Steven Squyres

Varga:

This is Ian Varga. I am interviewing Dr. Steven Squyres at Cornell University in Ithaca, New York, on July 26th, 2018. To begin, I believe you grew up in Woodbury, New Jersey, correct?

Squyres:

No, I was born in Woodbury, New Jersey. I grew up mostly in a nearby town called Wenonah. 

Varga:

Wenonah, New Jersey, correct?

Squyres:

Yep.

Varga:

What did your parents do for a living?

Squyres:

They were both technically and scientifically trained. My mom was a full-time mom, and very good at it, although her academic training was—she had a degree in zoology from Wellesley.  And my father had a PhD in chemical engineering—doctorate in chemical engineering—from MIT and worked for DuPont as a software engineer. 

Varga:

So, you think your parents might have had something to do with why you pursued science?

Squyres:

Oh, huge influence on me. I was sort of a geeky kid anyway. I always loved science, but they were very encouraging. All the physical science questions, I’d go to my dad, and all the life sciences questions, I’d go to my mom. Far as I could tell, they knew everything. So, yeah, they were a real source of scientific inspiration, I guess you could say, for me, from a very early age. 

Varga:

What was it like growing up in this town? Was it a small town, or small community?

Squyres:

Yeah, very small town. It’s suburban New Jersey, so it was immediately adjacent to other small towns. It wasn’t like we were surrounded by countryside. In those days you didn’t have to go—there was a very steep gradient. If you went north ten miles, you were practically right across the road from Philadelphia, and it was a very urban. If you went south ten miles—New Jersey is called the Garden State, right? There was all peach orchards, and that sort of thing—tomato farms. So, it was a small town, still is a small town, with a very small town feel to it. 

Varga:

Did you have access to any particular resources that were useful to you?

Squyres:

Mostly my mom and my dad. They were the primary resources because they were—like I said, they were scientifically and technically trained, and in the rare, rare instances where they wouldn’t know the answer to any question that I had, they would always find out for me very quickly. My father would frequently take me to the Franklin Institute, which is a well-known scientific museum in Philadelphia, and then my grandfather—my grandparents lived in North Jersey. My grandfather, in particular, enjoyed taking me to the American Museum of Natural History in New York City. We’d get on the train and go in, and that was great fun. 

Varga:

Were there any teachers or other major figures that you think had an influence on you?

Squyres:

Yeah, yeah, when I was in high school, I was an athlete. I ran track and cross-country, and there was a guy who was both my track and cross-country coach, and also my biology teacher. He taught advanced placement biology. He was a big, big influence on me. Not actually all that much in the scientific sense, because I was already—this was like 11th or 12th grade—by the time I got there I had done so much science and was so used to thinking as a scientist that that aspect of it was not major, but a very important influence on me was that when it came to running, when it came to athletics, I was reasonably good, but I wasn’t supremely gifted, athletically. Which meant that in order to do as well as I wanted to, I had to work really, really, really, really hard. That was, I think, the main thing that I got from this guy. He was a science teacher, but because was also my coach, helped me a lot with learning how to get the most out of myself. His name was Joe Folcarelli.

Varga:

So, did you have any interest in science growing up then? Was it consistent interest?

Squyres:

Oh, gosh, yes. I can’t ever remember a time when I didn’t consider myself to be a scientist. It wasn’t like—I mean, when I was six years old, I already felt like I was a scientist. I wasn’t a very good one, as it turned out, but I have considered myself a scientist as long as I can remember. 

Varga:

Was there anything in particular for geology or astronomy?

Squyres:

No. I can go back and look at my scientific notebooks. I kept notebooks from a very early age of all the experiments I did—all over the place. Everything. Physics, biology, chemistry, geoscience, astronomy, meteorology, psychology, everything that you can imagine. I did science in all directions in those days. I didn’t begin to specialize until I turned about 18.

Varga:

Probably when you had to, I would guess. 

Squyres:

Yeah.

Varga:

When did you originally expect you were going to do as a career when you were going into undergraduate?

Squyres:

When I was 8 years old, and then again when I was 16, my family went on a summer vacation in the Colorado Rockies—Rocky Mountain National Park. At 8 years old, was the first time I had ever seen a mountain in my life, and at 16 years old, I was very fit and just spent two weeks climbing everything in sight. So, by the time I was ready to go off to college, I knew I loved two things. I loved doing science, and I loved climbing mountains. Those were the two things that I knew I loved doing. So, it seemed like a natural thing to me to go into geology, because I figured I could do science in the mountains. That was the entire logic train, so far at that point. I was very fortunate in that the summer between high school and college, I had a very astute guidance counselor in high school, and he pointed out a program to me, and I managed to get funding from the National Science Foundation to participate in glaciology—glacial geology expedition on the Juneau Icefield, in southeast Alaska, which is quite an adventure for an 18-year-old from New Jersey. So, I spent the summer there doing science on glaciers and science in the mountains, combining science and mountaineering in the way that I had always imagined doing.

So, I arrived at Cornell determined to be a geology major. So, that was the direction that I went initially. Then what happened was, the other thing that I was always fascinated by, when I was growing up, was exploration—the history of exploration. I read books about Scott and Amundsen, in the Antarctic, and Crook and Perry in the Arctic, and Beebe and Barton in the Bathysphere. You name it. I was just captivated by that stuff. I also grew up during the ’60s, watching Mercury, and Gemini, and Apollo on TV. You know, the first steps in human space exploration. I remember Apollo 8 vividly. I remember Apollo 11 vividly. I remember John Glenn’s flight vividly. The exploration thing always kind of had its hooks in me as well. As things progressed, I wound up leaving geology because of that. What happened was, I was an undergraduate geology major here at Cornell—fascinating science—it was all great stuff. It was a chance to strap on my boots and go out and do science in the mountains, but I began to find it unsatisfying, not because it wasn’t intellectually challenging, because it was, but because it didn’t have that element of going someplace where no one has ever been, that I craved. I really did, at a very visceral level, crave that. So, that was a problem for me. I came to realize that there was hardly any place that I could go on Earth that I could do geology and not have to deal with the fact that somebody had been there first. I was drifting towards something having to do with the geology of the Earth’s seafloor, because it was the part of Earth that was most poorly explored, but it just wasn’t doing it for me.

Then, what happened was, my junior year, my third year at Cornell, in the second semester, I had a hole in my schedule. I had placed out of a language course that I didn’t expect to place out of, and all of a sudden I had room for a three credit course in my schedule, and I was in this building—I was in the Space Science Building, down on the first floor, and there was a bulletin board, and tacked up was this little light blue, 3x5 card that indicated that there was going to be a graduate level course taught that semester on the results of the Viking Mission to Mars. This was 1977, and Viking got there in ’76, so Viking was the hot planetary mission at the time. It was being taught by a member of the Viking science team. So, I thought, oh, that sounds cool. So, I signed up for that course, and I almost got thrown out because I was the only undergraduate in the course, but he let me stay. Then, because it was a graduate level course, for our term paper we were expected to do some kind of independent research. In those days, images from planetary missions—there was no internet, there were no CD-ROMs, it was straight off photographic paper, right? These big rolls of photographic paper. So, the pictures that came in were stored in the next building over, Clark Hall. There was a place called the Mars Room, where the images were stored, and a lot of them were just still in cardboard boxes. Some of them weren’t put in sleeves and binders. Anyway, I got a key to the Mars Room from the professor of the course, because I needed to write some kind of term paper. So, three of four weeks in, I thought, alright, I’ll start thinking about my term paper. I go over there and walked into that room thinking I was going to sit down for 15 or 20 minutes later and flip through pictures, and I walked out four hours later knowing exactly what I wanted to do with the rest of my life. That was it. I didn’t understand what I was seeing in the pictures, but the beauty of it was that nobody did. There had probably been 50 people in the world who’d seen those pictures at the time that I looked at them. So, that was it.

Now, the downside of that, and the terrible compromise that I had to make, was if I was going to do Mars, or if I was going to do space in general, I couldn’t go myself. So, that idea if I strap my boots on and I go out and do the science myself, was no longer accessible to me. Apollo was over. There was nothing other than low-Earth orbit in the cards for a long time to come. So, what that meant was that I was going to have to switch to doing things robotically. So, that was the compromise I had to make. 

Varga:

Do you know the name of the professor who taught that course?

Squyres:

Yeah, his name was Joe Veverka. He later became my PhD thesis advisor. 

