From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.

On episode 307, Psyche’s principal investigator Lindy Elkins-Tanton walks us through the ins and outs of the mission to a metal-rich asteroid. This episode was recorded on July 6, 2023.

Transcript

Host: (Gary Jordan):  Houston, we have a podcast! Welcome to the official podcast of the NASA Johnson Space Center, Episode 307 “Psyche.” I’m Gary Jordan, I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, astronauts, all to let you know what’s going on in the world of human spaceflight. But let’s be real, space is too cool to limit ourselves. On this episode, we’re going to be talking about an upcoming and uncrewed solar system exploration mission called Psyche. Its mission is to visit an asteroid of the same name, one that’s orbiting the Sun between Mars and Jupiter, named by Italian astronomer Annibale de Gasparis in 1852 after the Greek Goddess of the Soul. What makes this asteroid particularly interesting is that it is metal-rich, and scientists believe that this asteroid is the partial core of a shattered planetesimal or a small world about the size of a city or a small country that is the first building block of a planet.

This means that observing this asteroid can offer us a unique window into how planets are formed. Aside from the asteroid’s discovery in the 19th century, astronomers have also studied Psyche in the visible and infrared wavelengths. But this up close and personal opportunity with the Psyche spacecraft delivering new scientific instruments may give us the answers we seek. Not only is the science of this mission fascinating by itself, but Psyche will be using technologies like solar electric propulsion and deep space laser communications, technologies of particular interest to Artemis missions. To help us digest the science and technology behind the Psyche mission is Lindy Elkins-Tanton, the mission’s principal investigator out of the Arizona State University. Lindy is a professor in the School of Earth and Space Exploration at ASU and the vice president of the ASU Interplanetary Initiative. Her education is in geology, geochemistry, and geophysics, receiving a bachelor’s, master’s, and doctorate in these respective fields from the Massachusetts Institute of Technology (MIT). Lindy’s experience is extensive, and we’ll go through it a bit in this episode with field expedition experience, interesting research and leadership roles. She’s written books, done TEDTalks, and even has an asteroid named after her. We had a chance to speak with her on July 6, well before the busy prep period, right before the launch window opens October 5. I’m very excited for this episode. So let’s get right into our talk with Lindy Elkins-Tanton on Psyche. Enjoy.

[Music]

Host: Lindy Elkins-Tanton, thank you so much for coming on Houston We Have a Podcast today.

Lindy Elkins-Tanton: I’m so happy to be here. Thanks for inviting me.

Host: You are quite busy, right? This is not a slow time for you, so I appreciate your time. But man, you are really moving and making sure everything is set for this upcoming Psyche launch.

Lindy Elkins-Tanton: Yeah. We’re about three months out and there is a lot going on right now. But it’s an exciting time to talk about the mission because we’re all on point at the moment.

Host: Absolutely. Yeah. And that’s exactly what I want to get into. But I first want to talk about you, Lindy, and your role because you are the principal investigator. And I guess what I want to start with, cause I give a brief introduction of some of your biography, but it’s very interesting and I think the path that you took in your career to get to this moment as the principal investigator for this particular mission, is quite interesting. Can you give us a sense of how your career path, how your life sort of led you to your role today?

Lindy Elkins-Tanton: Yeah, I think that my path is a little bit different from some other people who lead and work on NASA missions. In that after I did my undergraduate and my master’s degree, I worked in business for almost 10 years and found that really, really interesting. Learned a lot about teams and budgeting and scheduling, and organization. And then I went back for my PhD, and I really was an Earth and planetary scientist working mostly on volcanoes. So that’s not a really typical pathway for this. But ended up working on planetary formation and then had some big questions that really needed a mission to answer them. And that’s how this all came about. Maybe a little bit more curving path than some people have.

Host: See, I think, a lot of us, maybe me included, kind of get a little nervous at the idea of dedicating so much time to a profession, only to take what seems like a left turn and just go on a completely different path. So what inspired you as you were going through business and you realized, “you know what? I actually want to go back and really get into the science. I really want to start doing that.” What was that? Was there a moment or just maybe a slow thought process that got you there?

Lindy Elkins-Tanton: Yeah, there was a little bit of a moment. You know, luckily, and during my undergrad, I had done some research, which I really encourage college students to do, scientists or engineers to do some research to get a sense of what that’s like, cause it’s so different than classes. And that became my master’s thesis. So I had a sense of a tiny taste of what an actual scientist does in knowledge creation. Then in business, I found that fascinating cause so much of the world is commerce, and I felt like I didn’t understand it at all, and I really wanted to understand it. So it was great to have experience as a management consultant and running some small companies, writing business plans for young companies. But eventually, that actually became boring to me. It became a little repetitive and I was teaching on the side also.  I was teaching math and I realized I really love teaching. I was teaching at the college level. So I thought to myself, “if I never ever want to be bored, then I should be a research scientist,” because you can always ask a bigger and more difficult and more challenging and more interesting question for yourself. That’s the freedom of that job. And in order to do that and teach, I needed to get my, as we call it terminal degree, I had to get the final degree in my field, the PhD. And so that’s what I did.

So when I was 31, so 10 years after most people start their PhD, I went back. Also at that time, I was a single mother and also contending with some depression and anxiety, which I mentioned just because that is a pretty common thing for people and also for people to feel like they can’t talk about and so maybe I’ll just mention that I had that challenge so that anybody else who’s having that challenge doesn’t, you know, can feel a little connection.

It worked out and my son’s doing great, and I got remarried and I finished my doctorate, but that was sort of that turn and maybe a through line, something that connects all of these pieces for me is that I discovered I really love working in teams. And I think that creating a team where everybody can succeed better than they can see can succeed by themselves is such an interesting human capability and something that definitely brings me right to a giant mission team instead of just doing scientific research by myself with my own lab.

