congress. That led to more efforts at private funding, first by The Planetary Society, and then with the formation of the SETI Institute adjacent to NASA – Ames, which had a number of the SETI scientists. Our principal funding was of a brilliant Harvard physicist who Carl knew, Paul Horowitz. He invented this new kind of radio receiver, and he didn't have any funding for it. He and Carl made the case that this would be a great thing to raise money for because he only needed $100,000 to do this first electronics step. We raised that money, and then that leveraged into a bigger project, which then Steven Spielberg—who Carl got involved, and he contributed money, and did the big grand opening forum with us. It just leveraged.

ZIERLER: What was Carl Sagan's view on searching for alien life? Did he believe that they were out there?

FRIEDMAN: I think Carl subscribed to the astronomers' viewpoint – it was likely. He thought it was a plausible and the search a worthwhile thing to do. His arguments were always about the numbers. But I know he didn't take it as a given, and he was practical – he once said if SETI cost billions of dollars (like a space mission) then it might not be worth it. The SETI programs were advocating and supporting were orders of magnitude less cost than that.

ZIERLER: What were the technological capabilities in the early 1980s to try to figure this question out? What could you use?

FRIEDMAN: Radio astronomy was well established, so we have radio receivers. If you just take the analogy of tuning a radio, maybe you'll get a signal. That's pretty haphazard until you can do it with powerful computation. You have to be able to tune into many frequencies, and run searches through them. Then you have to have a narrow enough bandwidth to recognize a signal that stands out, and then it has to be a purposeful signal. There's all kinds of both computation and electronics that go into it. In addition you don't know where to look so either you search the whole sky or you try to find likely targets – in either case a lot of searching. The technology is advanced radio receivers – really fast computers and electronics and very advanced circuitry. That was just what was goiong on and that is why I found SETI worthwhile as a technology, even though I did not buy into the underlying science.

ZIERLER: Lou, what were the institutional partnerships between The Planetary Society and SETI? How did that work?

FRIEDMAN: Who?

ZIERLER: SETI.

FRIEDMAN: SETI is a name. It's not an institution. I think you mean the SETI Institutes which formed a few years after us in the aftermath of the first shut down of the NASA program. Our relationship with the SETI Institute was generally good, although it had a bit of rivalry to it perhaps like two players on the same time, each trying to win but perhaps trying to be better than the other at the same time. It certainly was collegial. Each had a niche with SETI and therefore developed different funding sources for private support. But they soon branched out to be a government contractor for other areas of science besides SETI – mostly in astrobiology. Their principals: Bernard Oliver, who was vice president of Hewlett Packard, and Frank Drake, who was a pioneer in SETI and Professor at UC Santa Cruz were Advisors to the society and had been very supportive with our startup. They (before the SETI Institute was formed) arranged with Carl to give us funds they had made during the publication of a book about the the Voyager Golden Record. They felt the funds were not theirs personally since the project was a government supported mission, but they earmarked it for the advancement of SETI – which of course we were doing. Barney (Oliver) and Frank urged us to use those funds to engage a professional PR person for advice and direction. Someone (maybe Carl) recommend this high powered guy in New York, who I went to see in his 5th Avenue office overlooking St. Patrick's Cathedral. His advice: use Carl more and buy some NY real estate. Good advice. [laugh]

ZIERLER: [laugh]

FRIEDMAN: Thank you for allowing me to pay you to give me that advice.

ZIERLER: [laugh] Why? New York real estate for fundraising?

FRIEDMAN: He was a New Yorker, didn't take anybody serious who wasn't there. I am a New Yorker, too – and probably agree.

ZIERLER: Did you do it?

FRIEDMAN: No. Wish we could have. Maybe it was the right advice, but we weren't in that league at that point anyway.

ZIERLER: You said SETI was only a name. It was not an institution at that point.

FRIEDMAN: That is correct. SETI Institute got formed a few years later. This was in '80–'81, we were doing all this initial stuff with SETI, the people to go to the conference in Estonia, the meeting with the public relations people, the political advocates for the program, the initiation of the project at Harvard with Horowitz, etc. The SETI Institute hadn't been formed yet. It was founded in 1984 principally by Oliver and Drake with Jill Tarter and Tom Pierson. Sagan and Murray were positive, I was a little more territorial but still cooperative. We supported some of the same programs, though they mostly focused later on building the Allen Telescope, and as I mentioned they also developed a larger role as a NASA contractor in non-SETI science. And we focused on Horowitz's developments and of course the big donation from Spielberg to get that project expanded. Then NASA got a new lease on life and both Ames and JPL started programs culminating in a grand opening at the Deep Space Network antenna in 1992. I may be mixing up dates, and sequences.

ZIERLER: It's OK.

FRIEDMAN: I was out there for the ceremony. Spielberg, I don't think was, but Paul Allen, the cofounder of Microsoft, was there. I gave him a ride in my car out to the site where the antenna was. That was launch of the NASA-SETI program. It was a great event. Then one year later, it was canceled by another Congressional action spearheaded by Senator Bryan. A repeat of the earlier action a decade earlier. So, there was no NASA program then, and there has not been one since. The SETI Institute became more active then with their fundraising and that led to Paul Allen's funding of the Allan Telescope Array. Both the Society and the Institute funded developing projects at UC Berkeley as well. In general the collaboration was good, even when there were admitted rivalries.

ZIERLER: Lou, how much time in the early years did you spend actually in Washington, D.C.? Did you travel back and forth frequently?

FRIEDMAN: Yes, frequently. I knew Washington pretty well and got to know it better. Not so much about SETI – there was no government program with it, but about planetary.

ZIERLER: Who would you see? What would you talk about?

FRIEDMAN: Usually congressional staff of the committees who deal with the NASA budget, and NASA people about how to get programs started at NASA. Also in the Executive Branch with OMB, and when we were engaging with the Soviets, I would also meet with National Security Council people in the White House and sometimes with State Department folks. Occasionally I would meet with Congress --

ZIERLER: Were there any Congress—?

FRIEDMAN: —sometimes with principals in Congress, representatives or senators, but usually with staff. I also participated with Congressional testimony several times.

ZIERLER: Were there any principals in Congress, senators or representatives that really championed The Planetary Society, that were real allies for you?

FRIEDMAN: No, I don't think so. There were allies in our cause – for example Rep. George Brown and even, a little more erratically, Rep. Dana Rohrabacher. Also in his early days, Newt Gingrich. Senator and former astronaut Jack Schmitt was an ally. Most of the time I spent with staff. And, as mentioned, the Executive Branch and NASA.

ZIERLER: What about at NASA? Who were some of the key people you worked with at NASA in the early years?

FRIEDMAN: In the early years it was as much "against" as it was "with." We had a love of NASA in the broad sense, but a quarrelsome one with the leadership and policies of the 1980s. We had hostile, hostile relations with the administrator, James Fletcher. We had friendly relations with Hans Mark, the Deputy Administrator – he was a colleague and had led NASA-Ames during the time of the Pioneer missions. But we had strong disagreements with him – you may recall it was he who told Bruce that JPL should give up on the planetary business and get DoD work. He also strongly supported the stand-down policy of the Reagan Administration about planetary exploration. But we did have cordial communication with him. Hans Mark took me aside one meeting I had with him in DC, and he says, "What are you doing with this thing with The Planetary Society? You know that's not going to go anywhere. Sagan and Murray have got their heads in the clouds. Why don't you come to work for me here at NASA?" [laugh] I said, "Wow, thanks, that's an honor, but no thanks." [laugh]

ZIERLER: What would you have done with him?

FRIEDMAN: NASA has a staff there of 57,000 or so. He would have buried somewhere. It would not have been on planetary exploration.

ZIERLER: Because you believed in The Planetary Society? You were having fun?

FRIEDMAN: Yeah, and Sagan and Murray were people I did want to work for, and Hans Mark was somebody I didn't want to work for. NASA is a bureaucracy – which is great. Bureaucracies are the organizations that get things done: rightly or wrongly. But they also are organizations that can prevent things from being done – again, rightly or wrongly. At this time, they were a giant negative. You asked "fun?" How could it not be working with Carl and Bruce, starting new things, meeting great people and trafficking in great ideas with exciting goals.

ZIERLER: Wouldn't NASA, at least at the institutional level, have been welcoming of your efforts? Everything you were doing would be good for them?

FRIEDMAN: No, Fletcher hated us. We were not welcome.

ZIERLER: Why?

FRIEDMAN: First, we had a different agenda – not the Shuttle, but space exploration. Second, they had no control over us – they are very unused to not controlling their constituency.

ZIERLER: But that's an individual. I'm talking about the more general level of securing more funding for NASA.

FRIEDMAN: Fletcher and Mark defined the policy and the culture. And the Society never argued for money or funding as such, we argued for programs – substance. Industry argued for contracts and dollars, we argued for programs and missions.

NASA and Planetary Defense

ZIERLER: Lou, I want to touch on the near-Earth objects issue as well. How did The Planetary Society approach that issue in the early years?

FRIEDMAN: An astronomer by the name of Eleanor (Glo) Helin, I think she had an association with Caltech too, was an active observer, whose program was not getting funded. The Society was able to help, because the amount of funding she needed was relatively low, and because it was a newly emerging area of science in the solar system. Few Near-Earth asteroids had been observed then. It was an important subject, that did not get much funding attention. Astronomers called them "vermin of the sky." Their significance began only to be understood, not from astronomy, but from geology – the impacts on the Moon evident in all the craters, and impacts on Earth evident in a few craters. Glo (as she was called) was a close working colleague of Gene Shoemaker, a Caltech geologist known for training the Apollo astronauts on lunar geology and both a great geologist and astronomer who had his own observing program. It was around that time that the great impact that led to the extinction of the dinosaurs was understood as quite likely from a near-Earth object. Anyway, this was an ideal subject for Planetary Society promotion – interesting, consequential, underfunded, low-cost, and leading to potential missions of discovery and exploration. As knowledge grew, the subject became even more important as people deduced that future impacts posed a danger to Earth – one we did not know about fifty years ago, and one we now realize requires more knowledge and preparation. Anyway we supported Glo Helin's works, and others. Glo was grateful and named one of her discoveries, Friedman. Number 3651 is Asteroid Friedman.