Varga:

So, why did you originally choose to attend Cornell University? 

Squyres:

As an undergraduate?

Varga:

Yes.

Squyres:

Okay. So, my parents—I was the oldest child. They didn’t want me too far from home. So, they must have sat down and looked at an atlas, or something, but they came up with, “You can’t go to college any further than 350 miles away.” And I know they sat down with a map, and they drew a circle, and thought, okay that’s got Dartmouth, and it’s got Duke, and it’s got, you know, there’s a lot of good schools in there, so it’s not that big of a deal. I, being an independence minded, young teenager, decided I’d didn’t want to be any closer than 100 miles, so I had this annulus centered on Wenonah, New Jersey, from 100 to 350 miles out. So, that was what I had to work with, geographically. Then, I decided I wanted to go to a top research university. There’s a lot—there’s MIT, there’s Johns Hopkins, you know, there’s a bunch of stuff in there. But then I had one other criterion, and that was I wanted to be in a small town. I didn’t like cities, I didn’t want to be in a city. I didn’t want to go to Johns Hopkins, because that’s in Baltimore, and I didn’t want to go to Columbia, because it’s right in New York City. So, when I applied all those filters, I was left with two schools: Cornell, and Dartmouth. This was in the days before the common app, so every school had their own application. I wrote away to Cornell, and I wrote away to Dartmouth, and Cornell’s application was 4 pages long, and Dartmouth’s was 32. So, I applied to Cornell, and that was it. I’ve been here almost continuously since 1974, as a result of that. That was how it happened.

Varga:

You had a stroke of fate, there. So, why did you choose to remain here, then, for your graduate studies?

Squyres:

That’s a good question. I had applied to quite a few—I knew I wanted to go into planetary science. I wasn’t going to be a geologist. I applied to planetary programs at five different schools, got into all of them, was choosing among them, and they were all good schools and great opportunities. The big mission that was flying at the time was Voyager. The Voyager imaging team, which was the experiment that was going to do the geoscience stuff, there were only two geoscientists on the original Voyager team, and they were both at the U.S. geological survey, which means that they were not professors, which means that they were not taking on graduate students. So, I had no real way of getting to work on Voyager. Then what happened was, one day, somebody down in the main office here mentioned that Carl Sagan wanted to see me. So, I went to see Carl. I had never met the guy. I walked in and he says he wanted me to be his grad student for the Voyager project. My little heart starts going thump, thump, thump. So, that was a great opportunity. The other thing was I knew that Carl was going to be working on the Cosmos program at the time, so I then went and talked to Joe Veverka, and asked if he would sort of be my advisor, but then I could work with Carl on Voyager. Then, what happened later was Joe got added subsequently to the Voyager team. So, I worked with both of them, mostly with Joe, on Voyager. That was how I ended up coming here, was that it was the place that gave me a foot in the door with the big hot mission that was flying at the time. 

Varga:

So, what was Cornell like, broadly, during the 1970s, in terms of student atmosphere?

Squyres:

Same as it is now, really. That’s a hard question to answer. Politically it was a little different. We were still in the aftermath of the Vietnam War, so it was very active, politically, and very liberal-minded, as it is today. It was a typical Ivy League kind of campus. I don’t know. I can’t really give you much more than that. 

Varga:

Were there any protests that were contentious?

Squyres:

Yeah, sure, there was some of that stuff going on. The Vietnam War had wound down, and the Civil Rights Movement had moved past its peak of contentiousness, which was sort of in the mid to late ’60s, so things were a little bit calmer than they had been on campus, say 8 or 10 years earlier. So, there was some of that, but it was much less than it had been in prior years. 

Varga:

So, you said your major professor was Joe Veverka?

Squyres:

When I was doing my PhD, yes. 

Varga:

So, what was it like working with him then?

Squyres:

Oh, it was great. I had the opportunity to be at the Jet Propulsion Laboratory—be at JPL. I worked with the imaging team as the pictures were coming down from Voyager at Jupiter. Every 45 seconds there’d be some view that would come across the television screen that no human eyes had ever seen before. The thing that I was most interested in was the moons of Jupiter. Over the space of 48 hours, they were transformed from little dots of light that had only been studied telescopically, to these whole worlds that you can map and study in exquisite detail. That happened in 48 hours. Voyager 1 at Jupiter in March of ’79. It was one extraordinary experience. That experience, the Voyager 1 flyby—and I was there for the second flyby, too—but the Voyager 1 flyby was the first time I had experienced anything like that. I was hooked after that. I was willing to spend another twenty years sitting on airplanes and drinking bad coffee and looking at PowerPoint slides for another 48 hours like I had with Voyager at Jupiter. It was just a magnificent experience. You know, graduate students got to play a significant role in doing the science, and I got to work with some of the best planetary scientists in the world. It was just a mind-blowing, extraordinary, career-shaping experience. After Voyager 1 at Jupiter, I never wanted to do anything other than work on planetary missions. Right place, right time. 

Varga:

Yes, that’s very true. So, I have to ask, then, about what it was like working with Carl Sagan.

Squyres:

Yeah, I didn’t work with him much when I was in grad school, because as I say, he was very consumed with working on Cosmos at the time. We actually worked together collaboratively and wrote papers together more after I finished my PhD than while I was doing it. Very smart guy, very personable. He was a fabulous teacher, which would not surprise anybody. What few people realize… he taught Astronomy 102, you know, a big introductory course for hundreds of students, which is the same course I teach now, and have for many years. It’s at a very basic level, and he taught it brilliantly. But I took an upper, upper-level course from him called Physics of the Planets and he was just as brilliant teaching that. Carl Sagan waxing poetic about the wonders of the universe was no more impressive than Carl Sagan at the blackboard deriving eddy diffusion coefficients. What people lost sight of was that in addition to being a fabulous teacher, he was also a damn good physicist. He could teach… one of the most valuable things I ever got out of Carl, from that course in particular, was that he actually had the capability to teach scientific intuition. How do you even do that? But what he was able to do—and I remember him showing us this time and again—is there’d be some complicated physical process, right, and he’d put up this equation with twenty different terms in it that describes in a complete form all the physics, right? And then he’d look at this equation and he’d say, “Well, look, this term, this term, this term, and this term are so small and they're additive that we don’t need to worry about them. This one, we know the value to within a factor of two, so let’s just say it’s that.” And he’d go through and he’d take those twenty terms in the equation, and he’d knock them down to like the three that really mattered. Those three parameters—those three terms in the equation do not in any way convey the completeness of that complicated physical problem, but if you simply look at those three, and you start performing thought experiments, which you can do with three parameters, you begin to develop an intuitive—not a complete, not a fully quantitative, but an intuitive sense of how the problem works. Oh, if this goes up, phew, that’s going to really go down. You know? That kind of thing. That’s a tool that I use to this day. It’s just a very, very valuable thing to do. 

Varga:

So, what sort of influence did he have, then, on your department? Did you take note of any debates or conflicts between members of the department, or people outside of the department?

Squyres:

Not really. I mean, Carl was an anomaly in the department in that he was very much involved in interacting with the public and the media in ways that other people in the department did not. Moreover, in ways that scientists in general did not, at the time. Carl was really a pioneer in that regard. In those days, if you were a scientist and you went on television, and you talked a lot to the media, and you showed any glimmerings of something like charisma, you actually tended to be, sort of, looked down upon, in a sense. And Carl—and I think it was partly because he was a forward thinker, and a skilled communicator, and partly because he worked on these billion-dollar projects—Carl recognized that if we were to have any hope of continuing to receive funding to do these billion-dollar, multi-billion-dollar-class projects, we had an obligation to let the people paying the bills know what they’re getting for their billion dollars. If you couldn’t convey the beauty and the wonder and the elegance of what these projects were doing in terms that taxpayers could understand, you shouldn’t really expect to get a steady flow of taxpayer dollars. What happened is that a whole generation of young, young, young, younger than me, scientists grew up watching Cosmos on TV and absorbed that. So, now, being an effective communicator of science, and being able to communicate science well to the public is a good trait to have in our field. It didn’t used to be that way. 

Varga:

Were there any other faculty members or students here that left a major impression on you, besides the two we talked about?

Squyres:

Sure, there were plenty, but the two who really shaped me as a scientist were Joe and Carl.

Varga:

Okay. What was your dissertation about?

Squyres:

My dissertation was about Ganymede and Callisto, two of the moons of Jupiter.