Host: Yeah. We hear that a lot of Lindy. Here the team comradery is so, so powerful. I think you really have to enjoy that to really be successful. And Lindy, I thank you for sharing your experience. That hits home for me. I definitely empathize. I’m 31 now, so I’m trying to put myself in your shoes and I also have a son, right? So I’m trying to think about like that path. And it’s absolutely fascinating. But that sense of adventure, I’m glad that it never went away for you. You know, I’m 31, right? So I have a feeling that yeah, you know, I’m in this job and I love it, right? I’m not going to leave, not because I want a sense of adventure. I have a sense of adventure so I’m lucky in that regard.

Lindy Elkins-Tanton: Right.

Host: But I read your biography and I see the places you’ve gone: Siberia, Sierra, Nevada, Cascades, Iceland…I mean, these things have to sit in your mind and resonate with you when you reflect on these times and be like, “you know what, I’m happy. I’m happy that I went on these adventures.” Is there any adventure in particular that sort of sticks out to you?

Lindy Elkins-Tanton: Oh, yeah. The Siberia adventures were definitely the biggest adventures. Five field seasons and five field seasons in central Siberia. The Siberia stuff was related to the geology and geophysics that I’ve studied, but not really related to planetary science directly. We are trying to understand whether these big volcanic events that happened 252 million years ago in what’s now central Siberia, drove a global extinction, much bigger than the dinosaur extinction, and also before the dinosaur extinction. Something like 95% of ocean species went extinct, and 70% of species on land went extinct. It was almost the end of multicellular life for a little while on Earth. And we thought that maybe these volcanoes could have driven that extinction, but no one had been able to prove it, even though lots of people had studied it. So we went out in the field to find the rocks.

So there were lots of adventures in Siberia going down rivers and being way up above the Arctic Circle and camping out and hiking through bogs. And so those were fantastic, fantastic adventures, and I’m so grateful to have had them. But I will just add that there’s one adventure I’ve always wanted to have, and that is to go to Antarctica, and I’ve never had a science reason to go, but I mentioned this because my son is 31 this year, speaking of 31 and he and I are going to Antarctica together later this year. Later this year. So another adventure ahead.

Host: Oh, that’s awesome. Wonderful. Meteorite expedition? What’s the goal in Antarctica?

Lindy Elkins-Tanton: No, it’s not science. It’s totally tourism. We’re just going to get on a national—

Host: No way.

[Laughs]

Lindy Elkins-Tanton: Yeah, I know. I never had a science reason to go. So all these other places I went for science. This is a National Geographic boat, and we’re going to go to South Georgia and we’re going to go to the Antarctic Peninsula, and we’re going to look at albatrosses and penguins, and it’s going to be amazing.

Host: Oh my gosh, I’m so jealous, Lindy, that sounds so cool. My gosh. Yeah. The sense of adventure it’s a wonderful thing. And I think everything that you’ve done, everything you’ve described so far, your business career, your adventures and your research, your field expeditions, all the research has led you to now to the principal investigator of, Psyche. Let’s get into it. So let’s first understand what a principal investigator is and, and what that role is responsible for. So give us a sense, what’s your role in this mission, Lindy?

Lindy Elkins-Tanton: Yeah. What is a principal investigator? NASA, as you and your listeners know, has a series of sizes of missions that it flies in space. The biggest ones, the flagship ones, are run out of NASA Headquarters and they’re managed a whole different way. And then there are competed missions, including the discovery class missions, which is what Psyche is. And for them, a scientist is the lead of the proposal, puts together the team, the NASA center that’s going to be the manager of the mission, and an industry partner and the science team and all that, and becomes actually the lead of the whole thing. And so that’s what the principal investigator is with a competed mission. I actually sign my name that, if I know a reason that the mission is not going to succeed, I have to stand up and say so. And that by itself means that I have to be as involved in every aspect of the mission as I possibly can be. So it ends up being such an interesting position, a lot of responsibility, but not necessarily direct authority with everyone cause there are so many organizations involved and the need to learn about a lot of things I haven’t learned about before. So interesting.

Host: Yeah. So it pulls on a lot of that experience that we were just going over. You have to really understand the science. You have the science background, you understand the why, and you can speak with these teams and sort of understand their needs and their wants, but you also have that process, that business mentality, to get stuff done from start to finish.

Lindy Elkins-Tanton: It’s been so useful to me, that time as a management consultant and writing business plans and also leading large groups in academia, leading departments and units, has been extremely useful, extremely useful. And I spend most of my time, honestly, thinking about teams and how teams work and what kind of communications we need to do. And that’s the thing that’s good for scientists who are interested in NASA missions to think about that. Right now, not a lot of this work is science, and there’s a lot of work, but it’s almost all organizational, engineering, budgeting, scheduling, negotiating, strategizing, all these things that we’re not necessarily trained for. And so the bit of experience I had was very, very useful.

Host: Very awesome. All right. Lindy, let’s get into this mission. Let’s understand Psyche, let’s understand the asteroid, the mission that you guys are doing. Let’s start with just the asteroid, right? So really taking it high level, why are we going to this particular asteroid called Psyche? Of all the different places in the solar system we could have picked, why this thing?

Lindy Elkins-Tanton: The scientific paper that got this whole project going was about how the very first small miniature planets in our solar system formed, called “planetesimals.” These planetesimals, the size of cities or continents, collided with each other and stuck, we think, and became the rocky planets we have now. And so it’s like you took lots and lots of marbles and put them together to make a giant, giant globe. And so how did these marbles first form? Some of them melted and the metal that was in the original material that was melting, sank to the middle to form a metal core. And that’s the same structure as our Earth has and Mercury and Venus and Mars, and even the Moon has a little metal core, and we can never go visit our metal core, but we have a lot of questions about it. Is the source of our magnetic field perhaps is important in keeping our planet habitable?