ZIERLER: That's very cool. Lou, when did you feel that The Planetary Society was really making traction, that it was positively influencing science policy and funding in D.C.?

FRIEDMAN: There was another major thing that happened to the society early-on, in around 1982 or '83 when we discovered international cooperation. We discovered it in the context of the Cold War, and the concern about the U.S, and Soviet Union relying on mutual assured destruction. Several of our Advisors and colleagues, especially with Carl who was active in areas of nuclear non-proliferation, said the very active presence of the Soviet Union in space exploration presented an opportunity for international cooperation. This resonated strongly with Bruce and Carl, and later me learning from them. The peace aspect was appealing, but it wasn't just kumbaya, international cooperation is wonderful, put your arms around me, and we'll hug. It wasn't even just it's good for the world so, although of course it was. It was that it was both good for promoting planetary exploration and with the active program of Soviet planetary missions fit right into our agenda. Engaging with the Soviets would help U.S. planetary exploration, especially while it was being cut politically, and it would broaden our appeal to a world-wide agenda, not just the small space community.

FRIEDMAN: This changed my life; that's when Sagan introduced Bruce and me to Roald Sagdeev.

ZIERLER: This is Roald Sagdeev, the plasma physicist?

FRIEDMAN: Yes, it was Road Sagdeev the plasma physicist, the new Director of the Space Research Institutive of the Soviet Academy of Sciences, and about to be the scientist advanced guard for Soviet perestroika, a harbinger of reform there. He had a close relationship with Carl, and then with Bruce and me. He, like Bruce and Carl, became a mentor in my life – changing the course of much of what I did it. I am still close to him today. In that first meeting the three of us had with Roald, he invited me to go to the Soviet Union (this is 1983 during a cold part of the Cold War) and Carl and Bruce urged me to accept. They were doing Venus missions, preparing a mission to Halley's Comet, and future ones to Mars. So, now back to your questions about Washington. We were beginning get known in Washington as an organization. Of course, Carl was very well known, and I had a lot of contacts there from my days as Congressional fellow. Now, we didn't hire any Washington representative until later. Carl and I began doing testimony to Congress at hearings, and I was pretty good at getting us invited. I saw staff a lot also. That started to become influential because, for one thing, it was annoying NASA. We created a niche – public advocacy for space science, and filled it. It was not the NASA and space industry stuff. We didn't testify ever against anything in space, even when critical we tried to be positive. So we labelled our criticism of the Space Station proposal as "a a space station worth the cost," the implication being the one that NASA was pushing wasn't worth the cost. We connected it to our vision of space exploration, rather than the nonsense about valuable experiments on the space station. Our efforts for a U.S. Halley mission came to nought, but our presence in the coverage of international missions was significant. Later we conducted a public campaign against the NASA cancelation or delay of the Mars Orbiter mission that was being planned for 1990. Our SETI advocacy was also noticed. By the late 1980s we were well engaged in international cooperation and led a very noticeable campaign of advocacy for a joint Soviet-American Human Mars mission. Even with a full-page advertisement in the Washington Post, trying to get it on a Reagan-Gorbachev summit agenda. Then, for a while, there wen NASA would call Director of JPL, General Allen, then I think.

ZIERLER: Right, Lew Allen.

FRIEDMAN: Lew Allen got calls from NASA saying, "Put a lid on The Planetary Society," [laugh] and he laughed it off.

ZIERLER: What were the relationships?

FRIEDMAN: I mean, he didn't laugh it off with NASA. He laughed it off in real life. Then we did some big events. We did Planetfest '81 with the Voyager encounter with Saturn. What was that? Planetfest '89 was the Voyager encounter with Neptune. So we did these multi-day festivals, and they got us noticed and on the map.

ZIERLER: What was that like? What were the Planetfests like? Did it feel like a party?

FRIEDMAN: Oh, yeah, they were true festivals, festive. We had scientific lectures in some room, politicians and civic leaders in another, but then you had big displays and exhibits, an art show, and in 1981 we had a John Williams concert, and a live broadcast of Nightline. Movies and guest speakers and celebrities, everything centered about the spacecraft encounters and live connection to mission control and data streaming from the planet. JPL was very cooperative and well represented. There were all kinds of three-day festival things.

ZIERLER: Lou, did you ever get involved with international space agencies, the NASAs of other countries?

FRIEDMAN: Yes, we did. We got very involved with CNES, the French Space Agency, that Mars balloon I told you about.

ZIERLER: Yeah.

FRIEDMAN: We were involved with the European, French, Soviet and Japanese space agencies. We actually received funds from the French space agency as they integrated our work on the Mars Balloon into their program as part of a cooperative project with the Soviet Union. In Russia we had close relations with the Institute for Space Research, part of the Soviet Academy of Sciences, and with Lavochkin Association – a major space industry. In Japan we had close relations with ISIS, which later was absorbed by JAXA. I became close to a number of players during the Halley Comet encounters since I had both headed the International Halley Watch and helped to initiate the cooperative navigation agreement between Russia and ESA for the cometary encounters.

ZIERLER: What about Asia? Did you ever deal with JAXA?

FRIEDMAN: I mentioned our close relationship with ISIS, which became part of JAXA. So much so that we and them set up a Japanese Planetary Society with its own officers, office and fundraising. They used our magazine as part of the membership appeal. Japan of course was also part of the Halley Comet armada (Europe, Soviet Union, Japan – no America) and I was engaged in that.

ZIERLER: What was the value of that? Did NASA take notice in what you were doing internationally?

FRIEDMAN: Yes, and in general they resented it. This was the 1980s, when they had an agenda which did not include planetary and when we had pretty unpleasant relations with them. I think they even complained to the other space agencies about us. Later in the 1990s, under Dam Goldin, we had a collegial and cooperative relationship with International Affairs at NASA – but not so in the 1980s. We helped to create an International Mars Exploration Coordination Group, for space agencies and groups working on Mars missions. Within a year after we helped to form it, NASA kicked us off. They wanted to control.

ZIERLER: I think last question for to…

FRIEDMAN: But—

ZIERLER: Go ahead.

FRIEDMAN: I was going to say this about that, and I'm going to say this about some other things. Imitation is what? What's the expression? Imitation—

ZIERLER: It's the highest form of flattery.

FRIEDMAN: It's the highest form of flattery.

ZIERLER: Right.

FRIEDMAN: When NASA took over something that we were doing because they flattered us. This also happened in areas of public outreach.

ZIERLER: That's a good thing.

FRIEDMAN: Of course – but still annoying. They took it over in the naming of spacecraft, and in some of the public relations aspect of things on spacecraft, and they took it over, and they tried to take it over in the international relation, all those things. But when we started, there was a guy. I remember a NASA official came over, and I said, "I didn't know you were going to be at this meeting internationally." He said, "I'm here to stop whatever you're trying to do."

ZIERLER: [laugh]

ZIERLER: Lou, I did want to ask you about your trips to the Soviet Union, to Russia. What impressed you about their space programs?

FRIEDMAN: It's size, and I mean that in every dimension, not just the number of people and the number of institutions involved. But all their spacecraft are giant, big, monstrous things. Also, there was a certain combination of primitiveness of facilities, furnishings and equipment (like 50 years earlier, or like old textile and steel mills in the U.S. But, At the same time, they were working on and accomplishing the newest of achievements. At the time I went in the 1980s, they had a space station – we did not, they had a Mars program – we did not, they were going to Comet Halley – we were not. As far as the Solar System was concerned – the action was in the Soviet Union. I was impressed by their ambition – because none of these things was about communism or worker's paradise – although the ideology of achievement was real.

ZIERLER: Let me ask one last question for today. We'll pick up on this point for next time. What did you feel was your first real policy success at The Planetary Society, in other words, something that you were advocating that actually translated into a new program?

FRIEDMAN: It was in Mars, I think – maybe.

ZIERLER: We'll pick up on Mars as a policy success. Very good.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Thursday, November 10th, 2022. It's great to be back with Dr. Louis Friedman. Lou, it's great to be with you once again. Good morning!

FRIEDMAN: Good morning!

Roving on Mars

ZIERLER: Lou, today we're going to pick up on a question I asked last time. We weren't able to get to it. We've already covered the origins of The Planetary Society, your early path to making sure that things were working properly there. The last question I asked was your memory of the first policy success for The Planetary Society. You answered "Mars" but then we had to get off the call, and you didn't elaborate there. Let's pick up on what exactly was it about Mars that made it what you consider the first policy success for The Planetary Society.

FRIEDMAN: Let me quibble with myself about that answer of Mars – a little in the sense of the word "success." By what criterion – success at establishing the Society, success of financial return, success in changing some government decision or policy direction – and even with that, a big change of a small decision or a little change in a big policy – which is the bigger success? Especially to a nonprofit organization, success has many meanings.

ZIERLER: Sure.

FRIEDMAN: You asked "first policy success" and so I will answer that specifically. Probably Carl getting Proxmire to back down on his "golden fleece" for SETI. That eventually allowed NASA to start a SETI program – albeit it too was killed by a different senator's action. But personally, I regard that as a small and temporary thing. A bigger policy success in our early years was putting Mars on a national pollical agenda – even getting it into a U.S.-Soviet summit agenda. But that too was temporary and ultimately failed. The lasting positive success was elevating staving off the attempt to cancel the planetary program and getting planetary science to be supported with a restored Mars program and later the Cassini mission new start. That took the whole decade of the 1980s. During that decade we established ourselves on the international space scene and with our support for seeding new areas of planetary exploration. That led to a singular success in the 1990s – getting a Mars rover into the NASA program after years of opposition in the science community. That's actually several answers to your question.

