Suzy Dodd (BS '84), Engineer and Deep Space Pioneer

The Jet Propulsion Laboratory has operated at the frontier since its inception. Its leadership in building and launching spacecraft that operate at the outer edges - and now, beyond - our solar system, and in engineering and maintaining communications systems to communicate with those spacecraft, are perhaps the most dramatic examples of how JPL is always pushing the boundaries of what is possible.

Over the past four decades, Suzy Dodd has been a key operator in these areas. Currently dual-hatted as Project Manager for the Voyager Mission and Director of the Interplanetary Network Directorate, Dodd splits her time between the ongoing operations of Voyager 1 and 2 spacecraft, and managing the complex of technologies that keep the ground-based Deep Space Network (DSN) facilities in contact with space-based activity. A profound connecting point at this juncture in Dodd's career is that both the Voyager program and the Deep Space Network are old (at least by the standards of space exploration) and yet both are going strong, with DSN keeping humanity in contact with the Voyager spacecraft as they journey ever deeper into interstellar space.

Dodd's Pasadena roots go deeper than JPL; as an undergraduate, she participated in a unique program that combined study at Whitman College and Caltech. After completing her degree in engineering, Dodd saw a great opportunity in joining the Voyager mission at JPL in 1984. In the years after their launch in 1977, the spacecraft were entering their planetary encounter phase, and Dodd reflects below on the excitement and the time crunch in gathering as much data as possible during the all-too-brief flyby encounters. In the 1990s, Dodd worked on the Cassini mission and for Mars Orbiter, one of two Mars programs that experienced mission failure. For the latter, Dodd provides important insight on lessons learned and JPL's culture of always striving to improve.

The Spitzer Space Telescope project gave Dodd an opportunity to work back on campus at the Spitzer Science Center, and she explains how this project advanced JPL's contributions in astrophysics, and how it served as an opportunity to deepen partnerships between the Lab and campus. After continuing her work for Spitzer and for the NuStar mission back at JPL, Dodd rejoined Voyager which, by the early 2000s, was on a pathway to reach interstellar space. Dodd provides important historical detail on the fundamental surprise of this development - both because the mission could have been cancelled after the planetary encounters, and because of the near-miraculous longevity of the spacecraft and DSN's ability to stay in contact with them.

At the end of the discussion, Dodd speaks powerfully for the potential of a successor mission to Voyager. Incredibly, Voyager 1 and 2 continue to transmit important data about interstellar space, and their respective breaches of the heliosphere resolved profoundly important questions about the reach and composition of solar wind. If such a mission comes to fruition, there is no doubt of the possibility of further discovery in the vast expanse between stars. But in the more immediate term, Dodd is focused on a looming milestone: 2027 will mark the 50th anniversary of the Voyager launch, and with any luck, both spacecraft will remain operational but diminished as their power supplies inevitably decrease. This will undoubtedly be a poignant event for Dodd, whose career and longevity mirrors so much of what Voyager and its teams of scientists and engineers have accomplished over the decades.

DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Friday, January 6th, 2023. It is great to be here with Suzanne Dodd of the Jet Propulsion Laboratory. Suzy, it's great to be with you. Thank you so much for joining me.

SUZANNE DODD: Thank you. I'm happy to be here.

ZIERLER: To start, would you please tell me your title and affiliations, or I should say titles—plural—and affiliations at the Jet Propulsion Laboratory, or JPL?

Dual Hatted for Deep Space Responsibilities

DODD: I basically have two titles at JPL. I'm the Voyager Project Manager, and I'm also the Director for the Interplanetary Network Directorate.

ZIERLER: What is the overlap, if any, in those two areas of responsibility, both from a scientific perspective and an administrative perspective?

DODD: There is no overlap in an administrative perspective. There's a technical overlap, in the sense that Voyager is the furthest-out mission that NASA has, that exists in the world, and it talks to the Deep Space Network antennas here on the ground, underneath the umbrella of what we call the IND network, the Interplanetary Network Directorate—IND is the acronym—so the Deep Space Network is under that organizationally. So if I give a talk about Voyager, I always talk about the Deep Space Network, because people ask me how we get those signals back from so far away. Then if I talk about what we do in IND and what the Deep Space Network does, they talk about, "What's the furthest thing you talk to?" Well, the furthest thing I talk to is Voyager. "How far is it away?" So, we talk about Voyager. So, there is a technical overlap there, but there's no administrative overlap.

ZIERLER: Wearing both of those hats, what does an average day look like? What is the amount of time that you spend in each of these areas on any given day?

DODD: It's about 20% of Voyager, and 80% in the world of managing the Interplanetary Network Directorate, and then institutional JPL responsibilities which come from managing the IND Directorate. So, it's about a 20/80 split. Actually both of those jobs are kind of 24 by 7. You can imagine a flight project, like Voyager, it doesn't stop on the weekends, and a lot of times there's activities that the spacecraft is doing on the weekends. So, you don't really get a break. Your cell phone is always on, in case it's going to ring. Similarly, managing the organization over the Deep Space Network, the Deep Space Network operates 14 antennas around the world, 24 by 7, supporting 40 missions, so there's a lot of cases where you might get a call regarding something that's going on with an antenna, too. So, the cell phone is always on. From a charging standpoint, it's about a 20/80 split.

ZIERLER: The miraculous longevity of the Voyager spacecraft, what is the timeline? What is the working assumption for how long Voyager 1 and 2 will be operational, that we'll continue to be able to communicate with them?

DODD: I think we've obviously outlived our projected lifetime by decades. To give you a little history here, it was originally planned as a four-year mission. Jupiter and Saturn were the prime missions. They knew that they could get a spacecraft to Uranus and Neptune, which Voyager 2 did, but I don't think anybody had any thought whatsoever when they built it that it would last 45 years, which it has, and that it would be out in interstellar space. Of course, they didn't know how far away interstellar space was, too. Neptune's at 30 AU. I think there was some discussion post-Neptune when they approved what we call the Voyager Interstellar Mission that it would be out at about 50 AU. Well, we crossed it at 122 AU, so quite a bit further than what was projected when we left Neptune. It's also really miraculous that both spacecraft are still operating. I think you would do things differently if you were building a mission, say, for example, like Interstellar Probe, which is a proposed mission to also go out into interstellar space, and to last 50 years. If you were building a spacecraft that you wanted to last 50 years, you would do it differently than building a spacecraft for four years, which is what Voyager did.

ZIERLER: Although maybe those purpose-built spacecraft for 50 years would only have lasted for four years. Who knows!

DODD: Yeah, yeah! That's true. It's a really incredible story, even more incredible I would say than The Little Engine That Could. It's certainly the little engine that could, and has. But I would say that Voyager could last certainly to its 50th launch anniversary. Considering we have two spacecraft, too, I don't think both of them will fail in the next five years. One might, but I can't imagine both of them failing. We have a stretch goal, I would say, to get to 200 AU. We're at about 173 AU, I think, now. So a stretch goal of operating about 13 more years, 2035, get out to 200 AU. That would be a stretch goal for us.

ZIERLER: For all of the amazing discovery that Voyager has made possible, what is left? Literally in the frontier, in interstellar space, what more about the universe might the Voyager spacecraft tell us?

DODD: Well, the universe is much, much bigger than how far Voyager has traveled. In galactic distances, we are just barely outside of our heliopause. I'm trying to think of the numbers here. We crossed in 2012, ten years ago, so we're a good 35 astronomical units away from our heliopause. What's important about Voyager is getting this record of time, as we travel out, and seeing how things change in the magnetic and plasma fields as we get further and further away from the Sun. We are the only spacecraft there. We are the only spacecraft doing it. And we have two, so we can compare the data between the two spacecraft, as well as comparing it to the models that the scientists come up with. It's really that time record, and the further away from the Earth and the Sun we can go, the better understanding we have about how our Sun's heliosphere interacts with interstellar space. That's a model for all suns. That's a model for all stars.

ZIERLER: A really futuristic-looking kind of question—do you think that with the ongoing scientific value of the Voyager mission beyond the heliospheric pause, that this information may set the stage for some future space mission that has a much longer purview, much bigger purview than 200 AU out, that might be going way beyond that into interstellar space?

DODD: The one that is currently planned, or on the books, is the Interstellar Probe Mission, which is a 50-year mission, I think with a goal of going about 500 AU, so 10 AU a year. Beyond that, you could think of ways of a solar sail or something like. If your instruments were simple enough, and you could do enough data compression, you could probably go out to, say, 500 AU. But getting all that data back takes power on a spacecraft, which you could do with nuclear power. It takes a lot of antennas on the ground to capture that. That might be kind of tricky. So, there's a lot of challenges, and they're not just all technical challenges for long missions; they're people challenges. You've got to have good documentation. You've got to have a succession plan for the people that operate it. Certainly for missions that are funded by governments, you have to have a certain amount of commitment from the government to continue to fund a mission for 50 years. Even when political congresses change and presidents change, and wars happen, and famines happen, if you're funded by a government, you have to have that commitment to continue that funding over decades, which is also not an easy thing to do.

ZIERLER: Is the Deep Space Network as it is currently configured capable of receiving communication as far out as 500 AU, or would we need a different kind of network for that?

DODD: Currently the Deep Space Network really can't go out to 500 AU. It just doesn't have enough array power to do that. I think Interstellar Probe is looking at new other antenna systems and some new ones, which are very extremely large arrays, so it's multiple antennas that they array together. It has the DSN in its design right now. There's a point where it can no longer support Interstellar Probe and the downlink rates that it wants to do. You could think about, though, a system where you actually have relay satellites. Maybe you put a relay satellite in orbit around Neptune, or something like that, or in orbit out there, halfway to the heliopause. So, your spacecraft sends data to this relay satellite, and then the relay satellite sends it down to the ground. That's another way of doing it.

ZIERLER: In thinking about the miraculous legacy, I can't but help think about Ed Stone and his legacy for Voyager and so much else. I wonder, first, with him stepping down as project scientist, what does that mean operationally for Voyager on a day-to-day level?

DODD: From an engineering standpoint, other than just the incredible legacy he leaves behind, it's not an impact from an engineering standpoint. Our new project scientist, Linda Spilker, started on Voyager. She was a young scientist, and her first job out of college was on Voyager, so she's familiar with it. Similar to me, she started her career on Voyager and will probably end her career on Voyager. But Ed certainly, going back to the formulation of the project, was the vision and the driving force behind Voyager. I think in the back of our minds, we all want to keep this mission running for him. We keep his enthusiasm and his efforts—we carry those with us, as we continue to keep this going as long as possible.

ZIERLER: I'm sure he has commented to you—he wants to be there for the 50th anniversary as well. It's special in many ways.

DODD: Yes, it will be a big deal. I'm looking forward to a big party, one that I do not have to organize, though. Because it will be too big of a deal for me to try and catch everybody.

ZIERLER: In the way that you told me the split, in terms of your responsibilities—20%, 80%—why does Voyager take up a relatively small piece of the pie for you? Is that because it's such a mature mission, and it's sort of on autopilot, if that's the right way to think about it? What is it?

DODD: It's definitely not on autopilot. It's actually starting to take up more of my time, because we have to make difficult engineering trades to keep the spacecraft operating as long as possible. I've been the project manager since 2012, so it's definitely taking more of my time. But there's a good team of people working on it. They're very experienced with what they do. The processes of how we do things on the spacecraft are well-known. The challenge is that we need to change some of those processes, and that takes time to discuss how we do that, and what the risks with doing that are, and that type of thing. Sometimes I say it's 20% of my day job, but 100% of my night job, sometimes.

ZIERLER: [laughs]

DODD: I go home and work, and I primarily work on Voyager stuff.

ZIERLER: Administratively, the title "Project Manager," do you report to the project scientist? Is that the structure?

DODD: No. The project manager and the project scientist in the case of Voyager are sort of peers. My responsibility primarily is to report to NASA, to make sure we have the funding, to make sure we're reporting the information that NASA wants to hear, to make decisions on if we're going to change something. I do especially the decision part all in conjunction with the project scientist. The project scientist represents all the different instrument principal investigators, and has to make decisions across the different instruments. Sometimes you've got to make trades on who is getting data when, or what heater on an instrument to turn off first. That's the project scientist that finalizes those decisions.

ZIERLER: Who reports to you as project manager?

DODD: The flight team. The engineers do. The engineering staff does.

ZIERLER: The title as Director for Interplanetary Network, is that a lateral just organizationally, or is there an incongruity in the org chart in terms of you're project manager at a particular level and you're director at a different level?

DODD: The Jet Propulsion Laboratory has directorates. They're sort of like divisions of a company. I would be the senior vice president of the Interplanetary Network Directorate. The Voyager project actually sits under the Astrophysics Directorate. Voyager sits underneath a Directorate that's a peer to the IND Directorate.

ZIERLER: What does the day-to-day look like for IND? What are the most important things that you have to keep an eye on?

DODD: I would say the IND Directorate encompasses the DSN, and also encompasses the multi-mission software, which is used by not just JPL's planetary missions but also by other missions within NASA. We also do some technology development and research in the areas of space communications and automations for spacecraft, and that type of thing.

ZIERLER: One hat that you wear is director, and another is project manager. My question is just organizationally, if there's an incongruity in your seniority in one part of your job versus the other?

DODD: Yes, it is. As a project manager within JPL, I report to the Director for the Astrophysics Directorate, Keyur Patel. As the director of IND, I'm a peer to Keyur Patel, in that Directorate.

ZIERLER: Is this unique for you, to be dual-hatted this way? Are there others at JPL who have that kind of portfolio?

DODD: I think it's pretty unique. I got into it because when I got essentially promoted to this position as the director for IND, I asked if I could keep the Voyager project manager job, too. I said, "Can I try it? Can I see if I can do both?" Because I really liked the project. They said, "Sure." Luckily, for the last five years, I've been able to do it. You sometimes see scientists dual-hatted like this. Like Ed Stone was the director of the Laboratory at the same time he was the Voyager project scientist. So you can sometimes see scientists with both an institutional management role as well as a project scientist role. But you don't see that too much with project managers. I don't really know why, but you just don't.

ZIERLER: The term "multi-mission ground systems," if we could just unpack that, what is a ground system? What does that mean?

DODD: Ground systems are software on the ground that are used to either generate commands and send data to a spacecraft, or receive commands from a spacecraft and unpack them and turn them into wonderful science data. There's both an uplink side of it and a downlink side of it. Now, you can imagine that there's a lot of commonality in those functions between spacecraft, and so multi-mission software means that the common pieces are developed, and then a project can pick that up and do whatever specifics they would necessarily have to do to make it fit their project. But the core of it is the same across all the projects.

ZIERLER: Are there missions that use ground systems software that is not part of officially multi-mission ground systems, or is it the catch-all for all NASA missions?

DODD: No, there are missions that go it on their own. There are competing products. Industry has some products that would compete with something that NASA has built. Realize that NASA is not a for-profit company. NASA develops things and then tries to spin them off. And so there are ground systems, telemetry ground systems. There's planning software. We're in a big process now of putting things out in the cloud, so that anybody can grab this software for free. With the explosion of SmallSats and CubeSats and universities getting into flying spacecraft, a lot of the multi-mission software that's, let's say, maybe less complicated, for simpler spacecraft that are more geared toward CubeSats, it's out there, it's on Amazon cloud. Your university can pull it down and use that as its operating system and its ground system, for their spacecraft. It's developed at NASA, but it's completely publicly available.

At the Nexus of Caltech and NASA

ZIERLER: A question I've been looking forward to asking you—between your experience and your education, this magical triangular relationship between NASA, and Caltech, and JPL. First, at the tactical level, how do you understand that relationship? What do each of these institutions bring to the whole, that the sum is greater than its parts?

DODD: That's an interesting question. As you know, I'm a Caltech graduate. I got my undergrad degree there. I went to Caltech because it's one of the best schools in the country, and I was looking to do engineering at one of the best schools in the country. It's small. It's unique, that way. Similarly, when people think of NASA, it's probably one of the world's most premiere space programs. I do not know the history—well, I shouldn't say that; I know some of the history between Caltech and NASA. But they have a very unique relationship, where Caltech has a branch of it called the Jet Propulsion Laboratory, that is a federally-funded research center for NASA. It is NASA's FFRDC. I think what you have is two very unique organizations, high-quality, world-class organizations, between NASA and Caltech, and they've gotten together and agreed that JPL is the place where we're going to use all our smarts that we have at Caltech and all our uniqueness and ambitions that we have in the United States through NASA, to be the premiere robotic space exploration site. And, it really is.

ZIERLER: When we say that Caltech manages JPL on behalf of NASA, what does that feel like on a day-to-day basis? Do you feel Caltech management? Is there a unique academic imprimatur at JPL that might not exist at NASA Ames, for example?

DODD: I think in certain areas, there's a lot. I think there's a lot of pull and cross-fertilization, certainly a lot of pull to get some of the great Caltech students and scientists in particular to come up to JPL. And engineers. It's right next door. We have a large summer intern program where we get a lot of Caltech students that come up here and work, and then hopefully become full-time employees. So, there's that attraction. I think it's attractive to NASA, because you've got this great institution behind doing all these creative, unique things, like helicopters on Mars, and sky cranes dropping rovers, and really a lot of very unique, creative engineering ventures. I think NASA gains a lot by having Caltech associated with it. Caltech—I have heard the Caltech president say he gains a lot by having JPL under the Caltech umbrella, because they use that for their advertising, to get their best students, and their best researchers. So, I think there's a really good synergy that both Caltech and NASA can use, through JPL.

ZIERLER: What is your interface with NASA? What are the kinds of issues, either remotely or by going to Washington, really put you in close contact with your peers or colleagues at NASA?

DODD: NASA funds the majority of the work done at JPL, funds all the work that I do at JPL. They naturally want to know what you're doing with the taxpayers' dollars, so you do a lot of reporting on schedule, on performance. You do a lot of budgeting. How much do we need next year? You try to do that in a partnership with NASA. For example, with the Deep Space Network, we say, "You, NASA—we have 40 missions now. You want to add 20 more in the next five years. We need more assets. Either build new antennas or build new technologies to say, array antennas together, to be able to handle the growth that you want to have, in science missions." So, you have to work in partner with NASA, both tactically, sort of like on a year-to-year budget, but also strategically. "In five years, I need to have these capabilities, so let's plan out how we're going to get there in five years, together."

ZIERLER: As director of IND, where does that place you in terms of overall planning at JPL for all kinds of missions that JPL is involved in?

DODD: I don't know exactly how many people are on what we call the Executive Council at JPL. Probably on the order of 15 or 16. I do have an institutional role beyond just IND, in the sense that we may be involved with a lot of STEM activities, say. And we are involved with a lot of STEM activities. So I may be involved with institutional committees related to STEM, related to diversity, related to how we do work at JPL. What are our processes that we can improve? Institutional processes we can improve. Write down the things [laughs] near and dear to people's hearts like telework. How many days am I going to be allowed to telework? And working with my peers on the Executive Committee to come up with and recommend to the director what we think policy should be for the Institute.

ZIERLER: With IND, what is your relation, for example, with Mars exploration, or Europa Clipper? Do you have that day-to-day interaction with those kinds of missions?

DODD: Yeah, on a technical standpoint—those missions that you mentioned there, in particular, are in the Solar System Directorate. There's a few technical things. There's, what do your future missions look like? What do they need? What type of telecommunication capabilities do they need from the DSN, and what type of multi-mission capabilities might they need, if you're building a project. We try to be able to get in those discussions early in the formulation of the missions, so that the missions don't design something that's difficult for the DSN to handle, say, for example. Or we try to partner with the missions. If there's a new capability that we want to start infusing and we've got a new JPL mission that we might be able to get that infused on, as a first step. So, we have those kind of discussions, too. Like, "What do your missions need? Let's get involved early, so it's a win-win for both of our organizations." And that IND is not being reactive to something that you have designed without knowing the directions that we're headed in communications and autonomy.

ZIERLER: A nomenclature question: There's a Solar System Directorate. There's an Interplanetary Directorate. But of course the planets, the interplanetary of the planets, are in the solar system. So, where might the overlap be between those directorates, and where are there really separate responsibilities?

DODD: What I would say is the Interplanetary Network is an infrastructure directorate. It's the Deep Space Network. It's multi-mission software. It's things that missions need. Whereas a directorate like the Solar System Directorate is building missions that go to the solar system. There's the Astrophysics Directorate that is building astrophysics—missions looking at galaxies and stars. We are the infrastructure. We're a bit orthogonal to what we call the other programmatic directorates. I mean, there's an HR Department, and there's a Facilities Department, and there's the lawyers. Those are also people on the Executive Council. In a way, they're sort of infrastructure, too, to the institution. Whereas we're infrastructure to the missions.

ZIERLER: As you mentioned, or as you alluded to, the budgetary environment in Washington is quite important for JPL capabilities. Right now, just circa 2023, what is the overall budgetary environment, particularly with, at some point in the future, the House of Representatives becoming operational and starting to write checks?

DODD: I think in general, it's pretty good. Certainly, with the Democrats in charge—Earth science is a real biggie, right? Everybody has now acknowledged climate change, so there's a lot of funding going into Earth science missions. Now, the Deep Space Network does not generally support Earth science missions because they're too close. [laughs] We can do the Moon and beyond; we don't do the Earth orbiters. But our multi-mission software does. They're spacecraft just like any other spacecraft. They have thrusters. They need to turn. They need to dump data. So, our multi-mission software does support Earth-based missions as well as the planetary missions. I think in general, the budget is reasonable, and I think Earth science, because of climate change and the acknowledgement of that, is getting more push at NASA.

ZIERLER: What are the kinds of issues that compel you to go to Washington for real face-to-face time? Is that always crisis management? Are there other issues where it's just good to be across the table from your counterparts?

DODD: Absolutely. [laughs] Absolutely it's good to be across the table. I'm a big believer in meeting face to face. Obviously a lot of stuff changed during COVID, when we weren't able to meet face to face. It's best to build relationships, and the best way to do that is in person. It's not always the easiest, from the West Coast. You've got to get on a plane, and you've got to go—it will take you a day to fly there, and you may only be there for a two-hour meeting or something, and then fly home. So you've taken two days to have a two-hour meeting. But I think the face to face is important. One of the great pleasures of working with Ed Stone was actually to be able to hear some of his stories from being the JPL director. He had a lot of great wisdom about dealing with Washington. You get on a plane, the director gets on a plane. In those days, the 1990s, he's on a plane to Washington twice a month, and lining up meetings, and talking to people, and really selling the business of JPL to headquarters.

ZIERLER: For you, in headquarters, who are your most important counterparts or partners or directorates that you interface with, on a weekly or monthly or yearly level?