But how do we learn about it? Well, it turns out that of the, who knows, million and a half asteroids out there, there are about nine so far that we’ve identified that seem to be made of metal. And Psyche is the biggest one. It was the 16th asteroid found, that’s why it’s called 16-Psyche. And it’s about the size of say Switzerland or the width of Massachusetts. Its surface area is about the same as the area of California. So as asteroids go, it’s big. And so if we want to see a core, this is our best bet. We actually think Psyche probably is part or most of the core of one of these tiny original baby planets, planetesimals. And if we’re right, it’s also probably the only way that humankind can ever see a core. So that’s why we’re going.

Host Alright. So yeah, you keep referencing the core, the planetesimal. So if we go and we look at, we look at the planetesimal, and we investigate it, it’s metal-rich. What exactly about the metal rich asteroid is so interesting? And what can it reveal?

Lindy Elkins-Tanton: Right? Think about the Earth having melted maybe multiple times from giant impacts, including the one that formed our Moon, and then the vulcanism that occurs, and the interior melting and all of the processing of the rocks. Imagine that’s like, I like to say like a cake, you know, something that has been mixed and beaten and baked and then frosted. And what we’re really interested to know is what are the ingredients that go into making a habitable planet like the Earth that lets us live on it? And so every time we visit an asteroid like Vesta or like a Bennu or the other asteroids that have been visited on missions, we’re learning about some of these ingredients, some of the flour, the eggs, or the milk or whatever it is that originally went in. And one ingredient we’ve never seen before is that metal ingredient. And so what we would learn is maybe what did the little cores that originally formed the very first metal cores to form in our solar system, what did they look like? Did they have a structure that we could see? Did they make a magnetic field? Did they incorporate elements other than iron and nickel into them as they formed? So what were the ingredients that went into making our Earth’s core? Those are the things we’re hoping to learn.

Host:  Wonderful. The ingredient analogy definitely resonates with me.

Lindy Elkins-Tanton: Oh good.

Host: It helps me to kind of definitely understand, continuing to learn more about Psyche. You gave us an approximate size. I believe it’s orbits between Mars and Jupiter. Is it in the asteroid belt?

Lindy Elkins-Tanton:  That’s right. It’s in the outer asteroid belt. So it’s actually very far away. The outer main asteroid belt. Sometimes it’s closer to Jupiter than it is to the Earth.

Host: Ah, okay. Interesting. Now because it’s farther out into the solar system, it takes about five Earth years to complete one orbit of the Sun, right?

Lindy Elkins-Tanton: Exactly.

Host: But it rotates relatively fast.

Lindy Elkins-Tanton: Yep. Yeah. About four hours is a Psyche day. The other interesting thing about Psyche’s orbit is its spin axis, like the Earth spin axis we think of as vertical, perpendicular to the plane of the orbit or close to it. It’s got a tilt, which gives us seasons. But it’s spinning like a top as an orbit so to speak. But Psyche has been banged into, we think is the only way this could happen, its spin axis is lying down in the orbital plane, so it’s spinning on its axis like a rotisserie chicken, if that makes sense. Instead of like a top.

Host: Okay, yeah.

Lindy Elkins-Tanton: So that also makes it a little bit of a challenge for planning a mission cause there’s a quarter of the year when just the North Pole is facing the Sun, so it only gets lit up and another quarter of the year when only the South Pole is facing the Sun. So only it gets lit up.

Host: Oh. And obviously you don’t want to arrive at the asteroid and be looking into darkness, I guess. Is that the idea?

Lindy Elkins-Tanton:  Exactly. That’s exactly right. So we need to be sure to be at the asteroid for some of the time when it’s sideways to the Sun and it gets lit up all over.

Host: Okay. Yeah and we’ll get into the timing and the logistics of everything and just sort of how, you know, the spacecraft is going to eventually get there. I want to dive into more of the history, though. Now having a general sense of just the asteroid and why it’s interesting and why we’re going to go there, can you tell us the process? Were you part of the very beginning of submitting the proposals? Were you there in the very beginning?

Lindy Elkins-Tanton: Yeah, I was and oh my gosh, what a process this is really. You know, it’s on the same level as the adventurousness of going to Siberia in some ways in terms of a life event for me.. It was back in 2011, so 12 years ago that my colleagues and friends, Ben Weiss and Maria Zuber and I, when I was still at MIT, the three of us at MIT wrote this paper together. And it turned out to be an exciting paper in the sense of academic papers in that it was a very specific science subject that I led the paper on and it made about six people really upset. And it was very exciting and fun to have these conversations.

After that I got an email from two scientists who work at Jet Propulsion Laboratory saying, “we really liked your paper. Do you want to propose a mission to test your ideas?” That’s the kind of email that you say, “ah yes, I do.”

[Laughs]

So I started going out to JPL with Ben and with some other science friends. Eric Asphaug and Bill Bottke were some of the early people who were doing this with us. And we were all trying to figure out what kind of mission we could plan to test these ideas, which were about core formation on planetesimals. And so that’s how it all started. So in 2014, we had to submit our step one proposal. These opportunities to propose to the discovery mission just come around every few years and you have to be really ready cause they take so much preparation that if you wait for the announcement of opportunity from NASA, that gives you about six months and it’s too late. It’s too little time to do it, so you have to be ready.

So we had a team of about 50 people by then had been working on this. And, you know, it’s volunteer time or your employer is paying you to do this. NASA doesn’t pay you to write proposals at this stage. And we wrote, what was it? A 240-page step one proposal, I think.

Host: Wow.

Lindy Elkins-Tanton: It has to be the whole thing, the whole plan for the mission, soup to nuts. So the design of the spacecraft and how it’s going to be operated, and what is the science and why do we care and how long is it going to last? What is it going to cost? How many people? The whole thing. We competed against 27 other missions and then later that year, NASA called up and said, “you’re in the down select. We’ve selected five,” or what they call down selected five, to go on to a step two competition. So that was exciting and unexpected for many reasons. Mostly you don’t get advanced your very first time through this process.