ZIERLER: Right. I was thinking more, I mean, by the time that The Planetary Society was stable, that it was a strong operation, on the advocacy side, what happened in space science, space missions as a result of what The Planetary Society was set up to do.

FRIEDMAN: Going back to the early years, the Halley Comet experience of the mid-80s was, I think, a great success for The Planetary Society. It put us on the map – domestically and internationally. It established our bona fides both in advocacy as in doing things in planetary exploration. It gave us contacts around the world. We stood for something that was unique and had broader cultural and societal interest than just the interest of the space group. But it was also a policy failure because no US mission got accomplished, which was our goal. Now, Russian missions got accomplished, and European missions got accomplished, and we worked with them, and that was all good. And the Society had a presence in the U.S. response helping the International Halley Watch and advancing cooperation among the space agencies. After Halley, most of our planetary attention went to Mars – that program was still moribund in NASA, but active in the Soviet Union. By the late 1980s NASA and JPL came up with a plan for a Mars orbiter to fly in I think 1990. They were going to take a repurposed Earth-orbiting satellite, and said that they could adapt it for Mars. It was kind of low-budget approach – doomed from the start. They squeezed it into the program, with all kinds of constraints and compromises, and then when the good old Shuttle funding again became a problem, they delayed the mission and doubled the cost. So it ended up being an expensive, low-budget spacecraft that failed. In 1988, '89, when they made that decision to delay the mission, we went to war with NASA.

We wrote our members. We told them to write their congressman. "Don't let NASA delay the Mars"—I think it was called Mars Observer—"the Mars Observer mission. Write your congressman." We made noise and forced a public meeting with Congress and NASA. It was a confrontation. But. NASA got its way; they usually do. The mission was delayed. We didn't win that battle. But I think we set the stage for Mars advocacy in a big way, which proved important later in the 1990s. We proved there was popular support for Mars, both as an international goal for human exploration and for the public interest in the science on Mars. Following the loss of Mars Observer, the program could have collapsed. By this time, however, we had a different NASA, one that supported planetary exploration, and we worked closely with Dan Goldin and Wes Huntress to advocate and support it. Closely, but independently. We used the testing of Mars rovers with the Russians in a major public way to advance U.S. development of a rover. This probably was our major policy success. A group of us went to Kamchatka to participate with the Soviet scientists and engineers to test Marsokhods on the volcanic slopes there. As it turned out that was exactly during the time of the attempted coup against Gorbachev. That was an experience – you can read about it in my book: Planetary Adventures: From Moscow to Mars. Six months later the Soviet Union collapsed, the end of the USSR. One year later we invited the Russians (no longer Soviets) and the Marsokhod to test it in the ultra-dry Death Valley here in California. Have you been to Death Valley, by the way?

ZIERLER: Yes.

FRIEDMAN: We organized and got our membership engaged on this. We raised money. We got one of our members with a giant RV that could sleep 10 to dedicate himself for the week. We got about 50 people, I think, maybe even more, 70 people on our volunteer squad. We had 14 Russians brought over, with their rovers—they brought two rovers—and spent a week in Death Valley. [laugh] It's a big undertaking for The Planetary Society. We went to a site not far from the Phantom Ranch and Visitor Center, not far from the main area, and we named it Mars Hill. In subsequent years, due to the advocacy of some of our members, it became an official designation of the US Park Service. It's an informal one, but it's known as Mars Hill. We conducted those tests. They were very publicly visible. The next year, we conducted some tests on the beach in Santa Monica in something we called Roverfest – not just with the Russians but with JPL, too. Then we did one in 1992 in Washington, D.C., on the National Mall in connection with a World Space Congress. We were getting a lot of publicity and promotion. NASA couldn't ignore it, even though rovers weren't part of the NASA program. The scientists then began to say, "This is interesting." Dan Goldin became the administrator at NASA in 1990 or '89, and he was an advocate. He actually came up and saw one of our rover events out here in Pasadena, and then he took it to JPL, and said, "You guys should be doing this." Of course, they all started jumping around. Rover work got going, and led to the very successful Sojourner rover on the Mars Pathfinder mission. This is the long answer to your question. That was our policy success because in 1992 or '93, NASA committed to the first Mars rover and to a series of ones after that. On that Mars Pathfinder mission by the way we sent the first privately funded experiment to Mars. It was a tiny group of radiation sensors, along with a nano-lithograph of our members' names. It pioneered another achievement – a public-private partnership in planetary exploration. It took another decade or more for such relationships to be adopted formally by NASA. We just did it informally – with cooperation of terrific people at NASA like Goldin and Wes Huntress and at JPL like Donna Pivorotto and Tony Spear and Glenn Cunningham.

ZIERLER: Lou, what was the overall budgetary environment in space science after the Cold War, the idea that it was either going to be planetary exploration or the International Space Station or the SSC, that the United States would go all in on particle physics? What was your sense of in the early 1990s what the budgetary environment looked like?

FRIEDMAN: It's not just budget, it's what you do with it. It's program. In the 1980s, NASA had big budgets and little program. In the 1990s, pretty much the opposite – less budget, more program. Space science is a small part – usually not even noticed politically in the budget. NASA got lots of money for the Space Station in the 80s, but they did not accomplish anything with it. And it came at the expense of space science. In the 90s they built the space station and started again with accomplishments in space science. But the budget wasn't good – that is when Goldin came up with the mantra of doing things cheaper, faster and better. In the 1980s, the U.S. and Soviet Union were still competing in space – and the U.S. was undertaking Reagan's Strategic Defense Initiative – Star Wars. In the 1990s, we flew shuttle-Mir rendezvous and integrated Russia into the space station. At the end of the 1980s, Bush became president. He proposed something called the Space Exploration Initiative, SEI, trying to make it sound like Reagan's SDI, which was the Strategic Defense Initiative, a grand goal of back to the Moon and on to Mars. He supported it with words, but not money. I cite the contrast of Presidents who like space – Reagan and Bush, but not supporting it with money vs. a president who doesn't care at all about space, but gives it lots of money and uses it geopolitically – like Clinton and Kennedy. The SETI died for lack of funds and NASA's coolness to it – saddled as they were with the Space Station. Ironically it was Russian competition that drove us to the Moon, and it was Russian cooperation that enabled the International Space Station. But the budget was highly constrained. And Goldin, just the opposite of his predecessor was trying to do more with less. He saved and supported the Mars program. But he almost cancelled the proposed Cassini mission. because they needed budget. We fought for that hard. We lobbied. And we (the whole space science community) won. In the mid-90s, Earth science started to become important – one of the consequences of learning about our planet from space, and from looking at other planets. That created another demand on the budget. So the budget environment was tough, but the program was energized with new purpose and accomplishments. Notably, the Hubble Space Telescope, the Mars program including the Sojourner rover, the start of the Cassini mission and finally building the International Space Station. It was built with false promises of science and space applications but it was a huge international technological success. Its geopolitical goal of engaging the Russians and bringing much of the world's human space flight programs together was a huge success. It doesn't deserve any science prizes, but it deserves the Nobel Peace Prize.

ZIERLER: [laugh] Lou, on that note, just a current question, with the all the craziness with Russia and Ukraine, and Russia's various threats about the ISS and space science in general, are you concerned?

FRIEDMAN: If the Space Station goes away, I don't care. I won't shed a tear. It's not important anymore. But it proves my point. It isn't going away. It still is a link – a weak link – to Russia, and then to us. It deserves a Nobel Peace Prize. But it hasn't brought peace. Russia is trying to destroy Ukraine. But Russia has already destroyed Russia. Sadly, that country has no civil goals other than greed and conquest. They destroyed their space program, and don't support scientific research except for military applications. They have driven away many, if not most, of the creative and educated young people except those they keep for cyberwar and cyber theft. It is sad because you see really wonderful Russian people working all over the world as scientists, artists, writers, engineers, etc. – not for Russia but for new lives away from Russia. That is what I mean by Russia has destroyed Russia.

ZIERLER: Lou, back to the 1990s, when the SSC, the Superconducting Super Collider in Texas was canceled, did that reverberate? Were there research dollars that were funneled back into planetary science as a result?

FRIEDMAN: Not directly but probably. Can the nation afford two huge science projects simultaneously? The answer would've been, yes, they could've and should've. But I don't think dollars transfer like that. Certainly money did not transfer from fundamental physics to NASA's planetary program. But remember, it is not just about money – it is about the politics. And whether cancelling the SSC made politicians want to spend more in space, I am not so sure. Similarly, the environment, and Earth science. With the SSC we had an international out – a lot of collaborative research at CERN. I do not know enough to analyze the policy effects – I think the U.S. is doing well with physicists – but I am not in their shoes. Another aspect of science policy – or any policy – is bandwidth. How much can OSTP and the science and technology apparatus of the U.S. take on – I have been there when the policy world says, "we are giving all our attention to X now, and can't deal with Y." But I also think the space station was less of a science policy decision as it was a geopolitical and tactical one, as I have explained earlier.

ZIERLER: Lou, kind of a sad question. When Carl Sagan got sick, what did that mean for you personally and for The Planetary Society?

FRIEDMAN: Very sad question. It was huge, he was huge. But re-creating perspective from then is hard. He died late in 1996, and that was an intensely active period for us. Pathfinder was on the way to Mars – to become our first Mars mission in two decades, our first rover. The meteorite in the Antarctic was discovered to be possible evidence of Mars life. Cassini was about to be launched. The Planetary Society was proposing to do this CD—a CD then; DVD now—with science fiction writers, and the great stories about Mars. It was to become the first Mars library. We were engaged at high level policy discussions about international cooperation on future Mars missions. The Russian Mars '96 mission – which failed on launch. Carl recorded an introduction for that. We were involved in a lot of things and Carl was involved in all of these, not to mention his many-faceted other parts: nuclear disarmament, environmental, media, writing and policy advice.