DODD: I actually am fortunate to get to work with both SMD—most of JPL works with the Science Mission Directorates, because they fund the projects, and that's the main directorate that JPL works with. For Voyager, I certainly work with the Science Mission Directorate (SMD), and particularly the Heliophysics Division of that. But for the Deep Space Network, I work with the organization called Space Communications and Navigations. It's part of what is now known as the Space Operations Mission Director (SOMD). It was split off from HEO, Human Exploration. So, SOMD is different than SMD. The Science Operations Mission Directorate basically has all the ground networks under it, and the operations of things like the space station. So, it's quite a bit different than what most JPL organizations deal with here. So, most of the time when I go back to Washington D.C. it is to work with SCaN, and it is to work with the Deep Space Network funding and strategies about what we need to do going forward. But because of Voyager, I do work some with the Science Mission Directorate, also. All my past jobs, before getting this job as the director, all my past jobs have been Science Mission Directorate jobs. So, when I worked on Cassini or NuSTAR or Spitzer, they were all in different divisions of the Science Mission Directorate.

ZIERLER: Beyond the United States, beyond NASA headquarters, what about international partners? Do you have opportunity to interface with JAXA or ESA or China, India? Do you have any international collaborations?

DODD: Well, nobody talks to the Chinese, because that's illegal, from the U.S. government. But certainly JPL and NASA do joint missions with the Indians. JPL is building a mission right now with the Indians, an Earth-observing mission. And particularly the Europeans. The European Space Agency. They actually have their own set of large antennas like we do with the Deep Space Network. We have a cross-support agreement with them, which means if they need some time, say, for a particular mission, they can ask for it on the Deep Space Network, and we can do the same. It's a collaborative agreement, where there's no money exchanged; it's just somebody sort of keeps a record on paper of how many hours were given to each of the different organizations, but we don't have to exchange any money to pay for the different tracking times on the different networks. I personally have not done a lot of—my job is not to do those negotiations. I actually have people in my organization that spend a lot more time on working on those negotiations, and working with those foreign partners. Certainly NASA does. I've met a few people, but in my day to day work life, I don't do those negotiations, or trades.

ZIERLER: What about public outreach? Do you have opportunity? Do you enjoy interacting with the public and all of their curiosities about the solar system and the universe?

DODD: Yes, I do a lot of that. Obviously JPL has Explore JPL, which is sort of a version of an open house that they have been doing most years. I always support that. Primarily for Voyager, actually. Voyager, a lot of people have a love for Voyager. They either grew up with it, or I have people tell me that their grandfather worked on this project, and they've got documents or mementos in their garage, and things like that. I do that. I do public speaking engagements. As I started with, I give talks both about Voyager and about the Deep Space Network. You can tie those together very easily, because Voyager is the furthest out. How do you talk to it? Well, you talk to it with the Deep Space Network. So, it's pretty easy to tie those together. From a Voyager project manager perspective, it's fun, because I do get a lot of fan mail. Especially around the anniversaries, when we have a lot more press releases and things, and stories that go out. People will send notes and say, "I love this mission. Carl Sagan is my hero." They'll send me pictures of their Voyager tattoos, or drawings that their kids made, or something like that, so it's pretty neat. That's fun. That's what makes it worth doing.

New Directions at JPL

ZIERLER: What about specifically being a leading woman at JPL, being a role model or showing girls or young women, college students, female college students, that this might be an area that is available to them, too? Is that something that you think about?

DODD: It's something I've done in the past. I've been involved with JPL's technical women's organization, mentoring organization for new women at the Lab. I have two daughters, so I was keenly involved with their education as it related to science and technology fields. They happen to both be engineers now, too. It wasn't necessarily my push, but that's what they went into. But yes, I've tried to lead in that regard as a role model and a mentor, to women, whether it's schools, or Girl Scouts, or here at JPL, for sure.

ZIERLER: Relatedly, but coming from the other side, with Laurie Leshin coming in as director of JPL, what did that mean to you, and what do you think that means for the organization, the first woman director of the Jet Propulsion Laboratory?

DODD: I think it's great for JPL. I think she has received a lot of warm welcome. She has a lot of challenges ahead of her.

ZIERLER: That any director would have, of course.

DODD: That any director would have, but you can definitely sense a different style. I think it's probably almost stereotypical to how women lead, to how men lead. I think there's this aspect where women are more nurturing, in particular, and less—you can be a strong woman leader, but also come across as a nurturer, whereas I think a lot of times, if you're a male, you feel like you have to be more domineering, I guess might be the best way to say it. So, there's definitely a style change. I think it's good for JPL. I think it's the future. And I think Laurie will do great.

ZIERLER: On that basis, beyond your own immediate responsibilities, what are some of the really exciting strategic opportunities in the future for JPL? What are the things, as we look a decade into the future, for where JPL can make a real impact?

DODD: I think the key one that they are embarking on now is the Mars Sample Return. We've got a rover on Mars. It's taking samples. They're storing tubes of these samples. Now, it's dropping these tubes off at certain points. What's the next mission that is going to pick up these samples and get them back to the Earth? That mission is all designed. The problem is, it's expensive. We have international partners to work on that, but still, it's all new technology, and trying to get it to fit into a congressional budget is difficult. So, that's a challenge. I think the whole COVID, switch to telework, how much telework do you—what's good telework; maybe I should just say it that way—that's all over the map, in the sense that different industries look at it completely differently. Getting that right for a place like JPL is going to take some tweaking. I think there's divisions based on your age. If you're an early-career hire who has been in college most of your time, and you're really savvy to your technology, you might not think there's any issues. Whereas, as I mentioned earlier, I'm much more of a believer in the face-to-face, and the networking you build being face to face. So I think there's challenges from a leadership standpoint there, too. How do we go from here, and get the right balance between in-house, in-person, and telework, that we need to have to get our job done?

ZIERLER: As JPL has diversified the kinds of things that it does beyond the bread-and-butter stuff like planetary missions—as it has gotten more involved in astrophysics, and radar, and climate change—what are both the challenges and opportunities for that, both in terms of making sure that JPL is relevant to the things that are most important for society, but also ensuring that it doesn't dilute the areas that it is the best in the world at? How do you make those decisions, those balances?

DODD: JPL started pretty much as a planetary place, one flagship kind of mission. First it was the Moon. Then it was Mars and Venus. Then we got into missions like Viking and Voyager and Galileo and Cassini. They were big missions, but they were planetary missions. Goddard pretty much had all the Earth science missions. I think somewhere along the line, NASA decided that the competition between Goddard and JPL would be good, so they let them sort of compete for each other's missions. So, we have Earth orbiters now, and Goddard has some planetary missions. It probably is good. Good from a taxpayers standpoint, good for getting the best ideas out there. But there's what they call the war for talent. There's a lot of new space out there. SpaceX is the obvious one you think of. You can think of Blue Origin. That's backed by Jeff Bezos and Amazon. And just interesting robotics companies that are doing things. So, there's a lot of demand for the same talent pool that JPL would want to have. That's a big challenge for the Lab, too, is to get the right workforce. I think recently we've probably bit off more than we can chew, a little bit. Like we have too many missions and not enough workforce. That, again, leads us back to, maybe we need to be more selective about what we do. We need to be sure we have the workforce to do what we say we can do. That includes keeping the mentors for the newer employees, too. They have to be available. You need to have that passing down of knowledge to the next generation. I think that's one of the most important things that JPL can work on, is knowledge capture and mentoring.

ZIERLER: Beyond the recruitment challenges, now that we have companies like SpaceX and Blue Origin in the mix, in what ways might those be strategic assets to JPL, with the commercialization of space? In what ways does that allow JPL to offload certain responsibilities so that it can focus on the things that it's good at?

DODD: That's a good point, in the sense that we shouldn't think of these as competitors; we should also think of them as partners. Things that we may have traditionally done, we can give to SpaceX to do, or to Rocket Lab to do, or even a big company like Lockheed Martin. We could give the more I would say routine and/or—don't give away the IP, but partner with organizations that can build spacecraft buses because they do it all the time, or build rockets because they do it all the time. Or, design orbits because they're simple orbits. So, there's opportunities to partner, too. I think, again, culturally, we have found that difficult to do. We've always thought we do things the best, so we don't want to contract certain types of work out. I think we have to get better at that.

ZIERLER: For the last part of our talk today, we've been talking almost exclusively about JPL. Just a few questions personal to you. First, by virtue of your education and your sensibilities, do you think of yourself as an engineer? Is that how you approach your day to day? Or are you so high up in the org chart at this point that you're really an administrator, you're sort of divorced from the world of engineering to some degree?

DODD: [laughs] I think of myself as an engineer, but an engineer who knows that I can no longer do all the math, if that's an appropriate way to think of it. I think my strength would be a certain sense of understanding that there's politics to all decisions. I like to pass on some of that wisdom to employees and younger people who say, "Financially, it makes the most sense to do this," or "Technically, it makes the most sense to do this." I'm like, "Yes, that is true. But that's not the only part of the decision equation." What's the win-win for both sides? Whether it's NASA and us, or Goddard and us, what's a win-win scenario, one that we can live with, and it may cost more money, but it also gets the other side what they want. So I think bringing that mindset and helping to show newer engineers that there's more than just, A, either dollars, or technical expertise, to decisions, is what I can bring to the table.

ZIERLER: When you says that the math at this point is beyond you, is that because you've lost the muscle memory, or the equations just getting harder over the years?

DODD: [laughs] Yes and yes. Probably both. I haven't done a lot of equations in the last 30 years. A certain part of management is psychology, too, and I kind of like the psychology side of things, too. What makes people think? What's going to drive them to make a certain decision? How can I influence that? I can have smart people give me numbers and be assured that their math is correct, but I need to work with them to sell the ideas.

ZIERLER: As a manager responsible for so many people that report to you, what are some of the most important management techniques or feedback mechanisms you use to make sure that your team is doing the best possible job they can?

DODD: I try to have a really open organization. Sometimes that's easier said than done, because you're in meetings all day long. How do they get a hold of you, if you're in meetings all day long? I have regular quiet hours, tag-ups with people, one on one, to find out what's going on. Let them ask questions, give them some advice, give them some guidance. I try to give them all the tools they need. If they feel they really need some expensive computer, if they can justify to me—yes, you can have it. It's just a computer, right? It's not going to cost me that much. It's that kind of a thing. Touching bases with people, letting them feel like I'm open, they can ask me questions. They don't have to do everything the exact same way I do, or they don't have to do everything following a certain process. Now, certainly, like in the world of Voyager, there are processes for how you command a spacecraft. You better not deviate from those. Those are [laughs]—those are processes you have so that you do it right. But, if you've got a question, or there's something that's different about one sequence from the next, then we talk about if we need to do something different.

ZIERLER: Last question for today—after all of the years of service at JPL, what keeps it exciting for you? What makes the missions so personally meaningful?

DODD: I really think for myself personally, I like the work. I like the people we interact with. I like the challenges. Certainly Voyager is extremely unique, very well-known throughout the world. There are the day to day challenges there, sometimes, but I think the feedback I get from the general public about just how this mission has influenced their lives, is special, and it's motivating. Within the Directorate, I like the work that JPL does. I always have. I took the job out of college at Caltech. There are a few other places I could have worked, but this was certainly the most unique place. I took a job that paid me less than working for TRW, I think, at the time. But TRW wasn't sending a spacecraft to Uranus.

ZIERLER: That's right. And they still aren't. [laughs]

DODD: They still aren't, right! [laughs] And NASA actually might, here in the future. So it was the uniqueness of the work that was attractive to me, and I think that's still here. Now, when I took the job, it really was the only place. There is now probably more opportunity at some of the new space places. But, beyond SpaceX saying they're going to send somebody to Mars, you don't see—there's not a real commercial market to looking at Triton's methane geysers or something, right? That's not a commercial market.

ZIERLER: No, but it's a science market, and that's why JPL is gonna do it!

DODD: It's a science market, yes, so it's going to be JPL. It might be ESA. But it's not going to be SpaceX. And it's not going to be Jeff Bezos. They're not driven by that.

ZIERLER: This has been a great introductory conversation. In our next talk, we'll go all the way back to Gig Harbor, Washington, and learn about your family background. We'll trace the narrative from there.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Thursday, March 2nd, 2023. I am delighted to be back with Suzy Dodd of JPL. Suzy, at long last, it's great to be back with you. Thank you so much.

DODD: You're welcome. Thank you.

ZIERLER: In our first conversation, we did a great tour of your research interests and all of your wide-ranging career responsibilities at JPL. Today, let's establish some personal narrative. Let's start first with your parents. Tell me a little bit about them and where they are from.

DODD: My parents were both born right outside of New York City, in a town called Scarsdale. Their parents, on my father's side, the last name is Rosik—R-O-S-I-K. That's my maiden name. It hails from the region around the old Czechoslovakia. I think it's actually Slovakia, a piece of it. I think my father's grandparents were immigrants to New York City. On my mother's side, they had been in the country back since the days of the Pilgrims, and they're basically some combination of English and a little bit of Welsh and probably some other things. I need to do the 23andMe test, David, and then I'll have a much better history of my folks. But basically my parents were from the New York City area.

ZIERLER: What were your parents' experiences during World War II?

DODD: On my dad's side, his older brother fought in World War II, and he was killed in the Battle of the Bulge, right before the War ended. It was on Thanksgiving, so he was supposed to come home like a few weeks after. Right before, he was killed. What my father says is that it always made the holidays, especially Thanksgiving, kind of a depressing time. I can clearly remember one Christmas picture that my grandmother kept her whole life in her house, and it was—my father was the middle of three boys, and the picture she had was the two boys, my grandmother and my grandfather, and then on the table next to the Christmas tree was a picture of Bobby in his uniform, acknowledging him as part of the family, too. I don't have a lot of memories related to that, though, because, for one thing, I was born in Washington state. And I could describe how I got over to Washington state, or how my parents got to Washington state. My grandparents were still in the New York area, so we didn't see them as much as little kids. Actually, my grandfather on my dad's side passed away before I was born.

ZIERLER: You were born in Scarsdale?

DODD: I was born in Tacoma, Washington.

ZIERLER: How did your parents get out to Washington? Was your father in aerospace?

DODD: No, my father was a business major. He fought in the Korean War for a couple years. When he came back, after two years of being a stenographer, his younger brother got married to one of my mother's best friends. Basically they kind of knew each other from high school. One was a senior and one was a freshman, so they didn't pay a lot of attention to each other. But when my uncle got married—my dad's brother—my dad was the best man; my mother was the maid of honor, and they sort of reconnected and started dating. So they actually started dating after my aunt and uncle's wedding, and a couple years after that got married. My dad, he had gone to college, and then he got drafted to go to Korea, and then he came back, and he got an MBA from NYU, and kind of wanted to get out of the city. I think he wanted to get away from family for—I don't know the whole reasons, but let's just say he wanted to try a different adventure. My mom was all for that, too. They were going to go to—they were looking in the northeast, like Boston, Connecticut, even upstate New York, as a change of place. My dad ended up getting a job with Weyerhaeuser, the lumber company, and they moved him to Saint Paul, Minnesota, in the winter [laughs]. I have a brother who is three years older than I am. He was born in Scarsdale. He was about two when they moved to Minnesota. They didn't stay in Minnesota very long, only maybe nine months. Weyerhaeuser opened up a new headquarters in Washington state, which to me makes a lot more sense because all the trees are there. So, it was a big adventure that my parents took to drive my brother in a station wagon, in a playpen, across the country, and they moved to Tacoma. I was born about a year later in Tacoma. Then they bought their first house in 1962, I think, in Gig Harbor, which is now basically a suburb of Tacoma, Seattle, but at the time it was a little more rural, country.

ZIERLER: Is that where you grew up—Tacoma?

DODD: I grew up in Gig Harbor, yeah, which is by Tacoma. Puget Sound. I grew up in Puget Sound.

ZIERLER: Did it feel booming to you, growing up? Was it rapidly growing?

DODD: Not so much as a young kid. I grew up in the 1960s and 1970s. I graduated—I went to college on the other side of the state, at Whitman College in Walla Walla, before I transferred down to Caltech. I think in the 1980s and 1990s in particular is when the real boom took off in Washington state, in the Seattle area. Weyerhaeuser was a fairly big employer, but the biggest employer in the Seattle area was Boeing, by far. The economy was up and down, depending on how many airplane sales Boeing had. They would hire 10,000 engineers, and lay off 10,000 engineers when a program got done. Starbucks; I don't know when that started, but it was pretty much after I—probably in the eighties-ish, or maybe late 1970s.

ZIERLER: Was it public schools that you went to, growing up?

DODD: It was. Where I grew up in Gig Harbor, basically it's much more suburbia now. It was much more rural, so it was kind of a rural school district that carried a very large geographical area. And fairly diverse. Not in an ethnic way—everybody was Caucasian pretty much; maybe a little Hispanic, but nearly all Caucasian—but in what they did. If you lived close to the Tacoma Narrows Bridge, you might have a parent who was pretty affluent because they worked at a job in the city. But further out, you're in the country, you're on a farm, you're in a little trailer. So you had that sort of mix of incomes in the school district.

ZIERLER: What do you remember of the Space Race in the 1960s, and did that plant a seed for you, do you think?

DODD: We used to watch. It was part of our curriculum. I can remember being in second grade and watching the astronauts return from the Moon, in 1968. I remember watching the splashdown. The funny thing is, though—it's probably funny looking back on it now—I thought that the frogman that jumped out of the helicopter to go swim to the capsule as it was floating in the Pacific, I thought that was like the coolest thing, ever. [laughs]. I thought that looked like a lot of fun. Whether I really wanted to be the astronaut going to the Moon; maybe, maybe not.

ZIERLER: Did you gravitate towards science and engineering growing up?

DODD: Yeah, I did. We grew up in a house on the water. We had a waterfront property. So I would do a lot of fishing. My parents got me—I think when I was 13, we got like a small boat with an outboard motor, and our friends—we would go out fishing, I guess is the best way to say it, to try to catch some salmon and run around in the boat. It only had like a 15-horsepower motor on it or something.

ZIERLER: As a girl, with your parents or your teachers, did you ever feel discouraged that this was not the best path for women, or were you encouraged?

DODD: No, actually I think it was the latter. My dad obviously was very encouraging, saying, "You can do whatever you want." He was in the business end of the lumber world, and my mom was a homemaker. She had worked in a test kitchen before she got married, so she was a really good cook. She sewed. All those things that I never really picked up! [laughs] But it made for a great home life. I never felt discouraged. My family was always supportive. In high school, I had a math teacher who had two daughters, also, and he was always very encouraging. I was good in the math and sciences. He wanted me to go to the Air Force Academy, because that's where he went. An Academy didn't really strike me as that exciting. But, even in college, I never really felt discriminated against. If anything else, maybe you got a little more attention because you were not in the majority of the people taking engineering classes.

ZIERLER: Looking back, in high school, did you have a strong curriculum in math and science?

DODD: Yeah. We were able to actually offer like a calculus A/B class. I think there were only four or five kids in it. So, we were able to offer an AP class—or, a class that only had five or six kids in it. They offered that at the high school, too. But it was also a high school that had a shop, a wood shop, and automobile shop. I think it still does, actually. You don't see a lot of technical kind of trade stuff at high schools much anymore, but we had that, too.

Caltech Roots

ZIERLER: When it was time to think about colleges, were you aware of Caltech? Did you know about its connection to JPL?

DODD: I knew that it was a really good school. When I went to look at colleges, I didn't know exactly what I wanted to do. I mean, you can use math in everything, right? You can use it in economics. You can make models that are political models. So, I didn't want to go head-on into Caltech and be stuck in that route. So, I went to Whitman College, which was a liberal arts college in Walla Walla, Washington. This is pre-wine. Everything in the 1980s was wheat and asparagus and sweet onions. All the wine came in the mid- to late-1990s, when all the people from San Francisco made a lot of money and moved up to the Northwest. But, yeah, I knew that Whitman had what they called a three-two program with Caltech. You'd go three years and basically get training in liberal arts and all the math and science background classes that you needed for an engineering degree, but they didn't offer an engineering degree. So it was kind of the next step, and it gives you some time to determine what you really want to do with your career. But if you decide to go into engineering, you can go to one of the best schools in the country. And that's what I did. I think it helps to make you a much more well-rounded engineer.

ZIERLER: Are you aware, are there other schools that have this unique arrangement with Caltech, or what is it about Whitman that allowed them to do this?

ZIERLER: At the time, there were on the order of eight to ten schools that did this program. Occidental is one. Pomona College is another one. So, local schools have it. I think the program has changed over the years, mostly from the Caltech side of it. I'm not sure exactly what Caltech thought they were getting out of it. I know what Whitman thought they were getting out of it. They were getting a chance to offer an engineering program without offering an engineering program, essentially. Getting really bright students, and giving them a liberal arts background, before they went to get an engineering degree. But I think Caltech doesn't really do that too much anymore. The program is structured differently. I think they still have it, but I think it's structured differently.

In my case, if you did well in the courses you took at Whitman, you automatically got accepted into Caltech for this exchange program. I don't think that's the case anymore. I think that Caltech may either make you take a test or might just base your acceptance on what size enrollment they want to have. I do think what Caltech gets out of it is a way to offer—or at the time, what they got out of it—was to get a more diverse population. More women, for one, probably, and also just students with a different background. If you come into Caltech and you've had a bunch of liberal arts classes, history classes, political science classes, economics classes, and then you go into your engineering degree, I think it gives you—it's much different than the typical Caltech student, who has been taking math and science, and maybe even taking math and science at their local university before coming to Caltech. But they're very focused, right? And this is a way to get a population that's I would say more well-rounded.

ZIERLER: To clarify, when you went to Whitman, you went on the basis that you would ultimately transfer to Caltech? That was the deal going in?

DODD: That was the option I knew I could do. That was an option that was out there. I knew if I wanted to do that, I could do that. But I didn't have to decide on my 18th birthday. I didn't have to go all-in to Caltech at 18, without really saying what else I might want to do. In high school, I didn't take a political science class, really. You take U.S. history and you might take some world history. Heck, I took typing in high school, right? Like typewriter-typing. I just wanted a chance to really see more fields before I decided that I wanted to go all-in on the engineering side of it.

ZIERLER: Is this to say that Caltech sort of has to pre-admit you? Are they part of your application decision, if that's an option for you after three years?

DODD: The program was structured such that if your grades were good enough, Caltech would accept you. I think they changed the program in part because there was some abuse of it probably by some liberal arts schools, or they would get a lot of foreign students that would come into Caltech this way. I don't really know the rationale for why they've changed it. I think they still have the program, though. It's just not as much of an automatic acceptance, and I'm sure there's probably less students that they admit under this program.

ZIERLER: What year did you start college?

DODD: I graduated from high school in 1979, so I started at Whitman in 1979. I went three years to Whitman. I left Whitman in the Fall of 1982, and I was at Caltech 1982-1983, and 1983-1984 is when I graduated from Caltech.

ZIERLER: What during your three years at Whitman solidified your decision to go to Caltech? What were your experiences?