So imagine how many years of people’s lives it takes trying over and over again to win their favorite mission, the thing that they’re trying to do for their whole career and a lot of people never get to do this. And so we’ve been very, very lucky. So then we competed for another year and we wrote a thousand page rules of 150 people, and there was a huge site visit where the whole professional review board comes and grills you, and everyone wears, you know, their best business clothes. And we got professional speaker training, and we oiled all the chairs so nothing squeaked and we set the blinds just so, and oh my gosh. It’s just amazing. Then we got the amazing news that we were selected for flight. We and the Lucy mission were selected in that round, these two missions, Lucy and Psyche. And what a moment that was. So it was three years of competition, following a year or two of prep work.

Host: Reflecting on that moment when you finally got that call and after all this hard work, you said 150 people were involved years, years, years, years of work, and just a lot of preparation to get to that phone call. Hey, you are selected. Where were you? What was that moment like?

Lindy Elkins-Tanton:  It was really a funny moment actually.

Host: Really?

Lindy Elkins-Tanton: Yeah, because rather than being at home in Arizona, in fact, I was at this little house up in the woods in Massachusetts, where I happen to be right now, for the Christmas holiday. My husband James and I were here, and our son had already gone back to his house, and my brother. It was just the two of us. And I knew the day and time when I was going to be called, we’d had to arrange it ahead of time because we don’t really have cell service up here. And so it had to come at a time when I was going to be in the house waiting for the landline to ring. And so we’d made an arrangement, and I knew on this particular day I was going to get a call, and the answer was going to be yes or no.  I had to emotionally prepare myself for this. I felt, you know, it’s little maybe hard to express how invested we’d all become. It. It’s easy to say, you know, we’ve been working on it for almost six years at that point cause the call came in early 2017. Everybody on the team, we had bonded. We’d spent hours and hours and hours together. It’s been more or less every other week or at, at the least every third week out at Jet Propulsion Laboratory for me from wherever I was living, in the beginning in Washington D.C. and later in Phoenix where we live now. And so it’s a gigantic commitment, not just for every person, but also for their families and for the other job that they’re supposedly doing at the same time. And so the commitment is incredibly deep and everyone is bonded.

I especially felt a high responsibility for Maxar, which was then still called Space Systems Loral, our industry partner. This was their first attempt I believe at becoming a prime contractor for a NASA deep space mission. They have so much experience doing communication satellites around the Earth, over a hundred communication satellites they’ve built and flown. And we picked them as our industry partner for their very specialized knowledge in what’s called solar electric propulsion, which is what we wanted for our spacecraft. But it takes a big investment as you’ve gotten the sense already to compete in these NASA competitions. And they’d put a tremendous amount of money and time and effort and blood and sweat and tears into this. And winning these things means jobs for hundreds of people for a decade or more. It’s just a really big deal. And for them to have put in all that effort and maybe lose, I felt a lot of responsibility. Everybody else involved had been through this before. They understood the risk, and they’d lived through yeses, and they’d lived through nos. So I was less worried.

So James, my husband, he was great. He spent a lot of time kind of listening to me in the week up to this while I counseled myself and he helped me get in the right mindset. So I was ready for whatever. I was very calm and I went to sleep the night before, and James had left for a math conference. And so I was in the house by myself up in the hills, in the snow. In the morning, I don’t know what time it was now, maybe 7:30 I’m guessing, the phone rang, only it was my cell phone and it woke me up.

There’s just enough connectivity to get a ring out and maybe a word, and then you get cut off. And I could hear on the other end, it was Thomas Zurbuchen calling from NASA Headquarters and I suddenly realized he was calling me to tell me yes or no, but about three hours ahead of when he was supposed to call and on the wrong phone.

[Laughs]

Host: Oh, no.

Lindy Elkins-Tanton: So I was sound asleep when he called. And you know, one is never at one’s best. I was trying to clear my throat so he wouldn’t know I was asleep, but he could tell I was asleep, and I could hear him say, “you’re going to be glad I woke you up.” And so in that moment, I realized both that he knew I was asleep, which is embarrassing, and also that we won.  And then he would get cut off, and then he would call back and I would say, “call on the landline. Landline, call on the landline.” He would call back again. He would cut off. So I think this happened like three times. Meanwhile, I’m leaping out of bed and trying to stumble over to the real phone. So finally we got on the real phone together. That’s what it was. It was a bit of a comic and embarrassing start, but so amazing. And then the very first thing he said to me was, after, you know, congratulations or something, he said, “I want you to completely re-propose your student collaborations. I want us to do something much more bold with a much greater reach.” And I was very excited about that. And so Cassie Bowman at Arizona State University, who runs our student collaborations, she and I thought up a much bolder plan, which I’m so happy about. And I’ll just insert at this moment that now after six years, we’ve had over 1500 students at American two- and four-year colleges participate in the mission one way or another. And I’m really happy that he asked us to do that.

Host: Wow. What an experience, Lindy. Oh, my goodness.

Lindy Elkins-Tanton: It was crazy.

Host: Yeah. You were by yourself. You’re jumping for joy. You have this excellent news. Were you the one communicating out to your team? Like, “we won, we won, we won.”

Lindy Elkins-Tanton: Yes. Oh my gosh. This is something I reflect on. I think also, you know, in my book, winning things, I don’t think is a huge, fabulous goal. Like in terms of winning awards and things like that, those are a very momentary and fleeting kinds of joys. But the kind of winning that this was where it allows us now to do something really audacious that’s going to take up the next decade of our lives, like the kind of win that’s actually a starting line instead of a finish line is really, really an unalloyed joy. It was such a joy that moment. And you know, running downstairs and thinking to myself, it was just—whatever it was, the beginning of January—so cold up here. Thinking to myself, “I’ve got to call my husband and my son and my brother, and I’ve got to call the president of the university and I’ve got to call the team.” But I decided I just had to take stock of the moment for a minute cause this was something that was only going to happen to me once in my life. And so I turned off the tea kettle and I started the wood stove, and I shut down the damper and put on my boots and just walked up into the woods. That moment is so vivid for me even now. Seeing the water drip off the trees and the crunching snow and the silence and just taking in that now the rest of my life was going to be different. No matter what happened with the mission, it was going to be different. And then I came in and started making phone calls, and it’s such a fun thing, to have the university president’s cell phone number and be able to call him at, you know, the equivalent of five o’clock in the morning in Arizona.  Sadly, he didn’t pick up, which was, which was sad because it would’ve been really fun right at that moment. I got to talk to him later.