Varga:

Why did you choose this as your topic?

Squyres:

The reason I chose that… well, okay, I was obviously going to work… I had a geoscience background, so I was going to work on the moons, and the reason I chose, and primarily focused on Ganymede, was there was one particular member of the Voyager science team named Gene Shoemaker. Gene was at Caltech and also U.S. Geological Survey, and Gene had developed a fascination with Ganymede, and sort of had indicated to the rest of the Voyager team that Ganymede was what he wanted to work on. When we had the initial flyby, the big, big, big, cool science on the moons was the volcanoes on Io, which was this huge surprise, and Europa looking like maybe it had a liquid ocean. So, those were the sexy ones, right? Most of the members of the team wanted to go work on those. That left Ganymede and Callisto a little more clear, with not as many other people trying to do those things. And Gene was just… ah, what a gentleman; what a gem; what a brilliant, generous, kind, fabulous man. I mean, I admired Gene so much then, and looking back on it now I admire him even more. So, I realized if I picked Ganymede as my primary focus, not only would I be working in a less crowded field, but I’d be working with Gene Shoemaker, and that made it an easy decision. So, that’s what I did. It was a cool thing to work on. In the most simple-minded way, you can take the solid bodies in the Solar System, and you can divide them into two classes, based on what they’re made of. One is things that are made of rock and metal, and the other is things that are made largely of ice. The Voyager 1 flyby of Ganymede and Callisto was the very first time, ever, that we saw that second class of objects. Now, people have looked at the moons of Jupiter, moons of Saturn, moons of Uranus, moons of Neptune, comets, etc., etc., but at the time these were the first icy bodies ever seen. Boy, what an opportunity for a grad student. I wrote the first PhD thesis ever on an icy planetary body, with real data that could show you what that object was like. So, yeah, right place, right time. 

Varga:

Very much so. So, you already mentioned, briefly, a little while ago, the Viking missions. What did you think of these missions at the time? What was the overall significance of them?

Squyres:

Oh, jeez. 

Varga:

Especially considering the biological interest in the mission.

Squyres:

Yeah, yeah. So, honestly, it was always the kind of habitability questions that drove me the most. If you look at all of my early papers, they all had to do with ice and water and things that were necessities for life. So, the interesting thing about Viking from a, sort of, astrobiology perspective, is that Viking was fundamentally, at its core, a biology mission. Viking was all about the Viking biology experiment: those three instruments that they got down on the surface and they fed some soil to, and they were looking for bugs in the dirt. Turns out, there weren’t any bugs in the dirt. But the mission also carried two orbiters whose primary task was landing site selection and certification. So, they used the orbiters to select and certify the landing sites, and they picked the landing sites, and they picked the two most boring, safe places on Mars that they could find, and they went and landed there. But then you’ve still got those orbiters, and the orbiters functioned for years, and they mapped the whole planet. They did a terrific job of documenting all these water-carved features, the little sinuous valleys, and that sort of stuff, that could only have formed if conditions had been very different in the past, with liquid water flowing on the surface. You know, it cracks me up that we seem to keep discovering water on Mars. “Oh, there’s water on Mars!” We’ve been discovering water on Mars every six months for the last forty years, or something. Evidence for water on Mars was found for the first time only once, and that was Mariner 9 in 1971. It found water-carved features, no questions about it, and all the water on Mars stuff since then, including my Rovers, has been filling in the details, you know? So, credit to Mariner 9. Viking took a significant step beyond Mariner 9 in terms of the quality images, and the ability to do science related to water, and inhabitability, and all of that. So, the significance to me of Viking was not the lander. I mean, the lander was a magnificent technical achievement, fantastic instruments of sort of a negative result. But, boy, the Mars that was revealed by Mariner 9, and then the details filled in by the Viking orbiters was a fascinating place that obviously had been warmer and wetter, in some sense, in the past. So, that was what made Mars interesting to me. Even though I did my PhD thesis on Ganymede and Callisto, to me, the really fascinating object from Voyager at Jupiter was Europa, and the idea that there was potentially a water ocean beneath the surface there, which seems to be pretty well established now. So, that was the significance of those missions, to me, really kind of solidifying the case for liquid water and potentially habitable environments beyond Earth. It’s kind of a big deal. And it was fun to be there at the time that was happening. Voyager and Viking were landmark missions. 

Varga:

So, how, then, did you obtain your position at NASA Ames after graduation?

Squyres:

Actually, it was funny the way that worked out. The way that happened was the following: there were two guys at NASA Ames. Their names were Ray Reynolds and Pat Cassen, and then a guy at UC Santa Barbara named Stan Peele. Stan, Pat, and Ray, some years earlier, had developed all the mathematics behind Tidal Heating Theory, so the idea that when there’s a moon that’s in orbit around a planet, and it’s in a somewhat elliptical orbit, the tidal forces vary in a way that flexes it back and forth, and that can dissipate energy, and deposit heat. So, they developed all the math, and they did the tidal heating calculation for Earth’s moon, and it gets heated up by a few degrees. So, it wasn’t an interesting result. So, they wrote it up, and that was that. Then, years later, as Voyager is barreling down towards Jupiter, they got the idea to dust off their old tidal heating theory and apply it to the Jovian moons and see if anything interesting pops out. They do it for Io, and the thing burst into flames. It’s crazy what the thing does, and they checked it, and they checked it, and thought, my god, is this right? This is crazy. This thing would be the most volcanically active body in the solar system if we got this right. So, they checked it, and they convinced themselves that they had it right, and they dashed off a paper to Science. It came out in Science one week before Voyager flew by Jupiter. This was in the days when there was no online anything. You had to pick up a paper copy of Science, and there was nobody on the Voyager imaging team, who, one week before the flyby, was picking up journals and reading them. So, none of us knew. At the time we flew by Io, none of us knew about the existence of this paper. The discovery of the volcanoes on Io was the huge, big discovery, and the big surprise of the Voyager 1 flyby, and then a week or so later, we came to realize these guys predicted this. Holy crap, you know? I was so impressed, more than anything else, by just the sheer gutsiness that it took to throw yourself out there and make this prediction, that if they were wrong, they were going to fall flat on their faces in a week. And they had the balls to just put this out there, and I just thought that was fabulous, and I though, damn, I want to work with these guys.

So, I talked to my advisor, and he wrote a recommendation letter for me to go get a National Research Council postdoc. I worked particularly close with Ray Reynolds. Fabulous guy. Brilliant, generous, wonderful scientist. Just this fountain of ideas. He had some health problems, and didn’t have a whole lot of energy, but had a brain that was second to none, and he would just toss out these ideas, and I was young and full of enthusiasm and energy, and I’d just take his ideas and run with them. We wrote so many papers together, and just had a great time. So, that was how I started off at Ames. So, I was an NRC post-doc for two years and got hired on as a civil servant, and that’s where I ended up for a few years. 

Varga:

So, what is it like working for a NASA research institute compared to an academic position?

Squyres:

You know, it was surpassingly similar, I would say. Ames was… I didn’t realize at the time how fortunate I was to be in that particular branch at that particular NASA center, but it was a fabulous time. You mentioned Jim Kasting. He was there at the time. Jim Pollack, Jeff Cuzzi, Ray Reynolds, Pat Cassen, Brian Toon… I mean, you can go down a list of people who were there then—Chris McKay—you go down the list and you’re like, holy crap, and these were all on the same floor of one building. So, there was a remarkable collection of talent, and it was a place where people were generous with their ideas, where there were people who came from all—Bill Borucki was there, the PI for the Kepler mission. So, it was a fabulous time, and people were generous with their ideas. If you came up with some whacky, crazy idea that you wanted to work on, you could walk four doors down the hall in one direction, or five doors down the hall in the other direction, and somewhere on that walk you’d find somebody who knew about it, and would be happy to talk to you about it. So, it was a terrific place to work. It had a very academic feel to it. It didn’t feel like a stuffy government lab. There were no ties and pocket protectors and that kind of stuff. It was a great place to work. I had an enormous sense of academic freedom, intellectual freedom, and I could work on whatever I wanted to, with smart people surrounding me. It was a wonderful, wonderful intellectual environment. I loved it there. Very special place at a very special time. I’ve said this like three or four times now, but you look at the early years of my career, the good fortune that I had to be in the right place at the right time was extraordinary. Between when I took that course in the Viking mission in 1977, and left Ames eight years later, or something like that, I had just nothing but good fortune. 