DODD: I think I continued to show myself that I was good at the math and sciences, and I liked the math and sciences. I liked that more than writing history papers about the Civil War. Although I had a very good Civil War teacher who made it very enjoyable. I had a good physics instructor at Whitman and just kind of raced right through the regular math track. So, yeah, I thought I could do it. And actually, going to Caltech from Whitman, even though you got a bachelor's degree from each school—one from Whitman and one from Caltech—it was sort of like going to grad school. You've done three years—and I think this was important, too—because I've hung around Caltech a lot. My daughter went to Caltech. Caltech is a very tough school, a really tough school. You go from the top of your class in high school to the bottom of your class in college, and it challenges your psyche a little bit. "Am I really good? Was I just an imposter in high school?" Stuff like that. But I think having the experience at Whitman, and doing well at Whitman, allowed me to handle going from the straight-A student to the C-minus student. You get to Caltech, and it's just a totally different world. And, it's hard. It's really hard. The first term I was at Caltech, I did get, in my mind, pretty bad grades. I can distinctly remember getting a "D" on an AMA 95 class my first term. Of course, the professor failed nearly the whole class, so there's some ego in the professor department, too. I remember him saying, "If you wanted easy, you would have gone to Stanford." That's exactly what he said. It stuck with me all these years.

ZIERLER: [laughs] That's great.

DODD: I hope—I don't deal with a lot of professors on campus—some in the Astronomy Department, or Math, Physics, Astronomy—but I hope that there is less ego in the professors on campus than there was at that time. A little more kinder, gentler people. It doesn't mean your classes can't be hard, but you don't need to be so arrogant about it.

ZIERLER: That's about culture, less about the science.

DODD: Yes.

ZIERLER: From the first class of women who came in in 1970, by the time you arrived, did that all feel sort of normalized, or did there still feel something new about women undergraduates at Caltech?

DODD: Honestly, being even at Whitman, most of the classes, if they were math and science classes, were more men than women. In my career, it has always been—or my college career—it has always been more the 25% to 30% women. Which kind of was what it was at Caltech. It might have been maybe 25% women. I know they're close to half, now. [laughs] My daughter who went to Caltech actually brought this up, too—Caltech has the socially awkward and the awkwardly social set of people. Big Bang does a really good job of [laughs] emulating some of the issues at Caltech from the standpoint of the student student interactions between the male and the female students. But I didn't ever feel like because I was a woman, either at Whitman or Caltech, that people didn't think I wouldn't succeed. I spent a lot of time going to office hours, and the professors and even the grad students at Caltech that ran those office hours were always very open and helpful. I don't believe I ever got any disparaging remarks about, "You won't make it in this field" kind of thing.

ZIERLER: Did you come in knowing that you wanted to focus on engineering, or you made that decision in real time?

DODD: That's the program, actually. The program is, you come to Caltech—at that time, and this may have changed a little bit too—but at that time, the program was, you're going as an engineering major. You don't go in and become a math major; you go in and become an engineering major. Or a chemistry major. The three-two program was just for engineering. Now, you could do electrical engineering or you could do what they called—at that time, they didn't have a straight mechanical engineering degree; they had applied mechanics or something like that, is what I got my degree in, but basically it was mechanical engineering. I took a couple EE classes and I said, "No, this is not for me." [laughs]

ZIERLER: Why? What's the difference between EE and mechanical engineering for you?

DODD: I think mechanical engineering is—it's thermal analysis. It's fluid flows. It's classical mechanics like dropping a ball and rolling it down a chute, and knowing what happens. It's very tangible, actually. You think about mechanical engineering; you're touching things, you're building things, you're determining how heat flows across a system. Electrical engineering was more—I guess it was more abstract to me. I guess that's the best way to say it; it's more abstract. You don't see the electricity going through the wire.

ZIERLER: What was your visibility for JPL as a Caltech undergraduate? Were you a SURF student? Did you get to spend any time up on Lab?

DODD: I did not work on Lab. I actually spent a summer working at Weyerhaeuser, which was kind of interesting, looking at laser scanners for lumber, but that's a different story. I was a swimmer, so I was on the swim team, and I would go to the gym and use the pool, and several of the people that I met there worked at JPL. That's how I got my job at JPL. I was swimming with somebody who said, "Oh, I have a friend that's got a job on Voyager that's hiring. You might be interested." I interviewed, and they hired me, and the rest is history.

ZIERLER: Tell me about the laser work at Weyerhaeuser. What was that about? What were you doing?

DODD: It was in their research and technology field. When they make lumber, it's graded, like maple syrup is graded. "This is Class A lumber"; "This is Class B lumber." The grading has to do with how much pitch and knots and things like that are in the wood. The knot is like where the branch grows out through the wood. If you have a lot of sappy pieces in your lumber, or a lot of knots, it's structurally not as good. In fast-growing lumber, which, they grow Southern Pine—they're soft wood, fast growing lumber—can vary a lot in the quality of the wood. At a mill, they actually have people—and this was back in the 1980s—they were trying to be efficient and cut down on the number of people that you need to operate a mill, just the same way that cars wanted to get more efficient and have less people in the process of building a car. So, they were working on laser scanners that would essentially look for these defects in the lumber. Could look for knots and look for sap and count that up, and then make an automatic determination if that's an A Class piece of lumber or a B class piece of lumber, instead of a person sitting there and looking at it. So, when you think of a laser, it's kind of how much light it reflects back, that the shiny parts—the sap—might reflect more light, whereas the hard wood might not, or vice versa. I don't even remember anymore. It was a lot of algorithms and trial and error about testing how to automatically do grading on lumber.

The Voyager Opportunity at JPL

ZIERLER: When it was time to graduate, what were your options? What were you thinking in terms of industry, or government service, or graduate school?

DODD: I had had enough school, with five years. I had enough school. I had a professor at Caltech that really showed me the numbers, like, "If you get your master's"—because I could stay at Caltech and get a master's in I think a year, actually. "If you stay and get your master's, you can get this much more pay." That's what he was telling me. But I had had more than enough school. I said, "I'll probably get a master's, but I don't want it to be today. I don't want to keep following on." So, I was looking for jobs in engineering. I had an offer from TRW, right there in Redondo Beach area, working on intercontinental ballistic missiles. Which is okay. I mean, it was by the beach. I had an offer in Colorado with Storage Technology Corporation, which I don't know whether—they make spinning disks for storage, or they did at the time. I'm sure they got bought out by somebody else and the technology changed. And, I had an offer at JPL. I took the one at JPL, which paid the least, but it was also in my mind—I liked the Pasadena area, so I kind of wanted to stick around here. But it was also the sheer uniqueness of—the offer was to work on Voyager. It was going to fly by Uranus in two years. I was like, "Where else is this happening in the world? Nowhere. It's happening right here, at JPL, at Caltech/JPL. I want to be a part of that." And stay close to the campus. So, yeah.

ZIERLER: But no contact with JPL as a Caltech undergraduate?

DODD: Yeah, that's correct. Other than the people I met around Caltech that worked at JPL.

ZIERLER: Do you think looking back there was a missed opportunity? Or even in your subsequent career, are there more opportunities for Caltech undergraduates to have interface opportunities with JPL?

DODD: There certainly are now, yeah. And I know with our new director, Laurie Leshin, that's a big deal. I think both she and Tom Rosenbaum are looking for programs to enhance the interaction between campus and JPL, both for the professors but also for the students. I think now they have a program where every undergrad, at least that wants to, can come and get a tour of JPL, in their freshman year.

ZIERLER: How did the opportunity come about? Did you answer a job ad? Did JPL come down to campus to recruit?

DODD: No. Somebody I was swimming with in the next lane said, "My friend at JPL has some openings on Voyager. If you're interested, here's his name and number." So, I called him. [laughs] After that, I probably applied for an official job ad. But yeah, that was it. You know, networks are everything. Networks are everything.

ZIERLER: Do you remember the date or at least the month when you started at JPL?

DODD: Yeah, because I started before I graduated. I hadn't had enough credits that my last quarter at Caltech, I was taking like two classes and a PE class. I might have been taking springboard diving for the heck of it or something. They wanted me to start early, and I said, "I can start in May." So, I started in May of 1984, and I graduated in June of 1984. I started as a contractor, though. The position was a contractor position. I worked for the Computer Science Corporation.

ZIERLER: Computer Science Corporation was a contractor for JPL?

DODD: Yeah. The position was a contractor position. I stayed as a contractor at JPL for the Uranus encounter, and then they offered me a direct Caltech/JPL position in 1986, after the Uranus fly-by. So I stayed for Neptune as well.

ZIERLER: Tell me about your early impressions of JPL. What was it like?

DODD: It was fun. It was fun to be part of a team. I was just talking to somebody else about what it was like to be in space operations. I said, these projects are teams. It's great to be on a team, and have a mission, and all be working together. I was a very sports-oriented kid, for the most part, and enjoy the team aspect of work. There wasn't near as many projects at JPL then as there are now. Voyager was the flagship mission, so most people on the Lab were somehow involved with that. Or, I can remember the Magellan mission to Venus, and then they were starting on the Galileo mission, too. So there were some other missions in progress. Right now, we might have a dozen missions going on, in astrophysics, in planetary sciences, and even heliophysics at JPL. Back then, there were maybe three going on at the same time. But it was very exciting. And it was super exciting at the encounter timeframe, because they brought in these big trailers. I may have said this to you last time, but they brought in these big trailers for the press to be here, so you had the press people onsite. This was all sort of pre-internet. You did news by going there in person. So, you got to see all these newscasters go to von Kármán every day and listen to Ed Stone and the panel of scientists that were there. It just gave a great vibe to the laboratory. I think some of that happens today. It certainly happens around Mars landings and stuff. The press comes. But it was a bigger event during Voyager because that was the only way the press could get the information. They couldn't just do a Zoom call with somebody.

ZIERLER: What was your day to day like in the early years? What would it mean to show up for work and be part of the Voyager team?

DODD: I was working in the sequencing area, so you come in, you have a desk next to somebody else that comes in. This whole telework thing—quite a bit different than today.

ZIERLER: Oh, yeah. [laughs]

DODD: It was quite a bit different. But, you come in, and it was a fairly routine thing. You would be working on a sequence, and it would take six weeks to develop that sequence, and then there was different steps, and different software programs, and different reviews. That process then repeats itself every six weeks. From a work standpoint, you're doing a fair amount of the same thing, although you sometimes had special events. You sometimes worked with a particular science team on a special calibration they wanted to do. What I do remember is the Voyager team, the sequence area had a lot of pranksters in it. They would like fill a person's drawer with water and put fish in there, and so when they came in the next day, the water would splash and they'd have these goldfish swimming around in their desk. [laughs] It's that kind of a team camaraderie. Most people would eat lunch together, too. You just really were cohesive as a team.

ZIERLER: What areas did you have real responsibility, even in the early years?

DODD: I hired in when four other people hired in. Now, Voyager went through Jupiter and Saturn, and then it had a bathtub, because it had five years to get out to Uranus. So a lot of people left. Because Jupiter and Saturn were like 18—maybe two years apart, 18 months to two years apart in encounters. Then there was this lull, so they had to cut—a lot of people left, and/or they just needed to trim staffing. A bathtub in staffing, because there was such a long duration. So, I was part of the crew that came back in, new group of crew that came back in during Uranus. There were four of us that hired in all at the same time, to do basically the same job, which was sequencing. It was basically a very junior job on Voyager, sequencing engineer, but a super exciting mission. Really gets you going for liking this type of work. Then, when it came to Neptune, I got to be the lead sequence engineer. So, of the four of us that were doing it, I got the closest approach sequence.

ZIERLER: Which means what?

DODD: The one that mattered the most scientifically. The most complicated sequence to build scientifically, the Neptune fly-by sequence. So, others would build sequences that led up to that, and I had the critical sequence. That's probably the best way to say it. I try to be a little bit modest about that, but essentially that was really cool, because everything you know about Neptune from Voyager, 90% of that is taken in a 12-hour time span, and that was the sequence I built.

ZIERLER: When you say 12-hour time span, that's just the length of the encounter?

DODD: Yeah, it's the length of what they call the closest approach fly-by. You're going really fast, past this planet, and you're trying to cram all the different instruments being able to take data, the data that they need to get their science done. They all want to do it at the same time. Ed Stone had to build some consensus with the science team about what's the most critical science and whose instrument gets to go point where, when, type thing. But putting all that together, working with the scientists to lay it out, getting the calibrations in there that needed to be in there, it took a lot of time, took a lot of care. Then, when you finally send it up, it's like, "Fingers crossed, I hope it goes okay." And Neptune was a long way away. Nothing compared to Voyager now, but it was I think four and a half hours—over a four-hour light time, one-way light time. Again, everything—you see the data on the ground; everything has already happened four hours earlier.

ZIERLER: When you say light time, what does that mean?

DODD: That's the time it takes for the signal to go from the spacecraft to the Earth.

ZIERLER: Just to show how much farther away it is.

DODD: Yeah, exactly. The distance from the Sun to the Earth is one astronomical unit. Neptune is at 30 astronomical units. That's the difference.

ZIERLER: This is a question that might make it feel like a very long time ago, but what were computers like at JPL in the mid-1980s?

DODD: They're in history museums! When I first started, I started on a—I don't even remember the name of it, but I do recall it had an eight-inch floppy drive. That was our command medium, an 8-inch floppy drive. Not a memory stick, not even a CD. When we did these designs and plots that showed—there was a program that you could design an observation, like you want to make a mosaic over Uranus, and you could lay out the observation, and then it would tell you what the commands you need to do it are. That was done on a UNIVAC computer, so kind of more of a mainframe refrigerator-size computer. And it was really slow. [laughs] Really slow. You would start something in the morning and grab a cup of coffee and come back two hours later. We didn't have two-hour coffee breaks—don't get me wrong—but you'd have to check on it during the day to see if it has progressed and that it hadn't just crashed. Yeah, they were kind of dinosaurs, for sure.

ZIERLER: Looking back, that first promotion that you got, did you see that as putting you on a trajectory toward leadership?

DODD: No, I wouldn't say that. What I would say is it acknowledged that I was a very capable engineer. I would say that part of it. Not necessarily up into the management role at all. Because when Voyager ended, then you were like, "Well, what's my next job going to be? Where do I go? What's the next project?" You're kind of at a stopping point, a little bit. A reflection point.

Galileo on the Heels of Voyager

ZIERLER: On that very point, what was your sense, during the heyday of Voyager, right in the middle of the encounters, what was JPL's second act? What was in the works at that point?

DODD: Galileo was definitely in the works. I think Galileo was originally supposed to launch in 1989, and then it had the whole issue with the stuck antenna, so it came back and it launched later. They were starting on Cassini, the development. Cassini was originally going to be CRAF Cassini, two spacecraft, where CRAF was the Comet Rendezvous Asteroid Flyby mission that got cancelled. But I went onto Mars Observer, and instead of sequencing, I did mission planning. I had a very small group of people that I worked with, like two people; there were three of us total. We did the mission planning, and I was the lead of that three-person group. But Mars Observer failed. After that happened, I got onto Cassini, which had a lot more of the same people that were on Voyager, especially from a science standpoint. I got on Cassini I think in the Fall of 1993. They didn't launch until 1996. So, we were in the process of designing software, implementing our processes and our software to be able to build sequences. I got a much bigger team, then. I had like 40 people on that team at one point.

ZIERLER: For your time on Voyager, what was most exciting for you?

DODD: Good engineers like to do things that are out of the box. Like there was a time there was a supernova explosion when we were cruising between Uranus and Neptune. We all wanted to look at it, and our manager was a little bit hesitant, like, "No, that takes away from the daily thing we want to do." We said, "No, we want to do this." Engineers like a challenge. They would much rather be doing technical things than the same thing over and over again. So, we got to change our sequence, make a change midstream, do a sequence that looked at this supernova, particularly with the ultraviolet spectrometer. I think that sense of being able to do something—like a target of opportunity is one of the terms people use—that was proof that we as a team could change course and we didn't have to do everything the same way all the time. But again, I go back to the Neptune encounter, because I had the closest approach sequence. It was also sort of teary-eyed because it was the last fly-by of Voyager. Everybody thought, "Voyager, yeah, two or three years from now, the mission will end." That was 32 years ago, people thought that! So [laughs]—and it's still going. But quite a bit different mission. It was certainly in the end of the planetary mission. Having the Neptune encounter, having it be successful, participating in some of the media stuff, like Neptune All Night—I'm sure you've watched that, of me as a young-looking child [laughs]—

ZIERLER: [laughs]

DODD: —very nervously interviewing a scientist. Yeah. Then the whole party that the Planetary Society had on the Mall; you just can't beat that. I don't think I've seen anything as good as that since. Maybe for Voyager's 50th, we'll do that!

ZIERLER: There you go! To give a sense of the size of the Voyager team, and also Ed Stone's accessibility, did you interact with him during your Voyager years? Would you have been able to?

DODD: I didn't interact too much with him directly, no. I may have sat in a few meetings where he was talking, leading the scientists and stuff. Each instrument team had experiment reps who were JPL scientists who, on site, represented the science teams who were usually at universities. I interacted a lot with the experiment reps. Again, they were JPL employees. All you knew about Ed Stone is that he walked really fast. He walked really, really fast.

ZIERLER: The Energizer Bunny.

DODD: Yeah. [laughs]

ZIERLER: Did you have a sense of his leadership style, from your mentors?

DODD: I certainly do now, having worked with him during the Interstellar Mission, and then talking with folks like Linda Spilker and others that were part of the science team meetings and really used Ed as a role model. For Linda, she was a project scientist on Cassini, so trying to use what he did as a role model. I've talked to Ed over the years, over the last 10 or 15 years, about just what he tried to do to lead science teams. Because scientists all understand the greater good, but they want their instrument to be higher up than—it's not so much higher up than another instrument, but they all understand they have to fight for their science.

ZIERLER: Some science objectives are more equal than others. [laughs]

DODD: Yeah, exactly. Yeah, yeah, yeah. So the way that Ed was able to listen to everybody, summarize the key points, and kind of get everybody into agreement—or acceptance might be a better way to say it; it doesn't mean that everybody agrees, but everybody accepts it—really a great role model for project scientists.

ZIERLER: On that point, did you have a sense in the 1980s how scientists and engineers worked together, or not, for Voyager? That blend of engineering possibilities with science objectives?

DODD: Absolutely. There's very much a difference between scientists and engineers. I think actually that's one of my strengths, and I probably got it a lot from Voyager, and a little bit from Mars Observer too. Because Mars Observer was a young crowd of scientists. They were all grad students on Viking and then they got to be PIs on Mars Observer, people like Phil Christensen or Mike Malin, who are kind of movers and shakers in the world now in science. They speak a different lingo, and their objectives are different. The engineers like to solve problems. The scientists like to understand the mechanisms for how something works and look for discoveries. The engineers are enablers of the science. So, there's a synergy. The engineers don't have a job unless the scientists have good questions that they want to answer, right? And the scientists don't get the data unless they work with the engineers to be able to solve the problems to get them the data. That's actually one area I really feel I do well, and that I am happy that I can do this well, which is just helping communication between scientists and engineers, and seeing both sides of it. I think that helped a lot when I worked on Spitzer, because I was working in the Science Center, and I was trying to tell the engineers at JPL, "This is what the scientists are trying to do. Don't think of them as, ‘Those stupid scientists don't understand the issues.'" They do, but they also have valid reasons for wanting to do certain operations.

ZIERLER: On that point, and last question for today, given all of the miracles of Voyager, both all of the discovery and the engineering, that continue to allow the spacecraft to exist, what was it, what was that perfect blend of engineering and science that you saw from your perspective in the 1980s that helps explain what Voyager was and is able to do?

DODD: Since being project manager for the last twelvish years—the engineers on Voyager are extremely dedicated to it. There is a core group of people that have been there since Neptune and Uranus. Has the engineers, has the attitude control engineers, has the telecom engineers. So they are intimately familiar with the spacecraft. It is a big challenge now, because people are retiring out, and how to get that knowledge capture is difficult. It is difficult in particular because this mission has always been like, "It'll last three more years." Even when it was approved in 1990, I don't think people thought it would go for more than five years. As a matter of fact, I have heard that from some NASA people at the time. We were at 30 AU, and they said we'd cross the heliopause by 50 AU, and we crossed it at 122 AU. It has always been a mission of like four or five years at a time, [laughs] so we've never planned to have a 45-year mission, or a 50-year mission. We certainly have that goal now. The value of the data is extremely unique and important, if you want to study interstellar space and the heliopause. But I think getting back to your original question, as I digressed, you were looking for how the scientists and engineers worked together?

ZIERLER: Yes. What was that blend of engineering capabilities with science objectives that just made Voyager what it was?

DODD: I think there was a respect between the engineers and the scientists. I was not on the project in the first five or six years of the project. I'm sure there were much more rough times in interactions between scientists and engineers—

ZIERLER: That got smoothed out by the time you got there?

DODD: Yes, that got smoothed out over time. I'm sure that there was a lot more rough patches in personalities, and even in leadership. It's really leading the project. The project manager, who listens to the engineers, or the project scientists. See, you definitely have to have—a good project has a good working relationship between the project scientists and the project manager. Absolutely need that. If there's any little chips in there, or any little clinks where they don't see eye to eye, that can really undermine the success of a project.

ZIERLER: Happily, it sounds like you came in right at the perfect time, when all that got smoothed out.

DODD: Yeah, I think it took some time. I don't have the earliest history of Voyager, but by the time I was there, I think everybody kind of knew each other. And people hung on, mostly for Neptune, I think. A lot of people hung on. Then there was a big transition because the staff went way down.

ZIERLER: On that note, we'll pick up—big changes are coming next, in the 1990s, for you. Mars Observer, Ed Stone becomes director, and of course the end of the Cold War and what that means for JPL. We'll pick up next time.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Friday, April 14th, 2023. I am delighted to be back with Suzy Dodd of JPL. Once again, great to be with you. Thank you so much.

DODD: Thank you.

ZIERLER: Today we're going to pick up where we left off last time—the late 1980s, early 1990s, a period of transition at JPL, for the United States. As a beginning point, I wonder, did you get to know Lew Allen very well? Did you have a sense of his leadership style?

DODD: No, not really. I think I started right about the same time he started. Because before him, Bruce Murray was the director. I started in Spring of 1984, May of 1984, and I think that was right about the time there was a transition. Lew Allen came from the Air Force. I have seen some documentaries on him and his style of leadership, but I was, I would say, very far down in the food chain, so I really wasn't paying much attention to him. [laughs]

ZIERLER: When he announced his retirement and the Lab was searching for its next director, did you have insight into the key issues facing the Lab, and who the ideal next director would be, both in terms of looking from the outside and the inside?

DODD: I think it's only based on what I've seen in documentaries since then. My understanding is, back in the late 1980s, budgets were very tight. There was a lot of question about why we should have a scientific program at NASA. I think it was key there. I do remember that the late 1980s at JPL had quite a large military project, called I think ASAS, which was for the Army. It was like a remote tracking system for the Army. There were quite a few people there. The reason that project was brought in was because there was a big decline in the science missions that were going on at NASA at the time. You're probably going to get to this, but Ed Stone succeeded Lew Allen as the director of the Lab, a very prominent, well-known scientist because of Voyager, and because of his association with Caltech. I think he was viewed as an ideal person to bring in, for two reasons. One, Caltech runs JPL, so being a professor at Caltech, he was infinitely familiar with what goes on on campus, and how the inner workings of campus happen, as well as being the project scientist on Voyager, he was at JPL—frequently, if not regularly had an office here; I'm not sure. Ed Stone was here frequently, so he knew what JPL was like, and he was viewed as a scientific leader, at the time. That was what they were looking for—somebody who could demonstrate good scientific leadership, which Ed had certainly done during the course of the Voyager, and also sell that to Congress.

