Catherine Elder's office is a small, cavernous space decorated with pictures of the Moon and other distant worlds she studies as a research scientist at NASA's Jet Propulsion Laboratory. Elder has been interested in space science since she was young, but she didn't always imagine she'd be working at one of the few places that builds robotic spacecraft designed to venture to mysterious worlds. A doctorate in planetary science – the study of the evolution of planets and other bodies in space – first brought her to JPL five years ago for research into the geologic history of the Moon. She planned to eventually become a professor, but a sort of gravitational pull has kept her at the laboratory, where in addition to lunar science, she's now involved in projects studying asteroids, Jupiter's moon Europa and future missions. We met up with her earlier this year to talk about her journey, how a program at JPL helped set her career in motion and how she's paying it forward as a mentor to interns.
What do you do at JPL?
A lot of what I do is research science. So that involves interpreting data from spacecraft and doing some modeling to understand the physical properties of places like the Moon, asteroids and Jupiter's moon Europa.
I am also working on mission formulation. So in that case, my role is to work with the engineers to make sure that the missions we're designing will actually be able to obtain the data that we need in order to answer the science questions that we have.
Tell us about some of the projects you're working on.
A lot of my work right now is looking at the Moon. I'm on the team for the Diviner instrument on the Lunar Reconnaissance Orbiter. That instrument observes the Moon in infrared, which we can use to understand the geologic history, such as how rocks break down over time. We can also look at specific features, like volcanoes, and understand their material properties. I do similar work on the OSIRIS-REx mission [which aims to return a sample from the asteroid Bennu].
I'm on the Europa Clipper team right now. I'm the investigation scientist for the cameras on the mission [which is designed to make flybys of Jupiter's moon Europa]. So I serve as a liaison between the camera team and other parts of the project.
I'm also working on a project modeling the convection in the rocky portion of Europa, underneath the liquid-water layer. Our goal is to understand how likely it is that there are volcanoes on the seafloor of Europa. A lot of scientists in their previous work have suggested that life could originate in these volcanoes. So we're going back and looking at how likely it is that they exist.
Sounds like fascinating work and like you're keeping busy! What is your average day like?
When I'm analyzing the data and doing modeling, I'm usually at my computer. I do a lot of computer coding and programming. We do a lot of modeling to help interpret the data that we get. For example, if we think we know the physical properties of a surface, how are those going to affect how the surface heats up or cools down over the course of a day? I compare what we find to the observations [from spacecraft] and circle back and forth until we have a better idea of what those surface materials are like.
Then, for the mission work, it's a lot more meetings. I'm in meetings with the engineers and with other scientists, talking about mission requirements, observation plans and things like that.
Tell us a bit about your background and what brought you to JPL.
I have wanted to be an astronomer since I was nine years old. So I was an astronomy major at Cornell University in New York. I didn't really realize planetary science existed, but luckily Cornell is one of the few universities where planetary science is in the astronomy department. A lot of times it's in the geology department. I started to learn more about planetary science by taking classes and realized that was what I was really interested in. So I went to the University of Arizona for grad school and got a Ph.D. in planetary science.
I thought I eventually wanted to be a professor somewhere. A postdoc position is kind of a stepping stone between grad school and faculty positions or other more permanent positions. So I was looking for a postdoc, and I found one at JPL. It was pretty different from what my thesis work had been on, but it sounded really interesting. I didn't think I was going to stay at JPL, but I ended up really liking it, and I got hired as a research scientist.
You also took part in the Planetary Science Summer School at JPL, working on a simulated mission design project. What made you want to apply for that program and what was the experience like?
I've always been interested in missions. I began PSSS when I was a postdoc at JPL, so I was already working with mission data from the Lunar Reconnaissance Orbiter. But by the time I joined the team, LRO had been orbiting the Moon for more than five years, so it was a well oiled machine.
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I was interested in thinking about future missions and how you design one. So PSSS was a really great experience. They gave us a couple targets that we could pick between, and we picked Uranus. We had to come up with all the science objectives we would want to have if we visited Uranus [with a robotic spacecraft]. We had a mix of scientists and engineers, but none of us had studied Uranus, so we had to do a lot of background reading and figure out the big outstanding questions about the planet and its moons. We came up with a ton of them. When we did our first session with Team X, which is JPL's mission formulation team, we realized that we had way too many objectives, and we were never going to be able to achieve all of them in the budget that we had. It was a big wake up call. We had to narrow the scope of what we wanted to do a lot.
Then we had two more sessions with Team X, and we eventually came up with a concept where we were within the budget and we had a couple of instruments that could answer some science questions. Then we presented the mission idea to scientists and engineers at JPL and NASA headquarters who volunteered as judges.
Participants in the Planetary Science Summer School are assigned various roles that are found on real mission design teams. What role did you play?
