New Mars

At the end of 2003, half a dozen years after Sojourner finally ground to a halt on the dusty, boulder-strewn floor of the flood-carved Ares Valles, spiked wheels will once again be rolling across the surface of the Red Planet. But this time not one, but two rovers are going to be sent to Mars - the twin Mars Exploration Rovers. New Mars Staff Writer Stuart Atkinson talks to the principal investigator for the MER mission, Steven Squyres, about his previous experience in Mars missions and his hopes for the MER.

	Steven Squyres

In two years time, New Mars readers, and Mars enthusiasts around the world, will be glued to their TV screens and PC monitors, gazing in wide-eyed wonder at new pictures from the surface of Mars, pictures that will show us the Red Planet’s landscapes in greater detail than ever before. Because, although the public are largely unaware of it, and apparently even only a few Mars enthusiasts are talking openly about it so far, a NASA mission is currently taking shape which promises to revolutionise our understanding of the martian environment - and possibly even answer some of our oldest, most haunting questions. And in doing so, the mission will take us a giant step closer to truly understanding Mars - and to sending men and women there.

At the end of 2003, half a dozen years after Sojourner finally ground to a halt on the dusty, boulder-strewn floor of the flood-carved Ares Valles, spiked wheels will once again be rolling across the surface of the Red Planet. But this time not one, but two rovers are going to be sent to Mars - the twin Mars Exploration Rovers.

Larger, stronger, faster and above all smarter than the famous Sojourer, the twin MERs will be nothing less than robot geologists, sent out on the ultimate field trip. After landing on Mars in tried-and-tested Pathfinder fashion - their fall cushioned by airbags - the rovers will unfold themselves from their protective cocoons and then leave their parent landers behind, roaming across the surface on a mission to find out as much as they can. They’ll take the best photos ever seen of the martian surface, study the geology of the rocks, and begin the serious hunt for evidence of past water on Mars - the key, many scientists think, to finding life on the Red Planet.

Unlike Sojourner, which was unable to travel very far from its lander, the 180kg MERs will travel for over 100m every day, thoroughly-exploring the area and giving planetary scientists back on Earth a true “virtual presence” on Mars for perhaps the first time. Like all good geologists they will be equipped with hammers to allow them to look at the inside of any interesting rocks they find, but the MERs “hammers” are hi-tech abrasive tools which will bore into the rocks, instead of cracking them open.

The mission is gathering pace right now, coming to life as you read this. Landing sites are being considered by selection panels, and the rovers, and their scientific packages, are slowly but surely taking shape, being put together by their designers, engineers and technicians. In charge of the project, Principal Investigator for the MER mission, is Steven Squyres, a planetary scientist who has been involved in almost all the planetary missions of the last two decades. Between 1978 and 1981 he was a member of the Voyager science imaging team which gave us such amazing views of Jupiter and Saturn, and their fascinating moons. He worked on the Magellan radar-mapping mission to Venus, and was also involved in the history-making NEAR mission to the asteroid Eros. When the Cassini probe arrives at Saturn in 2004, Steve will be riding with it too. The upcoming Contour mission to study cometary nuclei will benefit from his great experience and dedication too.

MER is not Steve’s first Mars-related mission. He was involved in two of the missions which reached Mars only to fail. But those frustrations and disappointments are far behind us all now, and as we begin to look forward to the beginning of the next stage of martian exploration, New Mars talked to Steve about the MER mission, his interest in Mars, and his hopes for the future.

New Mars: Steve, your CV reads like a 22nd century space tourist’s passport; over the years you’ve explored Venus, Jupiter, Saturn, comets, Mars… you’ve “been” everywhere! It must have been exciting to have been involved in the historic Voyager missions, seeing those now-famous icy moons in detail for the very first time..?

Steven Squyres: Oh, yeah. Voyager was what got me into this business, really. I was a grad student working with the Voyager imaging team during the flybys of Jupiter and Saturn, so I was able to be right there for the discovery of the volcanoes on Io, the first good pictures of the rings of Saturn, and so on. It was a thrill to be part of it.