Oh, yes, and being a father of young children. When I got that phone call at 3 am (or whatever it was), it was both a shock and not a surprise. Carl had been in fragile health for some time. I had visited with him during his final months of treatment in Seattle, I knew it was touch and go, though probably not so much. Bruce Murray was terrific – he stepped right up knowing we had to act going forward. Carl was huge but even he never let him define The Planetary Society – he made it a synergistic effort of all of us. Bruce jumped in and immediately began working on getting our Board to step up into a post-Carl world. I remember that last visit in Seattle I had with him—I don't know if that was my last visit with him or not—but I said, "You think these treatments are going well?" I said something to that effect. "I hope they continue to because we certainly want you better." He said, "Don't worry. I have a lot to live for." But then he was dead in a few months. Like I said, God love Bruce Murray – he strategically directed us into the post-Carl world. Neil deGrasse Tyson became chairman of the board. Bruce Murray became president. Or, was it visa-versa? Bruce and I recruited new Board members, eventually getting Wes Huntress, Kathy Sullivan and later Elon Musk along with others.

ZIERLER: Was Neil deGrasse Tyson already established as a public figure in science? Was he sort of like filling Carl Sagan's shoes in that regard?

FRIEDMAN: Not yet, but he was getting there. He was well known, becoming, but not quite yet a celebrity. He occupies a similar public niche now, but he is different from Carl, By the way, I recruited Neil on to our Board by standing with him in a NY subway station late one night for about 40 minutes, talking while trains roared by. I don't think we would choose that as our meeting place today.

ZIERLER: That's right.

FRIEDMAN: But Neil was a persona, and beginning to be recognized.

FRIEDMAN: And as I said earlier, it was a hugely active time for us with Mars mission in 1996 and planned ones for 1998, On that one we had a Mars microphone that we were piggy-backing on a Russian experiment that itself was piggybacking on the Mars Polar Lander.

ZIERLER: The high-profile Mars mission failures at JPL at the end of the 1990s, how did that register for you and for The Planetary Society?

FRIEDMAN: Huge. On the Mars Polar Lander we had a microphone – the first to go to a planet and listen for whatever sounds are there. It was privately funded from donations of members and built by colleagues at UC Berkely. NASA wouldn't consider it, and science teams initially sneered at it as a stunt. But we arranged to piggyback on a Russian lidar experiment that was on the mission. My good friend, Slava Linkin, from the Space Research Institute in Moscow, was the PI. Including a Russian experiment on an American planetary mission was an initiative supported by Dan Goldin and Wes Huntress in support of the more general space cooperation that developed in the 1990 after the Cold War. Huntress had initiated a "Mars Together" initiative with the Russians, and we helped in facilitating it.

No Russian missions were possible, but a positive result was getting some good Russian experiments on American missions. On the day of the landing the LA Times published a picture of the Mars Polar Lander calling out only two of its instruments – the camera and our microphone. That annoyed NASA. But Slava was part of the science team and they were terrific. This mission was led by David Paige (a Caltech graduate) at UCLA and they were conducting the science operations there. So for the whole two weeks leading up to the landing Slava and I went down to UCLA and participated in the science operations planning and preparations. We were hoping to hear sounds in the Martian atmosphere – either natural ones, or what interested the engineers more, of the spacecraft itself. But MPL crashed. We were not inexperienced with mission failures, but after the Pathfinder mission success and the Climate Orbiter failure it was a huge blow – personally, for Slava and the Russian team, for our microphone team, for Paige and his science team, for JPL, for NASA, and indeed for the world. The twin failures of MCO and MPL was a huge embarrassment to JPL. But, again, God bless Dan Goldin because the reaction could've been to lash out and blame JPL or the technical team or to cancel the Mars program. Instead, he doubled down on the program, and personally took the blame for demanding too much "cheaper and faster" instead of better. Charles Elachi was in charge of the Mars program – and he determinedly moved on to fix things at JPL and to redefine the program. He could also have had a negative path after those failures, instead he rebuilt the program and took it new successes as a great JPL Director. Speaking of JPL, and by the way, I don't know if you noticed, as an aside, the very tough report JPL got this past week.

ZIERLER: I did.

FRIEDMAN: Did you see that?

ZIERLER: I did.

FRIEDMAN: It'll be interested to see how they react to that. But one way they already reacted is they delayed a Venus mission they were going to be working on in that timeframe. I suspect there's going to be some management changes in the projects divisions there. It's going to affect MSR for sure. If you remember, I was saying I have a lot of feelings about it, and I think MSR could be an albatross around JPL's neck. But back to the '98 mission, I mentioned it was a large personal loss because of the Society's Mars microphone on it. And because we had so deeply invested in the effort for "Mars Together" and for the new Mars program generally. We were very involved. Carl, Bruce and I were all close to Goldin, and worked closely also with Huntress and Elachi in defining the new Mars program after Pathfinder. Goldin also wanted a science component to complement the new space station cooperation and I went to Russia with Goldin to help develop that. When Mars Together collapsed (Russia could not deliver) . I wrote Dan a personal note, saying, "You can blame it on me." I thought we had it all set up. But, he didn't blame me – it was bigger than me. But we did pave the way for those two Russian experiments on Mars Polar Lander, and that in turn allowed us to piggyback our microphone on to the Linkin's Lidar experiment. What a loss. On many fronts, but none bigger than the end of Russian space science, in my opinion. We (Americans) recovered; they did not. The microphone experience, as part of that mission, was my first personal opportunity to sit in with the science operations planning for a mission – I mentioned it was led by Dave Paige at UCLA. The science team was wonderful, integrating the Russians and us in as they planned their primary mission for surface science. Not only was did the lander crash but two penetrators on the mission were also lost. A very good friend of mine who had worked with us since his student days at Utah, was the chief engineer on those penetrators – so the loss was even huger personally, as well as programmatically. The Society also had a Planetfest going on in Pasadena to celebrate the mission landing. JPL management and NASA management came down to Planetfest, addressed the crowd, and said, "It's a disappointment, but we'll be back"—and they were a couple of years later.

ZIERLER: Lou, did you have a working relationship with Ed Stone during his time as director of JPL?

FRIEDMAN: Yes. It wasn't anywhere near as close as with Bruce, of course, but it was solid and collegial. But, we were always outsiders, independent of JPL, you understand.

ZIERLER: Of course.

FRIEDMAN: —that we had no influence or no benefit from the JPL thing, other than collegial. There was some up and down tension with NASA from time to time, but it never was anything serious in those years, and Ed never let it be a problem. We had a good working relationship with Ed, and he was wonderful. By the way, it extended even after I left. When I was at that Keck Institute for Space Studies (KISS) study that I called Ed and he joined to lead a KISS study on Exploring the Interstellar Medium. I guess it was in 2013. I had already left The Planetary Society. Ed and I continued to see each other a little bit in the years afterwards, although I haven't obviously seen him now for a while.

ZIERLER: Lou, I'm curious. On the point of The Planetary Society being separate, and not officially part of JPL, of course, does The Planetary Society or you have any role in the decision of the next director?

FRIEDMAN: No, absolutely not.

ZIERLER: When Ed stepped down, is anybody from NASA calling you, and asking about your opinion of Charles Elachi?

FRIEDMAN: First of all, no. The director of JPL is not selected by NASA. It's selected by Caltech.

ZIERLER: But it has to be approved by NASA.

FRIEDMAN: Yeah, exactly. I had discussions with people about Elachi but, no, we had no role in that. It is possible that Bruce Murray as an ex-Director of JPL may have been consulted, but I don't know.

ZIERLER: Were you happy when Elachi was selected? Was that a positive development?

FRIEDMAN: Very much, yeah. We had worked closely with Charles over the years and were publicly and privately very positive. I mentioned we were closely engaged with him during Goldin's time when the Mars exploration program was structured. I knew Charles well, you may recall I mentioned that one of his first jobs at JPL was as study scientist on the Venus Orbital Imaging Radar study I was leading. I long-kidded him about once being his boss and he reminds me quickly that he went on to do better things.

ZIERLER: In the 2000s, beginning in the 2000s, the new century, what were some of the key initiatives of The Planetary Society?

FRIEDMAN: We were still very involved with Mars missions. We had major public engagement activist on the rover missions including a project with LEGO, called "Red Rover, Red Rover." We got our "Visions of Mars" DVD to fly on Phoenix in 2007. But it wasn't all Mars, we got behind the development for a mission to Pluto and became very active advocates for that in Congress, collecting signatures, lobbying, etc. Since that mission was not a JPL mission, Elachi was not very happy with us for that advocacy – JPL was working on an alternate outer planets strategy and the way too unrealistic Prometheus nuclear power program plan for a Jupiter Icy Moons Orbiteer. After our successful promotion of New Horizons, the Pluto mission became to be called, we did turn our attention to Jupiter's moon, Europa, and began heavily lobbying for that. Somehow I enlisted James Cameron in that effort with us and he joined us on a trip to Washington to meet with Sen. Mikulski. I had met Cameron through a contact with a startup company here in Pasadena, IdeaLabs, and we hit it off pretty well.

ZIERLER: Was the Pluto mission at all geared toward this controversy over whether Pluto is a planet?