ZIERLER: You mentioned that there were budgetary difficulties even in the late 1980s. I was under the impression that it was really the end of the Cold War when the budget crunch became a big deal, but your memory is that it was actually earlier than that?

DODD: Yeah, because I remember this ASAS project starting under Lew Allen. Now, maybe it continued into the 1990s under Ed Stone; I'm not really sure about that.

ZIERLER: At this point, what were you doing? Were you exclusively focused on Voyager? Were you starting to get involved in Mars?

DODD: The answer to that is I supported Voyager for the Uranus and the Neptune encounter. The Neptune encounter was August of 1989. By the Spring of 1990, I had rolled off of Voyager, and yes, I went on to a project called Mars Observer.

The Magic of Planetary Encounters

ZIERLER: Let's go to the planetary encounters. What is that like, for you, for public communication, for a sense of wonder? Just tell me about that.

DODD: You're talking about the Voyager encounters?

ZIERLER: Yes.

DODD: Oh, well, they're fantastic! It's so much excitement and nervousness in the air. The engineers are wringing their hands, hoping it's going to work. People from around the world are watching it, whether they're in Times Square, or Europe, or some other place. I just watched a little video on the Mars landings, and you could see the whole team nervously wringing their hands and squinting at their monitors to see what's going on. That was just a few years ago, but it was the same in the 1980s, as far as the nervousness that you had, and just the nervous excitement, and hoping—fingers crossed, and whatever tradition or superstition you liked to use to make something successful—was going on, amongst the people on the project, and the people at JPL.

Next Phase for Voyager

ZIERLER: We've talked previously about the heliopause and interstellar space. But at this moment, circa 1989, if Voyager had already demonstrated its capabilities to get that far out in the solar system, was the going assumption that it could keep on traveling? Or that was still an open question?

DODD: I think there certainly were discussions about turning Voyager off after the planetary encounters. I think there was some good salesmanship to say, "Look, half of our instruments on the spacecraft are designed to sense the environment that the spacecraft is traveling through." So, it's designed to sense fields and particles, magnetic fields, things like that. "We won't use the cameras anymore, or anything that is designed to look at planetary objects, but we can take the spacecraft, have five or six instruments still operating, and let them travel out as far as possible and see if we can get to the termination shock, and then out across the heliopause." I do remember when I came back on the project, as the project manager, in 1990, I got a nice little note from Frank Carr, who was a retired NASA administrator. He had been on a review board of another project of mine. He sent me a note, basically, "Congratulations."

NASA/JPL sold this mission, this Voyager interstellar mission, by saying that the heliopause crossing would be at 50 AU, and Neptune is at 30 AU, so it would only be maybe anywhere from five to ten more years that it would take to get to cross the heliopause. Well, it's not 50 AU; it's 122 AU, and it took us 32 more years to cross the heliopause. Anyway, I think it was sold well, and it was sold by the science. Even today, as a matter of fact, we had a senior review, and on Monday, Linda Spilker and I are presenting to a panel to basically tell them why we should continue Voyager. But it's so unique, and nothing is ever going to go to the same place, or get that data again, in the sense that you might send another mission into interstellar space, and you might travel faster than Voyager, but it's not going to go on the exact same course, and the solar cycles will be different. So you're not really going to see the exact same data. You'll get a collection of data that you can use with the Voyager data, but it's not going to be exactly the same data. So, that makes what Voyager is doing today very unique.

ZIERLER: To clarify, is one of the reasons why a hypothetical additional mission to interstellar space would be, by definition, different, because of the planetary alignment? The fact that what Gary Flandro discovered was not going to happen again for another 175 years, and we're in the interim of that now?

DODD: I would say yes and no. The alignment of the planets made it much easier, relatively speaking, to get out to the outer heliosphere quickly, because you've got this slingshot effect around all the planets. There is a mission that is under study—it's called Interstellar Probe—it's going to do a slingshot by Jupiter, because that's the biggest object you can slingshot around, and then go from there out into the heliosphere, and then into interstellar space. It is going to travel probably something on the order of five times as fast as Voyager does. So, it will get out to where Voyager is, in a distance standpoint. But if you recall that the Sun has solar cycles—so, every 11 years, you go through a cycle where it's low solar activity, and then it increases to high solar activity and goes back down again. So, these missions are not timed to match each other in the solar cycle., With Interstellar Probe, it probably depends a little bit on when it launches, and the exact direction out of the heliosphere it's going to go. What I would say is it's not going to be a duplicate set of data, but it will be an additive set of data to what Voyager has already captured.

ZIERLER: When you transitioned to Mars Rover from Voyager, was that at all related to the timing of Ed Stone becoming director of JPL?

DODD: First, one correction; it wasn't a rover. It was an orbiter.

ZIERLER: I'm sorry; Mars orbiter, right. [laughs]

DODD: Yeah, Mars Observer. No, it was due to the fact that the project at the time at Neptune was probably 250 people, and it was going to go down to about 50 people in a year. So, it was a big turning point in the Voyager's mission, in really the scientific objectives of the mission. It would go into an extended mission that would only study fields and particles instruments. It would need to be much more autonomous. So it didn't need as much staff, honestly. It didn't need the staffing. And so, I was ready to move on to another project. I had been on Voyager for six years, so I was ready to try something new.

ZIERLER: How well developed was Mars Orbiter by the time you joined?

DODD: It was undergoing at the time that I got on—it was already designed. It was sort of in the critical design review phase. They knew what the mission was, and they had the instruments already selected. Basically Mars Observer was a lot of a follow-on from Viking, although it wasn't a landing, but it was a follow-on, particularly with regard to the scientists. Quite a few of the scientists on Mars Observer, the lead scientists on Mars Observer, were like grad students on Viking, people like Mike Malin and Phil Christensen, who are pretty powerful people in the world of planetary exploration now. The mission was designed; it was being built when I got on. I came on to support the operations, the mission planning piece of it meaning what needs to go in, in operations. What's the cadence? How many calibrations do we do? When do we do them? Kind of laying out all those timelines, and then iterating them, and iterating them, and iterating them, between the science teams and the engineers, the spacecraft people.

ZIERLER: I was getting ahead of myself; I made the mistake saying Mars rover because my subsequent question was going to be, did you see or did JPL see Mars Orbiter as prelude to a landing mission? Or were the science and engineering objectives really independent and separate?

DODD: I wouldn't say they were 100% independent. Mars Observer was designed to be a global mapper. You're in a polar orbit around Mars, and you're mapping a strip of the surface. So, over a Mars year, you would get several passes over a strip, over the planet, and you could make a map of the surface of Mars, which has not been before, I don't think, from that standpoint. It would allow you to look at the whole surface and decide where are good landing sites to go with your rover.

Lessons from Mission Failure

ZIERLER: Unfortunately, we know how this story ends, of course, with the loss of communication. Suzy, can you reverse-engineer that problem when it happened back to when you started? In other words, were there systemic issues that never got fixed over those years, or was this more of a fluke accident kind of thing that nobody could have seen coming?

DODD: I'll go back to this: space is hard. Building spacecraft is hard. There are schedule pressures, there's budget pressures, and you have to trade those off while you're building a mission. Planetary missions have to launch at a certain time or they get delayed. For Mars, it's every 25 months. You either launch in this one-month window or you wait 25 months. We've seen that a lot, that Mars missions get delayed by two years. So, some decisions were made, I think based on the best information at the time, particularly with thruster operations and when you want to pressurize a tank before you do the main burn. Some decisions were made based on the best information at the time, and unfortunately for Mars Observer, that was a bad decision. And, you learn from that, right? So you don't make that kind of a design or a decision risk trade like that for a future mission. Something else will come up in a future mission, but you don't make the same error twice.

ZIERLER: Was there any overlap with Mars Polar Lander, or these were really completely separate missions?

DODD: They're very separate, and very separate failures. I don't know a whole lot about the Mars Polar Lander, but it's definitely not a type of failure that Mars Observer had.

ZIERLER: So you were not involved at all with Polar Lander?

DODD: No.

ZIERLER: Did you stay throughout the 1990s exclusively on Orbiter, or did you take on other things in your portfolio?

DODD: No, I was only on Orbiter—let's see, I moved there in 1990, it launched in 1992, and we lost it slightly—eight months later, as we were going to do our big capture burn. That's where we lost it, during that burn, or right before that burn. So from there, in 1993, I got on Cassini, and I spent six years on Cassini, four years before launch and about two years after launch.

ZIERLER: Tell me about losing contact with Orbiter. Was it a dramatic, like a, "Houston, we have a problem" kind of situation? What was that day like?

DODD: [laughs] Well, it was—yeah. Let me just describe what happened a little bit, because that will describe kind of the air. What happened was that we ended up—it was a liquid fueled engine, big engine, so when the two chemical elements combined, they start a combustion in the engine. So there's two lines. The review board—there's always failure review boards, but the review board found basically that some of that liquid had gotten into the lines early, so instead of combusting into the engine, at the engine, it combusted early in the propellant lines, and so there was an explosion in the propellant lines. So it never really did its burn. It put it into a tumble and flew right by. But we had turned off—one of the big lessons learned is we had—I'm trying to remember the reason why—we had turned off transmission during that burn, which is not typically what you want to do. You want to see what is happening and get the data back during a burn, during a big maneuver like that. Something in the design—and honestly I don't remember what, David—something in the design of the maneuver had us turn off the telemetry. So, the telemetry was turned off, the burn was supposed to happen, and then the telemetry would come back on. And, the telemetry never came back on, because the spacecraft was tumbling. It was losing power, because it's solar powered. Also, not having telemetry really hurts you in understanding exactly what happened, because you don't have that data. So, it wasn't like we were watching it, watching it, watching it, and then the signal disappeared and we knew we had a problem. It was, the signal disappeared, and we expected it to reappear, and it never reappeared. I was at home; I remember getting a phone call from the flight system manager saying, "We've got a problem. We don't have any telemetry from the spacecraft."

ZIERLER: When do you know that it's more than a communication issue? What level of time is there holding out hope that we've just lost contact, as opposed to an engineering failure and it's kaput?

DODD: It takes a few days. I wasn't really involved with this, but I'm sure we declared a spacecraft emergency. We probably had several DSN antennas looking at it, sending signals, trying to regain the spacecraft back again, and it just didn't work. After three or four days, you pretty much felt like, "We missed this mission." Because we would hear from the spacecraft if everything was okay, and we never did again.

ZIERLER: To broaden out your well-taken point about how space science, space engineering is hard, another view is that JPL is not used to mission failure. What was that like?

DODD: Absolutely! [laughs]

ZIERLER: What was that like at the Lab? Yes, space, this is really hard stuff, but JPL succeeds in its mission.

DODD: Yeah.

ZIERLER: What was the psychological impact of that, from Lab leadership to the whole team? What happened as a result?

DODD: Well, it was certainly—it was my first mission I had been on that failed. Actually, my only mission so far that has failed.

ZIERLER: Hey! Here's wood; I'm knocking on it.

DODD: It knocks you down a notch. It makes you feel like, okay, we are not impenetrable, or invulnerable to errors, and we need to pay more attention to what we are doing. You go through a lot of lessons learned. You change procedures and processes so hopefully that error doesn't happen again, but also other errors that might be oversights based on how you just develop a spacecraft or put a process together. There's a lot of review of that kind of stuff. Mars Observer was not a big mission. People were working on Cassini—and CRAF, which was a duplicate—but they were the next two big missions to be spun off of Voyager, to go to—in Cassini's case, to go to Saturn. Galileo, of course, had already started on its journey. So, me personally, it's like, "Wow. Everything doesn't go as planned." Because Voyager, everything went as planned. Uranus—fshoo!—Neptune—fshoo! There were a few tight moments there, but it worked. In Mars Observer's case, it didn't work, and you lost—everything. It's not like you lost one instrument. You lost the whole spacecraft and all the science that it was going to do.

ZIERLER: I'm sure you've heard the varying perspectives on the role of the so-called faster, better, cheaper approach. One school of thought is, oh, that's just a slogan, and JPL is always going to do things the right way. The other school of thought is, no, actually you can see how we were hurried, we didn't have all of the money that we needed, and you can really see that as an impact into what happening with Orbiter. What's your perspective on that spectrum?

DODD: I didn't have much history at the time. I had been working for less than ten years, so it was hard for me to have the wisdom of somebody who had been working 30 years, and in the business 30 years. I do think that Voyager in particular, it was built extremely robustly. We got to build two. Nobody ever builds two identical spacecraft anymore.

ZIERLER: [laughs]

DODD: To this day, we learn from one and use it on the other one. It's like an in-flight testbed almost, in situ testbed. I think in that case, Voyager was very well funded, very well built. There was obviously schedule pressure, because like you said, this alignment is only every 175 years. [laughs] So, there was some schedule pressure in there. But the money spigot just kept coming pretty much with an ask. Certainly nowadays, that's one of the big drivers, is just the cost, and how to do things as cheaply as possible yet while being robust. I think there was pressure on Mars Observer in the 1990s to try and get a smaller type mission. Not this big flagship mission of Voyager, but a smaller mission, and try and be successful with less funds and again, schedule pressure. Planetary missions always have schedule pressure because the launch windows are very constrained. But to get the Mars mission off and do it within a budget envelope successfully.

ZIERLER: Did you have good insight into Ed Stone's response, like a lessons in leadership kind of view of how he bucked up emotions among the staff at JPL, how he managed relations with NASA? How did he keep things on a successful course after this?

DODD: I would say that Ed was a very open person. He had a lot of all-hands meetings with the whole directorate, sharing what was going on with headquarters. I have seen some of those recordings where he is in von Kármán talking about failures and talking about the failure of Mars Observer, but also talking about where we need to focus, and lessons learned, and moving forward. What Ed told me—over the course of many years since I've been the project manager—when he was the project scientist—is that he made a lot of trips to Washington D.C. Like, he was on a plane twice a month to Washington D.C., just to be in contact with both NASA headquarters and the congressional staffers or things like that. He basically said the JPL director needs to be comfortable living on an airplane. I think somewhat that is still true today. Even though we've got video conferencing and Webex and Zoom and things like that, it's just not the same as seeing somebody face to face. And negotiating face to face. Whether it's budgets or schedules or new projects that you want to get started.

As a personality, I think Ed was very forthcoming. What we weren't successful with on Mars Observer, the lessons we're learning, and how we need to apply those to the next missions, which include—Cassini was the big one they were trying to get sold. As I mentioned earlier, Cassini was originally two—there were going to be two basically identical spacecraft, Cassini and then CRAF, which was Comet Rendezvous Asteroid Flyby mission. They were both going to be big like Cassini. CRAF got cut, and Cassini got scaled back in the sense that it didn't get a scan platform. Like Voyager had a scan platform, so its science instruments, like the cameras, could point independently of the spacecraft. On Cassini, everything is body-fixed, so if you want to take a picture of something, you've got to rotate the whole spacecraft. That's less efficient, but it also makes the mission less expensive. You're not developing this whole scan platform arm. That was one of the compromises on a budget standpoint they made on Cassini.

ZIERLER: A question about accountability in the aftermath of Orbiter. Does anybody get demoted? Do they lose their jobs? Is there a heads-will-roll kind of moment? Or that's just not the work culture at JPL?

DODD: It's not typically the work culture, although I would say if you were the project manager on that mission, the person that actually made decisions, you were probably feeling the most pressure, because you were the one that was going to go in front of whatever kind of hearings there were, whether they were at Congress, or NASA, and tell them why you made the decision you did, based on the information you knew. Also, hindsight is 20/20, so everybody that is grilling you knows what happened, right? But you didn't, and you needed to understand the trades you were making for the risks.

ZIERLER: It's almost a philosophical question, but from your perspective, was this really about human error, or was this just some really unfortunate thing that could not have been avoided?

DODD: I think it could have been avoided. I think it was a judgment decision. And engineers and project managers have to make many of those in the course of a mission. Do we launch this and maybe have it fail, or do we replace it and potentially jeopardize the schedule, type thing. Project managers have to make lots and lots of decisions like that. In this case, it was probably not the right decision.

ZIERLER: Moving on to Cassini, obviously if Mars Orbiter had continued, would you have stayed on, or that was already in the books that you were going to transition over?

DODD: No, I probably would have stayed over there for another couple years, because the mission was two years. Basically one Martian year was the prime mission. So, I would have stayed on, because I was doing operations at the time. I would have stayed on.

ZIERLER: The road not traveled—what would you have done, what would Orbiter accomplished had it continued?

DODD: It would have mapped the surface of Mars and provided detailed maps—altimetry data, obviously imaging data, infrared, ultraviolet, composition of the soils, that type of thing. And it would be one of the first—or I would say the most—the highest definition and resolution of the surface of Mars, global surface of Mars, and an ideal thing to then use to determine your landing point for Sojourner and the future Mars missions, Mars lander missions.

Joining the Cassini Mission

ZIERLER: Tell me about Cassini at the point you joined. What was the state of the mission at then?

DODD: It was pretty early on. Of course, in a mission, instruments get selected pretty early. They are selected five or six years before the mission starts. Same thing for whoever is building the spacecraft. In this case, JPL was the system contractor for Cassini too, just like they were for Voyager. From Voyager, Galileo, to Cassini, the bus and the design of that, they were all done at JPL, so there's a lot similarities between them. But you're always bringing in new technologies, too. All those missions don't have a 64K memory the way Voyager does [laughs]. There are advancements you bring in, too. But a lot of times, it's the same people designing the innards of the spacecraft. Really I got in on Cassini at the beginning of what I would call the development of the operations system. What software do we need to be able to send commands to the spacecraft? Defining what those commands should be. Doing mission planning, also. What do we want to do to get out to—I'm not a navigator. The trajectory is also decided pretty early on, like in an Earth-Venus-Earth flyby, or Earth-Earth-Venus flyby. I don't even remember what it was, but it was three flybys before we got out to Saturn, I know one of which was the Earth. Because people protested that flyby, because Cassini had nuclear power source onboard. That's another story for you, David!

ZIERLER: [laughs]

DODD: I got on at the beginning of designing the ground software that would be used to operate the missions. It's a combination of what tools do we need, but in order to develop the tools you need, you need to know what you want to do with the mission. So, developing both of those things, like the operation processes and plans, along with the ground software that you're going to use to implement those processes and plans.

ZIERLER: Given your experience coming on to this mission, where was your learning curve the steepest? What was brand-new engineering for you?

DODD: I would say new for me is—I'm not a software developer—learning how to manage software developers, that's one of the key things I learned. You'll find there are a lot of obviously very good software developers. They need some help keeping focused. From management, my perspective is, they can program just fine. I'm not going to tell them how to program anything. But I am going to say, "These are the requirements. This is what you need to do. Good is good enough." I find a lot of software programmers, they want to—use the expression "polish the cannonballs." Software code is developed like this, and then it never quite makes it to 100%. The lines never quite get to the top. So you've got to cut it off at the 95% level, because when you're looking for the last 2% of the code, it could take you years to get there.

ZIERLER: Managing software developers, is that to say that it was with Cassini that you really began your trajectory in administrative leadership?

DODD: Yeah. I had a small team on Mars Observer. I had two other people in the mission planning team. But we were not developing the software code or anything. On Mars Observer, our role was to interface between the science and the engineers and make a plan for what activities were going to go where. I actually learned this on Voyager, too, I think, because I worked with a lot of scientists to make the sequences for Voyager. But I think I have good skills, and over the course of my career I've developed good skills to help people understand the others' viewpoint, to bridge the gap between how scientists and engineers think. What's important to a scientist and what's important to an engineer. I would put the software developers in the engineering category. Engineers love to solve problems. You've got to keep them on track to solving the right problems. Because they can just go off track and say, "Well, this could be an issue. I'm going to go solve it." It's like, "No, don't focus on that. We've got 100 issues. Those ten are very minor, low-risk." You make a decision, right? "They're low-risk; don't worry about fixing those. Focus your energies over here."

ZIERLER: I don't know if this question is going to sound like from way too long ago, but as a woman in a management position, were you unique in that regard? Were there other women managers? Is that something that you felt?

DODD: There were not a lot of other women managers, but I would say I never felt put off by that, and I never felt that I was discounted because of that. In my whole career through high school and college, I've been female in male-dominated classes and roles. I do feel respected. Part of that might just be, again, the communication skills. I can listen. I know when somebody is being a jerk, and depending on their personality, I ignore them, or I call them out sometimes. Like, "That's not appropriate." Yeah, there were not a lot of women in any kind of leadership roles.

ZIERLER: Was there anything useful from Voyager, from the planetary encounters, for Cassini, to draw on?

DODD: Oh, absolutely, tons and tons and stuff. I think a lot of the science team was the same, so you already had a certain amount of network with the people you were dealing with, so you knew how they operated, worked, and thought. Mars Observer I think had—I'm not exactly sure how many instruments Mars Observer had; I'm going to take that back. But Voyager had like 11 instruments, and Cassini had 12 instruments and a probe. It was more complicated than even Voyager. So, what I learned in integrating and building sequences for a spacecraft with many, many instruments, I could carry over to Cassini.

ZIERLER: How much interface, if at all, did you have with ESA, for Cassini?

DODD: Not too much, actually. They would come to meetings at JPL. I never got to travel to Europe. That's one of the big disappointments on that project, anyway; I never traveled to Europe. But they would come out for science—

ZIERLER: Was there really not that much interplay, cooperation between the Americans and ESA?

DODD: There was quite a bit, but not in the area that I was on. The science team meetings they would do twice a year, and they'd usually have one here at JPL, so all the Europeans would come. So, I would get to meet them, and we would talk about—they were very big in the probe, the Huygens Probe. That was one of their major contributions. The Italians also I think built the antenna on Cassini. So, it was a collaboration with ESA, but it was more—both scientifically or specific to engineering hardware, and the role I played was not particularly—we didn't interface with either of those organizations too much, or with the scientists.

ZIERLER: How important was Jupiter for the Cassini mission? In other words, was the encounter there just because it was there, on the way incidentally to Saturn, or was the opportunity to really study Jupiter also important, central to what Cassini was all about?

DODD: Well, you went to Jupiter because it gave you the slingshot momentum out to Saturn, obviously. But it also gave you an opportunity to kind of test what you wanted to do in a very small subset of the type of science. You could turn on instruments. You could look at something. You could calibrate. And you could do all that at Jupiter, because you had a good—Galileo was already at Jupiter, so you had some understanding—and Voyager had flown by—so you had some understanding of what Jupiter—what the atmosphere was like, and what the chemical compositions were, and such. The flyby for Cassini allowed the instruments to turn on, take data, and calibrate that data, and really check out their instruments, so you didn't have to do that when you got to Saturn, in essence. You had done a certain amount of checkout at Jupiter, and you didn't have to repeat it at all at Saturn, when you first got there, which gave you more time just to take science data at Saturn.