NM: And at that time were you interested in Mars?

SS: Yeah, definitely. But that was back in the days when planetary missions were few and far between, and there was nothing going anywhere close to Mars when I was in grad school. Viking was over with, and Mars Observer wasn’t even a gleam in anybody’s eye yet. So I did Voyager.

NM: So were you a “Mars buff” from an early age, or did something trigger your interest later?

SS: I wouldn’t really say I was a Mars buff from an early age. Up until I hit my third year in college I was thinking about being a geologist, maybe working on the geology of the sea floor. But in ‘77 I took a course about Mars that was being offered by a professor who was on the Viking Orbiter imaging team, and after that I was pretty much hooked.

NM: You were involved in the Mars Observer and Russian “Mars 96″ missions, both of which sadly failed. I guess we can’t even begin to know how gutted you must have felt at the time…

SS: That was pretty bad. My involvement in Mars ‘96 was at a fairly low level, so that one didn’t impact me personally quite as much as it did many other people who worked really hard on it. But the Mars Observer loss really tore me up. MO was the first mission I was involved with after Voyager, and was my first mission to Mars. It was very painful to lose it. I learned an awful lot from that experience.

NM: …so it must have been a huge contrast to have been a planetary scientist at the time Pathfinder was trundling triumphantly around Mars? It certainly was an exciting time for us!

SS: Well, it’s funny, but I kinda missed Pathfinder. I was really focussed back in those days on putting together a mission that could follow after Pathfinder, building on some of the technology that Pathfinder was planning to demonstrate… like rovers. So when NASA went about selecting participating scientists for Pathfinder, I didn’t propose. The day that Pathfinder landed I was holed up in a cabin in the Rockies, working on the proposal to NASA that eventually led to MER. I didn’t have a television or even good access to newspapers up there, so I was pretty much oblivious to what was happening. I obviously missed a lot!

	The spacecraft carrying the MER enters Mars.

NM: Today your attention is centred on MER, another Mars mission. Does this mean Mars hold a special fascination for you now, or is it basically “just another target” for an intrepid planetary explorer such as yourself?

SS: Yeah, it does hold a special fascination. It has for many years. The only other target in the solar system that has comparable appeal for me is Europa. That’s one I’d like to get back to someday.

NM: What exactly is your role on MER?

SS: Well, my title is Principal Investigator. Officially, what that means is that I lead the team that’s responsible for providing all of the science instruments for the rovers, and for conducting all the science operations of the rovers and their payloads once we get to Mars. Unofficially, it means I get to poke my nose into just about every aspect of how the mission works, which is part of what makes the job so much fun.

NM: Could you give us an idea of a typical day for you, working on MER? I imagine things are rather hectic at the moment!

SS: Um, yeah, they sure are. The nature of my day-to-day work on the project is impacted a lot by the fact that I work at Cornell University, which is on the east coast of the US, while the spacecraft is being built at the Jet Propulsion Laboratory, which is out on the west coast. Even when I’m at Cornell, I pretty much live and work on west-coast time. We have a lot of meetings on this project! I know the JPL project staff real well, so I don’t need to be in the room with them face-to-face for every meeting. But I do need to be part of the discussions that are going on, which can range from landing site selection to spacecraft test plans to budgets. So I typically spend four or five hours a day on the telephone. Some of these meetings are with JPL managers and engineers, and others are with team-mates in the US and Germany who are developing parts of the science payload.

Telephones aren’t adequate for everything, though, and I fly to the west coast almost once a week for the face-to-face stuff. So I spend a lot of time on airplanes.

The nature of the day-to-day work is about to change dramatically as we move from the planning to the actual assembly and testing of the flight vehicles. But I think the amount of time I spend on telephones and airplanes is likely to stay pretty constant!

Airbags inflate around the vehicle during descent.