And you know, calling my family and then calling the mission team. Now we’re six years out from this, but I just found on the desk recently here in Massachusetts, the post-it note where I’d written the names of everyone I had to call that day so I wouldn’t forget. The responses were great. And Ben Weiss, was one of the best, you know, the other person who’d been in this from the very beginning and he’s the deputy principal investigator of the mission now. And he actually, he just screamed in my ear. He actually, you know, are you bleeping me? He screamed in my ear.

[Laughs]

He just couldn’t believe it could be true. So that was great. That was a lovely, lovely morning. Oh, and then a big press event, and then interviews and oh my gosh, everything.

Host: Yeah, honestly from there just soaking in that moment, what a powerful thing that you can reflect on and put yourself in, you know, even six years later. But really, it just catapulted, you said, this is what, the next decade plus of what life is going to be? And you just started working. So tell us about those next steps. What sort of went into “okay, we got the award, now it’s really time to kick into gear and move forward and build this spacecraft and make it happen?”

Lindy Elkins-Tanton: Yes. Yep. So, we had then five years. And five years to a naive person like myself felt like plenty of time to do all the things that we’d planned so carefully for so many years already. And that we had delineated in this, you know, now 1500 pages of documentation of different kinds. But a few curve balls came our way early. One was a decision to change the flight software that we are going to use for the spacecraft. That’s a decision that came out of JPL. And then also we had an invitation from NASA. We had proposed and were selected to launch in 2023, this year. And they said, “can you bring your launch back to 2022? Save us the money of that extra year of the marching army on the ground, and maybe even have a better trajectory.”

So we did a bunch of research and we found a trajectory for 2022 that was really amazing and it got us to the asteroid in 3.4 years. I don’t know if everybody appreciates, and I’m still just beginning to appreciate, how hard trajectory calculations are. It seems like it should be kind of straightforward physics. But particularly with a solar electric propulsion system as opposed to a chemical propulsion system, it’s quite difficult. And so these people are really artists. So NASA said, “that’s great, let’s do the 2022 one.” So then instead of just immediately starting the process after selection, we actually had to re-budget and reschedule the entire process for a different flight software and a different launch date. And so there was a lot of kind of churn that first year as we were building up the team and figuring out what to do. That’s how it all started back in 2017.

Host: Wow. Okay. So let’s jump forward. You know, a lot of work to build and design this spacecraft. And you mentioned there was a lot of thought that went into all the different components and how it would work, budgeting, you know, all that sort of thing. Let’s focus on the spacecraft for a bit. So all that thought that went into that thing that you built. You called it the same name or visiting Psyche and the mission is Psyche. I think the spacecraft is Psyche as well, right?

Lindy Elkins-Tanton: [Laughs] Yeah. People complain about this and I understand that it’s a little bit confusing. But there were very few things that I really kind of insisted on as principal investigator cause I really think that so many things are the individual experts and discussed as a team and kind of agreed upon. But this was something I kind of insisted upon because it was really for marketing. When we started writing this proposal, a lot of people, even in planetary science, didn’t know what Psyche was and hadn’t really heard of it. It’s difficult to compete against charismatic planetary targets like Mars and the Moon or Mercury or whatever, something you can think of, with an asteroid that no one’s heard of, and that no one has a photograph of. We’re very visually oriented. And so I thought at least one thing we could do was help people, remember what its name was. If we could just keep everybody focused that this target, Psyche, was so interesting. And so, you know, name the mission after the target so that no one can forget what we’re doing. So that was a very purposeful marketing move, and it’s kind of stuck with us. So we can always say the Psyche spacecraft or the asteroid, and then everyone understands what we’re saying.

Host: Yeah. Can’t get confused, right? Where’s Psyche going? Oh, you’ll never guess, it’s going to Psyche. Yeah. I know.

Lindy Elkins-Tanton: Yeah, you’ll never guess.

[Laughs]

Lindy Elkins-Tanton: Exactly. Thank you, yes.

Host: Very good.

Lindy Elkins-Tanton: It’s not an acronym, it’s really the name.

Host: I love that. Yeah. I’m so used to acronyms here, so I actually appreciate it. So it’s after a Greek goddess. So it’s very cool. The way that I saw how the spacecraft was designed and how it looks and to get a sense for scale and just how this thing is built, I love the way that this was—I found this online. It says, “park a smart car in the middle of a tennis court.”

Lindy Elkins-Tanton: Exactly.

Host: Yeah, right, exactly. It’s just like, okay, I can see that. I can get a sense of just how big this thing is.

Lindy Elkins-Tanton: This is the great work of our fantastic suite of student interns that work on the project and the student collaboration artists trying to help people understand what this is all about. So they all looked the numbers and figured this out and brought this to us as a great analogy. So what’s called the chassis of the spacecraft, the box that holds the power system and the propellant and the science instruments, that’s the smart car. And then folded up against the sides of the smart car so that they fit all in the fairing of the rocket are big five panel solar arrays. So there are five panels on each side and after spacecraft is released from the rocket after launch and the fairing falls away, then that smart car’s out there in space by itself. And those solar arrays will unfold one big wing from each side. The wings are shaped like pluses, if you can picture five panels that make a plus. And so if you had that on Earth unfolded with the two big solar wings on each side, they would fill up a whole singles tennis court. So that’s where the singles tennis court comes from.

Host: Perfect. Now you mentioned the science instruments, right? When it comes to Psyche, a lot that you described in the chassis and the solar arrays and everything is making the spacecraft work. But I think one of the beautiful parts are the instruments cause ultimately when you get the spacecraft over to that asteroid, it’s these precious instruments that get you ultimately what you’re after. And that’s the scientific data. So there’s a lot of cool things. There’s the multispectral imager, gamma ray neutron spectrometer. There’s a magnetometer. Very interesting kind of science-y sounding things to me who’s a nonscientist.

