Exploring the Solar System with Dr. Abigail Fraeman
Abigail Fraeman '05 is a Postdoctoral Fellow in the Division of Geological and Planetary Sciences at Caltech. Dr. Fraeman is broadly interested in the origin and evolution of terrestrial bodies, and through her research has been involved with several planetary missions, including the Mars Science Laboratory Curiosity rover. Previously, she received her Ph.D. in Earth & Planetary Science from Washington University in St. Louis and a B.S. in Physics and in Geology & Geophysics from Yale University. She recently spoke with Xinyi Zhou '10 about her education and research.
Certainly the classes. I remember really clearly Mr. Donaldson for his freshman physics class. The first day he had us do an experiment making soap bubbles. We had to make giant soap bubbles at home and figure out why we saw colors in the bubbles we made. That was such a cool jumping off experience.
The SRP (Senior Research Project) obviously had a huge impact on me because I went into research. To see what working in a lab was like, what I was getting into, and learning that you need to be able to take initiative in a lab -- these were all important things that I learned as a high schooler that really benefited me later.
It looked like you were doing astronomy research pretty early on.
What do you remember from your time at Blair?
So many great memories, the friendships that I formed there, that shared experience in the Magnet -- I'm still really close to my high school friends even though we've all gone to do different things. I remember the classes, the Wallops island field trip and jumping into the mud [in the marshes at Wallops], which was tons of fun. All the R&E (Research & Experimentation) projects were very memorable too.
What experiences were particularly influential?
I've always loved astronomy, I've always loved science, but astronomy in particular. When I was in high school I did an outreach program that was sponsored by an organization called The Planetary Society. The [Red Rover Goes to Mars Student Astronaut program] was something I found on my own but the Magnet program was really supportive of my participation in it even though I had to miss classes for a week. I got to work with the rovers Spirit and Opportunity and I discovered that this could be a career.
What exactly was the program like?
I got to be in mission control when Opportunity landed, and I got to interact with all of the scientists there and be in that room when the first images came down. I realized you could make a career out of studying these images and figuring out where to send rovers on Mars and spacecraft throughout the solar system.
Did you have ESS (Earth Systems Science) at Blair?
Yeah, it was taught by a man named Leslie Rogers (who unfortunately passed away). But it focused a lot on things such as remote sensing and spectroscopy and how you study the surfaces of planets remotely. Looking back on my Terrablair project (in which you had to build a rover and explore), the instrument that we built for our rover was a really simple version of the instrument that I specialize in now.
We had circuit boards that you could program and you had to design a rover to measure one property of the fictional planet Terrablair. We had one instrument in our payload and we had to successfully program our rover to drive on this planet without falling off or getting stuck. I remember at the time it was very tough and I was frustrated, but it obviously made an impact because it's what I do now.
How did you decide to pursue a PhD?
I kind of always knew I wanted to go into science and be a researcher, and that type of career path really requires you to have a PhD.
How do you pick a good advisor and project?
My advisor [Dr. Ray Arvidson] was fantastic in terms of being someone that I work well with, who worked well with me. Before I chose an advisor, I talked with their current and previous students to see what the work environment in the lab was like and to see if I would mesh in that environment. Personally, I like a hands-on advisor who interacted with students often, but I can think of other situations in which you'd want an advisor who is more hands-off, in which you show up every few months with a paper to give them. That was not for me, but I think it's important to know what your style is.
What was your dissertation on?
I worked on a whole bunch of stuff. My dissertation focused on remote sensing observations, specifically studying visible to near-infrared spectral reflectance data collected over the moons of Mars and also the area on Mars that the Curiosity Mars rover is currently exploring to understand what they are made it. The idea is that by understanding these compositional properties you can begin to infer the history of what you're looking at and understand how it may have changed and developed over time.
How did you transition to your postdoc?
I am continuing to work on some things that are similar to what I studied for my PhD, but I am also starting some projects where I can learn new techniques. For instance, I'm still investigating orbital data over where Curiosity is right now to help pick places that are scientifically interesting for the rover to visit based on what we see from orbit, and also trying to understand how the measurements we make on the ground correlate with what we see in orbit.
I remember Mr. Rogers teaching us about ground truthing!
Yeah, it's a real thing! It's always fun to compare what you think you see remotely and what you actually see on the ground. Curiosity landed in area on Mars (Gale Crater) that looks really cool based on the orbital data -- we see in minerals that must have formed in water and that document environmental changes throughout Mars’ history, we see lots of layers in a 5 km high mound in the middle of the crater that are also evidence of these environmental changes. So we really wanted to land in Gale Crater and explore this mound of material to help us understand exactly what those environmental changes might have been that caused the variations in mineralogy and morphology that we see in orbit.
How far can these rovers travel in a day?
It depends on the terrain that we're in and the amount of power that we have. I think the record is on the order of magnitude of about 100 - 120 meters but it's usually less than that. The reason why we're so slow is we're limited by the power and because we need to include a lot of autonomy, and time-consuming onboard processing, into the drive commands. We need autonomy because the length of time for the data transmission from Earth to Mars on the order of minutes -- you can't drive these rovers real-time because it takes 10-30 minutes for a command to go round trip between Earth and Mars.
But it's okay because there's so much to see and it takes time to make all those careful observations on the way. It's one of the things I really like in planetary geology -- the tangible nature of everything when we're looking at pictures sent back from Mars.
You've been involved with several planetary missions such as the Curiosity rover -- how do researchers outside of NASA get selected to work on these missions?
I was involved, still am involved through my advisor and my postdoc supervisor -- they are involved as a participating science team, and I recently wrote my own proposal to be able to stay on the team with them. So ~100 people submit proposals and say this is the kind of science I would want to do, and a panel of our peers read it, they select about 20 to be members of the science team. Other ways to be involved are to be a member of a specific instrument team that's on the rover -- like the camera has a group of scientists that design the camera, so there are multiple methods to become involved and it's different when you're a grad student compared to when you're an on your own scientist.
What is it like to work on really big, international teams?
It's actually one of my favorite parts of the job, working in these teams. Of course sometimes it's difficult because there's a saying you can have 10 minds and 11 different opinions, so you're always trying to find a consensus on the best course for the rover. But I get to interact with some really smart people with really different backgrounds, to bounce ideas off people and get their feedback. So it's really cool to have really internationally diverse team to collaborate with. I think about 40% of the Curiosity science team is international.
What would you like to do next?
Well you have perfect timing in asking! I actually yesterday accepted a job offer at the Jet Propulsion Laboratory, so I'll be starting at the begining of February as a permanent research scientist. I hopefully will continue to work on Mars rover exploratory missions.
Congratulations! Where's the Jet Propulsion Laboratory?
It's in Pasadena, which is right outside LA. This is the institution that built the Mars rover so all the engineers are there, so to be a scientist right there is hopefully a cool opportunity to be involved with building the next generation of spacecraft and to have the fun job of analyzing the new data when it's acquired.