NM: And have there been any particularly heart-stopping moments recently?

SS: All the time. This is Mars exploration - there’s hardly anything that isn’t heart-stopping. (How’s that for an artfully-dodged question?)

NM: As you work on the next major Mars mission, are you inspired by the ongoing - and some might say publicly-overlooked - success of the Mars Global Surveyor?

Of course. MGS has been a spectacular success by any reckoning. I’ll be delighted if we turn out to do as well as MGS has.

NM: Even though its been dead in the dust for almost five years now, images of Sojourner rolling around Ares Vallis are still fresh in everyone’s mind. Is that slightly intimidating? It will be a tough act to follow, after all.

SS: Well, like I said, I really missed Pathfinder, including all of the media attention that it got. So maybe that helps me in not being intimidated. But frankly, I think that if you judge your success in this business by the amount of instant media attention you attract, you’re missing the point. We’ll get what we get, but it’s history that will tell whether or not what we’ve done really matters. What I care about is what we find at Mars, how well we’re able to understand it, and how well we’re able to explain it to anybody who wants to listen.

NM: For those people who aren’t up to speed on MER, what are the main differences between “the plucky little Sojourner rover” and the twin MER rovers?

SS: Well, ours are still plucky, but they’re one heck of a lot bigger. Sojourner had a mass of about 17 kg; each of our rovers is about ten times that. Sojourner travelled just over 100 meters over its entire lifetime; each of our rovers can travel as far as 100 meters in one martian day. So our rovers are big, and they can cover a lot of ground.

The other big difference on MER is that all of the science instrumentation is on the rover. On Pathfinder, most of the instruments were on the lander, and images taken from the lander were used to manoeuvre Sojourner, staying right in the immediate vicinity. On MER, everything is on the rover; we take all our instruments and head out across the countryside with them. Once we leave the lander, there’s nothing left behind but airbags and scrap metal.

NM: Are there any plans to give the rovers their own names? I remember how Sojourner was given that name after a school competition.

SS: We definitely intend to have names for the rovers. NASA is just now putting together a detailed plan for how the names are going to be chosen.

	The landing structure opens to reveal the rover.

NM: As on previous Mars missions, like Mars Polar Lander, the MER website offers people the chance to “send their names to Mars”, on a CD which will be carried by the rovers. How pleased are you with the response so far? How many names are there on the CDs at the moment?

SS: I haven’t followed that effort closely, but from what I understand the response so far has been enormous. I think they were shooting for a million names, and the last I heard they had something upwards of 2.25 million. I’m not sure that all of them are serious, though. I checked the website quickly this evening, and found, for example, that 8 of the people who signed up are named Donald Duck, 40 are named Britney Spears, and 73 are named Bill Clinton.

NM: Can you tell us which aspect of the MER mission is most exciting for you personally?

SS: That’s the hardest question you’ve asked. I can’t narrow it down to just one aspect, so I’m going to cheat and give you two. One is whatever we’re going to find scientifically. I don’t know what that’s going to be, of course, but with this kind of payload and this kind of mobility we’re bound to discover new stuff. MER is pure exploration, and that’s exciting.

The other is just the day-to-day grind of meeting all the technical challenges. What I’m learning is that figuring out how to land and operate a really complicated machine on the surface of another planet is just fantastically hard; the hardest thing I’ve ever been part of. And being part of a team of literally thousands of people who are trying to do stuff that’s never been done before is one of the most exciting things I’ve ever experienced.

NM: And what should New Mars readers be looking out for in January 2004 in terms of results and pictures? If the simulations of the panoramic camera - which can be found on the MER website - are anything to go by, we’re in for a real treat!

SS: Well, the pictures will be the most obvious thing, and they’ll deservedly get a lot of the attention. Our panoramic cameras have three and a half times better resolution than either the Viking or Pathfinder cameras did, so you’re going to see a much sharper-looking Mars than you’ve ever seen before. And some of our possible landing sites may just look very different from anything you’ve ever seen before either. So visually it should be quite a show.