FRIEDMAN: No. [laugh] That was, in my view, a tempest in a teapot. Alan Stern, the PI of the New Horizons Mission, felt that not calling it a planet diminished its importance. Others among us felt that making it the largest of a newly realized important class of objects, first called Dwarf Planets, later Kuiper Belt Objects, made it more important. And people became emotional over it – but this was all after the lobbying to get the New Horizons project approved. I'll tell you the story. Let's see. No, I can't tell you the whole story on that. But that just became a tempest in a teapot of arguing over names. I forgot where it started, but Neil Tyson became kind of one of the lead advocates of selling the idea that it's a new class of object. Pluto will be the biggest of this new class. First, they called them dwarf planets. Then they became Kuiper Belt objects, and things like that. Instead of being the last among the planets, it became the first among, and so that was a positive. But the International Astronomical Union, IAU, got into it, and they decided to intellectualize it to death, and come up with these criteria, and it failed their criteria, and so they made it a non-planet. There was this whole notion of whether or not it should be a planet or not. Neil ended up becoming publicly famous because he was the director of the Hayden Planetarium, the most visited planetarium in America. In the exhibit, they took Pluto out of the planets, and stuck it somewhere else, and so it made front page on The New York Times and everything else. He and Alan Stern were like this, and there was all this controversy and everything like that. But a rose by any other name is still a rose, which is ironic because the Hayden Planetarium is the Rose Center. Neil Tyson, who was Chair of The Planetary Society Board became a face in the argument when, as Director of the Haydn Planetarium in New York, he had their planetary exhibit changed to remove Pluto. But for me, it was much ado about nothing – but created teachable moments to discuss planets.

ZIERLER: Right. [laugh] Lou, did you see all of the Mars missions as sequential, in other words, one leading directly to the other, or is that not how you think about them?

A New Age of Exploration

FRIEDMAN: Yes, I did see that. That's how it was done. Mars is big – as much land area as Earth. And it is varied. So always we see Mars exploration as a series of missions for different places and different investigations. In addition the program has always been moving for the goal of sample return – a big, complicated, multi-faceted mission, and toward the even bigger goal of human exploration there. So always we see Mats mission in the context of a program or series of missions. In a slide I prepared this past year for a talk I gave in Armenia, "50 Years of Mars Exploration," I compared the pace of Europe's exploration of the Americas with that of the Earth's exploration of Mars over the first 50 years, or 58 years, as it turned out, of each. They were counting from 1971 the date of the first Soviet lander mission (unsuccessful) instead of 1964, the first Mars mission.

Comparing 1492 to 1550 exploration of the Americas to 1964 to 2022 exploration of Mars we find that the pace was about the same – in fact exactly the same number of missions or expeditions. And they had similar fits and starts. And projecting ahead, one could plausibly argue that Martian settlement (whether by robots or humans) will be at about the same time period as it took to get American settlement after Columbus. I found that interesting. The big open question is when humans will go to Mars – the way robots and AI are evolving, there may turn out to be no interest in that.

ZIERLER: Lou, in our first conversation, you shared some of your misgivings about Mars Sample Return. Did that happen for you from the beginning, in other words, from the beginning of the Mars Exploration Program, you saw these problems?

FRIEDMAN: No, I've always been an advocate of Mars Sample Return. I led one of the early studies. I made presentations to the National Academy of Sciences in favor of it. But what I observed is every time the technical presentation came together, it then hit a wall because the cost and the complications that went into it. It needs international cooperation and a rationale beyond science interest. I'm still an advocate of Mars Sample Return. What I'm concerned about now is it's a fragile design of the NASA plan for it. It depends on European politics, which we'll see in three weeks how much support they give to it. It depends on this now no second rover, so they're going to have a helicopter, which has never done a mission, to go out, pick up samples, and bring it to someplace. It has a whole bunch of single point failure modes on an $8 billion mission, and their only solution to the failure modes is, "We'll just try it again." They'll have to build all those political alliances and that thing all over again. I think now what's changed—and this is what's changed from my day—is Mars is big; a lot to explore. Every time we go to a different site, it's something new, interesting, new discoveries.

Furthermore, Curiosity was the tip of the iceberg to what you can really do with good instrumentation. The first couple of rovers didn't have much because they were just engineering developments. Curiosity had a science lab. It was the Mars Science Laboratory. It really had some good geochemical analysis and other things. Perseverance has almost nothing because it's only about picking up samples that will later be analyzed. If we can send Curiosity type rovers to 10 places on Mars, that would be one hell of a lot of information that we would gain. Furthermore, instrument development is really miniaturizing, so we may be able to do not the full equivalent of Earth-based Earth laboratory analysis, but we'll do much better analysis. I think now, there's a much stronger argument for doing multi-site repeat investigations, sending out a fleet across the Martian landscape.

ZIERLER: What were the prospects when you were still at The Planetary Society—?

FRIEDMAN: Look, I've got to tell you, just to make it clear, even if I was director of The Planetary Society, I wouldn't take any position on that. We at The Planetary Society didn't claim to second guess NASA/JPL mission design, even when we knew better. [laugh]

ZIERLER: [laugh]

FRIEDMAN: —we didn't claim that we knew better than NASA how to technically do the mission. We took a much broader perspective on that. At least publicly.

ZIERLER: What was The Planetary Society's position on ocean worlds and icy words when you were director? Was it advocating for rover missions and things like that?

FRIEDMAN: Very much so – rovers as I have explained earlier, Europa and ocean worlds generally, we're very, very excited. I told you already. We became great advocates of the Europa mission because it has an ocean, likely, underneath the surface. By the way, not just Europa but even Ganymede probably has some surface lakes if not oceans. The discovery of water vents on Enceladus and, ultimately, even on Europa, it's pretty exciting. We were cheerleaders. Look at The Planetary Report. You'll see great pictures of these, and articles about them. We use it all to advocate for the Europa mission. We went along, because it was the right thing to do, with the NASA mantra or the Wes Huntress mantra in the planetary, "Follow the water." That was the mantra for all of the early 2000s and everything like that. It applies to Mars, to other worlds of the solar system and even to exoplanets. Wherever water is, there's a good chance of life. You learn something. Follow the water.

This also came at the time when exoplanets were beginning to show themselves. That was a curious thing. Carl, in the mid-90s, was early-on commenting on the significance if these exoplanets. He had very much entered into the field of astrobiology, and helped to define it. Goldin at NASA was discovering the field and he, too, realized that exoplanets were entering the age of discovery. I didn't get it right away – I am all about space missions, and at first I considered exoplanets as just another observing thing for astronomers. But I soon learned. It was funny, Carl was out there advocating exoplanet observations and astrobiology studies in NASA, and then Goldin comes up to us during a premiere of the movie, Contact, Carl's movie, and says to Bruce, Carl and me together and says, "We've got to do something about these exoplanets. You guys have got to be advocates more. I'm starting a group in Astrobiology Institute at NASA to look into the questions of life on other worlds." Carl was a great supporter of that. I was still fussing about it being "only" Earth-based astronomy, but Carl says, "Shut up, Lou." And Bruce agreed. [laugh]

ZIERLER: [laugh]

FRIEDMAN: To be more precise, I got it completely about the importance of astrobiology and seeking to study life on other worlds. It is just that I didn't initially see how exoplanets related to our mission of getting out there to explore new worlds. Stupid on my part, since I full well understood the importance of comparative planetology and studying planets everywhere. Well, I have corrected that and my next book will be all about exoplanets and suggesting a new fieled of comparative astrobiology. Dan started the Astrobiology Institute, and Carl got into the exoplanets, unfortunately, just as he was dying. But the result has been an explosion of activity.

ZIERLER: Lou, on that point, what opportunities were there for advocacy of interstellar travel when you were director?

FRIEDMAN: We co-sponsored a conference way back in the '80s at NYU in NY about practical interstellar travel. Bruce Murray had held a couple of meetings at Caltech, looking at the issues involved in the subject. Then when we started to do the solar sail, I thought at at the time that it was the segue to interstellar flight. Interstellar flight with any kind of propellant is essentially impossible, or impractical. Even with nuclear energy it is unreachable. Absent some un-invented means of propulsion like anti-matter drive or wormhole travel, the only practical idea seemed to be to be powered outside the spacecraft from an external source – laser sailing or some other form of electromagnetic sails. I had thought of solar sail as the first step along the path to enable that. So were interested and participated in workshops and discussions, and made it part of our solar sail story. But as I got deeper into the subject I have come to understand that even laser sails don't make for practical interstellar flight, and that solar sails don't technologically lead to laser sails. But this is a realization I have come to understand and develop after my time with The Planetary Society.

ZIERLER: What does laser sailing look like? What does that mean?

FRIEDMAN: It means you take a laser either from Earth or from space, and you fire it at the sailcraft, and that transfer of momentum from the energy of light creates a force that accelerates the spacecraft. The idea of using it to enable interstellar flight was proposed by Bob Forward, a physicist who worked for the Hughes Corporation here in California in the 1960s. Forward was not only a brilliant physicist who published the idea with all the technical equations, but he was an excellent science fiction writer who also wrote a novel further elaborating on laser sails. Forward was also a bibliographer of interstellar flight, peripatetic and prolific on the subject. I knew him veery well. The concept has been updated and taken to new levels of details by Prof. Philip Lubin at UCSB, and adopted by the Breakthrough Initiatives group hoping to develop an interstellar flight. Lubin's work is comprehensive, and while it led to a serious proposal for creating an interstellar flight to the nearest star, I think it shows the opposite – namely the impracticality of it. Lublin's work forms the basis for the current effort by Yuri Milner and the Breakthrough Initiatives Starshot project. But the numbers tell the real story – hundreds of gigawatts of laser, with miles and miles of laser arrays, focusing a beam on a one gram spacecraft – that's right one gram total mass for the spacecraft, payload, and sail – and accelerating it to 20% the speed of light for a 20 year journey to Proxima Centauri, the nearest star. And then they go by whatever is there, say a planet, at a speed of approximately 10 AU per day! Not going to see or measure much at that speed. And, that is just to the nearest star – not the most interesting one for habitable exoplanets. They are ten to a hundred times further. If that makes me sound like a naysayer on interstellar flight, it is because I am. You can see this when you go to interstellar flight conferences and notice they have only ideas from the science fiction world for propulsion, and indeed are populated with science-fiction authors. I earlier mentioned to you that I was drawn to the subject when I thought solar sailing would lead to it – but after working with Lubin's calculations and others, I am convinced it is not practical. We did delve into it with conferences and articles at The Planetary Society and I had a wonderful discussion with Freeman Dyson about it which we published in The Planetary Report. You know who he is?