Varga:

So, while you were there you worked on some of the earliest research about Europa and water and life on it?

Squyres:

Yeah, yeah. Ray and I wrote a paper predicting an ocean on Europa. We did a lot of stuff about ice and water on Mars, and liquid water on Enceladus. There was a whole bunch of stuff. Yeah, I wrote a lot of papers back then.

Varga:

How was this research received by the scientific community at the time, about water on Europa?

Squyres:

It was pretty well. Yeah, I would say it was received well at the time. Some of the key things that we came up with in those days, the story’s gotten much more solid since then. I don’t remember anything we ever published where we got any significant negative blowback. 

Varga:

Kasting mentioned that he left NASA eventually because he thought it started to decline somewhat. Do you agree with him on that?

Squyres:

Jim left considerably after I did. I left because I had a particular opportunity for a faculty position that opened up here. No, I was very happy at Ames. A faculty position opened up here in 1986. They called me and asked if I was interested. My wife was born and raised in Ithaca, and had family here, so we had close connections here. Plus, you just compare the cost of real estate in Silicon Valley and the cost of real estate in rural Ithaca, New York, and things differed by like a factor of three. It was crazy. So, believing—and I think we were correct about it—that Ithaca would be a much better place to raise a family, because that was what we were about to start doing at that point in our lives, we came here. No regrets. 

Varga:

Okay. So, how has Cornell been like since you started working here?

Squyres:

It’s been great. The key thing for me was—two things. First of all, there had long been, sort of, a tradition. That’s maybe overstating it, but there had been a number of years of Cornell scientists working on NASA planetary missions, going back to Viking, even Mariner 9 before it. Yeah, Mariner 9, Viking, Voyager—Cornell scientists had been involved in early NASA planetary missions. So, the idea of somebody coming in who wanted to do that was not in any way unusual. I was following in the footsteps of other more senior faculty.

The other thing was that after I’d been here three years, or so, I got tenure. What that did was it freed me up. You know, there’s the “publish or perish” treadmill, and if you are not in a tenured position, then in order to keep putting food on the table, and paying your mortgage, you’ve got to keep writing proposals, and getting them funded, and writing the papers, and getting them published, and you’ve got to turn that crank endlessly. You’re on soft money, and there’s no guarantee that you’re going to be funded in the next year, or two, or three, unless you write more good proposals. The nice thing about having tenure was that it enabled me to take on high-return but very-high-risk goals.

While I loved working with the Voyager and Viking images—Voyager flyby, Viking from orbit—I found them intensely frustrating. My initial training had been as a field geologist. That’s what I first learned to do. And I would look at these pictures taken from a flyby, and I would look at these pictures taken from an orbit, and I would say, “Well, it could be this. Or it could be this. Or it could be this. Or maybe it even could be this.” And I just knew if I could just get down on the surface with my boots and a rock hammer for five minutes, I would figure out the answer. It drove me crazy. So, out of frustration, around the time I first came to Cornell, was about the time that I first became seriously interested in trying to do field geology on the surface of Mars—real field geology on the Martian surface. I started working on that in 1987. I recognized that in order to do that, I was going to have to write proposals to NASA that would take up an enormous amount of my time. I was going to have to learn a lot of engineering. I was going to have to do things professionally that would prepare me for that road, but that would take me away from the “publish or perish” kind of thing. I also recognized that there was no guarantee of success, in fact, a high, high, high probability of ultimate failure. But because I was a tenured professor here, I was able to risk my career without simultaneously risking my family’s livelihood. That was enabling. So, I was able to go off and do crazy things, and from when I first started to work on the Mars Exploration Rovers, to when we had two spacecraft on the launchpad at Cape Canaveral was 16 years. It was 16 years invested to get to that point, and the rockets could still blow up, and the landings could still fail. But I was able to take that risk, so that was really fundamentally important. So, I did. After I had been at Cornell a few years, the first time I had a sabbatical leave, I took it at an aerospace company. That’s a weird thing for an astronomy professor to do, but I went and I worked at Ball Aerospace in Boulder, Colorado, and learned a whole lot of engineering. So, I had made this decision that I wanted to do robotic exploration years before, but having found the orbital thing just too unsatisfying, I decided, okay, I’m all in. Let’s get down on the surface. Turns out it was hard to do. 

Varga:

Yes, it was. So, what are your teaching responsibilities here at Cornell?

Squyres:

Teaching responsibilities here average about one course per semester, something like that. So, it’s a pretty light load, which enables me to spend time on other things. Between 1987 and 1997, I spent ten years primarily writing one failed proposal after another to NASA to try to do something on the surface of Mars. It wasn’t until the fourth try when we got selected, ten years after I’d started. So, yeah, I burned up about ten years just writing proposals. 

Varga:

How has Cornell changed over the years, if at all, in any way?

Squyres:

The changes have been more physical than in the character of the university. If you walked around campus, Cornell is situated in a beautiful place. It’s a very beautiful campus. What has happened is a lot of the green spaces have been filled in with boxy buildings, so it’s not nearly as open and pastoral a physical environment as it was back then. Other than that, in terms of the fundamental character of the place as being very open, very welcoming to people all over the world, very intense and challenging academically for the students, world-class research university, none of that has changed. 

Varga:

So, the 1980s have often been thought of as a very unproductive period, in terms of planetary research, especially about Mars. Would you agree with this assessment?

Squyres:

Be careful about saying “unproductive,” because, well, there was a substantial lull in planetary launches. New missions were not being launched. Now, you look at the Voyager flybys—the Voyager Saturn flyby was ’81, Uranus I think was ’86, Neptune ’89, so that was paying off all the way through there. But there was a dearth of new launches. There was stuff coming down from Voyager, there was still a lot of good science being done with the data from prior missions, Viking orbiter being foremost, probably, among them. But there was a lack of new missions, new launches, and ultimately, that’s going to lead to a certain amount of stagnation in the program. So, yeah, in terms of new missions flying, it was a bad time. 

Varga:

So, during that time, you worked on the Comet Rendezvous review panel in 1986, for Comet Halley. I saw it on your resume, so I thought I’d ask about it. 

Squyres:

What? No, no. 

Varga:

Okay, because I was interested in that. 

Squyres:

No, no. No. I did a bunch of other comet-related things in that same timeframe, but there was no Halley-related stuff that I did at all. 

Varga:

So, let me ask about the Galileo mission.

Squyres:

Sure, but again, that’s one that I was not involved in.

Varga:

Yeah, I know you were not involved in it. But how do you think the Galileo missions are contributing to the understanding of Europa?

Squyres:

Oh, tremendously. You know, the magnetometer experiment—the way that Europa interacts with the Jovian magnetosphere, provided really pretty solid evidence for there being an electrically conducting fluid beneath the surface of Europa, and boy, salt water fits the bill pretty well. But also the images… it was unfortunate that the Galileo high-gain antenna never deployed properly because it severely restricted the [data link] from that spacecraft. Even so, the quality of the images was fantastic, and even though the quantity wasn’t what people might have hoped for, Galileo was a huge success, scientifically, and really was a big step forward in understanding those moons—all of them. 

Varga:

So, what was it like when some of the Martian missions, like Mars Observer, failed? Was that at all disheartening?

Squyres:

That was horrible. That was really horrible for me. I had decided that I wanted to be a planetary scientist, and in particular, I wanted to work on missions. So, I had worked on publicly available data, from the Viking orbiters. Didn’t need any special status. Anybody could work on it, as long as they had access to the pictures. I was a graduate student riding on the coattails of my advisors for the Voyager mission. But I decided I wanted to get onto a mission team under my own power. It’s a competitive process. You don’t just write a letter and say, hey, can I be on the team? You don’t just get invited. You have to compete with many, many other people. And so the first mission that was going to really kick the planetary program back off again after this long hiatus was Mars Observer. I looked at Mars Observer, the way it was formulated, and principal investigators were invited to propose instruments. At that point, very early in my career—this is still mid-to-late ’80s—I didn’t feel that I had the knowledge or the experience yet to be a principal investigator for a flight instrument. I just didn’t have the experience. I was a kid. So, I couldn’t do that. They had two facility instruments. One was an infrared spectrometer, which was a subject that I knew something about, and the other one was a gamma ray neutron spectrometer, which I knew nothing about. Absolutely nothing. But when I first began to look at the capabilities of those two instruments, it turns out that the one that really had the ability to tell us about water and ice at the Martian surface was the GRS, the gamma ray spectrometer instrument. I knew nothing about gamma ray spectroscopy. Nothing whatsoever. So, I went out, and I bought a—in fact, I’m sure it’s still on my shelves here somewhere—I bought a book about nuclear physics, and I read it. The whole thing. And then I read all the existing literature on planetary gamma ray spectroscopy, which had been done at the Moon back in the ’60s and ’70s. And then I got in touch with a scientist at Goddard—his name was Jack Trombka—who was a real expert in the field, and I picked his brains, and he very generously shared his knowledge with me. It took me 8 months to write a 10-page proposal, but I was selected for the Mars Observer Gamma Ray Spectrometer team. So, that was a big deal for me. And three days out from Mars, the thing disappeared on us. That was, first, a very rough introduction to the way in which missions can go wrong. I learned a lot from that one. So, yeah, that was a bad experience. 