ZIERLER: The rings of Saturn—that's what everybody wants to know about. How much was that really what Cassini was about in terms of securing funding, in terms of engaging the public? How central were the rings of Saturn to what Cassini was designed to do?

DODD: I think it was very central, and you can see that with just how they ended the mission. They dove through these rings, very dramatically, trying to not get hit by ring particles, into the atmosphere. But it was sold as a ring mission. Because that's what you can see from Earth. You can see the rings of Saturn through a not particularly strong telescope. That's kind of the mesmerizing piece of it. Now, we did know that there were some moons of Saturn that would also be very interesting. Then we could compare those moons of Saturn to our moons, and the ones we knew at Jupiter as well. But I think the rings were the big draw. The atmosphere, too, but the interplay between the atmosphere and the rings. Yeah, the rings are a draw, because, what are they made of? How do they stay as rings? How do they form? All of those. And you knew that Saturn had a fantastic ring system before you even launched the mission. So, yeah, the key science objective was to study the rings.

ZIERLER: By definition, this is uncharted territory. In terms of the composition of the rings, what were some of the engineering challenges to make sure that Cassini would be safe, would not get damaged, as it encountered these rings?

DODD: Initially, you stay pretty far away from them, and then—

ZIERLER: Because there's just too many particles; you can't know how to avoid them all? Is that the idea?

DODD: Yeah. I think you start—and typically, the way orbiters work, too—you need to get capture. You get a lot of speed, you're going fast, to get out to that planet. Then you've got to do a super big burn, engine burn, to slow it down, so it gets captured in an orbit around the planet, in this case Saturn. The initial orbits are going to be very big, because you've slowed it down enough to be captured, but it's not in its final orbit. But the navigation team—you can control that, in the sense of how long you want to spend in this orbit, and when do you want to go to a lower orbit. You can control that through your navigation system and your onboard thrusters. That's designed well in advance. That is designed before you launch. Because you have to launch a certain amount of fuel, and you have to size your rocket engines and all of that, so that's all designed before launch. But initially, going to someplace like Saturn, you don't really know the extent of the ring system. You don't know the extent of all the particles. And you'll find that what you thought were gaps in the rings aren't really gaps; they're just really fine particles. But as the mission goes on, you can take more risk. Your initial science requirements are done; you can take more risks. So you can fly closer to the rings. You can do some observations that could be riskier than you would want to do initially.

ZIERLER: Were you involved exclusively with Cassini from the time you joined through launch in 1997?

DODD: Yes. I was involved from 1993 through 1999. I never made it to Saturn. It was a seven-year tour to Saturn. That's a long time. 1997 to—I think they got in orbit July 4th. I think it was July 4th, or real close to July 4th, in 2004. I had already been on the project for six years. Now, there were a lot of people, quite a few people, that stayed on Cassini for 20 years. I did not. I went to work on the Spitzer Space Telescope, actually. In 1999 is when I transferred to campus to work in the Spitzer Science Center.

ZIERLER: What was launch date for Cassini like, October 1997? What was that like for you, that day?

DODD: I don't even remember. I'm sure I was at JPL watching it. Oh, I do remember now. Yeah, October 1997. I was in von Kármán. I didn't have any direct work with the launch, but it was a late-night launch, and we were invited to watch it. Some of the employees were invited to watch it on the big screen in von Kármán. So, my dad was there; my husband was there. My husband was an athletic coach at Caltech, and one of his students, his grad students, came. His grad student is now a very well-known astronomy professor in UC San Diego. So, as a grad student, he got to come up and watch the launch, too, which is kind of fun to think about how people's careers go after a time. But yeah, it was great. Big rocket. We could sit and listen to the first couple hours of it from von Kármán so you knew things deployed. You knew you were getting telemetry from the spacecraft. It was all healthy, so all of that was really good.

ZIERLER: By the time of launch, were you still in the same role as when you joined, or had you moved up the ranks at that point?

DODD: I was pretty much in the same position. When I first joined, the team that I joined, that I was managing, was smaller. It was maybe eight or nine people. By the time it was launched, it was closer to 35 or 40 people.

ZIERLER: Had you known you were going to transition to Spitzer at the time of launch? You wanted to stay on another two years? Or that came later?

DODD: It kind of came later. That came after the first Earth flyby. It came later. It was just like, "I'm ready to do something different."

ZIERLER: How did your day to day change, once Cassini was airborne?

DODD: Cassini had a lot of deferred development, meaning—because it had a seven-year tour—this is the same thing they're doing on Clipper right now—because it took so long to get there, you didn't have to do everything before launch. So, we did more software development, particularly for the tour phase, after launch. We did some planning for the flyby encounters, like you mentioned, at Jupiter. I guess it was not so much the pressure to get to launch, so it did become probably a little more routine, which is why I decided I'd try something different.

Spitzer and JPL Astrophysics

ZIERLER: Tell me about how you got to Spitzer. What was the opportunity there?

DODD: Spitzer is the first and only—well, not only; I'll take that back—it was the first astrophysics telescope that JPL had worked on. JPL had been planetary. This is an astrophysics mission, so you're building a telescope to look at stars and galaxies. Spitzer in particular is infrared. I went down to work at campus. There were Mars missions coming up, and I had talked about getting on some of the Mars missions, but the opportunities really weren't there, so I decided I would try to work on campus. I'm a Caltech grad, and my husband was working on campus, so it wasn't a big deal. They were looking, at the time—so, the way a telescope works is different than a planetary mission in the sense that the telescope is there for a community to use. It doesn't have designated principal investigators for instruments. They were building software tools at the time that were going to be used by the astronomy community around the world to design observations and propose these observations on the telescope. Because I had this experience both in mission planning and in managing software developers, and because the interface was with JPL—Caltech did the science planning aspect of it and built science planning tools, but JPL would be sending the commands, basically, generating the commands for the telescope and sending them through the DSN. So, there was this interface, again, between science and engineers, which manifested between Caltech and JPL.

It was a great experience for me, because I could sit with the scientists, but I knew the language that the JPL engineers would understand. There was a lot of tension between those two groups early on. There were a couple other people. The manager at the time down there, Bill Green, came from JPL. So, he understood that, and I think one of the reasons he hired me was because he knew that I could work that interface between the scientists and JPL. And frankly, JPL at the time, they only sort of seemed half interested in supporting Spitzer. I shouldn't say half-interested, but they had a lot of engineers come and go. It was like a holding point for people. So, the JPL side of the development was kind of slow, and they had some staffing issues. From Caltech's side, I could try to help that, and just say, "Look, these are what is important to the scientists, and design your software this way." I really liked that role. I really liked the role of being the communicator or the interface between scientists and engineers. I had done a fair amount of that previously, but on Spitzer that was by far the real role there, was to get Caltech and JPL to work together.

ZIERLER: Coming back to Caltech for Spitzer, was that a bit of a homecoming for you? In the past 15 years, did you have much opportunity to spend time on campus?

DODD: I spent some time on campus because my husband was a coach, so I got to see the kids that were on the swim team, basically, and using the pool, and using the gym. Which is not the majority of people at Caltech, but it is [laughs]—it is some. What was new was actually really learning about astrophysics. I've seen a lot of geology. I worked in a lot of atmospheric science. And a lot of the Cassini and Voyager PIs were from Caltech. They were professors at Caltech. But this was different, because this was astrophysics. This was stars and galaxies. It wasn't planets. It wasn't atmospheres of planets. It was astrophysics—stars, x-rays, stellar nurseries, and a whole different group of scientists. It was pretty exciting. It was fun.

ZIERLER: You seem to indicate that JPL kind of institutionally needed to be dragged into the astrophysics business. Just to fast forward to today—how central, how important JPL is for astrophysics—was the success and experience of Spitzer really the foundation point for JPL embracing its astrophysics mission?

DODD: Yeah, I think so, absolutely. Spitzer was the first—well, I'll take that back. There was a mission called IRAS that JPL supported, which is a similar infrared telescope. It launched in 1992, maybe, so it was ten years before Spitzer. A lot of the science team was on campus, too. Spitzer was by far bigger, both in budget, and in scope, and in staffing, than IRAS was. I think that the success of Spitzer really put JPL on the map to work on some of these large telescope projects now, and instruments like the infrared MIRI instrument that is on James Webb.

ZIERLER: Last question for today. Do you think JPL would have been involved in astrophysics at all if not for the Caltech connection? In other words, was the core of its mission so planetary-focused that without the Caltech connection, it might not have ever gotten involved in astrophysics, given all the other labs and agencies that do that?

DODD: Yeah, I think so. Others might dispute that, but I think so, just based on my knowledge. When you think about it from a campus standpoint, astrophysics is in the Math, Physics, Astronomy Division. Voyager and Cassini folks, they're all in geology, in geological sciences. So, two different divisions at Caltech.

ZIERLER: Given that its focus traditionally of course has been in planetary, what has JPL's unique contributions been in astrophysics, in space exploration, space science, that a different lab might not have been able to accomplish?

DODD: I think our success with building spacecraft—and now we have quite a bit of success in building telescopes, and managing telescope vendors, like a Ball Aerospace, or a Lockheed Martin. We've had a lot of success in managing those people, in working with those vendors of those spacecraft. I think that is what makes JPL stand out, is being able—now, a telescope mission typically can launch whenever, right? It doesn't have the planetary window. That's not to say that you're not going to get a lot of heat if you miss your launch date and slide it out. There's no missing launch dates without adding costs, so the key is to keep the costs in control, and I think JPL has done a really good job in the astrophysics world of keeping costs within the budget they state.

ZIERLER: On that note, another great talk in the books. Next time we'll pick up on another transition point, the end of the 1990s. Ed Stone steps down, Charles Elachi becomes director, and we'll see what that means for you going forward. We'll pick up from there.

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Thursday, April 27th, 2023. It is great to be back with Suzy Dodd of JPL. Suzy, once again, wonderful to be with you. Thank you so much.

DODD: You're welcome. Thank you.

ZIERLER: We're going to pick up at the turn of the century, a moment of transition for JPL of course. Charles Elachi succeeds Ed Stone as director of JPL. Just to orient us in the narrative, when that transition happens, what does that mean for you at that period? Are you affected by this at all?

DODD: Actually, in June of 1999, I left JPL and I went back to Caltech campus. I actually worked at IPAC, the Infrared Processing and Analysis Center, and I got a job in the Spitzer Science Center, which was on campus. So, I was not there at the transition of the—because when did Ed Stone leave? 2000?

ZIERLER: Yes.

DODD: Yeah, I was on campus at that time. I think Ed retired from the directorship about maybe a year after I moved to campus.

ZIERLER: Just administratively, is that considered—it's all Caltech, right? Is it a detail? What does that mean when you are now at Caltech?

DODD: The way I look at it is they're sort of two different divisions of the same company. The company is Caltech. They have a campus division that is both a college/university and a research center. Then they have JPL, which is a division that primarily—or you might say 100%, really—works for NASA, as an FFRDC. So the color of the paychecks is different, but the benefit packages are the same, you can keep your Credit Union account, all that kind of stuff. But when you're working on campus, you're not necessarily following a lot about what goes on at JPL, and vice versa.

ZIERLER: Tell me about the opportunity at IPAC. What was it, and why was it attractive to you?

DODD: I had been on Cassini at that time since 1993, I think? So, more than six years, or six and a half years. I was ready to do something different. It was good timing for me. My husband worked on campus in the Athletic Department. My kids were old enough that they weren't going to daycare, preschool anymore. The youngest one was going to start kindergarten, so I didn't have to drop them off at the CEC up here by JPL for child care. So, it was good timing for me to try something a little bit different. Not like campus is hugely different, and I don't have to sell my house and move across country or anything. And, the Spitzer project office was at JPL. The project manager for the Spitzer Space Telescope is at JPL, but Caltech ran the Science Center. It would be similar to the project management of the Hubble Space Telescope being at Goddard, but then there's a Space Telescope Science Institute that's separate from Goddard. It was that type of model. They were hiring up, down on campus. The hiring manager actually came from JPL, so he was familiar with that. They were looking for somebody to help them on the uplink side, like sending the commands to the spacecraft, which was an area I had worked on, on Cassini, and Voyager, and Mars Observer, so it was definitely in my background.

ZIERLER: Tell me about your responsibilities day to day. How was it different being on campus then at JPL?

DODD: At JPL, you're mostly working with engineers, and at Caltech, you're working with scientists, primarily. Scientists and software developers, because the software developers are writing the code that the scientists want to use. When I first got there, I was working in the Spitzer Science Center, in the uplink area, helping them build tools that would interface with JPL tools. Because JPL was still going to do the sequencing and sending the commands to the spacecraft. JPL still did that. JPL was responsible for merging any engineering activities with the science activities. At the Science Center, you're just focusing on what target are you going to look at it, how long are you going to look at it, what are the parameters that the instrument needs to be set to, to look at it; that type of thing. And building software that creates a template for any scientist all over the world to use to build an observation. So, a lot of what I did was spend time iterating between Caltech and JPL, actually, which I enjoyed quite a bit, having just come from JPL, and knowing the people working at JPL in the sequencing area. So, talking to them, and then learning the science side down there, and what they were looking for, and kind of bridging that gap so they could talk to each other. Being the dictionary or the communications translator between the two organizations.

ZIERLER: How well developed was the Spitzer Science Center by the time you joined? How long had it been in existence?

DODD: It had been there a while; I would say five or six years. But a lot of that early part was with maybe a couple dozen managers and scientists who were designing the processes and the architecture of how the Science Center would work. When I got there, we were writing code and getting into the details of interfaces and that type of thing. The architecture was already there. It was more doing the engineering that makes that architecture work.

ZIERLER: Having a science center associated with a telescope, how frequently does that happen? What's the bigger story of why Spitzer needed a science center?

DODD: That's actually very common, but it was something brand-new to JPL. I think Spitzer was probably the first—or I guess IRAS was probably the first telescope, but it was much smaller in scope—for JPL. Spitzer was the last of the four great observatories, and the infrared observatory. Having a science center is really the organization that works with the scientists all around the world, for both getting their proposals—giving them tools, telling him how to write proposals to use the telescope, running all the reviews of those proposals to see who is selected, and then working with the scientists to actually technically build those observations that they want to take. Then, once that is all kind of set up in the sense that you have a pool of observations for six months, you pick out of that pool—the software will pick out of that pool what observations it can do when, based on the constraints, and the spacecraft will execute them. Then the data comes back actually to the science center again, and they do all the final processing maps and data archiving also at the science center. A science center represents the very front end of a mission, from working with the scientists and developing observations, and the very back end, where you're receiving the data, and then processing it, and sending it out to the scientists to write papers with, kind of thing, and archiving it. This piece in the middle—which arguably is probably a smaller piece than the two outsides—the piece in the middle is the piece that JPL does, which is turn those command requests into sequences, into ones and zeroes, send it to the DSN, have it come back from the DSN, separate it into the right packets, and then send those packets down to IPAC, down to the science center. That's a very standard process for telescopes.

ZIERLER: Was your hire as manager influenced by the planned timing of the launch in 2003?

DODD: That is certainly what made the project staff up, yeah. As a matter of fact, I think we were technically going to launch in 2002. Then that was the same year that I think Spirit and Opportunity—one of the Mars missions—my memory is not as good as your history, David.

ZIERLER: [laughs]

DODD: One of the Mars missions needed the rocket that we were going to use, and so we got pushed out so that the Mars mission could launch. We got pushed out a year.

ZIERLER: What was your sense of the science objectives of Spitzer? It was a new era in infrared astronomy. What were its goals?

DODD: I think its goals were to see back in time, which I guess is a goal of every telescope. But infrared in particular, you can see through dusty objects, so you can see where stars are being created and born, the so-called stellar nurseries. That was one of the keys, is understanding how star formation happens. It was really clever—and we can talk about this later—but when we ran out of cryogen, we were actually able to repurpose the Spitzer telescope to get something like another ten years of operations out of it, and one of the biggest things that happened was this whole discovery of exoplanets. Spitzer I think was probably one of the first flight-based telescopes to look at exoplanets and discover exoplanets. That all happened in the extended mission.

ZIERLER: Was that part of Spitzer's program, that they were—?

DODD: No, it wasn't part of the initial—I'm sure some scientists thought about it that way, but it wasn't the sales pitch to NASA headquarters—"We're going to go find exoplanets." It wasn't an exoplanet hunter the way the TESS telescope is now. It was a lot about stellar nurseries and star formations and galaxies and counting galaxies. How many are there actually out there? And there's techniques for that.

ZIERLER: How much of your previous work was translatable, working on a telescope? In what ways is it different than a planetary mission, for example?

DODD: For one thing, you work with a lot more scientists. And the science team changes. On a planetary mission, you've got—I'll just use Voyager for example. We have currently five operating instruments, so there are five principal scientists. That's it; those are the five people you work with. On a telescope, you can work with anybody around the world, and there's a selection process for determining who's going to have time on the telescope. That process is a peer review of proposals. And you have to put out documentation so that any scientist can read it, understand it, understand how to put in proposals, and how the instrument works, and that type of stuff. There's a lot of description of the spacecraft that you provide to scientists. But it could be scientists from anywhere. There's not really any set scientists that have control over the telescope. It's basically what gets selected is done by a peer review. So your peers think that your science is worthy to do on this telescope and take time away from potentially other observations. So, it works quite a bit differently. But it is very similar to Hubble, to James Webb, or to any ground-based telescope. That's how all the ground-based telescopes work. Unless you're lucky enough to just own your own, which some private investors do, and then you can do whatever you want with it, I guess.

ZIERLER: Who are some of the key people you worked with at Caltech on Spitzer, both among the astronomers and at IPAC?

DODD: I worked with Professor Tom Soifer. He was the Science Center director. His deputy director was George Helou. They were the management of the team. Bill Green was the Spitzer Science Center manager. He's the person that came from JPL. He had done a lot of imaging processing in the image processing group. He had been a manager there that got hired down to Caltech. From a science perspective, I worked with a woman named Lisa Storrie-Lombardi, who has since left. She and I were teamed up a lot to develop the—me on more the engineering side, and her on the science side—to develop the uplink software and processes involved there. I'm trying to think of other scientists. There were three instruments on Spitzer, and they each had a prime scientist that worked with others, but there were three scientists—Bill Latter, Kartik Sheth, and Bill Reach. Two of them are actually at headquarters now—they work for the Science Mission Directorate at headquarters—and I think the last one is up at Ames, now. They were the lead scientists, one for each instrument down there, too.

ZIERLER: You mentioned you would go up to JPL with some regularity. What were the kinds of things that prompted you to go back on Lab?

DODD: We would have meetings to talk about interfaces. What kind of a product is the Science Center going to pass off to JPL? What does JPL need in that information in order to use the tools they had? And then, what are the checks in that system? What's the timeline? I need this by t0, so that I can send something to the spacecraft by t+3 weeks. We had a regular process, and then we also had a target of opportunity process. If some big solar flare went off—or not a solar flare, but say a gamma ray burst, or some of that—we just had the BOAT, the biggest-of-all-time gamma ray burst, just recently. But if there was a supernova or something like that, they had a target of opportunity process, where you could interrupt your planned schedule and turn to that target to take observations within a 48-hour period. Actually, that's something that JPL is not—it's not done frequently with planetary missions. Everything is really planned out, and you just follow that schedule. So, to have a process where you can actually interrupt it late in the game was a little bit new to JPL. I think the process of spending the time to explain to the engineers at JPL what we were trying to do based on the science, and not just speak down to them, like, "It has to be done this way, because this is how we do it," type thing. But if you spend the time, and you—it's good advice for anything, about anybody—but educate the people you have to work with, and then it will probably be a lot easier to work with them. [laughs]

ZIERLER: What about the data analysis? How would you compare the amount of data coming in from a planetary mission versus a telescope?

DODD: I think they're similar from the imaging standpoint. But telescopes create a huge amount of data. James Webb has a huge amount of data coming down. And the next large telescope will just have a huge amount of data coming down. In part because they're closer to the Earth, so it's easier to get large data volumes down from a Lagrange point mission that is from Mars or Jupiter or something like that. But I think also, if you want a high-resolution picture of Mars, that's a lot of data, too. That's a lot of data. In a lot of cases, the data volume pieces are similar. What I think is a little bit different in an astronomy mission is you're really trying to pull the signal out from just the noise. So, one of the techniques they do frequently in astrophysics missions is they stack images. You'll take the same image a hundred times, and you'll stack them up just to pull out one little feature that in an individual image you can't see, but when you have 100 images and you've overlaid them, you can start to see that very faint dot really means something. I don't think you do that a lot in the planetary missions.

ZIERLER: Do you recall if anyone around that time was starting to think about machine learning and artificial intelligence as a tool to deal with all of this data?

DODD: I'm sure they were. Actually some super clever programmers and data scientists at IPAC, they actually—one guy down there has algorithms named after him. Certain data processing algorithms are actually named after him. I don't remember it being something that we spent a lot of time investigating, but I'm sure it was something that was sort of just beginning to get thought about more. Once the data is in the archive, the scientists can do whatever they want with it, in the sense that if they pull it out, they may do machine learning on it after we've made the final product. Doesn't mean that they can't continue to refine it. Just means that we've made our requirements to put this final product in the archive.

ZIERLER: Being on campus, did that give you opportunity to work with graduate students or even undergraduates?

DODD: Mostly postdocs, actually. There would be people in IPAC who were postdocs. Maybe a couple graduate students, but not the undergrads. In essence, it is a research part of campus, not an academic part of campus. But there were postdocs in there, and they would do research on the data.

ZIERLER: There's a theme in your career; five or six years, and you want to do something new. Did you envision that you would stay with Spitzer for as long as you did?

DODD: No, not really. I think when I got there, it was just, how long does it stay interesting? But I advanced my career there, too, because when I first came down, I was just an engineer in the organization. Then I took over being the Science Center manager from Bill Green. He ended up retiring due to health issues before launch. And so I went from being an engineer, being a manager of a small group in the uplink system there, to managing the whole Spitzer Science Center, which was 200 people by launch. So I advanced my career down there, as well.

ZIERLER: What was launch day like for you?

DODD: It's exciting! We were there, in the big conference room, at campus. It was an evening launch on the West Coast, maybe seven or eight-thirty at night, which would have been more like 11:30 at night at the East Coast. I didn't get to watch it in person, but I watched it with most of the rest of the Spitzer Science Center there. It's great to see it go off and be successful.

ZIERLER: Did you know that you would ultimately return to JPL? Or could you have envisioned a scenario where you would have remained on campus for your career?