ZIERLER: Of course!

FRIEDMAN: I knew Freeman. I got to know him very well. I'll tell you a story about him, if you want – it is an aside, but it is a Caltech story.

ZIERLER: Yeah.

FRIEDMAN: The aside is, remember I told you about this KISS workshop that we organized—

ZIERLER: Yeah.

FRIEDMAN: —with Stone? Freeman was invited to it, and he participated with us for the 33-4 day workshop. At the end, I'm sitting up at the podium and I ask everybody, go around the room, "What have you learned in the last week, three days we were here? What's your takeaway?" When I call on Freeman, and he says, "This was so wonderful for me. I learned so many new things. It was really an honor and a pleasure for me to be able to get out of my ivory tower in Princeton," where he is, "and come here with you in the real world." I said, "Freeman, you realize you're probably the only guy on Earth who would call a week at Caltech the real world"

ZIERLER: [laugh]

FRIEDMAN: He goes, "Oh, yeah."

ZIERLER: Oh, that is great. [laugh]

FRIEDMAN: Anyway, we did this conversation on interstellar travel, and I remember kind of the one question I asked him. "Are we any closer to interstellar travel today than we were 50 years ago?" The answer was kind of no. It's still true now, 30 years later.

ZIERLER: Lou, is that both about the technology in getting there, and also the timescale of making it something that we could track from generation to generation?

FRIEDMAN: Yeah. First of all, interstellar travel is easy. Voyager's doing it right now. If you just ignore time, and just say, "Eventually, we can do it," yes. If you believe in generational spaceships where we're going to build it, and then there are going to be either self-replicating or people-replicating colonies or a Star Trek type thing, no. I'm talking now about practical missions within a century. I come at it two ways. One is the technology is impossible, and if you could do it like this one-gram payload with a 500-gigawatt laser and all that, you would still be going 20% the speed of light. It makes no sense – and even if it did, it's doing the wrong problem. We want to find out about life on other worlds – not just the nearest one, which is not a very likely place to find it. This is what has led to my new book coming out this year, Alone But Not Lonely, Exploring for Extraterrestrial Life. We have to think differently - real interstellar exploration will be virtual.

ZIERLER: But is it all worth it, talking about discovering exoplanets, the search for life beyond ours? Is it all ultimately worth it because even with the best telescopes—?

FRIEDMAN: Is it all worth it? Depends on what each of those "its" are. Discovering life on another world will be priceless. On the scale of finding out that the Earth is not the center of the Universe, or that humans evolved from earlier species on Earth. How it's done, how we cam explore for other life and then ultimately explore what we find will of course involves expenses that society will have to judge as worth it or not. I gave an example of SETI, which I think is unlikely to bringing any results about extraterrestrial life as still "worth it" because it isn't very expensive. I could give an example of the other extremes – a remote discovery of life on an exoplanet 10 light-years from us. Would it be worth it to mount a mission to go there and make contact with that life – certainly a huge value, but still not worth the cost because of its impossibility – better to find alternate ways to seek that knowledge. In our own Solar System it is certainly "worth it" to investigate the water worlds of Mars, Europa, Enceladus, Titan – because it is within our means to conduct planetary exploration and whatever we learn as we explore will be part of a growth of knowledge and understanding about our place in the universe and ourselves. The mission concept we've been working on for the last several years, going out to the solar gravity lens foci of interesting potentially habitable or inhabited exoplanets that I believe will be worth it.

We will see, up close, tens of billions time magnified those worlds and maybe life on them. ou can see continents and water and vegetation on them and that exploring will be of new worlds – literately and figuratively. And, as I see it, we will bringing that data back to Earth and creating VR models with those data and making those new worlds not just places to explore, but to visit. That's real interstellar exploration because by the time we do that, we'll have new technologies available to us: artificial intelligence to do the searching; and virtual reality to build the models that can bring them into 3D holograms that allows us to explore them right here on Earth.

ZIERLER: Let's get back to that reset that you wanted to do.

FRIEDMAN: Yeah, because you asked me what else we were doing in the early 2000s. And I answered all about planetary exploration – that's my love. But for the Society, I started something else which became dominant in time – our ventures into solar sailing. The solar sail. We ended up being the first nonprofit space organization to do its own space mission. Solar sails have eluded NASA – only we and the Japanese space agency have flown successful solar sail missions. It was a pretty long road for us – begun in 1999 and not completed until ten years after my retirement. It began like this: In 1999, my friend, who I mentioned already, Slava Linkin, and Russian colleagues came to us, and said, "We can do a solar sail mission. We'll give you a free launch. We have the launch vehicle," which always was an impediment to doing it because launch vehicles are expensive. They also were working on inflatable booms for some other application. They said, "We can take those inflatable booms and the spacecraft to deploy them and the sail, if we could supply the sail itself.

So, we checked them out – we put our own team together and went to Russia to check them out. The team we had included Bud Schurmeier, retired from JPL, an assistant director and one of the legendary project managers of Voyager and Galileo there. Also, Jim Cantrell, a seasoned aerospace engineer with a broad background in systems engineering for NASA and DoD. To fund our initial study we went to a new startup entrepreneurial group in Pasadena, IdeaLabs, whose principals were Caltech alumni, Bill and Larry Gross. We concluded the project was feasible and reasonable – but the startup company under IdeaLab hired a new CEO who was not interested in our solar sail. They were focused on a lunar lander project (which never happened). We regrouped ­– fortunately it was during the Internet bubble, before it burst. We had contact with a real space and SETI enthusiast who committed to major donations to the Society – Brice Murray led that effort with me. And with his funding, we launched the project which became known as Cosmos 1. The Internet bubble burst and our funding was about to disappear until Ann Druyan who was co-venturing what became Cosmos Stuidios with the Internet entrepreneur used that venture to sponsor Cosmos 1.

Ann, you know, was Carl Sagan's widow. Thus the Society bit the bullet and started its own journey into space. The development of Cosmos 1 took five years. We got a free launch opportunity to test deployment of the sail on a sub-orbital flight launched by the Submarine Launched Balliustuc Missile, Volna. I got to go out in a Russian Navy boat in the Barents Sea and watch the launch. They screwed it up and lost the payload instead of recovering it in Kamchatka as planned. But that was nothing compared to big loss of Cosmos 1 itself, launched on a defective Volna in 2005. It fell into the Arctic Ocean. The Russian scientists and engineers we worked with on the project were decent and excellent, but their comrades in the military launch industry were dishonest and crooked. After the loss of that spacecraft I was ready to give up, but Ann continued her support, and our team and staff wanted to keep trying. It took a few years, wooing potential sponsors and donors, but finally we started LightSail, based on a NASA CubeSats design that we improved upon. We got one large donation to kickoff the project and great member support for our funds and built LightSail. We actually built two LightSail spacecraft – one for test. When there was no certainty about launch, we put the spacecraft in storage and I retired. But the Society carried on, arranged for launches in the newly emerging capability of secondary payloads, and LightSail ultimately flew a hugely successful 3 year mission – only one of two successful solar sail missions, and the only American one. That was our big project of the 2000s.

ZIERLER: Lou, when did you start to think about stepping down as director?

FRIEDMAN: In the mid-2000s. There were two driving factors: one was the Internet, especially the development of social media. That brought forth a whole new approach to building constituencies and advocating for public interest. I felt that was a new generation's thing and didn't want to be playing that techniques game all over again like I had done in the 1980s with direct mail. The second was an increasing dissatisfaction at the evolution of the Society's Board of Directors. The loss of Carl was huge, and then we really lost Bruce – not to death, but to Alzheimer's. Without them the drive for excellence diminished. Probably that was partially due to me – I could not engage our Board in its own development. The Board became more pedestrian. If LightSail had a clear path to its finish line, I might have stayed on, but it too was bogged down with no launch vehicle. A third factor was that I was approaching 70 and I did not want to become the old guy that everyone was waiting to die or disappear, as I had seen in other organizations. I wanted to step out while I was in control.

ZIERLER: With the emeritus status, did that give you an opportunity to stay engaged, to keep your voice in the mix?

FRIEDMAN: That was the intention, and indeed, the Board and I made an agreement for me to do so in a couple of particular areas including LightSail and International relations. But, it did not work out – my replacement was uncomfortable with me around.

ZIERLER: [laugh] Did you have a say or any strong opinions about who your successor should be?

FRIEDMAN: Yeah, I did. We had interviewed several people. We put out announcements about it. We weren't finding the right person.

ZIERLER: Who was the right person? What did The Planetary Society need at that point?

FRIEDMAN: It's a good question. We wanted the person to be committed to space exploration but to have the ability to run an organization, to be familiar with the workings of the space program but to also be familiar with the workings of leading an organization. We had to balance two conflicting aspects – inside (a person who could run the organization) and outside (a person who was a popularizer and popular with the public). As it turned out, we gave up and soon after we selected Bill Nye, within a year we needed a Chief Operating Officer, for the inside part. We interviewed some very good people but they ended up not wanting this job. I then began thinking about Bill Nye – he was at this point, Vice-President on our Board, and he and I had been working closely together on various initiatives of the Society. Bill was very well known and a desire for organizational involvement despite having been a gadfly for most of his career. I began discussing it with other Board members and staff, and came to the conclusion it would be a boost to the organization to have a popular figure – even if not one specifically engaged in planetary science. Other Board members were supportive for the most part.

ZIERLER: Bill Nye, of course, has been very public about climate change and environmental issues. We see with JPL, the Lab has gotten more involved in Earth science and things like that. Has The Planetary Society gotten pulled more into looking at planet Earth?