Varga:

So, what do you think drove this theory about Mars being warmer and wetter in the past?

Squyres:

Well, it goes back to Mariner 9. It goes back to Mariner 9 showing features on the surface that could realistically only have been carved by liquid water, and not huge floods of liquid water, but relatively small trickles of liquid water. And there was just no other plausible explanation. There never was. I remember taking courses from Carl Sagan and Joe Veverka in the late ’70s, and it was abundantly clear that there had been liquid water at one point in the past on the surface of Mars. It was a no-brainer. I know I have my notebook from… yeah, this is my notes from Astronomy 671. That’s that course that I took. Somewhere in all of this… well, I can’t find it, but somewhere in all of this there’s compelling evidence that there was liquid water on Mars, and this was in 1977. So, we like to keep discovering the same things over and over. And, you know, in fairness, these new discoveries really do add depth and detail to the story, but it was obvious then that Mars had once been a warmer and wetter place. There’s just no question about it. 

Varga:

What did you think of James Lovelock’s Gaia hypothesis when it was announced? Were you involved in that?

Squyres:

Don’t know enough about it to give you a good answer to that one. 

Varga:

Okay. Some scientists have described the mid-to-late 1990s as a turning point in astrobiology. Would you agree with this assessment?

Squyres:

I think the main thing was that it went from being sort of disreputable to being reputable. It went from being hard to get money to being easy to get money in that field. It came about as a consequence of a number of findings that were relevant to the notion. People began to take different, disreputable threads in different scientific disciplines and pull them together. So, yeah, it was a time of a shift in people’s thinking about that sort of thing. 

Varga:

So, why do you think it went from disreputable to reputable?

Squyres:

Uh, disreputable is the wrong word to use. But it used to be called exobiology instead of astrobiology, right? And around that time was when it changed. I think it was just—there was a time when exobiology tended to be viewed as the study of something that has not been shown to exist. I think as we learn more about the probable existence of habitable environments on other planets in the solar system… let’s take some of the key threads. So, one of the key things that became clear around that time frame was—talking ’70s through ’90s—was that there probably have been, and maybe are today, habitable environments elsewhere just in this solar system. Another thing that happened around that timeframe was the very first discovery of exoplanets, and the notion that planets are… I mean, everybody sort of suspected there were planets around other stars, but the realization that planets are commonplace, which means that habitable environments are probably commonplace. You’ve got habitable environments in maybe three or four different objects, at least historically, in this solar system. So, consider all the other planetary systems that might be out there. Wow. Another thing was that in the life sciences, the advent of sequencing and genomics and the realization that archaea… I mean, the whole phylogenetic tree just completely transformed itself. Archaea were shown to be this completely different thing from bacteria, in that same sort of time frame. Then there’s the realization that if you look at the root of that phylogenetic tree, the most primitive common ancestor looks like something that might’ve lived in hydro-thermal systems. Then around the same time was when these incredible ecosystems were discovered at deep sea hydrothermal vents—you know, 9 North, and all the stuff on the mid-ocean ridges—all of that, sort of, fell into place in a decade or decade-and-a-half-long period. You take all of those things and you put them together and all of a sudden you go, well, wait a minute, there could be something to this. So, I think there wasn’t any one discovery, or any one breakthrough that changed everything, but there was a realization from four or five completely un… you know, RNA sequencing and astrophysics looking at other stars, and planetary probes out in our solar system, and submarines going down to the bottom of the ocean. Those are four completely, completely different scientific disciplines, but you take those four threads and you twist them together, and you’ve got something. That was in that timeframe. 

Varga:

So, what was your experience with and what did you think of the Martian meteorite controversy at the time?

Squyres:

Well, the Martian meteorite thing had a very immediate, and substantial effect on me and what I was trying to do, because at that time the Mars exploration program was kind of limping along, and the kinds of landed missions we were looking at were very small landers, very limited in their capabilities, no mobility, nothing like that. What I wanted to do was I wanted to put substantial mass on the surface and have it be mobile and carry around instruments. I wanted to build a robot field geologist. There was nothing in the Mars program at the time—there were these tiny little landers. There were these Mars surveyor landers, they were called. They were very limited in their capabilities, and they didn’t really enable the kind of science that I wanted to do. Then, all of a sudden, the ALH 84001 thing hits, and there’s Bill Clinton on TV saying we’re going to get to the bottom of this. And what happened was that virtually overnight there was renewed interest, in particular, in Mars surface exploration, and in doing real geoscience, meaningful geoscience on the Martian surface because that was the way you were going to get to the bottom of that. After all, the evidence reported to have found was from a Martian rock, so let’s go look at some rocks, right? So, what that did was it opened the door in a somewhat confused, haphazard sort of way, but it opened the door to what ultimately became the significant missions—Opportunity, Spirit, Curiosity, Mars 2020—these significant missions of Martian surface exploration. So, it had a big effect. 

Varga:

Would you characterize the meteor as overhyped at all, as Kasting characterized it as an issue of too much hype for one discovery.

Squyres:

I certainly would not say that it was overhyped by the people who wrote the paper. They have no responsibility whatsoever with what the media does with it. 

Varga:

Do you think that the media has a tendency to overhype in things related to Mars, or anything?

Squyres:

I mean, what’s “overhype”? 

Varga:

Put too much emphasis, perhaps.

Squyres:

I mean, that depends on your point of view. I’m as excited about new discoveries on Mars as anybody alive. So, no, for me it’s not overhyped. I want to read news articles about discoveries on Mars. I think they’re exciting. I think they’re a lot more exciting than a lot of the other news that I read. But other people are going to have a different view. That’s a hard question to answer because it’s very, very dependent on your personal perspective. I don’t really have a good answer for that one for you. 

Varga:

So, what did you think were the biggest obstacles that you had to face in order to organize and promote your rover project and designs?

Squyres:

My own lack of experience is very high on the list. That was definitely one thing that I had to overcome. You always face very stiff competition. The competitive nature of these mission selections is brutal. It’s disheartening. It grinds you down. And it’s utterly necessary. I mean, NASA is going to throw, typically, at one of these missions, half a billion or a billion dollars at somebody. What is it that makes your idea good enough that it’s worth a billion dollars of taxpayer money? When we were doing the Mars Exploration Rovers, I would talk to my team endlessly about how much money this thing cost, and it’s very easy to play the… oh, geez, that’s two and a half slices of pizza for every American. That’s no big deal. Let me tell you, I’ve spent a lot of time traveling in rural Africa, involved in poverty relief issues and so forth. You could do a hell of a lot of good in the world with a billion dollars. And you better have a damn good story if you want to spend a billion dollars of anybody’s money. So, it’s a competitive process, and if your ideas aren’t good enough, and you don’t win the competition, you go back to the drawing board and you start again. So, the competitive nature of it was tough. Like I said, I lost three times before the fourth time we wrote a successful proposal. So, yeah, that’s definitely an obstacle. Another thing is that the political winds, if you will, blow to and fro. What’s the trendy thing this fiscal year might be different from the hot thing the next fiscal year, or what have you—what was the latest thing in the news, you know, who’s the new NASA administrator, and what do they care about? That kind of thing. The solution to that is to come up with a crystal clear, very crisp vision of what it is you are trying to achieve, and do not deviate. Stick with it. Find something so compelling that you know once it finally happens it’s going to be great, and you just keep pushing, and pushing, and pushing, and pushing until it happens. In my case, it was sixteen years. But having that clear vision of what it is you’re trying to do—something that you can express clearly enough that you can write it on a t-shirt, and yet is compelling enough that people are willing to devote their careers to it. That’s the thing that you want to come up with. One of those, right? And once you’ve got one, you don’t let go of it. 

