Down to Earth With: Planetary scientist Steven Squyres

by Terri Cook
Friday, June 17, 2016

Steven Squyres is the James A. Weeks Professor of Physical Sciences at Cornell University in Ithaca, N.Y., and the principal investigator of NASA's Mars Exploration Rover mission, which landed the rovers Spirit and Opportunity on Mars in 2004. Credit: NASA.

Squyres already considered himself a scientist, and, with his father’s help, would conduct rudimentary experiments with a chemistry kit. By the time he was 10, he had become fascinated by meteorology and erected a weather station in his backyard. He vividly remembers building an anemometer out of funnels, and realizing that his device would need to be calibrated in order to accurately measure wind speed. So, he asked his father to drive the family car up and down their street. While perplexed neighbors looked on, Squyres excitedly hung the instrument out the window, shouting to his dad to drive 5 miles per hour as he counted how many times the kitchen funnels spun around. Next, Squyres asked his dad to drive 10 miles per hour, and then even faster, repeating his counts at each speed until the calibration was complete.

(MER) mission, Squyres oversaw the scientific development of two robot-geologists, Spirit and Opportunity, and assembled the team of scientists whose long-term objective has been to determine how liquid water shaped the Martian surface, and whether the environments that existed when water was present were conducive to life.

Squyres has said he particularly likes this panoramic image, which hung in the National Portrait Gallery in 2010–2011, because his first project with the Mars program in 1987 was building the panoramic camera later used on the Mars Exploration Rovers, and also because the building that held the "Mars Room," where he discovered his passion for the Red Planet as an undergraduate at Cornell, can be seen through the window. Credit: Steve Squyres in his office at Cornell University, Ithaca, N.Y., Wenyon & Gamble, 2005, collection of the National Portrait Gallery, Washington, D.C., made with assistance from the National Academies of Science.

Squyres, in 1998, in the Mojave Desert, testing an early prototype of what became the Spirit and Opportunity rovers. Credit: courtesy of Steven Squyres.

" about what drew him into planetary science, how the rovers developed their own personalities, and what he learned about himself in the process of exploring Mars.

TC: Why did your photograph in the National Portrait Gallery show you talking on the telephone?

" When I’m doing flight operations [for the MER mission], I typically spend six to seven hours a day on the phone. I’ve been doing it for 12 years now. Our schedules are dictated by the alignment of the planets and the spin of Mars, whose day is 24 hours and 39 minutes long, so Mars time is always shifting relative to Earth time. Plus, the rovers are solar-powered vehicles, so they don’t care if it’s daytime or nighttime in Ithaca; they only care if there’s daylight on Mars. But I think the most important thing driving our schedule is that taxpayers have spent almost a billion dollars on this mission. You can’t just say, “We’re tired. Let’s just let the rover sit for a day.” We have a responsibility to get everything we can out of this vehicle, every single sol [Martian day]. We’ve operated with that mindset since day one. I hammered that number into my team’s heads. It’s very easy to convince yourself that it’s a small amount of money, like the cost of three slices of pizza for each American. But you could do a lot of good in this world with almost a billion dollars. When we first landed on Mars, the expected cost of the mission worked out to $4.5 million per day. I wanted the team coming in to work every morning scared, knowing that we needed to do $4.5 million worth of science that day. Now it’s down to less than $100,000 a day, which is a bargain. But we can’t step off that treadmill, ever.

TC: The rovers were originally designed to last 90 days on the Martian surface, but Opportunity is still operating today, more than 12 years later. How do you manage a project when you don’t know how long it will last?

" Dealing with the open-ended nature of this project is interesting. It affects you in the planning of your life and your career and what you’re going to do with your time. But I think about it most while planning what we’re going to do with [Opportunity]. If you could look into your crystal ball and tell me the day it’s going to die, we could come up with a plan to utilize that capability as fully as possible. But without that knowledge, you’re always trading the interesting science you have in front of you against the really exciting stuff that might still be out there. The key thing I have come to realize is that, at any given time, you need to make strategic and tactical decisions based on the knowledge that you have. I can think of a thousand things we would have done differently had we known that we’d still be going strong at sol 4000. But you just have to let go of that and make the smartest decisions you can using the knowledge you have at the time.

TC: Did the two rovers develop their own personalities, like children?

SS: Comparing rovers to children would be trivializing parenthood, but the rovers definitely assumed their own personalities. We built them to be identical, but even before they launched, even back when they were babies and we were testing them, they behaved very differently. Developing a piece of hardware is a learning process. You learn by making mistakes, and you tend to make your mistakes on the first one. It turns out that Spirit was first and Opportunity was second, so every major test failure took place with Spirit. Right from the beginning, Spirit was sort of the problem child. Once we got to Mars, Opportunity had wonderful science all around it, beautiful conditions, and everything went right for that rover. Spirit landed in this rocky wasteland and had to climb a mountain just to start doing science, so it had a much rougher ride. The result was that we used the two vehicles differently, and as we used them, their personalities diverged, so much so that if you were used to operating one rover, it was a real shift to go operate the other.

TC: Do you think about how the mission will end?