Lindy Elkins-Tanton: Yeah, aren’t they?

Host: But can you go through and just sort of describe what these things are and why you picked these instruments to go on Psyche?

Lindy Elkins-Tanton: Absolutely. Such an interesting process, trying to decide what instruments we want. Think about this. We’re going to an asteroid that we’re pretty sure from Earth data is largely made of metal. But we’re not even really sure what the other part of it is. Is it regular rock? Is it carbon sulfur? Is it void space? So we’re not really sure what we’re going to see. So we have to design a science suite to be able to answer questions about an unknown object. That’s a real trick. So one thing we knew we had to have right from the beginning is a magnetometer. We need to be able to know whether or not it had a magnetic field. If it had a magnetic field, then we’ll either be learning about a magnetic dynamo that the parent planetesimal had, which would be amazing, or a magnetic field that it inherited from the spinning gas and dust disc that existed in the very first eye blink of our solar system.  So either way, that would be fantastic to measure a magnetic field. We’re very hopeful that we’ll measure a magnetic field. We have to bring magnetometers.

Then the other thing that we absolutely have to bring no matter what is imagers, cameras. We have to be able to see where we’re going out in space. I love, by the way that the Mars rovers now have microphones going on them so we can get sound recordings. Cause the human race does tend to be very visually oriented, but I know there are people who can’t see and would like to experience space exploration. So sadly we don’t have a microphone on our kind of budget mission, so to speak. But we do have pictures. So these are special imagers that have filter wheels so that we can also learn about something about the composition of the surface, not just how it looks, but because we love to see pictures so much and that is such a big part of space exploration, just seeing and experiencing. We’ve actually already written the software that we’re going to put our images on the internet, free for everyone in the world to see within a half hour of our receiving them from the deep space network. We just want everyone in the world to experience space exploration together because we believe this space exploration is for all of humanity and for inspiration. So we’re not going to edit them first. You’re going to see the glitches and the excitement and the stuff that’s weird all at the same time as the team.

I think it’s going to be really fun. So those are two of the instruments, the magnetometer and the imagers. And we need to know more about the composition of the surface. We need to know what the metal is made of and what the other stuff is made of.  There are a suite of different kinds of instruments designed for space flight that tell you about composition, but there aren’t that many that work on metals. And so the best option was this thing called the “gamma ray and neutron spectrometer.” This one’s being built by Applied Physics Laboratory led by David Lawrence. I’ll just tell you briefly how it works, because it blows my mind and I think it really appeals to the science geek and everyone. I think we’ve all heard of things called “intergalactic cosmic rays,” high energy radiation created near the black holes at the centers of galaxies and at the acceleration fronts of exploding stars. So not even created in our solar system, created elsewhere in our galaxy. And they come whizzing through the whole galaxy and therefore through our solar system all the time. We’re shielded from a lot of it by our atmosphere. But poor Psyche has no atmosphere. And so it, and every other body without an atmosphere, it gets bombarded by cosmic rays all the time.

So every cosmic ray that hits the surface gets absorbed by an atom, and then that atom needs to give off that extra energy away again. And when it gives off the energy, it gives it off as a gamma ray and a neutron. It doesn’t matter, you don’t need to be a nuclear physicist. It’s just the idea that it’s giving off another kind of radiation. Our spacecraft is going to be out there ready to measure that radiation. It turns out that gamma ray that the atom gives off has an energy that is particular to that kind of atom. So we can measure the gamma rays with the special instrument orbiting the asteroid, and know that gamma ray came from an iron atom, that one came from a nickel atom, that one came from a magnesium atom. And that way we’ll actually be able to figure out the composition of the surface atom by atom, which I think is astonishing.

Host: It is. That’s such an interesting way to get that data, not just looking, feeling, like “oh, that, oh yeah, okay, that’s iron, you know?” No, it’s like we’re talking about these rays coming from different parts of the galaxies. Absolutely fascinating.

Lindy Elkins-Tanton: Isn’t that amazing? I think it’s incredible.

Host: Amazing. Now on top of the instruments, right, that are studying Psyche, there are a lot of really cool technologies as well on Psyche. There’s a couple that I wanted to point out specifically because on this podcast we talk a lot about human spaceflight, and some of these technologies are going to be used on some upcoming human spaceflight type kinds of missions. You’ve been mentioning this one quite a bit, solar electric propulsion. Now what’s this all about?

Lindy Elkins-Tanton: Right, right. Amazingly for the price point of this mission, which is a lot of dollars, even though it’s not a flagship, it’s hard to be able to afford to get all the way out to an asteroid this far away. One way to do it is through super high-efficiency propulsion. Our best choice here was, was solar electric propulsion. So all the energy for everything that happens on the spacecraft is solar energy. We don’t have a radiation source or any other kind of chemical propulsion. It’s just the Sun on these giant solar arrays. And what happens to, what are the Thrusters that push the spacecraft forward, are called hall-effect thrusters. And the material they use is actually the noble gas Xenon that is our propellant. Our propellant is Xenon. We’re flying well over a thousand kilograms of Xenon.

We use our electricity from the solar panels to ionize those Xenon atoms to give each one of them a charge. And then we send them through a little potential field, an electric or magnetic field that pushes the Xenon atoms out of the thruster. And it’s just that transfer of momentum of the little ions leaving the back of the thruster and therefore pushing the spacecraft forward that moves our spacecraft. That’s the whole thing. Super high efficiency, very low thrust but you just leave the thrusters on basically all the time and so you just accelerate and accelerate and accelerate. And that is how we’re going to get to the asteroid. And it’s also the solar energy side is what powers everything that we do, the heaters and the coolers, all the communications, our technology demonstration, all of the science instruments, everything we do.