Varga:

So, how do you convince the government, or NASA, whomever, to fund large projects like this? What’s the key to getting them on board?

Squyres:

You write one of these. That was the original proposal that my team wrote. That doesn’t look anything like Spirit or Opportunity. That was a rover that hasn’t existed. But that was the proposal that we wrote that ultimately became Spirit and Opportunity. This is the proposal that I most recently worked on, and this is the CAESAR mission. I’m working on the step 2 version of this, which is going to be about that thick, right now. So, yeah, you write an absolutely compelling proposal, and if the process works the way it’s supposed to, in the end, the best proposal wins. This proposal was preceded by a bunch of earlier ones—here’s one—that when I go back and look at them now, I can see the flaws, and I can see why we weren’t selected. It was the best I could do at the time. It was the best my team could throw together at the time, but if it’s not good enough, you don’t get to fly. And then what happens to some people—I’ve seen this happen again and again to friends and colleagues—is you go to all that effort and you get selected, and you get to build it and it blows up and crashes. Decades of work is just gone, like that. I have good friends and colleagues that that has happened to, and they devote decades of their career to something, and there is nothing to show for it. Then there are all the people who spend decades writing proposals and never get selected. That happens a lot, too. That’s even more common. It’s a tough game, but it needs to be. It needs to be, because, like I said, we are spending billions of dollars that could be very well spent doing other really good things. 

Varga:

Do you think publicity is important, as some scientists have said, for getting these projects advanced?

Squyres:

I think for getting your mission selected, no. I don’t think that publicity is important, because if you look at the proposal review process and the way that it works, it’s pretty well set up to not be influenced by… for example, we kept CAESAR as secret as we could during the competition. No website, and no news about it. The article in the New York Times, the day before the selections were announced, described most of the missions that were being proposed, and then there was one sentence that said there’s a mission called CAESAR, and we don’t even know what the acronym stands for, or something like that. I did it that way on purpose. I didn’t see any advantage to publicity, where… I hate to use a word like publicity, but where publicity matters is in the overall health and vitality of the program. If the American public do not support robotic space exploration, these missions, in general, will not happen. So, continuing to have mission success, not having large overruns, not having cancellations, returning scientifically valuable results that are exciting and compelling and interesting, and doing that again, and again, and again, so people have a sense that you have a vibrant program being conducted by people who know, more or less, what they’re doing, that’s the key to a healthy program. On a project-by-project, or proposal-by-proposal basis, publicity shouldn’t matter, and my experience is that it doesn’t very much. 

Varga:

Why did you write your book, Roving Mars?

Squyres:

Partly as therapy. No, why did I write it? I felt like it was a good story. I didn’t want to write an engineering book. I wanted to write an adventure story. I wanted to see if I could tell a good, ripping adventure story. It’s a robot, I get that. No human lives were at risk. But I wanted to try my hand just once at writing a good, true, this-is-what-happened, adventure story. The other thing was Spirit and Opportunity were enabled by an incredible team of people—thousands of people. Most of them labored in complete obscurity. The names were never on TV, they never became famous, nothing like that ever happened. I wanted their stories to be told. In fact, I even say something like this in the preface of the book, that I wish I could have told the stories of hundreds of members on the team. As it was, I told the stories of maybe a dozen. They had to serve as proxies for everybody. I would pick one individual, and it wasn’t because that one individual was more important than other people, it’s just I had to pick a small group of people. If you try to tell everybody’s story, you’d wind up telling them all badly. So, I picked maybe a dozen, and told of their contributions, and what they did, and how they made MER possible, in enough depth that you really got it. You understood what their breakthrough ideas were, what sacrifices they made, what their joys and sorrows were. I wanted to get that across. They’re two robots on Mars, but at its heart, it is a people story, through and through, and I wanted to tell the story of the people and the adventure that we had together. 

Varga:

How are these teams organized? 

Squyres:

It’s tremendously different from mission to mission. There’s no “one size fits all” answer to that. Missions are organized in different ways at the outset. For example, on MER, the person at the top of the chart was Pete Theisinger. Pete was the project manager. The buck stopped with Pete. He had a whole bunch of people under him, and one of the boxes under him was me. I was the principal investigator—not for the mission; I was the principal investigator for the scientific payload. That’s it. The rover vehicle itself, entry, descent, landing system, parachutes, and so forth, I was a passionately interested observer, but I was not in charge of anything. I was in charge of getting the payload onto the rovers on time and make it all work. That was my responsibility. So, that’s one form of organization. There are other missions, like Curiosity, where there are individual PIs for each instrument. They’re all fighting each other for resources, and then there’s a project scientist who tries to organize and manage the whole thing. That’s a different structure. On CAESAR, on the New Frontiers mission, which are these PI-led missions, the box at the top of the chart has my name on it, and I’m the one who NASA is going to take a flame thrower to if things don’t work. These are all different models for how missions can be organized. They all can work, or not work, depending on the complexity of the technical problem at hand, depending on the personalities and the capabilities of the individuals involved. There’s an element of luck in some of this stuff. All of them can be made to work, but it’s quite different from one mission to the next. 

Varga:

How would you characterize Daniel Goldin, the leader of NASA who approved of your mission? I know, in your book, you called him aggressive in ways. 

Squyres:

Yeah, yeah. Dan is a brilliant strategic thinker, and is really, really good at stirring things up. He was the one who suggested that we fly two rovers. Not one of us on what was then the project even thought to suggest that. We wouldn’t dare. He said, well, how about if we fly two? But he could be a tough guy to work for. He said what he thought and did so in ways that was sometimes disheartening to the people who heard what he had to say. He was a real interesting, and really complicated guy. Very smart, very committed to NASA, better at strategic thinking than winning people’s hearts, let’s put it that way. 

Varga:

Was he really an enthusiast for Mars, as I’ve read about?

Squyres:

I think he really was. When he made the suggestion that we build two rovers instead of one, that required a lot more money, and he went off and got it. He found it within the agency. He didn’t get more money out of the White House or Congress, he rearranged priorities within the agency so we could do that. So, to me, that’s a pretty good definition of enthusiasm for Mars for a NASA administrator. 

Varga:

So, when these rovers landed, were you involved at all in interfacing with the public, or did you just work behind the scenes?

Squyres:

Constantly. That was actually really interesting. There was a huge spike in public interest when that happened. Just an enormous amount of public interest. So, we did nationally televised press conferences every day for weeks. It was a very interesting experience for me, because NASA has an established way of presenting new scientific findings. A NASA mission produces some results. They get peer reviewed, and they get published in Science, or Nature, or someplace, and then NASA calls a press conference. Then there’s the associate administrator, and the head of the planetary program, and then there’s the principal investigator, and the lead author, and there’s another author, and then there’s somebody who’s not on the team, but who knows about the subject, and they’re sitting at a podium, or a thing at the front of the stage, and they go down the line, and each one speaks in turn, and it’s a very organized, very structured sort of thing. There was so much interest in what was going on with our rovers that the press was clamoring for a press briefing every day. Every day we would have new information, but we didn’t always have new understanding.

Initially, some of the NASA public affairs people were really uneasy about the idea of NASA scientists getting up there on nationwide TV and saying, “Well, we don’t know what the hell is going on here. This is the craziest damn thing I’ve ever seen. What are these little blueberry things in the soil? We don’t know.” So, they were a little uneasy about scientists getting up and saying we don’t understand this. That made people very queasy, and understandably. People are paying billions of dollars for these missions, and they’ve got a bunch of scientists who don’t know what the hell is going on, right? So, I can understand their unease. I looked at it as a wonderful opportunity to show people how science really works. By the time you read science in the textbook, all the drama has been sucked out of it. The facts are established, the paper has been published, it’s established facts, and you read about it in the textbooks. But when people first discovered the 3 degrees K cosmic background, or, you can go down the list of scientific experiments, and scientific discoveries over the years, and the first thing—they always begin with a “what the hell?” kind of thing, right? That moment when they go, “What is going on here?” And that’s the way science really works, and that’s what makes it so much fun. That’s what makes science so cool—that moment, “aha!” of discovery. I saw this as this wonderful opportunity to show people science as it happens, and let kids, especially, see a bunch of scientists doing what scientists really do. So, what we started to do was we found a way of presenting it that was sort of acceptable to everybody. So, basically, we get up there and we say, look, we had just made this new observation. Now, it could be this, but it could be this, and it could be this, which is multiple working hypotheses, which is what scientists use. So, we present the multiple working hypotheses, and then, this is the key, we’d say “tune in tomorrow.” Because the thing about the rover is it moves. It gets closer to something. You get more data, and you learn more each day. These were a bunch of television people, and they definitely understood the virtue and value of “tune in tomorrow.” So, once we started doing it with multiple working hypotheses, and showing people the evolution of scientific hypotheses, and how we learn things, and so forth, everybody got comfortable with it. It was a really fun experience. 