FRIEDMAN: This is the irony. I was trying to get us pulled more into the Earth science. I had discovered indeed that Earth is a planet! I led an advocacy campaign for the OCO, Orbiting Carbon Observatory mission when NASA was canceling it. I was pushing hard on the Earth is a planet argument, saying that everything we learn about the Earth is what we're learning about other planets. Intellectually, it's connected, and we need to broaden our base. I was trying to make alliances with environmental organizations, not to become engaged in regulation and political issues, but to advocated and educate about the science of climate and other Earth processes. It was consistent not only with planetary science, but with planetary scientists – Carl and Bruce both had extensive involvement with comparative planetology and Earth as a planet understanding. We had some staff and some little Board pushback – fear of controversy, which I of course, loved.

Controversy is good for organization development and attention. Except when you are on the scientific side of the argument. But the irony is, that after I left and Bill took over, the Society dropped the subject. This, despite Bill's personal public engagement against climate change deniers. I think they became worried about mixing his personal opinions as a popularizer with the Society's advocacy. The Society is doing well with Bill and its Chief Operating Officer is running the place well – but they have not broadened their base; in fact that have, in my opinion, narrowed it. But, it is a good base and I am happy with the organization's development. Proud of it in fact.

ZIERLER: Lou, when you stepped down, what aspects did you see of this as a retirement, and where was new opportunity for you to take on other ventures?

FRIEDMAN: I didn't have plan – I had ideas about staying engaged with the Society and with others in space activities. I did not have one of those usual ideas about say travel more – we had done a lot of that, pursue a hobby, woodworking or something – I didn't have anything like that. Not even stamps, although I have an old collection.

ZIERLER: [laugh]

FRIEDMAN: —but I never look at them. Connie and I did like to travel, and I mentioned already anticipating continuing my international involvement. Financially, we were OK – retirement did not require a reduction in our lifestyle. We had no desire for less, and no need for more. Then Connie became ill, which led to more demands on things at home.

ZIERLER: Lou, what about consulting, particularly in industry with the rise of Blue Origin and SpaceX?

FRIEDMAN: I did a little of that. I started doing a little of that. Maybe I should've tried to do more. But I soon got involved with the Keck Institute for Space Studies here at Caltech, with a couple of studies – and one outgrowth of that was a many year involvement studying the mission concept for reaching the solar gravity lens and imaging exoplanets. I did consult with both JPL and Aerospace on this. And I got involved with the subject of interstellar exploration through the Breakthrough Initiatives, ending up on the Starshot Advisory Board and then writing a book about the future of human spaceflight. That has been a big surprise – me becoming an author.

ZIERLER: At a general level, are you welcoming of industry getting into space science, the kinds of things that SpaceX is doing? Do you see this as a positive development?

FRIEDMAN: There's two ways you can put that because SpaceX isn't into space science at all. They are a rocket company whose founder has a visionary goal of moving off this planet. Very little of the commercial space industry is into space science or exploration – it is basically not a commercial activity. That said, I am not negative about those commercial activities – they are more or less for me like other commercial ventures, space or non-space. Not my thing, and value judgement depends on individual cases. I am a little skeptical of the hype because the success of most of these commercial ventures has little to do with their product and more to do with their stock prices. I do however want and encourage a vibrant space industrial base – big, traditional companies like Lockheed Martin and Northrup Grumman that did get into space science, Northrup Grumman building the James Webb Space Telescope, for example, Lockheed Martin on planetary missions. As for commercial companies, I don't care much, except maybe as a consumer, what internet or communications services they are providing or their remote sensing sales – I wish them well, like any other industry, as long as they are legitimate and not harmful. Same with space tourism – its exciting, but so is Mt. Everest or the Antarctic. It is tourism, not space exploration. I like communication satellite companies and I like baseball with equal relevance. Elon sending a tourist around the moon, it's pretty damn exciting and noteworthy, but so would've the Yankees winning the World Series—

ZIERLER: [laugh] Fair point.

FRIEDMAN: —been exciting and noteworthy. It's kind of other things that are going on, not me. Now, if you ask me which I'd rather do, go to work for SpaceX on their moon mission, or go to work in the front office for the New York Yankees, I'd rather go to New York Yankees.

ZIERLER: [laugh] Lou, moving the conversation closer to the present, what was the inspiration for writing the book? What were the ideas? What did you want to convey?

FRIEDMAN: This is really weird because I never considered myself a "writer" nor did anyone else. I did not expect to write three books during retirement. But, perhaps as a result of having a shorter future or else of having a longer past, I got interested in the question of life in the Universe more after I retired. Of course, I always regarded it as the driving question and rationale for space exploration. And I always found the notion of advancing human kind as a multi-planet species, getting us to Mars, as the goal of planetary exploration. But the fiction about human space flight – so-called Moon, Mars and Beyond drove me nuts. It was offered as if there was nothing else going on since the 1950s vision of human space flight. As if there has been no progress in robotics, electronics miniaturization, processing speed, artificial intelligence and virtual reality. Human spaceflight seems to be based on ideas of clunky space suits and cumbersome life support systems for big people stepping in a hostile environment. So what motivated me was a combination of debunking the old thinking and offering some new thinking. That characterized Human Spaceflight From Mars to the Stars and the new one, Alone But Not Lonely: Exploring for Extraterrestrial Life. In between, I got motivated to tell the story of my remarkable adventures that I had while at The Planetary society working with Russians – so as not to let those stories be lost. That resulted in the memoir: Planetary Adventures From Moscow to Mars. Soon after my retirement, I was invited to a workshop run by DARPA and NASA, called the 100 Year Starship – considering the possibility of interstellar flight. There were 25 to 30 participants, and spent all day talking about interstellar flight possibilities.

At the end of the day, they took a vote about what should the 100 Year Starship goal be, humans or robots? The vote was 24 to 1 for humans. I was the robot, because the technologies that people are talking about are evolving so fast for robots, and they're not evolving at all for humans. As I said, old ideas about human spaceflight which haven't changed in 50+ years. That realization was an epiphany for me, and that is what sent me off to the post-retirement interest relating to the future of humans in space and exploring for life on other worlds. That and the fortuitous connection with Slava Turyshev at the KISS Workshop examining the possibilities of the solar gravity lens. Anyway that association with the 100 Year Starship, now an organization led by Mae Jemison who I have really enjoyed getting to know, and with Starshot and Breakthrough, that led to Human Exploration: From Mars to the Stars in 2014. The work on the solar gravity lens led to Alone but Not Lonely: Exploring for Extraterrestrial Life. I am hoping that is legacy will be suggesting a new field of comparative astrobiology to drive space exploration in the next century.

ZIERLER: That's exciting. I'm so happy.

FRIEDMAN: That's where I'm up to. But who knows really what, if anything, will come of it.

ZIERLER: For sure.

FRIEDMAN: I did get asked to do a couple of things that I don't do. There's a few things. I'm 82 years old. I don't need a lot to do. I was undisciplined when I was working. I'm less disciplined now.

ZIERLER: [laugh] Lou, to bring the conversation right up to the present, you were in Armenia recently. What's occupying your time these days?

FRIEDMAN: The book is still being finished up. It just finished its copy edit. Now we're going into production. The solar gravity lens focus mission study has ended. However, we have a lot of people interested in it, so we've begun talking. We're going back to NASA and to Applied Physics Lab, APL, next month to talk about it. They may want to do some joint work together on it. We have tried to interest the Breakthrough Group into privately funding some continued development work. They have not been able to do that. If that goes nowhere, I really have nothing to do anymore. Beyond that, no specific work plans – a bunch of person plans, travel and get together with people, reading Boks, going on walks, taking care of the dogs, etc. I am interested in what is going to happen in planetary exploration in this decade – we spoke of my concerns about the Mars Sample Return and my fear it will actually eat up Mars exploration. The Europa Clipper is a big mission too, and I have been working with others to develop a low-cost, fast, small missions. But I doubt I will programmatically get involved with that. I will follow the space program but won't be a part of it. Part of that following is the international aspect – I am impressed with what China is doing, and believe the U.S. is not doing well with China relations. I am following it both in space stuff, and more generally in our foreign policy. I think my experience in and post-Cold War with Russia is applicable in approaching the issue of China and the question whether engagement with a competitor is better than barriers to them.

ZIERLER: All of these advances by China, do you welcome this? Is this good for America, for US competition?

FRIEDMAN: Oh, yeah. First of all, there's three things you can do with China. You can try to confront them, be combative. You can try to hide from them. Try to isolate them, and not deal with them, or you can try to engage. We have chosen the middle path so far of isolation. I think that is self-defeating and weakens us more than them. I have enough confidence in the United States that I think we can constructively engage them for our own benefit. As far as space exploration goes, I would welcome China into the solar system doing space science especially, Mars missions, and moon missions, of course. It's what I care about. I want them to explore the planets. It's not bad for America. You can pretend China doesn't exist, but how does that help America? [laugh] It doesn't. What are we going to do, fight and pretend that half the world's population doesn't exist? But they're going to be the biggest economy in the world by the end of this decade, no matter what. We don't want them to be the biggest military in the world but they probably will be. If we do nothing, they will be. Maybe if we engage them a little bit, it could be diffused some.

ZIERLER: Lou, now that we've worked right up to the present, for the last part of our talk, a few retrospective questions. Then we'll end looking to the future. For all that you've accomplished, what are you most proud of in terms of moving the ball forward in planetary exploration and space science?

FRIEDMAN: You're so good at this—

ZIERLER: [laugh]

FRIEDMAN: —but you still ask the questions that I resent that CNN anchors ask [laugh], which is, "What's the single-most thing?" They want an answer that big. "What's the single-most important thing in your life?"

ZIERLER: This isn't a five-minute news segment. We've been talking for hours. You can be an expansive as you want.