But the other results should be pretty compelling as well. They won’t look as jazzy to the eye, but much of the real science from the mission will be contained in the compositional data from our spectrometers, and what the data tell us about what Mars was once like. To me, the really exciting thing is going to be whatever scientific story we can tell by putting the data from the cameras and the spectrometers together.

The RAT prepares to grind into a Martian rock.

NM: The “RAT” hardware is very intriguing. Can you tell us a little about it, and what you hope it will achieve?

SS: Well, the RAT (the Rock Abrasion Tool) is our answer to a geologist’s rock hammer. What we want to learn about Mars is contained in the geologic record in its rocks. But the surface of a rock that has been sitting out exposed to the elements for millions of years may not be representative of what that rock is really like on the inside. That’s why geologists carry hammers; to break rocks open and look inside them. People have tried to teach robots how to swing hammers, and mostly what they’ve gotten is broken robots instead of broken rocks. So the RAT takes a different approach. We place it gently but firmly on the surface of a rock, and it slowly grinds its way into the rock, essentially opening up a window into the rock’s interior.

NM: Is there any one particular thing you are hoping MER will tell us about Mars?

SS: Not one specific thing. But in the broadest sense, we’re hoping that the rovers will tell us what it was like to be on Mars back when the rocks at our landing sites formed. The MER rovers are robotic field geologists. We’re sending them to Mars to read the record in the rocks, and to try to help us understand whatever stories the rocks tell. We’re picking landing sites where there’s evidence that water was once present on Mars. One of our candidate sites is an ancient lakebed, another may be an ancient hydrothermal deposit, and so forth. And we want to go to those places to understand what they really were like: was there really water there, and if so what was the environment like and how suitable might it have been for life?

NM: Looking forwards in time now, have you any plans - or hopes - to be involved in post-MER Mars-related programs? Maybe working on even more advanced rovers, or on a Sample Return mission?

SS: I honestly can’t look forward that far. I wish I could, but I just can’t. I’ve been focussed for so many years on getting this thing to the launch pad - and it’s getting so close now - that contemplating life after MER is pretty much impossible. Sometime late in 2004 I’m going to sit down and have a good think about that question. For now, though, the focus is on what’s right in front of me.

NM: Where do you stand in the “probes vs people” debate? Are you a supporter of “manned Mars exploration as soon as possible”, or do you think we have a lot more reconnaissance to do with unmanned probes - and rovers - before we start thinking about sending human explorers?

SS: I’m not a hard-liner on either side of that issue, and sometimes I think the debate gets a little more heated than it ought to be. For something as complicated - technically and politically - as Mars exploration, you need to have a bunch of different techniques in your toolkit, and you need to use all of them wisely. Think of it as having a diverse portfolio. I’m a big fan of robots, and humans are not a viable substitute for robots when money is tight. But one thing you learn when you work with robots a lot is how dreadfully limited they are in their capabilities relative to what a human could do in the same environment. For in-depth exploration, there’s just no substitute for humans, nor (I think) will there be one in the foreseeable future. So clearly the right approach is to lead with robots that are helped by humans, and follow later with humans that are helped by robots. I’m not very patient, and I want to move from robots on the ground to humans on the ground as soon as possible. But when we get to that robots-to-humans transition point will be driven largely by politics and funding, and those are things that I haven’t learned how to hurry along.

NM: Lastly, if you could snap your fingers right now and transport yourself to anywhere on Mars, where would you go, and why?

SS: I’m going to cheat again and pick two places instead of one. I’d go to wherever the two MER rovers are going to land. Except for my home, those are the two most important places in the solar system to me; wherever they turn out to be. I’d give almost anything to see them with my own eyes.

NM: Steve Squyres, thank you very much for talking to New Mars.

Visit the Mars Exploration Rovers homepage for more information.

Filed under: Interviews on June 18th, 2002