Varga:

Are there any aspects of science that you think that people don’t generally know about, or think about?

Squyres:

Sure, sure. It’s very easy to think of science as this static body of knowledge that you learn from a textbook. I told you, I teach… it’s now 1102, but Astronomy 102, Astronomy 1102, here at Cornell. One of the things I have always done, as long as the rovers have been on the surface, is I start of each class with three or four minutes, no more than that, on here’s what happened on Mars in the last 48 hours. I’ll give you a great example—this is one I remember vividly. This is probably three or four years into Spirit’s mission, or something like that. This was after the right front wheel had failed, probably a few years after, and we had done a drive and the right front wheel, as we were dragging it through the soil, had dredged up this very bright, white soil. We’d seen stuff like this before, it was ferric sulfate salts, and we kind of understood it. So, it was on a Monday, and that picture came down an hour or two before class, I dumped it into my lecture, put it up, and said, look, this just came down—very bright, white soil. We’ve seen this before. It’s ferric sulfate salts. We’re going to go over and take a taste of it with the spectrometers. I’ll let you know on Wednesday, for sure, but that’s, I’m quite certain, what it is. Half an hour before class on Wednesday, data comes down from the data alpha particle x-ray spectrometer, that this thing is 91% pure silica. It’s this “what the hell?” moment. Just, good god, nobody’s ever seen anything like this. What is going on here? But there it was.

So, I took the APXS spectrum, I put it as the first slide of my lecture, I cracked it open, I put it up, and I said, look, this just came down—the white stuff is not ferric sulfate salts; it’s almost pure silica. I don’t know what the hell is going on here. I’ve never seen anything like this before. I don’t know what this is. I’m sure it’s important, but I don’t understand it. I just saw it myself for the first time 20 minutes ago. Uh… I’m going to have to get back to you. There’s this sea of faces, and you could look up there and you could see some of them going, in their heads, my god, my parents are paying $50,000 a year for this? The professor doesn’t even know what’s going on. But it was this beautiful moment of complete genuine surprise, where I could show them how science really worked. Okay, I’m the lead scientist on this billion-dollar NASA mission, and I am just confused as well. And it was a beautiful thing. We eventually figured it out, and published it, and it all came together. But it was a really cool opportunity for students to actually see how a scientific discovery is made less than half an hour after it had been made. So, stuff like that is cool. It’s nice to be able to do that. 

Varga:

So, what role do you presently play for the Martian rover Opportunity?

Squyres:

I’m still the principal investigator. So, what that means is I lead science operations for the rover. Obviously, we’re not developing hardware anymore, but we—Opportunity has been caught in a dust storm for 7 or 8 weeks now, and we don’t even know if the thing is still alive. But my role is to lead the science team, which now means leading science operations. 

Varga:

So, how does that work on a regular basis?

Squyres:

So, several times a week, anywhere from three to five times a week, we begin the day with a meeting of the Science Operations Working Group, and that is the group of scientists who are conducting tactical operations for the rover that day. We always distinguish tactical from strategic. Our strategic operations are operational decisions that take the long view. Where are we on Mars? What are the broad set of scientific hypotheses that we’re trying to test? Where do we want the rover to be six months from now? How much energy do we have now versus six months from now? So, we get sort of a long view of what we’re trying to do. Tactically, it’s what’s the specific command load that’s going to go to the rover today—to turn the wheels and take the pictures and get us new stuff for tomorrow. You always want what you’re doing tactically to make sense within that broader strategic framework. We kind of separate the two, because the time scale is very different. So, the SOWG is the group that conducts the daily tactical science operations. There’s an SOWG chair, the person who leads science operations for the rover for that day, and those are people who I select, who I schedule. I do it a lot myself, when I can. It’s a job that I love. It’s very tactical. You just focus on what we’re going to do today. Tomorrow is another day. But what we do is we get the team together, virtually—the scientists who are going to do that, plus a whole bunch of engineers. The engineers are there, initially, to tell us here’s what the rover is capable of today. “You’re going to have probably 450 watt-hours of power out of the array.” So, if I’m going to get 450 watt-hours out of the array, I can’t come up with a science plan that’s going to consume 600 watt-hours, because it’s not there. It’s gotta fit. “You’re going to get 60 megabits of downlink.” Okay, so I can’t generate 90 megabits of data. I’m not going to see some of it, right? So, all of the engineers are there for that. They’re there to assure, first and foremost, rover safety, and then, once we decide what we want to do, they’re there in large measure to implement it.

So, at the end of the SOWG meeting, what we’ll have is a set of very-high-level descriptions of what we want to do today. We want to take a 3x1 nav cam panorama, and then we want to do an 11-meter drive with a dogleg in the middle, and at the end we want to lift the arm up, so we can see what’s in front of the vehicle, take two pictures with the haz-cams, and take a 360 nav cam panorama. Something like that. And that’s going to consume 400 watt-hours of power. Roughly, more or less, it’s going to generate 50 megabits worth of data. Looks like it’ll fit. Okay, that’s the plan. Then, a small subset of the team spends the next six or seven hours taking that set of desires from the science team, and turning it into hundreds of lines of computer code that can then be radiated to the spacecraft, and executed on board the vehicle, to do what we wanted to do without breaking anything, without putting anything at risk, without exceeding any limits. Sometimes you get into the process, and you go, oh crap, we can’t actually do this. Something’s gotta go. And that’s the tactical process. Command scope to the vehicle, data comes down from the vehicle, we get up the next morning, and we do it again. It’s a lot of fun. One thing I should also mention is that we have a subset of the team, and they’re called the long-term planning leads, whose job it is, solely, to track how we’re doing strategically. So, every SOWG meeting, which is a tactical meeting, begins with a presentation from the LTP lead of the strategic situation. Because what’ll happen is in tactical ops, people will come and go. Somebody might do ops for a week, and then they go on vacation, and then they come back and something has happened, right? The thing about having someone with a strategic vision who is embedded daily in the tactical process, what that does is it assures that everybody is on the same page strategically, before they start implementing tactics for the day. It keeps you synced. 

Varga:

That makes sense. So, are you surprised at how long the Opportunity rover mission has gone on?

Squyres:

Oh, hell yeah. I mean, if anybody tells you they expected these things to last 14 years, they’re lying through their teeth. I can actually prove to you that we didn’t think they were going to last more than a couple years. Each rover carries an X-band transponder. That’s the radio. You can’t adjust the frequency. You can’t change the station. It’s hardwired in. You’ve got two different vehicles, and they communicate to Earth on different frequencies so you don’t get them confused with each other. We’ve got four transponders. We built two flight units, and two flight spares for both vehicles. Flight units were fine, so now we’ve got two spare transponders sitting on the ground identical to the ones that we flew.

The next mission comes along, MRO—these transponders cost a million bucks a piece. MRO comes to us, they haven’t launched to Mars in 26 months, and they say, “Hey can we have one of your flight spare transponders? You could save us a million bucks, and you guys don’t need it.” We said, “Sure, take one.” We gave them Spirit’s. For years, MRO and Spirit communicated to Earth on the same frequency. It was a colossal pain in the butt. You can only talk to one when the other one is out of sight. It was awful. We never would have given a Mars mission one of our flight spare transponders if we thought we were going to last 26 months. So, I can prove to you that nobody thought we were going to last that long. Opportunity flight spare transponder, I think, was on the Dawn mission. That was no problem, because they were in a different part of the sky. But, yeah, so I can prove that we didn’t think we were going to last more than a couple of years. 

Varga:

So, what do you think is the broader significance of geological research on Mars that people would care about?

Squyres:

I don’t want to try to answer that for you. I’m too close to it. I mean, we’ve been at this for 14 years now. This is the point at which you start thinking about what’s the legacy? What’s the significance of it? I’m too close to it to judge it. What it means to me personally is what it means to me personally. It’s nothing more. What it means to the public at large, I’m just too close to it to tell. I can’t give a good answer to that. 