Host: So when picking, you know, this kind of propulsion when picking sort of this system, it was really just the efficiency, the diversity of what this could accomplish and how this could power different parts of the spacecraft. Is that sort of the reasoning why you went with solar electric propulsion over other considerations?

Lindy Elkins-Tanton: Yes. Yep, and it was the only technology that would get us into the cost cap of the mission proposal. But also because it’s been used so often around Earth, well over a hundred times, Maxar has really worked out the bugs. They know how this works. And so that gave us a lot of assurance. You can basically worry about everything on the spacecraft breaking or misfunctioning, it’s very easy to worry about everything. But lower on the list of worries are things like the solar panels. Like we feel very confident they’ve done this so many times. And so that’s a great thing in a mission to have really tried and true technology.

Host: Oh yes. That confidence is great. And of course cost is definitely a consideration with really all missions. Now the other one, and funny enough, we just released an episode on this one for the Artemis II mission, but Psyche is armed with some optical communications as well.

Lindy Elkins-Tanton: Yes. Yeah, the Deep Space Optical Communications, DSOC. We are very proud to be flying this technology demonstration for the human spaceflight side of NASA. It has nothing to do with our science mission at all. It’s just because we’re flying a spacecraft, at a distance from the Earth equivalent to the distance to Mars. And so that’s where NASA really wanted to practice with this. They wanted to practice doing laser communications instead of radio communications out from that distance.

You can encode a lot more information in a laser beam than you can in a radio wave. And so we joke that this is how we’re going to do Netflix streaming to Mars.

[Laughs]

So this is going to be the test, and it’s going to be one of the first big things that this mission does after launch is start testing the Deep Space Optical Comm and we have high hopes that is just the craziest and most amazing technology.

Host: Yeah. Very, very cool. We had a whole, podcast episode on it, to be honest. We got into a lot of the nitty-gritty just on Optical comms. But—

Lindy Elkins-Tanton: I love it.

[Laughs]

Host: It’s really, really cool. It’s an awesome technology. But focusing on Psyche and thinking about what’s coming up. So Psyche’s going to launch, and you mentioned this a little earlier, Lindy, was you said trajectories are harder to figure out and there’s interesting physics than you might anticipate. But if you can give us a brief sense of what happens to Psyche after launch to get the spacecraft to the asteroid. In terms of the physics and trajectory, what is happening to get us there?

Lindy Elkins-Tanton: Right. First, I just have to say we’re launching on a (SpaceX) Falcon Heavy. So that’s the central core and two side boosters and the side boosters are going to be re-landed and reused, which is a good ecological thing to do. And it’s also going to make it a very dramatic launch. So, beautiful SpaceX rocket gets us off the Earth and the spacecraft separates from the rocket. Then we’re going to more or less do a loop around the Sun so that we can get a gravity assist from Mars. And so that gravity assist is going to really help sling us out into the outer solar system, into the outer asteroid belt. And when we encounter Psyche, then we’ll do a bunch of maneuvers to get into orbit around Psyche, which is a pretty great also set of knowledge that Jet Propulsion Laboratory worked on in particular. And that pathway, Earth, Mars gravity assist all the way out to the asteroid belt is going to take 5.8 years. And so we’ll be arriving in 2029.

Host: 2029. All right. Arriving. Now, what does arrival look like? We’re not talking about like a landing or an impact. The idea here is Psyche, you want to enter into an orbit around Psyche, right?

Lindy Elkins-Tanton: That’s right. Yep. We want to enter into an orbit around Psyche and easier said than done. Psyche is a small object with a small gravitational force. But beyond that—oh, and I’ll just insert here, I’m sure your listeners know this, but OSIRIS-Rex’s asteroid that it visited, Bennu, very, very tiny, so much smaller than Psyche, really negligible gravity field. For a while they orbited it in an orbit shaped like a square because they weren’t relying on the gravity of the asteroid to hold them. They were just basically, you know, zooming around, which I think just blew my mind. So Psyche’s got enough gravity that we’re going to be able to orbit it based on its own gravitational field, but that gravitational field isn’t going to be smooth and even, even as smooth and even as the Earth, which is also not perfect because Psyche itself, first of all is not a sphere. It’s an oblong of a shape that we don’t have fully, fully understood. But we’ve measured a bit from the Earth, I like to say it’s shaped like a potato. It gives me a lot of leeway because potatoes come in lots of shapes.

[Laughs]

Host: There you go.

Lindy Elkins-Tanton: So I’m sure whatever shape it is, it’s going to be a potato. But we don’t know the details of how its composition is distributed, if it’s made of metal and rock, metal is twice as dense as rock. And so imagine an extreme case where one end of the object is made of metal and the other one is made of rock. It’s going to have a very weird gravitational field. So in order to calculate a stable orbit, we have to learn what that gravitational field is like. So we’ll start orbiting at a long distance where we can really treat Psyche as a point mass, something that’s familiar to anyone who ever took first year physics, just estimate it as a point mass and then we can orbit it. And then as we learn more and more about its gravity field, we’ll be able to step closer and closer to the body. So that’s the strategy.

Host: Understood. Yeah. There’s a lot of adaptability built into the mission, right? You have an idea and it gives you some flexibility, but with, you know, with the level of confidence that you have, you can slowly, as you get your measurements, slowly get into something a little bit more comfortable as you understand the asteroid.

Lindy Elkins-Tanton: That’s right. And I’ll just add briefly that the review panel, of course understood the risks of what we were talking about. So they said,” well, how are you certain that you’ll find a lowest orbit that is stable, the lowest orbit that you need for your gamma ray neutron spectrometer?” So we just did a thousand Monte Carlo simulations of what Psyche’s gravity field might be, in the worst case, a thousand different versions of it to show that we could always find a stable orbit. So it gives us some confidence.

Host: Wow. That’s awesome. Yeah. Okay. Now, once you enter into an orbit, when you talk about mission duration and how long you guys are going to be doing this, what does that look like until, you know, end of mission?