I had the role of principal investigator [which is the lead scientist for the mission].
How did that experience shape what you're doing today?
Actually, quite a bit. Learning how you develop a science objective and thinking through it, you start with goals like, "I want to understand the formation and evolution of the solar system." That's a huge question. You're never going to answer it in one mission. So the next step is to come up with a testable hypothesis, which for Uranus could be something like, "Is Uranus' current orbit where it originally formed?" And then you have to come up with measurement objectives that can address that hypothesis. Then you have to think about which instruments you need to make those measurements. So learning about that whole process has helped a lot, and it's similar to what I'm doing on the Europa mission now.
I also got really interested in the Uranus system, specifically the moons, because they show a lot of signs of recent geologic activity. They might be just as interesting as the moons of Saturn and Jupiter. But Voyager 2 is the only spacecraft that has visited them. At that time, only half of the moons were illuminated, so we've only seen half of these moons. I really want a mission to go back and look at the other half.
Recently, me and a few friends at JPL – two who also did PSSS and one who did a very similar mission formulation program in Europe – got really interested in the Uranus system. So now, in our free time, we're developing a mission concept to study the Uranus system and trying to convince the planetary science community that it’s worth going back to it.
Are there any other moments or memories from PSSS that stand out?
Actually, one I was thinking about recently is that I was in the same session as Jessica Watkins, who recently became a NASA astronaut. I remember I was super stressed out because we had to give this presentation, and me and the project manager, who is a good friend of mine, were disagreeing on some things. But I talked to Jess, and she was just so calm and understanding. So when she got selected as an astronaut, I was like, "That makes sense," [laughs].
But the other thing that stands out is we worked so hard that week. We were at JPL during the day. And in the evening, we would meet again and work another four hours. Now that I'm working on mission development for actual missions, I realize there's so much more that actually goes into a mission, but PSSS gives you a sense of how planetary missions are such a big endeavor. You really need to work as a team.
You've also served as a mentor, bringing interns to JPL. Tell us a bit about that experience and what made you interested in being a mentor?
I've worked with five students at this point, all undergrads. I've always been interested in being a mentor. I was a teaching assistant for a lot of grad school, and I really enjoyed that. I like working one-on-one with students. I find it really rewarding, too, because it helps you remember how cool the stuff you're doing really is. The interns are learning it for the first time, so being able to explain exciting things about the solar system to them for the first time is pretty fun.
What do you usually look for when choosing an intern?
Enthusiasm is a big one. At the undergrad level, most people haven't specialized that much yet; they have pretty similar backgrounds. So I think enthusiasm is usually what I use to identify candidates. Is this what they really want to be doing? Are they actually interested in the science of planets?
What kinds of things do you typically have interns do?
It varies. It can sometimes be repetitive, like looking at a lot of images and looking for differences between them. One of the projects I have a lot of students working on right now is looking at images of craters on the Moon. There's this class of craters on the Moon that we know are really young. By comparing the material excavated by them, we can actually learn about the Moon's subsurface. So I have students going through and looking at how rocky those craters are. We're basically trying to map the subsurface rocks on the Moon. So that can get a little repetitive, but I find that some students actually end up really liking it, and find it kind of relaxing [laughs].
For students who intern with me longer, I try to tailor it to their interests and their skill set. One student, Jose Martinez-Camacho, was really good at numerical modeling and understanding thermodynamics, so he was developing his own models to understand where ice might be stable near the lunar poles.
What's your mentorship philosophy? What do you want students to walk away with?
I think mentors are usually biased in that they want their students to turn out like them. So I'm always excited when my students decide they want to go to grad school, but grad school is not the path for everyone.
One of the important things to learn from doing research is how to solve a problem on your own. A lot of times coursework can be pretty formulaic, and you're learning how to solve one type of problem so that you can solve a similar problem. But with research, unexpected things come up, and you have to learn how to troubleshoot on your own. I think you learn a little bit about that as an intern.
What's the value of JPL internships and fellowships from your perspective?
We're lucky at JPL that we're working on really exciting things. I think we should share that with as many people as possible, and internships are a good way to do that.
Then, for me personally, participating in PSSS solidified that I was on the right path. I knew I wanted to continue to be involved in mission formulation, and that was a big part of why I decided to stay at JPL, to be really deeply involved in the formulation of space missions. There's only a handful of places in the world where you can do that.
This feature is part of an ongoing series about the stories and experiences of JPL scientists, engineers, and technologists who paved a path to a career in STEM with the help of NASA's Planetary Science Summer School program. › Read more from the series
The laboratory’s STEM internship and fellowship programs are managed by the JPL Education Office. Extending the NASA Office of STEM Engagement’s reach, JPL Education seeks to create the next generation of scientists, engineers, technologists and space explorers by supporting educators and bringing the excitement of NASA missions and science to learners of all ages.