FRIEDMAN: Fair enough. But still there are many answers depending on context. At The Planetary Society, I am perhaps most proud of our success in getting Mars rovers into planetary missions. There weren't any until we went way out on a limb with Russian rover testing leading to American program advocacy. But maybe I am even more proud of the existence of The Planetary Society – we created and nurtured it, and it has grown up. I am proud to have put a library of Mars for future explorers. And, I am proud of our LightSail – which we conceived and flew. One more thing ranks up there in "most proud" – from my JPL days, the invention of the Galilean satellite orbit tour which became the Galileo mission. I didn't invent it alone of course, but I was a part of the invention. That feels good. But while we are being retrospective, let me say that most of all I am gratified about how interesting, exciting and stimulating it has all been.

Connie and I would always remark about this. We never imagined when I started out as an engineer working on the celestial mechanics of trajectories, that it would lead to the such a varied and adventurous life, with travels all over the world and with peoples doing so many interesting things. Remarkable people. I recall the first hint of what was to come when as a relatively new engineer at JPL I was told, with about a week's notice, to go to Paris for a meeting with the European Space Agency about Jupiter orbiter possibilities. Neither Connie nor I had ever been out of North America. We didn't have passports. I come home, and I meet Connie up at the Altadena Little League field where our two sons were playing in baseball games. I said, "Hey, you want to go to Paris in 10 days?" She said, "We can't do that. What are we going to do with the kids?" "We'll find something to do with them," [laugh] so we did (my parents stayed with them), and we went to Paris. That began a whole life of being able to go places. Of course, I told you about the experiences in Russia. But experiences in Japan and elsewhere, not to mention in the U.S. itself, I don't know if I ever got to tell you about those. It was always built around the space cooperation or space activities but making it so much broader. It's not a big thing. It's a good thing but not a big thing. But for me, I made it into something that had this great cultural worldwide thing of it. It's very rewarding.

ZIERLER: Lou, to the extent that starting off with Bruce and Carl, The Planetary Society was a professional risk for you, in light of how it turned out, what are the lessons? What are the takeaways from that key decision in your career?

FRIEDMAN: Work with smart people. When all else fails, smartness is good. It's not only good but it is exciting and interesting. Smart people aren't automatically better people. But in work when you have kind of tough things to work out, it's a good thing to go with the smart people. Bruce and Carl were terrific at that. That's the thing I thought I mentioned it maybe in one of our discussions. I think it's lacking now. When you have a narrow focus, you tend to work with the specialist or the narrow foci, where you're at. But you have a broad view like they did, they find the John Gardners and the Harry Ashmores that I mentioned, people who you wouldn't think had any interest in your subject but turned out to be so influential in so many ways that they had this really broad view of things, because they were the smart people. I don't mean to denigrate or I don't mean to be an intellectual snob when I say find the smart people. As I say, there are lots of smart people who I wouldn't let into my house. [laugh]

ZIERLER: [laugh]

FRIEDMAN: There's lots of not so smart people who are wonderful friends. I won't mention any names. [laugh] But they're wonderful people. But They are really good people, and they do so much good; more good than I ever do. I am only talking about smart people in relation to choices you may have at your job, at your work. In life generally, it takes all kinds. I wish I could've associated with them all better than I did, but, no, I spent too much time on my job. I'm not trying to do it as a judgmental thing about people. But you asked me what I learned from Bruce and Carl about my work, and I said that's where I was focusing the smart comment on.

ZIERLER: Lou, from the curiosities that got you into this business in the first place, what have we learned about the universe, and what remains as big a question mark as when you were back in grad school?

FRIEDMAN: That's of course the biggest question, the one that drives all interest in space exploration and astronomy and everything else is the uniqueness of life. Are we unique, or is life just present everywhere, and is it an accident of evolution, or an inevitable product of the universe? What is the nature of the conditions that formed this? It drives us in all these missions, and things like that. We've learned a lot. We've got a whole field of astrobiology. We've learned a lot about these things, but we don't know the answer any better than we did in 1950. I keep thinking back to that comment about, you don't get answers from science. You get questions. Even when we discover life on another world, there won't be an answer. It'll be a little answer but it'll raise many more questions, and lead to other things. That's what science is about. The fact that we haven't gotten that big answer, disappointment, yeah. But the questions that we've been asking, and investigations we've been doing, are pretty exciting, and make us better people.

ZIERLER: [laugh]

FRIEDMAN: There was an example that Phil Morrison, Professor Phil Morrison from MIT—I don't know if you've heard of him. He was one of the great physics minds of the previous generation. He never won the Nobel Prize but he could've. He was up there at that level. He was also a big thinker about the search for extraterrestrial intelligence. He once brought up the example of what'll happen when we discover life on other worlds? He says, "There'll be whole new fields of inquiry that'll open up, and a whole new thing." I'll give you an example. Copernicus discovered that planets go around the sun. It didn't change anybody's life on Earth; not the year he found it; not the year he published; not in the decade he published; not even after his lifetime. There wasn't a lot of, "Oh, gee, now my life's never going—we're going around the sun. Oh, gee, I can get vegetables growing faster. Oh, gee, I can get more food in the house." People's lives didn't change much; in fact, not at all.

But what is the impact of knowing the motion of planets around the sun? It's everything we've done in the space age. It's everything we've done in celestial mechanics that taught us the mathematics of calculus and all the differential equations, and all the things we learned in the 18th century, and it was having those data that we can compare to that. It's hard to say wherein these inquiries lay, and giving an example basically of that. I think, to me, huge disappointments we didn't discover life. We haven't gone beyond the moon. I have a thing in the file cabinet over there, which you can't see but, believe me, it's over there. It's written under my kids' names. In 1970, '69, I told them I bet them $5—some huge amount of money for the kids at that age—that they would be taking their kids on camping trips to the moon. Hell, they can't even show their kids a mission to the moon.

ZIERLER: [laugh]

FRIEDMAN: I could but they can't.

ZIERLER: Yeah.

FRIEDMAN: From that perspective, there's all kinds of things that both didn't happen and did happen.

ZIERLER: Finally, Lou, last question, looking to the future, if we can extrapolate, as you said, we haven't really made much progress on these questions really in the past 70 years. One way to look at that is all of the technology that has been developed would suggest that there will be big discovery in the next 70 years. The other way to look at that is that the nature of the question is so difficult that even with all of those advances, we still might not be anywhere in 70 years. Where do you fall on that, if you could extrapolate?

FRIEDMAN: I was afraid you'd bring that up.

ZIERLER: Listen, that's why I leave it for the last. That's the big one. What do you think, Lou?

FRIEDMAN: Let me first not leave the impression that I think we have learned little or accomplished not much in the past 70 years. Quite the opposite – what we have learned and are learning and what we have done and are doing is breathtaking. 70 years ago, we thought of planets as dots, we were not just bound to Earth, we barely traveled on it. To gain knowledge we took a trip to a library, checked out a book in the reference section and spent an hour reading, and another hour copying. Now I do that same thing in about sixty seconds on my computer. I could go on – the counterpoint I was making was to be careful and humble in asserting what we predict – we still don't have flying cars, underwater cities, camping trips to the Moon, or humans beyond low Earth orbit. On the dreamy idea of interstellar flight and on the fundamental question of extraterrestrial life, we haven't advanced. But what we have done while exploring those and related questions are fantastic advances. Now, if you are asking me to predict the future – sorry, that is as technically impossible as interstellar flight. If you are asking me to reconcile the science of cosmology with the philosophies of religion, that too I won't try.

I don't know. It's hard because you're on the border of that whole area of cosmology and philosophy. Are we just using the wrong tools to investigate these problems? I know that the philosophers and the religious will say, "Maybe you're using the wrong tools." They know the meaning of life or they're not confused about the origin of life. Yet, from my perspective, they may not be confused about it, like I am, but they're selective – ignoring what they don't know, taking only what they think they know. You asked, "is it too big a question?" Yes, for now – but that isn't to say it won't be too big a question forever. That's why we explore, pursue knowledge, analyze and synthesize. A discovery tomorrow might change things – life on another world, synthetic creation of life, a fossil record on Mars, or even a alien signal. Absent those deus ex machinas, we just keep inching up on the big questions. I prefer science to guide that rather than the arbitrariness of religion. But I, on the other hand, I don't reject the notion that we have nothing to learn from philosophy or religion. To me, the cosmology argument has already drifted into that. They're just using scientific words to get what the philosophers and the religious thinkers, theologians. Anyway, I find some of that cosmology argument leaking over in that area. I have given up reading cosmology books – and even wrote Max Tegmark after reading one of his brilliant books, "Reading your book is like reading the Talmud. It's just not going to work for me anymore." [laugh]

ZIERLER: [laugh]

FRIEDMAN: But those are good questions that don't have answers. Like with SETI, I think it is good to study them even when not expecting an answer – because we learn as we go, especially when we it brings out the best in us. I think it's good, and I think the public is good, and this is another thing that I think Carl Sagan taught me. I think the public is pretty good at dealing with uncertainty about the answers. If it is honest. They'll tell you they want to know if there's life on other worlds and things like that. But with the Mars discovery in 1996, I was so positive about that because the public reaction was, "Gee, that's interesting. Gee, we got to find out more. Gee, I wonder if it's true or not." They didn't say, "Oh, gee, you scientists never know what the real answer is. We're going to give up on you." They had the opposite thing. "No, we got to know more." I think that's what the public reaction should be and was, and I'm encouraged by that kind of thing. I think we see that even now when we get scientific discoveries reported on the news.

ZIERLER: Lou, it's been great fun spending all this time with you; a treasure for history.

FRIEDMAN: Yeah, it's fun talking to you. I'm sorry it's over. I liked it so much, I'm going to suggest we now do it in reverse. I'll interview you.

ZIERLER: [laugh] I love it.

[END]