DODD: Oh, yeah. I could definitely envision a scenario where I remained on campus. But Spitzer went into an extended mission five years after its launch, and there wasn't a lot more new things coming in at the time. I wasn't necessarily looking to get back on campus, but they came looking for me; JPL did. So, when the Spitzer project manager retired, it was kind of clear that I could go from the Science Center manager to being the project manager, but the position was at JPL, not at Caltech. At the same time, then, the Voyager project manager retired. So two of the main JPL project managers retired at the same time, and so they asked me if I could come back to JPL—this was in the 2010 timeframe—if I could come back to JPL and do both projects. They're extended missions. Both of them are extended missions. I said, "I think I can. Yeah, I think I can."

ZIERLER: You said yes times two.

DODD: Again, it's another growth in your career, right? You become a project manager instead of the mission manager or the Science Center manager.

ZIERLER: For 11 years, as you explained, you stayed because it was interesting. It kept your attention. Why? Why was it so interesting for so long for you?

DODD: Well, the science was great. I enjoyed the people I worked with. I got to travel more down there than I did anyplace when I was previously at JPL. It was fun seeing my husband at lunchtime. That was good. It worked out family-wise pretty well, too. I think you stay in a job as long as it's interesting and you feel like you're learning and you're growing something. Eventually, some jobs get to more routine, and you'd like to go on and challenge yourself someplace else. Then if the opportunity knocks, you say, "That sounds pretty good! I'll take it."

ZIERLER: Being back at campus, with Ed Stone going back at least as part of his responsibilities to being a Caltech professor, did you ever spend time with him? Did he ever share his views about his legacy as JPL director with you?

DODD: Not during the Spitzer days. Not during the 2000s, when I was on campus. Because I wasn't working on Voyager at the time. I was only hearing little bits of pieces that, "Yeah, it's still flying." "Wow, that's really amazing." [laughs] That was the little bits and pieces I was hearing about. That, and the fact that they were always fighting for a budget. But I didn't really interface too much with Ed at all during that time period. No.

ZIERLER: What were you learning firsthand, or when you were there, about what Charles Elachi was doing, what some of his big initiatives were?

DODD: Charles is a radar guy. I worked on Cassini, and he was a PI for the radar on Cassini, so I knew his background from scientifically what he likes to do, which is radars. He had also spent a lot of time previous to becoming the JPL director on Earth missions. Like the shuttle-borne radar, he worked extensively on that. So when he came on board, I would say it was not surprising that he tried to get more radar and Earth-borne radar type missions going and to expand beyond planetary missions into Earth missions. Not that Earth is not a planet, but typically that was the realm that Goddard did all the Earth-observing missions, and JPL did all the planetary missions. That kind of changed in the 2000s. Goddard got a planetary mission. We got Earth missions. That's probably healthier to have the competition between the two NASA centers, so that one is not always doing one type of science.

ZIERLER: Back now in 2010, there was not one but two project manager jobs for you to fill, simultaneously.

DODD: Yeah. My predecessor on Voyager, Ed Massey, as a project manager, he had been half-time for quite a while. So that job was half-time. Bob Wilson, the Spitzer project manager, retired. I think that was more of a full-time job, but they asked me if I could do it on a half-time basis, and so I said, "I think so." I had a lot of experience with Spitzer. "I think so." And do that half-time and do Voyager half-time. They're not related whatsoever, but they're both really interesting. But they have no relationship to each other at all. [laughs]

ZIERLER: If you could explain just the titles, the nuances there, what it means? You're on Spitzer, on campus. You return to JPL. It's a different title. What's the distinction?

DODD: In the case of Spitzer, the Spitzer Science Center is run from campus. What is run at JPL is the engineering side of Spitzer, and the project management. The project management is the organization that deals with headquarters, and gets money for the whole project. JPL gets money from headquarters. Some of it stays at JPL, and some of it, JPL sends to campus for the Science Center. So, it sets the budget. The project management basically sets the budget for the whole project, all the pieces of the project, no matter where they are located. In this case, the JPL project office was responsible for funding the Spitzer Science Center. It might be funding people at Goddard to help with the proposal cycle, calls. There's a lot of just logistics that go around that, doing that. The project office is responsible for making sure all of those pieces of a project play together and get funded.

ZIERLER: Both missions, you said these were extended missions.

DODD: Right.

ZIERLER: What does that mean, just administratively? Who makes that call? What is the significance?

DODD: When a project is designed, and NASA agrees to fund it, it has what we call level 1 requirements, science requirements. This is what must happen for the mission to say it's successful. We've mentioned in Voyager's case it was a flyby of Jupiter and Saturn, with two spacecraft. That was the level 1 requirement. We are a successful mission if we did nothing else after that. Now, Voyager is the extreme, because Voyager 2 went to Uranus, Neptune, and then the next 30 years out into interstellar space. That's an extreme. But in Spitzer's case, it was an infrared telescope. It had a cryostat. So it had helium cooling the detectors. The prime mission there was two and a half years. In other words, the helium had to last two and a half years, and they had to take a certain number of observations. It turned out that the helium lasted over five years, so they got nearly double a cryogenic mission, a cold mission, and then they were able to identify science they could do with a warm telescope. Warm is relative; it's like 24 degrees Kelvin instead of five degrees Kelvin. But they figured out science objectives they could do with a warm telescope, and they made a proposal to NASA headquarters to continue operating Spitzer to do this warm science. NASA said yes, agreed to it. So, extended missions are when basically missions finish their level 1 requirements but are still operating very well and can continue to do more science. You have to go to headquarters and you have to make a case for continuing the mission beyond its level 1 requirements.

From IPAC and Back to JPL

ZIERLER: What was it like to be back at JPL? You had been gone for so long.

DODD: It was different, yeah. A few different people, or same people in different jobs. That was it, too. But it was great. It was nice to see more people again. Obviously I interacted with the Spitzer people that were up here, but coming back to Voyager, boy, fshoo, that was like 20 years later, and all the acronyms still came back to my mind! "Oh, I know what an SFOS is."

ZIERLER: [laughs]

DODD: "I know what the CCS and the FDS are and what they do." It was like, "Wow, they use the same process!" And the people were the same. That was probably the biggest shock, is many of the subsystem experts—not that we have that many subsystem experts, but a half a dozen of the people were there on the project when I left, and 20 years later, they're on the project when I come back! Still doing the same job!

ZIERLER: In theory, two half-time appointments, does that really become one full-time role, or is really you're operating at like 150% or even more than that?

DODD: Yeah, some weeks are better than others. You'll have a lot of work on one project and not so much on the other, and then it will switch. There's these time periods like in the spring when both projects are going through budget exercises, and then it's kind of crazy. Then you have to support both of them at a high level. But in general, it's manageable.

ZIERLER: Both missions being extended, was Spitzer more surprising? Was Voyager built at that point, was it assumed that it was on its way to interstellar space and of course it would be extended? Was there any question about Spitzer being extended?

DODD: Spitzer had to come up with a very good science case once the cryostat ran out. Because it's prime mission was—the detectors were all designed to be cold. Two of the three instruments do not operate warm, or do not have any science value when they're warm. So the only instrument in the Spitzer extended mission is the infrared camera array. So, we went from three instruments to one instrument during the extended mission for Spitzer. But it had come right about the time after we had discovered the first of the exoplanets, so that was new science, and that was new science that we could continue in this warm mode. I think that was a big selling point to NASA.

ZIERLER: How did the science change for Spitzer as a result of going down to one instrument?

DODD: The scientists always get clever. I would say that. It doesn't matter whether it's a telescope or a planetary mission; they always get clever. When you build these missions, you expect to have discoveries and things that you didn't know of, or didn't think of before. The long wavelength instruments, so the instruments that are really going to see and peer through dusty starfields and things, that waned once we went into a warm mission. We couldn't do that kind of science anymore. But we could do more of the near-term imaging type things. Particularly one of the neat things that you can do with telescopes is you can take an image in infrared with Spitzer; you can take the same image with a Chandra telescope in the x-rays, and you can overlay them. Then you can use the overlay of the different wavelengths to pull out the feature in the image. We did a lot of that, too—in other words, taking images with Spitzer, but then taking the same image with other telescopes at different wavelengths and combining them together to get a whole image of a supernova that describes then this explosion, which are where are the x-rays, where's the infrared, where's the heat source, that type of thing, that you can see when you have multi-wavelength images.

ZIERLER: Being at JPL in a different role, what did you learn new about Spitzer? What simply was not possible to understand or work closely with from your previous role at Caltech?

DODD: I think I worked a lot closer—Spitzer, the engineering team at Spitzer was partly at Lockheed Martin, because they built the spacecraft portion of Spitzer. Ball Aerospace built the telescope, but Lockheed Martin built the spacecraft that steers the telescope. I got to work more closely with the team at Lockheed Martin. They were very good. Spitzer was in a very unique orbit, what they call an Earth-trailing orbit. So it would follow the Earth around the Sun in the Earth orbit, but it kept drifting and drifting further away from the Earth. That trajectory made it—the longer the mission went, the further the telescope got away from the Earth, so the more—due to the trajectory, the more you had to be careful downlinking to the spacecraft, in the sense that the Sun was becoming more and more of a factor, getting into the bore of the telescope, which would heat it up, which you wouldn't want whatsoever. So during the extended mission, we spent a lot more time on the engineering side, with the Lockheed engineers, to redesign how we do downlinks, and how frequently we need to do these type of things, and any other kind of maneuvers, just based on the geometry of the orbit changing.

ZIERLER: Going down to one instrument, was there a specific timeline for how long the mission just technologically could last?

DODD: The driver to how long the mission could last was actually the geometry of the mission. Because eventually, the Earth and the telescope have the Sun in the middle of it. You can't downlink the data through the Sun. So, as it drifted away, you got shorter and shorter downlinks, because you would have to get closer and closer to the Sun. You didn't want to heat up that telescope bore site. So there were actually a lot of changes done just to get some amount of data down. You also have solar panels, so you have to balance how you're charging that. How much time you need to charge versus when you go off the Sun to point at the Earth, how much that depletes the battery. So there was a lot of engineering balancing and challenges. That's kind of really what in the end caused the mission to end. The science was still good, but there was just not enough of it coming down to make it worthwhile. Because the geometry of the orbit kind of limited the amount of science we could get back.

ZIERLER: Are you surprised that Spitzer lasted as long as it did, going all the way to 2020?

DODD: Absolutely. Absolutely. It didn't me surprise me too much. Obviously, you made your level 1, two-and-a-half year requirement. So I would expect that. And you got five years, so you got almost double what you wanted. But I think how long they were able to operate as a warm mission, coming up with new science, exoplanet science, and coming up with new geometries and new tricks from an engineering standpoint to be able to keep all the subsystems, between power and thermal, in balance, and still get data back to the Earth, and they were able to do that for another 10, 11 years—that's pretty remarkable, actually. Very remarkable.

ZIERLER: You cycled off Spitzer before the end of the mission in 2020.

DODD: I did, about a year before. That's when I took over in the current role I have, as the director for the InterPlanetary Network. I cycled off of Spitzer. I was also on a project called NuSTAR. At one point for about three years, I had three projects I was project manager for.

ZIERLER: What years were NuSTAR?

DODD: NuSTAR launched in June of 2012, so I guess I was on that for four years. They had their ten-year anniversary last year, I think. So that four or four and a half years. I came on right at launch. Fiona Harrison is the principal investigator. She's at Caltech. In 2016, Mike Watkins became the director of JPL. He made some—changes—and one of them was to put me in as the director for the Interplanetary Network. At the time, I think the writing was on the wall with Spitzer. NuSTAR was pretty routine, and NuSTAR is a very small mission. Small team, small mission. But Voyager I think had always had my heart, since I started on it, so I asked if I could stay as the Voyager project manager while doing this Directorate job. I had a couple people say, "That's too much," but Mike Watkins was willing to let me try it, and I've been doing it ever since. It is a lot. Voyager doesn't get easier. It only gets harder.

ZIERLER: The last topic we'll cover for today—because obviously we want to talk more about your current role and NuSTAR and bring the story right up to the present to wrap up for next time. But the last topic for today of course is when you returned to Voyager. Just, emotionally, it was always close to your heart. What did it feel like to be back on the team?

DODD: It was great. I hadn't really followed it that closely for the 20 years I was not on it. I learned a lot about, especially in the 2000s, how it was almost cancelled, and all the reviews that it had. Ed Stone told me right away, "We're past the termination shock. We think we're getting close to the heliopause." He said, "Headquarters is not going to cancel us now, but they could bleed us to death, in a sense." They could just keep cutting your budget and cutting your budget so you couldn't operate anymore. He was very concerned about that. Fortunately, I was not on the project too long—maybe just two years—before actually Voyager 1 went and crossed the heliopause. So, I didn't have to do a budget exercise during that two-year period, or go back for an extended mission during that two-year period. So that was kind of nice, that my predecessor, Ed Massey, had done one right before he retired. But you've got to keep these missions, including Voyager, in front of NASA headquarters. You have to keep them in front of the public. Voyager is very lucky, because everybody in the public knows about Voyager, and so it's an easy sell to nearly everybody. Especially now, the science is so unique, traveling through interstellar space and away from the Sun, and away from us, and how does the plasma change, how do the magnetic fields change. You need that time strip in order to do the science. And nothing is going to get out where Voyager is for multiple decades. I would say realistically the nearest term would be 30 years, realistically, for the quickest thing to get out there. What makes it challenging is we have a lot of engineering challenges. How do you get that last little drop of power out of the spacecraft, out of this 1975-designed spacecraft.

ZIERLER: What else works from 1975?

DODD: Exactly! [laughs] The joke was—one guy was like, "We have a spacecraft that is operating from 1975. Not very many people have a clock radio that operates from 1975!"

ZIERLER: [laughs]

DODD: Or a car with an 8-track tape recorder. Coming back to your original question, getting on Voyager, it was a reacquaintance. It's still fun. I wouldn't do it if it wasn't fun. I was really kind of shocked how many people were still on the project and had spent 20 years on the project. These people who have been on the project for 35 or 40 years, or 45 years now, it has been their whole life. It has been their whole life. Sometimes I have to remember that as a project manager, when we have a debate about how to do something, and they'll say, "We've never done it like that before." And I'll say, "Yes, but, the goal is to keep it operating as long as possible, and this is what we need to do, to keep it operating as long as possible." I would say it's a really dedicated set of engineers.

Rejoining Voyager

ZIERLER: By the time you rejoined Voyager as the spacecraft was headed to interstellar space, was the Deep Space Network already upgraded at that point to the larger dish to accommodate the distance, or were you part of that planning?

DODD: The Deep Space Network, the last time it got upgraded for a larger dish was back for the Uranus encounter. So it was a long time ago that they went from the 64 meters to 70 meters.

ZIERLER: The 70 meters was sufficient?

DODD: For planetary, yeah. For all the planetary stuff, it was. Now, everything we do is arrays. Voyager cannot communicate with one antenna. We need two antennas, typically. I guess for a downlink, since we're only 160 bits per second, we can use a 70-meter, or we can use three 34s arrayed together. But Voyager, because of the distance, is just a huge DSN hog. What the DSN has done over time, starting in the late 1990s, early 2000s, they've built new 34-meter antennas. You build multiples of those, and you can array them together. If you array four of them together, you are able to capture the equivalent downlink rate of one 70-meter. You can work those antennas in any combination. You can do them solo, like you do for most Mars missions, or you can put them together like you do for Voyager. It's more versatile to have multiple antennas that you can array together than just that one large antenna that for a lot of missions, it's too much. A lot of missions don't need that large antenna.

ZIERLER: Is arraying—mathematically, is that basically the equivalent—if you array two 70-meter dishes, is that giving you the equivalent of one 140-meter dish, or how does that work?

DODD: We don't have two 70-meter antennas at the same site. But four 34-meters are equivalent to one 70-meter. It's not like a two-for-one. It's sort of an r over a square factor. Actually I don't really have it in my head, David, except I know that it takes four 34s to be equivalent to a 70-meter antenna.

ZIERLER: But obviously arraying is sufficient for the needs of the mission.

DODD: Oh, yeah.

ZIERLER: What was it like to work closely with Ed Stone again?

DODD: We got reacquainted. He's great. As a lower level engineer during my planetary days, I didn't work that closely with Ed Stone. I wasn't on the science team. I saw him walk really fast by me in the hallway or something—

ZIERLER: [laughs]

DODD: —but I didn't work that closely with him. Then, coming back, as a project manager, I worked with him all the time. Because we'd work on budgets, and I would make appointments, come down by his office on campus, and tell him what was going on from an engineering standpoint. We just would catch up probably on a monthly basis. It was great, because he would pull out his science charts, what was going on with the science, and explain it to me like I was in his class. So I had my personal instructor telling me all about the Voyager science data. It was great. He's very giving, and he makes a lot of time for you. And he wants you to understand the science, so that was great.

ZIERLER: By the time you rejoined Voyager, was it already clear, was it on the trajectory to get to interstellar space, to find the heliopause?

DODD: Yes. As a matter of fact, both spacecraft were, because they had both crossed in the 2000s—I think they both passed the termination shock, which is where the outflow of the particles from the Sun go from supersonic to subsonic. They have to slow down when they hit this heliopause boundary, but they come off the Sun at supersonic speeds, and then there's what they call the termination shock where they slow down, before they sort of get to the wall of the heliopause. They had crossed that termination shock, both spacecraft had, in the 2000s, so we knew we were close. We knew we were getting there, to the heliopause. But we didn't know exactly when.

ZIERLER: Just the timing, were you back on staff for the transition point for both spacecraft?

DODD: Not for the termination shock, but I was for the heliopause crossing, yeah. I got on in like September of 2010, and we crossed the heliopause in August of 2012 with Voyager 1.

ZIERLER: Is it the kind of situation where you don't know where the heliopause is until the spacecraft actually get there?

DODD: Yes. It is. What you're looking for is a change in plasma density. You're looking for a change in the energy of the particles that the spacecraft is detecting. And, you're looking for a change in the magnetic field. That last part, the change in the magnetic field, we didn't ever really see. It was very subtle. This is one case where the model of the heliosphere didn't match the actual in situ data.

ZIERLER: Really the experiment upended the theory, to some degree.

DODD: Absolutely. As it always does, right? As it always does. And it took us a while—we saw two of the three signs we were expecting, but there was a lot of debate about whether we had actually crossed the heliopause or not, and whether we could tell the press we had crossed the heliopause. So there was a good eight months, I would say, of science discussions, both within the team, and then looking at experts that aren't on the Voyager team but are experts in helioscience, to decide that, yes, we can say we crossed the heliopause, and were outside the heliosphere. But that took like eight months to work through the science, to say, "Yeah, we can announce this," type thing. When we announced it, we said, "Oh, it happened way back here." [laughs]

ZIERLER: What was the tipping point for all those months of debate and analysis?

DODD: It was a lot to do with the plasma wave science instrument. You could see a rise in the plasma density from what we determined to be—we kind of backtracked into it, actually. The plasma wave subsystem—one, it's playback data, and we don't do playbacks that often. We have to wait like every three months to six months to get that chunk of data down and then look at it. But you could see in that data how the density of the plasma rose, and then it got flat, which is a characteristic of what you would think would happen just outside the heliopause. You could also see it in the charged particle count, right away, where—especially on Voyager 2, we have the PLS instrument. It's a direct measurement of plasma. And you can just see the particles go, "Vloop!" Just completely dropped out. And the density changed. So on Voyager 2, it was actually much easier, because of the difference in the instruments, to determine that we had crossed the heliopause.

ZIERLER: Did your day-to-day change when the spacecraft crossed the heliopause?

DODD: Not from an engineering standpoint, no. We get to have a press conference, so that's not an everyday thing, but—

ZIERLER: But the operations of the spacecraft, is there anything different?

DODD: No. You still send up the same sequences, still do the same calibrations. I think we did change—and this didn't happen right away—we changed a couple of the filters and power settings on some of the instruments, just so they could count the particles that they were seeing in interstellar space better. It's like tuning. A couple of the instruments got tuned. The cosmic ray subsystem got tuned to the new environment we were in. But that's pretty minor, actually.

Calculating Spacecraft Longevity

ZIERLER: Last thread for today. When did the project team start to extrapolate for the life of the Voyager spacecraft? When could you get a good idea of just how long the spacecraft can last?

DODD: Well, it's interesting. This team on Voyager has made a lot of decisions since the Neptune encounter based on thinking that the mission would last another three to five years. I don't think anybody thought it would last 45 years. If you had known in 1990, when you started on the Voyager interstellar mission, that you were going to last for another 30+ years for an interstellar mission, you would do things differently. It can be little things. It can be little things like writing down how you do a process or a procedure because somebody new might have to come over and take over for you. If you always thought the mission was going to last three more years, you might say, "Okay, I'm going to stay on the project for three more years."

We've run across cases where we've looked at documentations—like we wanted to change some fault protection, and the last time it was changed was in 1990. We'd say, "Why did you have this setting in 2010?" And they're like, "Well, we thought that was way beyond how long the spacecraft would ever last, so we just picked a wild number and used that as the end point." "Well, we're still going, and we need to update that end point. Can you tell us how to do it?" A lot of times, they're like, "Nope! I don't remember." [laughs] Anyway, I think you would make decisions differently if you thought that the mission would last 30 years past Neptune, or 32 years past Neptune. You would definitely, from an operational standpoint, do things differently. But that said, the team that has worked with it for 35 years, they intimately know the spacecraft, and they've been good stewards of it. They haven't taken risks. They've done the calibrations that need to be done and got the data back.

The spacecraft basically has been very well-behaved on its own. It hasn't had any—every once in a while, we have a little blip anomaly, but nothing super serious. Even if we have something that seems pretty major, like what we had a year ago with the telemetry data from the AACS all garbled, once we figured out what happened to make it garbled from a technical standpoint, we set it, and so it comes down just fine. It could have been serious depending on how it had happened, but it turned out not to be serious. The more difficult challenges now are just, do you make a flight software patch? You don't have a simulator to test that on, so you're just counting on somebody's eyeballs. And this somebody is retired, but they're the only ones that know the spacecraft, and you believe they're doing what's correct, and you have other people inspect it, but it's not the same as having a simulator. So, do you want to risk the patch, in order to prevent this type of anomaly from happening again? Or, maybe the anomaly won't ever happen again. It has only happened once, on one spacecraft, in 45 years. The risk is kind of epsilon, so you don't need to do the patch.

It is those kinds of decisions that we make frequently on Voyager now, and those are difficult. They are really difficult. The trades you're weighing are whether you think this anomaly will happen again, because we've only seen it once in the lifetime of two spacecraft. What is the risk if it happens again? Could you lose the mission? Maybe, yes. Maybe. How difficult of a workforce is it to mitigate this risk? Because we don't have a lot of workforce, and we have not a lot of knowledge anymore. The original knowledge of the spacecraft and how it was built is mostly gone. And we don't have test beds or simulators anymore. If we were to build the commands and send them to the spacecraft, the only way that we would know that the commands are right is just by your own eyeballs, and inspecting the code you wrote, or inspecting the code somebody else wrote. So it's a lot of different risks that you have to put together to make a decision. That doesn't make it easy. It makes it hard. It makes it kind of a slow process, too, because you're really talking through things, and weighing through things, and getting a lot of different opinions from different people. Even commanding Voyager and getting data back from Voyager is a slow process anyway. The data rates are low. The distance is far. It takes a good week to send something to the spacecraft, get the data back down, look at it, determine that it looks okay. You may need to send something back out, or you may not need to send something back out. A lot of missions can do that on one eight-hour pass. We need a week to do that, just because of the data rates and the round-trip light times.