Lindy Elkins-Tanton: Right. So we’re going to be orbiting for 20 odd months, and so more than two years. So we’re going to be orbiting around this body, stepping down closer and closer, and then eventually also stepping up again to get some more data as lighting conditions change. All of this data will be coming back and all the pictures will be streaming onto the internet and all of us will be scratching our head and thinking, “given what we’ve now learned about this body, what is it and how was it made?” So that’s what it is. We’re just an orbiter. We are not a lander, and we’re not sample return. This is just too far away for those things.

Host: Sure. So then after your two-year orbit, is there disposal plans and thinking about any, you know, planetary contamination, that sort of thing? Like what happens after you’ve gotten the data that you’re hoping to get?

Lindy Elkins-Tanton: Yeah, we’re not too worried, or I should say NASA is not too worried about planetary protection for Psyche because it just does not have the particular characteristics that we would think are needed for life. Of course, maybe we don’t know. That’s always nice to think about, but it has no atmosphere and so that makes it a very low probability for life. We have an extended mission sort of proposal. Nothing would get approved until we do our main mission and reach mission success. And then there’ll be a meeting and a discussion and decision. But what we proposed is that we would just orbit down closer and closer to the surface, getting better and better, better data, and eventually crash onto the surface of Psyche. It turns out there are not, as far as we’ve been able to determine right now, any close enough other asteroids that would be worth trying to leave Psyche with the amount of propulsion we’d still have left to go visit. So it would be a matter of getting to know Psyche itself even better.

Host: Got it. Okay. Yeah, just get more refined data. Excellent. Okay. That’s right. Alright. Well, Lindy, so we’re recording this in early July, and we’re looking towards the end of the year for Psyche. What’s left for you? What do you have left to do to make sure that this spacecraft is ready to go until the end of the year?

Lindy Elkins-Tanton: For me it’s, it’s mostly working with and supporting the teams both in Florida where they’re doing the assembly test and launch operations and in Pasadena where they’re continuing to work on mission operations plans and the final tests of operations plans and the flight software. And so we are hoping—July, August, September, October—we’re hoping that in three months we would’ve launched one day ago. And that’s how close we are. October 5 is the beginning of our launch period. So next week actually, I’ll be down in Florida at Kennedy Space Center with that team. And then a few weeks later back out to Pasadena with that team as we finish up all the testing and down in Florida, they finish the final test and start the propellant load. Actually, they’ll be loading Xenon.

Host: Excellent. Wow. Yeah. When you say it out loud, it’s like, wow, this thing is really around the corner. And, and all this, you know, you talk about—

Lindy Elkins-Tanton: It’s around the corner.

Host: I mean, you talk about, you said 12 years or something is when you finally were submitting that proposal. A lot has happened up to this point to get to get us now. I mean, just thinking about everything we’ve talked about and what this mission is. What’s going through your mind? What are your hopes? What are your thoughts about what you’re about to do and what you may find out about the formation of our solar system? What are you thinking?

Lindy Elkins-Tanton: It’s hard for me to let myself really dream about the science quite yet because it’s been such a challenge to do this during COVID. And the thing we didn’t talk about a lot at all is really the launch slip because we had planned to launch last August and we just realized over a year ago that we weren’t going to make it. And so that is a very big dramatic and very upsetting, catastrophic kind of moment missing the launch for a planetary mission like this. We did eventually get permission to go for this year and it looks like it’s all going to work and I’m so grateful. The team was heroic, making it through COVID and coming as close as we did to actually launching, we actually built the whole spacecraft. It was a miracle, really. So right now it’s just the dawning optimism that we’ve really done it and are going to launch in October, but we’re not there yet. You never know, there’s always surprises. So just trying to temper myself and go one day at a time, that’s what I’m doing right now.

Host: Right. Yes. And thank you for circling back on that. I did mean to, to ask you. So yeah, COVID just made things a little harder for you. You already had an ambitious timeline, right? Cause you said NASA called and asked you to move up a year cause 2023 was the original plan. That’s right. But moving up a year plus COVID just kind of made things a little difficult.

Lindy Elkins-Tanton: Yeah. And JPL was really swamped for work and it was very hard to get the staff that we needed. You know, it’s a great kind of curse to have more work than can really be handled. So it’s been a really big learning year and lessons learned just so many of them and painful, but incredibly valuable. And so now feeling very optimistic and grateful that we’re moving forward the way we are.

Host: Wonderful. Wonderful. And on that note, Lindy, on that positive note, I want to go ahead and wrap up. I just appreciate your time and walking us through everything about this mission and what it’s about to accomplish. Your sense of energy and optimism is so contagious throughout this episode and this conversation. So I very much appreciate it. Wishing you and the team that has put so much work into making this possible all the success. So thank you. Thank you again.

Lindy Elkins-Tanton: Oh, thank you so much. This was really a pleasure. Thanks a lot for doing this.

Host: Alright, take care, Lindy.

[Music]

Host: Hey, thanks for sticking around. Lindy’s energy was so contagious. Talking about Psyche and everything that she did and the experiences she had and shared with her team to get to this moment just ahead of Psyche’s launch were absolutely inspiring. Wishing her all the best for the upcoming launch. Hope you learn something today.

You can check out the latest on NASA.gov on everything Psyche. If you want to listen to more podcasts, there are quite a few across the agency. You can go to NASA.gov/podcasts and check out us, Houston We Have a Podcast, on that page and listen to any of our episodes in no particular order. On social media, we’re on the NASA Johnson Space Center, pages of Facebook, X, and Instagram, and you can use #AskNASA on your favorite platform to submit an idea or ask a question. Just make sure to mention it’s for us at Houston We Have a Podcast. This episode was recorded on July 6, 2023. Thanks to Will Flato, Justin Herring, Dane Turner, Abby Graf, Heidi Lavelle, Belinda Pulido, Jaden Jennings, Pat Ryan and Sona Sealey. And of course, thanks again to Lindy Elkins-Tanton for taking the time to come on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us what you think of our podcast. We’ll be back next week.