SS: My intention is to be the last guy to turn out the lights when Opportunity dies. I started working on this in 1987, and it took 16 years just to get to the launch pad, so I want to see it through. We lost Spirit six years into the mission. That was hard, but it was actually easier than I thought it was going to be. I think the way you view the end of the mission depends very much on how it ends. If we screw up and drive the rover off a cliff, it’s going to be horrific, no matter what sol it’s on. I always thought that the one honorable way for the mission to end is to wear the rovers out. That’s what happened with Spirit; it was an honorable death. We got the team together and had an Irish wake. We drank beer, told stories, clinked our glasses, and that was all there was to it. I hope we can also wear Opportunity out.

Squyres with his first telescope, a three-inch Newtonian reflector he received for Christmas in 1964. Credit: courtesy of Steven Squyres.

TC: Did your parents help foster your love of science?

SS: They enabled it in a very important way. My mother’s undergraduate degree was in zoology, and my father got a doctorate in chemical engineering, so they were both scientifically adept. There was never anything that I came up with that one of them couldn’t help me out with. When I was 8 years old, they got me a telescope for Christmas, a three-inch Newtonian reflector from Edmund Scientific. Even though it was freezing cold, I would go outside and set up my telescope and draw what I saw. One of the very first things I observed was the moons of Jupiter, the four Galilean satellites, which looked like little stars. I would draw dots where I saw them, and then I’d go out the next night, when they were in different positions, and I’d draw them again. It was like a magical dance. I knew their names, and I wanted to know which moon was which. But the orbital periods of these moons are just a few days, so it was impossible for me to figure this out. I mentioned this to my dad, who worked as a software engineer at DuPont. He took my drawings and digitized the data, and worked out a computer program … all by punch cards, of course, because that’s how you did it back in those days. A few days later, he came home and told me which [orbital] path he thought belonged to each moon. Then he said, “If I’m right, this is what they’ll look like tonight.” I’ll always remember that night, when we set the telescope up and looked through it, and the moons were exactly where my dad’s computer program had predicted they would be. All of a sudden, I realized the predictive power of science: that if you understand something well enough, and can describe it precisely, you can predict the future. Twenty years later, I wrote my doctoral thesis about one of those moons. That was one of the formative scientific experiences of my life.

TC: Why did you switch from studying geology to planetary science in graduate school?

SS: When I was a student at Cornell, I took a course on the results of the Viking Mission to Mars. We were expected to write a term paper, and I needed to come up with a topic, so I got a key to what we called the “Mars Room” and went there thinking I was going to flip through pictures for 15 or 20 minutes. I wound up staying for four hours. I’d never seen spacecraft pictures of Mars before, and they were dazzling to me. There were ones with the valley systems and ones with impact craters, and a few other things that sort of looked familiar. They weren’t sorted in any kind of organized way; it was just “Boom! Mars! Here it is. Figure it out!” I’d always been fascinated by maps that had blank spots on them. When I was a kid, we had an atlas in our home that was 15 or 20 years old, and there were places where there wasn’t a whole lot drawn. I always thought that the idea of a map that had blank spots on it that needed to be filled in was incredibly cool. I realized in the Mars Room that this was the blank canvas I’d been looking for. I still haven’t gotten over that rush, that feeling of excitement that comes from seeing something that nobody’s ever seen before.

Squyres in 1980 at Cornell, working on his dissertation on the moons of Jupiter. Credit: courtesy of Steven Squyres.

TC: Of all the awards you’ve received, which has been the most meaningful?

SS: That’s hard, because I’ve received awards that were named for scientists who had important impacts on my career. But if I had to pick one that I simply enjoyed the most, it would be the Franklin Medal. The reason is that the Franklin Institute, where it was awarded, is in Philadelphia, and my parents, who are now in their late 80s, were able to come. The ceremony is a big formal to-do, and I didn’t tell them I was going to do this, but I ordered a limo that came and picked them up, and all their neighbors were wondering what was going on. They got there and walked up a red carpet while a brass section played a fanfare. It was a fun, fun evening for them. Gene Shoemaker had an enormous influence on my career as a scientist. Carl Sagan had an enormous influence on my career as a scientist. But the two people who had the biggest influence on my career got to be there that night, and that really meant a lot to me.

TC: How did you learn to communicate science so effectively?

SS: This is something I took away from my association with Carl Sagan, who was one of the best communicators of science who’s ever lived. Carl understood deeply that the health of our society depends on people knowing and understanding science, and that those of us who are fortunate enough to be involved in these science projects that cost hundreds of millions or billions of dollars have a profound responsibility to let the people who made this possible understand what they’re getting for their investment. I would argue it’s the most important thing we do. Part of this project’s legacy is learning more about Mars, which was the goal. But I think our most important legacy may be the generation of young people who were drawn into science by this mission. I cannot tell you the number of young engineers and scientists who have told me they’re pursuing their careers because when they were young they saw our team jumping up and down on TV [when the rovers landed on Mars] like we’d just won the Super Bowl and they thought it was pretty cool. You can’t put a price on that. I know that our rovers were built by people of my generation who grew up watching Mercury and Gemini and Apollo and dreamed of sending spaceships to Mars. And now we do. I can’t wait to see what this next generation is going to do. This doesn’t happen unless you do the communications job well.

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