ZIERLER: To understand further, in gaming out the lifespan of the Voyager spacecraft, how much of that involves guesswork into just how much more power they have to give? In other words, when you look at the percentage on your cell phone, you have a pretty good idea of how long it's going to last. Was there really that much guesswork involved in how long they could keep going based on the power system?

DODD: We know how much power we have, and we know how it's going to decay, and we know that—as a matter of fact, I just got a chart yesterday—Voyager 1 has 224 watts of power, and we need 200 watts just to run the transmitter. Just to run the transmitter. That's not putting any data through the transmitter. So there's this 24-watt margin, and if we don't change anything, then we know how long it will take to get to that point. I can look it up, actually, if that's of interest. I'll show you, David.

ZIERLER: Please!

DODD: There's the plot.

ZIERLER: Oh, wow.

DODD: What you're seeing is the light-colored curve that goes all the way to zero is just the half-life of the plutonium. It's very consistent. We march right down that curve at four watts a year, as the plutonium decays. We cannot change this curve. What we can fiddle with a little bit is what we do to draw less power, in that sense. What we've done is essentially—you may read that story—there's a story online now, because we've gone to—it just came out yesterday—we've gone to voltage management on Voyager 1, and what that means is we're going below—we're regulating the voltage instead of the power now, so it allows us sort of to use what you might consider a safety net of power—a couple watts. But if you're able to use those couple watts, every two watts is six more months. We're really trying to figure out how to stretch out this curve so that the transmitter doesn't turn off at 200. Maybe we can stretch it out down here somehow. But that's all clever engineering. Physics is physics; the decay will happen at the rate the decay happens. But the clever engineering is to say, "Well, what else can we turn off, and leave the science instruments on?" The most important things is to get the science on.

ZIERLER: Last question for today. I wonder at a certain point if you made a promise to yourself, so long as you're able, that you would stay with Voyager for as long as Voyager was operational?

DODD: That's a tough question, David. [laughs] That's a very tough question. I probably have made a promise to try to get to 50 years, because I want to be at that party. Am I the last project manager for Voyager? I don't know. I don't know the answer to that right now.

ZIERLER: But it's understood that Voyager won't have power after 50 years. Or is it possible to stretch it even more?

DODD: No, no. We'll have a 50th anniversary in four and a half more years. Voyager will certainly—at least one of those spacecraft I think will certainly make it to that milestone. We're hopeful that as we turn off things and turn off things, we can get out to the 2030s, and maybe even 200 AU. It's going to take a lot of good fortune to happen. If I look at this chart—if I look at the bottom part—I don't know if you can see—the bottom part of this chart is 2032. So, we should get to 2032, on Voyager 1.

ZIERLER: Wow.

DODD: Whether I'm there, still working as project manager in 2032, I don't know.

ZIERLER: To be seen! Suzy, thank you so much. We'll catch up next time. We'll bring the story right up to the present.

DODD: Okay. Thanks, David!

[End of Recording]

ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Tuesday, May 23rd, 2023. I am delighted to be back with Suzy Dodd of JPL. Suzy, once again, it's wonderful to be with you. Thank you so much.

DODD: You're very welcome.

ZIERLER: We've talked already about your role at the Spitzer Space Telescope Science Center, but just as a point of clarification, if you can explain where the Infrared Processing and Analysis Center fits in with that enterprise, and what your responsibilities were there.

DODD: The Infrared Processing and Analysis Center is located on the Caltech campus. It's a NASA center for archiving and processing infrared data. The Spitzer Science Center sat underneath that IPAC umbrella. It was a big project underneath this umbrella. There are other projects there dealing with data archiving that were separate from Spitzer, but Spitzer was by far the biggest piece of that, under that umbrella. The separation is that IPAC is the overarching organization, and the Spitzer Science Center was a piece of that, a very large piece of it.

ZIERLER: Were you dual-hatted, in these roles at the same time?

DODD: I was dual-hatted, yes. I got both of those roles at the same time, because my predecessor had both of those roles. Bill Green—when I first went down to campus to work on Spitzer in the Science Center, I went there to work in the uplink organization. That was in 1999, and Bill Green was the manager both of IPAC—the Infrared Analysis and Processing Center—and for the Spitzer Science Center. Due to health reasons, he had a fairly quick retirement, surprising retirement I would say, right before the Spitzer launched, so right in early 2003. At that point, I was appointed or selected to replace him in both of those roles, both the IPAC manager and the Spitzer Science Center manager.

ZIERLER: When you were named project manager for Voyager Interstellar, is that what pulled you back to JPL from campus?

DODD: Yes, that and the fact that—what happened at JPL in 2010 is both the Spitzer project manager, Bob Wilson, was going to retire, and the Voyager Project Manager, Ed Massey, was retiring. They were retiring within a few months of each other. Bob Wilson had been a full-time project manager. Ed Massey was a part-time project manager. But they asked me if I thought I could do both roles. I had the Spitzer knowledge already. To some degree, I had the Voyager knowledge. I know what the mission is. I haven't been on it for 20 years, but they're both extended missions, and I thought, yeah, I could probably do both of them under—both at a half-time level. The Fall of 2010 is when I came back to JPL to be the project manager both for Spitzer and for Voyager.

ZIERLER: And as we discussed previously, you did not shy away from being dual-hatted in multiple portions of your career.

DODD: Yeah. Still doing it, yeah. [laughs]

Crossing into Interstellar Space

ZIERLER: Circa 2010, what was the timing? There's the Voyager Interstellar Mission. Were both spacecraft already in interstellar space at that point?

DODD: No, it was a great time to get on the project, actually, because Voyager had already gone across the termination shock, which is where the particles from the Sun slow down from supersonic to subsonic, so it means you're getting close to the edge of this bubble of charged particles. That had happened in the mid-2000s. So, we thought we were kind of getting close, but neither spacecraft was there yet. Voyager 1 got there first, in August of 2012, so I was only on the project for two years before we had crossed the heliopause which is a really big event. In reality, we didn't know whether we had crossed or not, because we didn't see—we saw a data shift in the plasma density, and in some of the temperatures, as well as the type of particle counts we were seeing. The particles from the Sun dropped down, way down, in count, and the ones from interstellar space increased. But we didn't see a magnetic change, which is what everybody had predicted—that the magnetic field direction should change substantially when you're in interstellar space. And that didn't happen. So there was a good nine months of debate about whether we had actually crossed interstellar space or not.

Especially because this was Voyager 1, and it did not carry—the PLS instrument, the plasma subsystem was broken on Voyager 1, had been broken for a good ten years, and so we didn't have a direct measurement of the change in the plasma density the way we did with Voyager 2. It works on Voyager 2. So, for Voyager 1, it took a lot of debate about whether we had actually crossed the heliopause, or if we were in some in-between region or not. So we didn't really announce it for—can't remember exactly, but something like seven, eight, or nine months—that we had officially crossed. Based on getting outside scientists to look at the data. That was something Ed Stone was very particular about. I remember quite a few phone calls, internal to the team, and not everybody internal to the team agreed, not all the PIs or co-Is. And so we went external to get some external experts on the heliopause and on the Sun, and let them make a judgment that essentially determined that we had crossed the heliopause.

ZIERLER: When did Voyager 2 cross the heliopause?

DODD: Voyager 2 crossed in November of 2018. Because we had that plasma instrument, we knew right away we had crossed. And, we could see it coming, because we could see a sharp decrease in the type of particles that we were measuring. We knew it was coming within a few months of it actually happening.

ZIERLER: To clarify, just as a thought experiment, because there was no question given that the instrument was working on Voyager 2, if that instrument was working on Voyager 1, would that have obviated all of those debates over those seven to nine months?

DODD: I think it would have obviated a lot of it. But also, this was the first time, so you didn't know what the signature really looked like. You had a much better idea the second time, to know what to expect from the data. But I think if we had had a plasma subsystem working on Voyager 1, we would have been a lot quicker to say, "Yeah, we crossed the heliopause."

ZIERLER: So basically the scientific consensus that Ed Stone was seeking was essentially validated once we saw what Voyager 2 was seeing in real time. They made the right call.

DODD: Are you talking about the Voyager 2 crossing?

ZIERLER: For Voyager 1, when the scientific debate was happening, obviously they were doing it without the benefit of this instrument. I guess my question is, when Voyager 2 crossed, and we now, as you said, we obviated this debate, did the scientific consensus about where exactly the heliopause starts—was that vindicated? Did the scientific consensus get it right, once we had this?

DODD: Yeah, it was, because, A, we knew that there wasn't going to be a magnetic field change, probably, because we didn't see it in Voyager 1. We did know that there should be a plasma change. We eventually saw that on Voyager 1, but it wasn't a direct measurement; it was sort of an indirect measurement. Literally we had to wait for a solar flare to go out to where Voyager 1 was after it crossed the heliopause, and then using the plasma wave instrument, see how the flare vibrated in the plasma media in order to measure the density of the plasma. So, it's an indirect measurement on plasma density. But you have that set of data from Voyager 1 that you say, "Okay, this is what Voyager 1 measures in interstellar space." So, you're looking directly for that when Voyager 2 crosses.

ZIERLER: Just as a matter of capturing the public imagination, Voyager is so famous for the planetary encounters, but sort of for the history of understanding our solar system and the universe, I wonder if you could speak to the significance of really pinpointing, figuring out where the heliopause is, given the fact that this was under debate, and it wasn't known for so many years. What does that mean in the grand scheme of history?

DODD: I think it tells you a lot about the formation of our star, how it formed, how it interacts with interstellar media, and also kind of gives some insight into the formation of our solar system, like the planets in the solar system, and how they interact with the Sun, and how the Sun affects the planet. We've got a lot of light here on Earth. We're adapted to the amount of light we have here on Earth. You get out to the outer planets—Uranus and Neptune—there is very little light. The Sun is a bright star. And now, where Voyager is, the Sun is—any star. It's not anything particularly shiny, maybe a little bit shiny. But I think scientists really didn't know how far out the heliopause was. I think I previously mentioned that they thought it was about 50 au. That's kind of how they originally in 1990 sold the Voyager Interstellar Mission to NASA. "We're at Neptune. That's 30 au. If we get to 50 au, we'll probably cross the heliopause, so we should be able to do that, in the next ten years or so, so let's get out there in the next five years. Let's go for it." And we didn't cross until 120 AU, 121 AU.

To keep that mission going for that amount of extra time actually took a lot of persuading from Ed Stone and the other scientists. You're really learning a lot of things about how the effects of the Sun change as you get further and further away from it. One of the things that's interesting is that both Voyager spacecraft crossed—even though they're going out in different directions—they both crossed the heliopause about the same distance from the Sun, and from the Earth. So, 120 AU—you could make a model that says your heliopause is very circular, at least very symmetric. Because you've got one north and one south, so it's very symmetric that way. And there are models out there that say, well, the heliopause is much more circular, and more like a sphere, than just comet-shaped, which is the more traditional model of it. I think if you had just one spacecraft cross the heliopause, you couldn't have any of those models or make any assumptions about the shape of the heliosphere.

ZIERLER: This was really Exhibit A in the founding vision that there should be two spacecraft for exactly this kind of scenario, what you need to verify.

DODD: Exactly. But they didn't design it for the heliosphere mission at all. They designed it for the planetary mission. Space is hard, rockets blow up, spacecraft fail. We want to be successful at Jupiter, and at Saturn. So we're going to build two spacecraft so at least one of them will be successful. They don't really do that anymore because it's too expensive.

ZIERLER: Were there any unique challenges or special protocols in this transitional period, where Voyager 1 was in the heliopause or had crossed the heliopause before Voyager 2 did? Was there anything unique about that moment in time?

DODD: I think by Voyager 1 crossing, and having that record of how the particles changed and the plasma changed both before and after, you could map the Voyager 2 data on top of the Voyager 1 data, and have a prediction for when Voyager 2 was going to cross, based on what you had seen on Voyager 1. That turned out to be pretty accurate, actually. The trending up of the particles coming in and making it through the heliopause, and the trending down of the particles from the Sun—we had a lot of charts where we overlaid Voyager 2's data on top of what we had seen from Voyager 1, and it was pretty accurate. Essentially the data pretty much match each other, as you go out of the heliosphere.

ZIERLER: Either with the crossing of Voyager 1 or when everything was confirmed with the crossing of Voyager 2, did that allow for the kind of far-out thinking that JPL sometimes can do, about what might space travel look like 50 years from now? In other words, now that we've established where the heliopause is, does that make more concrete those far-out conversations about solar sails, or visiting other stars, or exoplanets, or things like that?

DODD: I think it reignited some of that. Now that you know where the heliopause is, yeah, I think it did reignite a lot of interest in, how do we get out there faster? Whether it's solar sails, or larger rockets, or something like that. And, what is there out there to see? I think seeing being relative. What is out there to take science data of? The particles, the plasma density, dust. There's dust out there, which we don't have a good instrument to measure. So I think it certainly kickstarted thinking, like, "What's Voyager 3 going to be? What should we have on Voyager 3? How can we get it out there faster?" That type of thing.

New Missions Beyond Voyager

ZIERLER: Is there a Voyager 3 that is defensible on the basis that there's interesting things that could be discovered within the laws of physics and what engineering can do? I mean, absent fast—traveling at the speed of light, or getting to the next star, is there enough scientific appetite for a new Voyager to explore parts of interstellar space for which Voyager 1 and 2 simply would never be able to?

DODD: I think absolutely there is. There's absolutely an appetite for more information, newer instruments tuned specifically for measurements of the environment around the spacecraft—plasma densities, charged particles. The instruments are like 50 years old. You can imagine if you built that instrument today—A, it would be a lot smaller [laughs]. It would be a lot lighter. It would be much higher resolution. The hard part is getting it out there quickly. You don't want to wait—how many years? You don't want to wait 35 years until you get to interstellar space. The hardest part is to get it there quickly.

ZIERLER: But isn't even the additional difficulty here that the push to get the launch in '77 is all about gravity assist? It's all about catching that 175-year calendar.

DODD: Right, exactly. And most of the missions that look at going out to the heliopause quickly use Jupiter as a gravity assist. It's big. It's big. But nothing for another 120 years or 100-plus years will be able to have the alignment of the—all the outer planets to get it out there quickly.

ZIERLER: Are there advances in rocketry and propulsion that only using Jupiter could get another spacecraft to interstellar space in a time span quicker than 30 years? Is that feasible now?

DODD: Yeah, the Interstellar Probe Mission, its design is one that uses a very large rocket. We have big rockets. Honestly they're more equivalent to the size of what Voyager was on, because Voyager was on a very big rocket. But the complement of instruments that you're going to put on and the size of the spacecraft is smaller, so the mass that you're trying to throw out there is smaller. You can get out to interstellar space in about 15 years, I'd say. Then you want to continue flying it for another 25 or 35 years, if you want to fly it for 50 years the way Voyager is going, so that most of the mission is in interstellar space. A quarter of it is from Earth to the heliopause, and the other three quarters is out in interstellar space. That's kind of the design of the Interstellar Probe Mission.

ZIERLER: Are we talking hypothetically, or this is really in the works now? There's a plan to do this?

DODD: Well, there's a 600-page paper to do it. It's not hypothetical but it's not funded yet. So it's not science fiction—it could be done—but it will take more design work, and funding.

ZIERLER: What's your over/under? Are you confident that it will happen?

DODD: Am I confident it will happen? Well, I think when I started on Voyager, I started at the Uranus encounter, and I was confident that we would have another mission to Uranus, probably, before I retired, and I don't think that's going to happen now. So [laughs]—that's tough to say. It's tough to say what the priorities of NASA and the science community are. But it's definitely feasible. It's more feasible than what Mark Watney was doing on Mars.

ZIERLER: [laughs] Do you have a sense from Ed Stone—did he conceive of a Voyager 3? Did he have a grand plan, that ultimately this was something that might come to fruition?

DODD: I don't think he had a grand plan. But I definitely think that Ed Stone is, as he rightly should be, very proud of what Voyager has accomplished, all through the mission, all the planetary encounters, and all the discoveries, and the continuing discoveries that Voyager makes to this day. And, I think he's very proud of all the missions that have come after Voyager. What I like to call it is the children and the grandchildren of Voyager. First, at Jupiter, you have Galileo. That was a follow-on to Voyager. A follow-on to Galileo is Juno. And now you're going to have a Europa Clipper mission. All of those come from the fact that Voyager flew by Jupiter and took great data. Similarly, Cassini was a child of Voyager. I think Ed was very proud of making those first discoveries, and proud of the fact that there were other missions that came after it that could really do the orbiting in situ environment around the planet.

ZIERLER: As you were explaining in a previous discussion, there's all kinds of work that still needs to be done with Voyager 1 and 2. They're still doing interesting things. It's still something that occupies and is worthy of JPL's time and resources.

DODD: Absolutely.

ZIERLER: And as you were saying just earlier today, if given the opportunity, it would be wonderful—there's lots of great science that a Voyager 3 could capture in interstellar space today. So, if it was up to you, this would absolutely happen.

DODD: Yeah, I think it would. I mean, there's a lot of competing missions, but I think that would be probably maybe the last legacy of Voyager, in the sense that sending another probe out to interstellar space and following on in Voyager's footsteps would be probably—that would be one last feather in the hat of Voyager's legacy.

ZIERLER: All right, so here's a crazy question based on the unexpected. So, it's a big, wonderful surprise that Voyager 1 and 2 are even in interstellar space. That wasn't the idea from the beginning. If you could use your imagination, if we get a Voyager 3 into interstellar space, what might be the big happy surprise there in terms of, "Oh my goodness, we planned for this, but look what it's doing now"—50 years from now? What might that be? Could it be the nearest star? Could it be something that we can't even imagine that's beyond our solar system?

DODD: We would certainly learn things about how our solar system moves through interstellar space. Our galaxy, and our—well, not our galaxy; let's just say our solar system, our planetary solar system, our Sun and its bubble—move through interstellar space. I think we would learn a lot about that movement and how it impacts with the interstellar medium. Whether there's a bow shock. Are we traveling fast, or are we traveling slow? I think that's one that certainly that you could get some direct measurements on, is the speed of how fast our Sun moves through the solar system. Does it match what our models are for that? We're just at the very tip, or the very edge, of the interstellar space with Voyager. We're barely above wading out through the waves, right? We want to get in 100 AU, 200 AU. We want to get over the last breaker and say, "This is what it's like out here." "It's flat and boring"—or, "It's never flat and boring." [laughs] There's always changes. There's these clouds of dust that are out there that we go through. I think a lot of that goes into the realm of astrophysics as much as it does heliophysics.

ZIERLER: When we talk about interstellar space, we're just talking about the space between our star and the next star? We're still in the Milky Way galaxy.

DODD: Absolutely. You're correct on that.

ZIERLER: And there's no conceivable engineering or law of physics scenario where we could think about a Voyager 4, 5, or 6, where we actually escape the Milky Way galaxy?

DODD: I don't think so, no. You can do it if you travel very, very fast, but I don't think that we're capable of doing that. The Milky Way galaxy has a black hole in the center of it, and we will all eventually be sucked into that. That's how Earth will end, eventually. If it doesn't get destroyed by our star exploding, it will all get sucked into a black hole.

ZIERLER: Is that also an explanation for why it's really not feasible, at least in our imagination, to leave the Milky Way?

DODD: I think anything in your imagination is feasible!

ZIERLER: Fair, fair.

DODD: It would be great to put let's just say a Voyager 8 and send it directly to another star. We know where the stars are, and we know how fast we're going. We know how to catch up there. Or send it to an exoplanet system. We will have many, many exoplanet systems. We've found many; we'll find many, many more in the future. Let's send Voyager 8 to a planet that's in the habitable zone, and see if somebody picks up the signal, around a different star.

NuStar and X-Ray Astronomy

ZIERLER: So exciting to think about. Well! Back to planet Earth, Suzy, tell me about the Nuclear Spectroscopic Telescope Array. You said that this started in 2012, or that's when you joined?

DODD: That's when I joined. It's a small telescope, X-ray telescope. It measures what's called hard x-rays, which are the higher wavelengths, I think. You're going to test my knowledge of X-ray science. Fiona Harrison at Caltech is the principal investigator. It's still operating just fine. It was originally a two-year mission, and it's on year 11 now. It's in an Earth orbit, about a 600-kilometer orbit, but the telescope obviously looks outward. It is taking a lot of data on black holes. Everything I learned about black holes, I learned from being on this mission. Black holes, exploding stars, galaxies—about anything that can give off x-ray light. What's interesting is, you might have Spitzer, an infrared telescope, look at an object, say a newborn star, or let's just say a star-forming region, which is basically happening in the dust that's out there, in our galaxy. Spitzer looks in the infrared; NuSTAR can look at the same object in x-rays, and then you can combine those, and get a much better sense for how stars are formed, how they grow in that environment, when you use multiple wavelength telescopes. You can imagine putting a Hubble image, an optical image on top of that. You can color code the different wavelengths, and then you get a much better idea of how stars are formed, how they explode, that type of thing. What happens. The X-rays come out first, and then comes the cooler material, and that type of thing.

ZIERLER: Are you still part of the project? Is it still ongoing?

DODD: The project is still ongoing. I am not part of it anymore. I left both NuSTAR and Spitzer at the same time when I came over to manage the Deep Space Network Directorate. But I hung on to Voyager, my true love. I hung on to that.

ZIERLER: Of course. You'll never leave. [laughs] You'll want to be there for the 50th.

DODD: Yeah.

ZIERLER: What was the timing for DSN when you joined?

DODD: I got that job, which I currently still have, in 2016. I'm the director for the Interplanetary Network, which the Deep Space Network sits under as well as multi-mission software.

ZIERLER: I wonder if you can explain both administratively and from an engineering perspective, what the relationship is between DSN and the Interplanetary Network? They're not synonymous, obviously.

DODD: No, they're not synonymous. The Interplanetary Network is a directorate here, like a division here, at JPL. The biggest project under that directorate is the Deep Space Network project. Similar to the way IPAC was the processing center that the Spitzer Science Center was under at Caltech. The Interplanetary Network directorate is the umbrella organization for which the DSN project is underneath.

Sustaining the Deep Space Network

ZIERLER: When you joined in 2016, what were the big imperatives? What needed to be done at that point?