Varga:

Do you think Mars can tell us a lot about the history of the Earth, or the geology of the Earth as well? Is there a comparison there?

Squyres:

It’s easy to overplay that. Knowing terrestrial geology is very, very, very useful. It’s essential for understanding what we’re seeing on Mars. The processes that operate… you know, the laws of physics are the same, the processes have similarities, but the physical environment of Mars is so different. The chemical composition of Mars is so different. The climatic history of Mars is so different that these familiar processes get combined together on Mars in uniquely Martian ways. There are limits to how far you can take that. Let me put it this way: I don’t think you can justify the cost of Mars exploration by what it’s going to tell us about planet Earth. I don’t think that’s—there’s not enough there to make that a justification for how much money we’re spending. It’s got to be because you find what we’re learning on Mars to be sufficiently compelling. And it keeps coming back to habitability and life. That’s got to be the reason. We’re not going to learn something about how to fix global warming. I mean, there are links, right? There’s no question that there are links. Mars has greenhouse effect too. But, no, when we study Mars it’s to learn about Mars, fundamentally. 

Varga:

This is a very broad question, but do you think that life ever existed on Mars?

Squyres:

I don’t know. I don’t mean to sound elusive or snarky. That answer actually encapsulates what’s for me actually a very important point. That is, that one of the worst mistakes that you can make as a scientist is to want the answer to be something. I’ve heard scientists say, “I wouldn’t have seen it if I hadn’t believed it.” You don’t want to fall into that trap. So, in a situation where, as is the case at the moment, we have insufficient data to answer a profound question, my preference is to see people try to maintain an open mind and design a better experiment. So, I say, “I don’t know,” and I really mean it. There’s a significant point to be made right there. 

Varga:

So, what do you think about the current state of space science in the United States?

Squyres:

It’s great.

Varga:

What do you think should be priorities going into the future?

Squyres:

Oh… what do I think should be the priorities? I’m going to dodge that question. I’m going to dodge it for two reasons. One is that I recently—not recently, it’s been five years now—chaired the planetary decadal survey—I was the chair of that—which is the formal NRC-sanctioned planetary community statement of what the priorities are. So, because I was the chair of that, I want to just simply say, okay, I think we worked very hard to produce a document… here it is. That’s the decadal survey report. We worked very, very hard to produce a document that, as accurately as we could, represented the consensus of the community, and there it is. So, in one sense, I think that does pretty well represent group consensus priorities. The other reason I want to dodge your question is because I’m the principal investigator on a mission that’s competing to be selected as the next thing for flight. So, if I say I think the single most important thing is to return a sample from Comet Churyumov–Gerasimenko, there’s a large measure of self- interest there. So, a question like that is just a place I don’t want to go. 

Varga:

Do you think that a manned operation of Mars is a good or bad idea?

Squyres:

Human exploration of Mars? I think it’s a great idea. Humans have far more capability than robotic systems do, and will for, as far as I can see, years to come. They’re expensive. It’s not going to be easy. You want to do robotic exploration first. But I ultimately believe that the most significant, and certainly most inspiring science is going to be done by humans. As somebody once famously said, nobody’s going to give a robot a parade. That inspiration thing is important. Like me, many of the people who worked to build Spirit and Opportunity grew up in the ’60s and ’70s watching Mercury and Gemini, and Apollo on TV, and dreaming of sending spaceships to Mars one day. And we got to do it, you know? But that inspiration came from somewhere. I think that the ability of human explorers to inspire as well as inform is significant.  

Varga:

Do you have any comments on the recent news on Mars that came out yesterday about the lake?

Squyres:

It’s not a lake. It’s an aquifer. It’s been hard to describe this in ways that people without a little bit of geologic knowledge can understand. The polar layer deposits, we have known for a very long time, are very thick, and are very rich in water ice. That’s been known for a very long time. It would be physically and chemically impossible for Mars not to have a geothermal gradient. It gets warmer and warmer as you go down, just like it does in the Earth. The reason is that, like Earth, Mars has a natural endowment of radionuclides—uranium, potassium, and thorium being primary among them—that put out a steady source of heat. So, the heat leaks out, and it goes down a gradient, and the gradient is such that it gets warmer and warmer with depth. So, if you have a big, big, big, big, big stack of ice, or ice and soil mixed together, with a geothermal gradient embedded in it, sooner or later you’re going to get the 0 degrees C isotherm. Or, if there’s some salt, maybe you get a freezing point depression, and you get to sum up, but you’re going to get to a depth where that groove can be present below the surface. Beautiful piece of work. Elegant detection, wonderful experiment, very tough data processing to pull that signal out. Compelling result. To me, it’s not a surprise. It’s cool. It’s incredibly cool. But to me it would be surprising if liquid were not present somewhere below the surface of Mars, given the preponderance of water ice on the planet, and the fact that the regolith, especially at high latitudes, seems to be chock full of it, and the fact that there must be a geothermal gradient, at some depth you’re going to get to a place where liquid water, you would expect to be present. It’s wonderful that somebody’s found some. It’s not a lake. 

Varga:

Have you considered giving any important documents or records to an archive?

Squyres:

Nobody’s asked. I don’t know if I have important documents or records. I guess, maybe I do. See, this is another tough one for me. I mean, the answer is no. The direct answer to your question is no. This is a tough one for me, also, because, as I say, I feel like I’m too close to Mars surface exploration to, in any way, judge the significance of anything that we’ve done. I can’t tell. I’m just too close to it. The reason this is a little bit ironic is that I actually teach, here at Cornell, a course on the history of exploration. I co-teach it with another professor who is a real historian form the history department, Professor MaryBeth Norton. We’ve been teaching it for a number of years now. I love it. It’s the most fun I’ve ever had teaching. The first lecture is Polynesians across the Pacific in dugout canoes, and the last lecture is rovers on Mars, and in between we do Magellan and James Cook, and Christopher Columbus, and Zheng He and the Chinese treasure fleet, and the Arctic, and the Antarctic, and deep ocean, and all that stuff. So, I said at the onset of this discussion, that I’ve always been keenly interested in the history of exploration. Now, we’ve done our little tiny thing ourselves, and is that part of the history of exploration? I can’t even tell. But, no, I have not contributed anything to any archive. It’s all just sitting around here on shelves and boxes, and a lot of it’s on this computer. 

Varga:

Yeah, I was thinking some of those things, like those proposals. Your notes would probably be useful. You might want to consider talking to an archivist about those.

Squyres:

Yeah, I don’t know. Right now, my focus is not on what we did in the past. It’s what’s coming next. 

Varga:

So, I might as well ask to conclude what the CAESAR mission is about, because I haven’t heard of it until this point. 

Squyres:

What we hope to do is to fly a spacecraft to Churyumov–Gerasimenko, which is the same comet that was visited by the Rosetta spacecraft. We’d go to that one because we can actually design our sampling system for the known properties of the object we’re going to explore, collect something like a hundred grams of sample, and bring both the non-volatile and the volatile portions of it safely back to Earth, and get them into the Earth’s best laboratories. From that, learn fundamental science about the prehistory of the solar system—what are the materials from which the solar system formed?—the fundamental and earliest processes of solar system formation, and how the building blocks of life were delivered to Earth. How did organic molecules get here? How did water get here? Comets were probably a major part of that story. So, that’s what the mission is about. It’s incredibly technically challenging. I’ve got a fantastic team, and I’m having more fun than I have since before we launched the rovers.

Varga:

Is this similar to a lot of proposals for Martian return missions that were popular?

Squyres:

It has some—I mean, all sample-return missions have certain things in common. You have to have a sample return capsule—a vehicle that can come down through the Earth’s atmosphere and deliver the sample. So, all sample return missions involve a very tough problem of getting samples back on Earth, very, very, very severe contamination knowledge and control requirements. You don’t want to contaminate your sample in any way. Very challenging curation requirements. You need to have a receiving facility that will treat them properly and make them valuable scientific materials for decades to come. So, there are many challenges that sample-return missions have in common. The challenges of getting a sample off a comet are rather different from the challenges of getting a sample off of Mars. Mars, you’ve got a gravity field, which helps you on the way down, and hurts you on the way up. Comets, you don’t have any atmosphere, and you can’t use a parachute, so the sampling methodology are dramatically different for the two, and the science objectives are quite different. We’re not looking for fossils on a comet.