DODD: For the Deep Space Network? I think we were just starting to see the tip of what is a real issue now, with the DSN—that it's oversubscribed. There's more users who want to use the DSN, particularly with Artemis, and CubeSats—the explosion of CubeSats—more missions want to use the DSN than there is antenna time. So figuring out how to be more efficient. Tracking multiple spacecraft at the same time with one antenna. You can do that if the frequencies are slightly different and they're in the same beam width. So there has been a lot of work on making the antennas more efficient, as well as making the case that the antennas just need more funding. That's kind of the least glamorous part of the job is saying, "Look, you've been neglecting—" The DSN budget has been cut every year for ten years, including not any inflation. They're real cuts, plus no inflation. That also drove some of the efficiencies. But trying to put a case out there where all of NASA's missions depend on this and its infrastructure. You need to fund infrastructure. You have big visions of doing big things like Moon to Mars with astronauts, and Europa Clipper, and sample returns on Mars. But you're counting every bit of data that comes back from outer space, and particularly in deep space—comes through this directorate, comes through these antennas. And oh, by the way, the buildings are 50 years old, and we have deferred maintenance, because you can't fund it. Kind of just telling NASA, in many different ways to get their attention, that you've got a mismatch between your appetite for missions and your infrastructure that is going to support it.

ZIERLER: The two narratives here that are going in opposite directions are resources and maintenance, but also an increased demand for what the DSN's capabilities are. How do you square that circle? What has been the solution to this?

DODD: Well, it hasn't been solved yet, A. I think the future solution space includes more commercial, getting more—NASA not doing it all or owning it all. You can see that with NASA now. SpaceX is going to land—getting the astronauts to and from ISS. There's commercial contracts to put the first or to return the astronauts to the Moon. There's commercial contracts for bases. So there is a lot of commercial interest, at least in the astronaut world. There's probably a lot less commercial interest in a Uranus probe [laughs], frankly. But I think there's commercial assets on the ground that can be used to augment the DSN, and let the DSN focus on what the DSN does well, which is tracking deep space missions, those to Mars and beyond. If NASA is going to go to the Moon and they're going to go there frequently, it's probably better to do that with smaller antennas and more commercial services. I think that's the way NASA is going. NASA is congressionally funded; these projects are not within that two-year window of your congressman's election time period. They're a decade or more in the making. So, to keep political eyes on the end goal, and funding on the end goal, is constantly needed.

ZIERLER: To clarify, if you had your way, the Deep Space Network should be exclusively focused on, obviously deep space missions. That it should not get caught up in more of the commercial and Moon landing kinds of aspects.

DODD: I would say I'm not against supporting—I don't want to be misquoted here because [laughs] I'm thrilled that we can support astronauts at the Moon and we're being asked to support astronauts on the Moon. I would be happy to do that.

ZIERLER: But that's where the drain of resources is, you're saying?

DODD: Well, it's all of it that's a drain of resources. It's all of it. We need some guidance from NASA about what their priorities are. Again, it's the big appetite, which includes astronauts, and it includes returned samples from Mars, and includes orbiters around Europa. It's all that appetite of missions and data on an asset, a DSN asset, that they don't adequately fund. It's aging infrastructure. It's going to fail, if you don't do something. I don't want it to fail when there's astronauts there. I don't want it to fail any time, but I definitely don't want it to lose communications with astronauts. So, my real wish is that we got better funded. I guess I can say that here. [laughs]

ZIERLER: Sure; not a controversial point to make. With that better funding, if the concern is that the Deep Space Network is just getting pulled into too many directions, does that mean new installation sites? Does that mean expanding it from the current three, to four, five, six, however many? Does it mean making the extant dishes bigger? What does that look like?

DODD: It could be expanding to more sites, but it's more economical to, say, build an additional one or two 34-meter antennas at the current site. Because when they're close together they're easier to array, and that's what you like to do. Sometimes you want one antenna by itself; sometimes you want three antennas together. When they're closer together, that's a much easier thing to do. It definitely means more antenna assets at current sites. Even with that, we need to get more of our missions to go to higher frequencies, like Ka-band, because we can get the same amount of data down in less time, when they're on higher frequency. Move to optical. We've got technologies out there for deep space optical. We're actually flying a test of a deep space optical terminal on the Psyche mission. It's a demonstration test. If that goes well, then I think you can get a lot more data down in a much smaller time period. That's the way you make your antennas more efficient. You don't have to track for eight hours; you can get all that same amount of data down in half an hour or something like that.

ZIERLER: As you noted earlier, we don't have the luxury—we can't go out into interstellar space and upgrade Voyager 1 and 2. But the Deep Space Network dishes, they're right here on planet Earth. When you talk about building a new dish, how much different would it be in light of all of the technological advances? Would it be a totally different animal than what's already there, or is it just more of the same?

DODD: It's kind of basically more of the same, from the structure, from the size, and from the architecture of it. But you can do a lot with the electronics. You can put next-generation receivers in there. You can put in, again, other frequency receivers. The other frequency receivers don't help Voyager, because I can't change what Voyager is broadcasting in. But if you have another antenna, instead of arraying four antennas together, I can array five antennas together, and that will get me another two more years of data from Voyager. Because as Voyager keeps going further out, it gets harder and harder to get the signal from it.

ZIERLER: You've got me excited about the importance for upgrading the Deep Space Network. What are the opportunities that you have to make that case to the people who actually fund the program? Do you get to go to Washington? Do you get to advocate these kinds of things?

DODD: I get to go to Washington far too frequently. [laughs] Yeah, I do. I do. The processes—there's a yearly budget cycle where we look at the needs of the missions, and where we are, with the DSN, and what we need. You look at the future mission set, and say, what do we need on the ground to be able to support that future mission set. That's done on a yearly budget cycle kind of process. It's done tactically, but it is also done strategically, when you're looking at 10 or 15 years out. What's the mission set 10 or 15 years out, and what do we need to support that? And how can we have those antennas ready when the missions are ready, to send us the data? It takes a good four to five years to build a 34-meter antenna.

ZIERLER: Because DSN just globally is an international project—it's located one site in the United States, and two that are not—what kind of cooperation does that require on an international level? Do you have peers at international space organizations that you work with? Is this an entirely American project but part of it is based on foreign soil? How does that work?

DODD: The Deep Space Network is NASA's network, so it's a U.S. network. They have treaties and cooperative agreements with Spain and with Australia, to be able to operate these antennas in foreign countries. So, it is international, and it's done basically through treaties, State Department agreements, and things like that. We also have exchange agreements with antennas. Like the European Space Agency, similar to the DSN, has a deep space network. They don't have as many antennas. They basically have one antenna at each site. But they have three sites around the world: Western Australia, I think Argentina in South America, and then one in Europe, is where the other one is. So, there's other countries with other antennas, and we have cooperative agreements where we say, "This is a very busy time for us. Can we send this mission over to your antenna for a week? And then if you have a similar need at a different time, we will track your spacecraft." So it's kind of a quid pro quo. There's no exchange of funds or anything. It's just an agreement that we can offload to you, and you can offload on us, if needed. For deep space in particular, as more countries start building these larger antennas—the Japanese have a great set of large antennas; the South Koreans just built one—we can do more of these exchanges of time, for tracking particular missions.

ZIERLER: To go back to this idea of the wonderful surprise of how long-lasting the Voyager spacecraft are, is there a similar narrative there with the Deep Space Network? In other words, was it conceived to be useful for only so long, and we're now beyond that period, so it's just a matter of keeping it up for as long as possible?

DODD: There definitely is that story with the 70-meter antennas. They were built in the mid to early 1960s. As a matter of fact, I think I might have a coaster here—so, Goldstone, 70-meter antenna, had its 50th anniversary in 2016. This is how I remember it, because it's on the coaster! Anyway, mid 1960s was when the 70-meter antennas were built. They were never expected to last this long. I should say that they were built as 64-meter antennas, and they got expanded out to 70 meters for the Uranus encounter, for Voyager. So, Voyager actually grew the 64's to 70-meters, for the outer planets, for Uranus and Neptune. Every five or so years, there's talk about shutting those 70-meter antennas down. They're older. They take more maintenance. They're quite a feat of engineering. But they're very much a workhorse in the DSN, and nobody—they talk about it, and they say, "Well, we'll replace it with 34-meters, and you can array 34-meters," and then when they look at what you can do with a single dish—it's everything from tracking Voyager to rescuing a spacecraft that's tumbling, and only intermittently getting any kind of a signal. The larger the antenna, the better you are off at getting a very faint signal. So, when you have a spacecraft emergency or something like that, they often use 70-meter antennas. So, the 70-meters are frequently talked about being shut down but—never happens. I don't think it will happen, at least not for a couple more decades.

ZIERLER: What are the flagship missions for NASA that give you that confidence that there's a demand, there's a need, for the DSN capabilities, that will simply have to be there if these missions are going to be successful?

DODD: The one that's going to launch the soonest is Europa Clipper. Mars Sample Return is another one that needs 70-meters, just because of the data volumes. Then if you think about a Uranus probe mission, which might launch in the 2030s, that's going to need a 70-meter antenna. So anything very distant—certainly Jupiter, Saturn, Uranus, Neptune—those would all need 70-meters. And even some of the Mars missions, the 70-meters are handy because they can get a lot of data down in a shorter period of time.

ZIERLER: Is this to say that your leadership for the Deep Space Network—does that give you a perspective into these flagship missions that you might not otherwise have, if you were exclusively focused on Voyager?

DODD: I think my perspective of coming to the DSN is really that every bit of data counts on the DSN. I think for the longest time, it was taken for granted. It would always be there. It would always operate just fine. I think now, there's a lot more acknowledgement that the DSN is aging. It hasn't been kept up due to funding. It hasn't been kept up the way it should have been. And we have grand plans for the next generation of missions, and if we're willing to spend a billion dollars on a spacecraft, or two or three or four billion dollars on a spacecraft, we should be willing to spend a few hundred million dollars at the DSN. Percentage wise, it's not that much. I think people are beginning to realize that the infrastructure is important.

ZIERLER: Bringing our conversation closer to the present, something we all had to deal with—when COVID hit, and we were all remote, what did that mean for you, and what were some of the challenges in managing everything—not coming into the office, not seeing your colleagues face to face?

DODD: I think the hardest part of that, from a DSN perspective, was dealing with the NASA headquarters people, and even the overseas sites. You couldn't travel overseas. You couldn't go visit the sites and meet the people. Personnel changes happened over COVID, so you couldn't meet those people except online. There are still people I haven't met, because I haven't traveled yet overseas, who joined during COVID. The focus was definitely on people's health, and the health and safety of workers, which was important. We built two new antennas in Spain during COVID, so that was a real big success, to have that happen during that time period, while keeping people healthy. I think especially internationally, the personal relationships help a lot, and so if you're not meeting people in person, and experiencing their culture, or just kind of getting to know them, it's much more difficult to be open and honest and trusting with each other. From a Voyager standpoint, we had to move [laughs] during COVID. We moved from Building 600 to Building 264 during COVID. We just had one or two people come in at a time and be at opposite ends of Building 600. We actually had a schedule—"You two or three people, don't mingle with each other, but you can pack up your offices this week," and "You can pack up your offices that week." To get everything moved. That was actually a challenge. We did it. Didn't have any impact on the spacecraft. The spacecraft were flying remarkably very well, all during COVID. COVID didn't affect them. Thankfully, we didn't have any spacecraft issues during that time. No spacecraft emergencies. Just kept doing what it was doing, so that's good.

ZIERLER: What about from an HR perspective, as a manager, as a leader for so many people? What were some of the challenges in just keeping your team together, even if it was remotely, during the pandemic?

DODD: We did some of the things that other groups did. We'd do video happy hours, so to speak, or trivia games, that kind of thing. We did a couple outdoor lunches, too. Like, "Okay, if you feel comfortable, we'll meet outside in a park and have lunch, just to socialize." We did a few of those, too, which I think really helped. It really helped people, being able to see each other more socially. It helps keeps the team bonds going, too.

ZIERLER: For you in that transition period of coming back to work, did you jump in with two feet, or did you have a hybrid approach for a little while?

DODD: Most of the time I came back. Being a directorate lead, they wanted us back online and more presence at JPL. Because there were people that worked at JPL the whole time. They work in labs, they're building spacecraft; that didn't stop. The people operating the DSN in Building 230 here, they were in every day. So, having a presence, supporting the people that did have to work on Lab, was important. I came in—at first it was maybe once a week, and then two or three times a week. Now, I'm in every day. I think for the last year I've basically been in every day.

ZIERLER: When Laurie Leshin was named director of JPL—this is something we talked about in our very first discussion—what did that mean for you as a woman who was here when there really weren't many women at all in positions of leadership?

DODD: I think it's great. She's really good. She has a unique-to-her leadership style which is different than what I've seen in the past with JPL directors. She's very engaging. I think coming from being a college president, she definitely connects with new fresh-out type engineers, early career people, and she has a much better sense for what they want in their careers, versus somebody like I was, who says, "I think everybody should have a career like I had! And think the same way I do." They don't. My kids don't think the same way I do, so I don't know why I would expect new engineers at JPL to think the same way I do. I think just by being female, without even having to say it, she has put a lot more emphasis on increasing female and minority leadership positions, and making an effort to get people into those positions at JPL. Minorities and women into leadership positions at JPL.

ZIERLER: Bringing the story right up to the present, an issue that's in the news almost every day now—artificial intelligence and machine learning. Has this influenced your day to day? Can you see how it's changed things at JPL more generally?

DODD: I think JPL is still trying to figure out the best way to get that into their missions, and how to make smart spacecraft. What's the best way to do that? What's the most important thing to make smart? For us, from a DSN perspective, we'd love to have spacecraft on board determine what data should come down and what data shouldn't come down. Anything that limits the stream of data, can make decisions there that can cut back on the amount of information that you have to send to the ground, that would be great for us. It makes us more efficient. We can support more missions if they don't all need to send down all their data. But I think at JPL we are still trying to figure out the best way to use that type of automation and AI. I think we do a good job once the datasets are on the ground, like how to parse datasets and how to match data up to get the best information out of that data set. I think we've done a pretty job at using automation and artificial intelligence to do that. But I'd like to see more infused in flight, and on board the spacecraft.

ZIERLER: Just as a fun thought experiment, if you could reverse-engineer the Voyager spacecraft to have an AI or an autonomous component, would they be able to achieve things that are currently not possible?

DODD: The Voyagers have very little memory. If we had enough memory and the ability today to do automation that allows the spacecraft to determine what to send back, I think we could continue longer, in the sense that we wouldn't need to get all the data back we get back. But it's hard for me, just knowing the history of Voyager, to imagine designing it differently for that. There was a question that was answered during the screening of the It's Quieter in the Twilight; I don't know if you saw that or not. One of the questions was like, "If you could change one thing, what would you do?" It was pretty [laughs]—Linda Spilker said, "I want another RTG." That's more power, right? So, any artificial intelligence that allowed you to use your power more efficiently would be great. The second answer was "more memory." If I had more memory on the spacecraft, I could do more things. I think both of those areas, if you could apply some artificial intelligence to that, it would let Voyager keep going longer.

ZIERLER: When we talk about more memory—there's the famous saying about how all of NASA, the computational power during the Apollo program was less than what's in our iPhone right now. Essentially, that's the same thing we're talking about, in the 1970s, when the Voyager spacecraft were built. That's it!

DODD: Mmhmm. I do. But I do think there's something to the fact that the simplicity maybe makes the spacecraft a little bit easier to operate, too. You can put in a basic loop of commands and just set the spacecraft to execute it. It's not fancy. It has a certain amount of fault protection or self-checking, but not a lot. It's not complicated. I do think there's this sense that, because it's perhaps more simplistic than today's missions, that it is one of the reasons it has lasted so long.

ZIERLER: I hope that is a point that is very well taken into consideration for when Voyager 3 is conceptualized. Because I'm sure there would be a very strong urge to gunk it up with all kinds of tech that might make it last not nearly as long.

DODD: Exactly. And I've used this example before, where I've said there's not a lot of memory, so the people that programmed it had to be very good programmers, because every bit counted. Today, tons and tons of memory. You want to put in lots of fault protection. You don't have to be a good coder. It could be spaghetti code. I'm sure the current programmers would hate me saying that, but that kind of ability to program whatever you want because you have so much memory also leads the system to be much more complicated, and much more prone to errors that you can't solve.

ZIERLER: Be careful what you wish for, I guess is the lesson.

DODD: Exactly.

ZIERLER: Now that we've worked right up to the present, for the last part of our talk, to wrap up this wonderful series of conversations, if I may, a few retrospective questions, if I could ask you to think back on your career. One, as we've alluded to—it has sort of been a theme in these discussions—the magic relationship between Caltech and JPL; what at the end of the day makes it so special? How do you account for all of the things that both institutions are able to accomplish because of their partnership?

DODD: I think they feed off each other, and I think that's something we need to continue to nurture. We shouldn't let them drift apart. Continue the connections. Have students work at JPL. Have JPL researchers work on campus. I think the connection between those two is important. It's important for new people starting their career. It's important for some of the fundamental research that campus wants to do. We could do better with facilities we have here at JPL. I think keeping the exchange of students and staff and professors between the two organizations helps both of them, so I think that's key.

ZIERLER: In all of your service as a mentor to young engineers, people at JPL who are just starting out in their career, what has been most satisfying to you, in showing them the ropes, in helping them nurture their careers in the way that you were helped at an earlier stage of your career?

DODD: I'm a people person. I like interacting with people. I like to understand their background and what brings them to this business. It is always kind of interesting. I think what I enjoy is giving them maybe what you might consider more an aspect of the culture, how JPL operates. I'm not going to teach them calculus, or fluid mechanics, but I can teach them about a job, and I can teach them about what's important to your manager, beyond just getting the problem right. I can teach you how to interact in a work environment. I enjoy sharing that. It's perhaps more the psychology and less of the academics, but I enjoy sharing that aspect of what I've learned over my career.

ZIERLER: In all of your administrative responsibilities, all of the ways that you're dual hatted, all the meetings that you have to be involved with, how have you managed to stay close to the engineering and close to the science, to keep it interesting, on a day to day basis?

DODD: The science is great, and I think that's first and foremost at JPL. We always talk about science, and we always talk about missions. There's a lot of information that's given to employees. Obviously with Voyager, we have science team meetings twice a year, and we really get in there. Anybody on the Voyager team can come and listen to the science talks, so it's not exclusive to scientists. The propulsion engineer can come and listen to all the science talks he wants, for Voyager. It's open. I think that's one of the hallmarks of JPL, is that almost all of their meetings are open. To some degree, right? To some degree. And you have a lot of opportunities for JPL-wide talks. It can be everything from, say, Cassini science, or they could be more mundane, like, what does Mission Assurance do, and what kind of things do they check, and how do I make a five-by-five risk chart, kind of thing. They can be both technical or they can be scientific. Campus has the same idea, right? They have lunchtime talks. They have science seminars in astrophysics. I think JPL probably has more talks related to engineering, like, how do you build a better radio. What are new technologies in radio? There's a lot of those kind of talks, that anybody can go to, at JPL. I think that's great, too. That makes the JPL environment a little bit more like a college campus, from a learning standpoint.

ZIERLER: You have a career span where you've witnessed all kinds of political changes in Washington—Republican presidents, Democratic presidents, all different kinds of congresses. If you step back and look at it in the whole, what have those changes meant for the budgetary environment for JPL? Is it possible to say whether Democrats or Republicans are better for the budget, or how do you make sense of the ups and downs of JPL's fortunes?

DODD: I don't know if you can say whether Democrats or Republicans are responsible. I think the general economic environment has an impact. If you're feeling good about where you're going to go, you're probably going to put more money in the space program. If you're very hesitant and you think the banks are going to collapse, and you want to sort of circle the wagons around the money that you have, you're probably going to put less funding into the space program. But, looking forward, space is the new frontier, right? Who's going to get the first astronaut on Mars? Is it China? Is it Russia? Is it Jeff Bezos? Is it NASA? There is a space race and that's what got us to the Moon in the first place, was the space race, politically-driven space race. There's a lot of similarities going on right now, particularly with the Chinese, but you've got this whole commercial aspect, too. The commercial guys can, for the most part, do whatever their [laughs] funding allows. I think that drives a bit of NASA. And, certainly the military aspect of space is growing now, too. The Space Force wants to know what all the assets are, around the Moon, and they want to know what people are doing, by using antennas like the DSN to see what they can see, because others aren't telling them what they're doing. So there's that kind of a sense of going forward, too—that it might be more—a lot of stuff might be politically driven.

ZIERLER: Do you have any hopes that unlike with the Cold War and the competition with Russia, there might be opportunity for cooperation with China's space program?

DODD: I'm always very hopeful. Russia is still one of the biggest partners in the space station, our space station, the International Space Station. Even though they're in a war that we don't support, we still count on them for supporting programs at NASA. So I think space can also be used for good, in the sense that it gets countries who might not agree on things to work together.

ZIERLER: On the opposite of that, we have now the Space Force and the concern about the militarization of space. What productive role can JPL play in ensuring that space does not become the next frontier of military conflict?

DODD: I don't know if I'm qualified to answer that. [laughs] I think JPL has a certain amount of engineering knowledge and knowledge about communications that are helpful to the Space Force. I would say not JPL but I think NASA possibly could play the role there, where we want to be more cooperative and less competitive. Science cooperation, or just space cooperation, and not silo ourselves from other countries. I think NASA can do that well. I don't think JPL alone can do that, but I think NASA can play that role.

ZIERLER: One last fun retrospective question before we end looking to the future. When you started at JPL, obviously you could have no idea all of the twists and turns that your career would take. If you think about all the things that you've been involved in, what has been the biggest surprise, in terms of what you've achieved, what you've contributed to?

DODD: I don't think that I ever thought that I would get frankly as high in the organization at JPL as I am. I'm enjoying that, though. I do enjoy that. [laughs] If that's okay to say that.

ZIERLER: Absolutely! Well deserved! Well earned!

DODD: I think I've always tried to be open and honest with the people I work with, both the people above me and the people below me. I try to empower my employees and grow them to be leaders in their own right, wherever they want their career to go. I'm proud of that. I'm proud of how I interact with people and am able to communicate, put organizations together and get them talking together. I think I mentioned probably in one of our talks, I really—my time at Caltech, and working with scientists, and teaching them how to talk to engineers at JPL and vice versa, I think really put me on a path that helped my management career quite a bit.

ZIERLER: Last question, looking to the future. We've already talked about the magic of what would happen at the 50th anniversary of Voyager, what that would mean for you. Besides that single event, for your own career, is there a particular goal that you have in mind that you want to achieve before you're ready for retirement and the next phase of your life?

Looking to Voyager After Fifty Years

DODD: I think getting Voyager to 50 is probably the biggest goal. But also, if I end up retiring shortly after that or whatever, to make sure that the people that fall behind me have the tools and the skills and the enthusiasm to do the job after I leave. That would be the other thing. I would want to leave the job knowing that it was left in good hands.

ZIERLER: Just as an addendum to that, are you confident that you'll know how to retire?

DODD: [laughs] No, I'm not. I'm talking to more and more people that are retiring, just because of my age. But no, I don't know how I will retire, yet. [laughs] That's something I will be thinking about in the future.

ZIERLER: But not until Voyager is 50.

DODD: Yeah.

ZIERLER: This has been a phenomenal series of conversations. I want to thank you so much for taking time out of your busy schedule. It's a treasure for Caltech and JPL history. Thank you so much.

DODD: Oh, thank you.

[END]