Planetary Radio: Space Exploration, Astronomy and Science - A Year of Roving Across Mars

Episode Date: January 3, 2005

We celebrate one (Earth) year of Mars Exploration Rovers on the red planet with Principal Investigator Steve Squyres and Project Manager Jim Erickson; Emily Lakdawalla goes where no spacecraft has gone before.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

A year of roving the red planet, this week on Planetary Radio. Hi everyone and welcome back to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan. We're celebrating a remarkable anniversary. Mars rover Spirit bounced down to Mars on January 3, 2004. We'll talk about a year of excitement and discoveries with Mars Exploration Rover Principal Investigator Steve Squires and Project Manager Jim Erickson.

First, though, here are a few headlines from around our solar system. The Huygens probe remains on track for descent into the thick atmosphere of Saturn's moon Titan on January 14. Meanwhile, Cassini has taken some spectacular close-ups of Iapetus. You can see them at planetary.org. Deep Impact is almost ready for a launch that will send it hurtling toward a violent encounter with a comet on the 4th of July. We'll have more about that mission on next week's show. And speaking of violent encounters, NASA reports that we won't be having one with an asteroid called 2004 MN4.

Further research has set aside fear of a 2029 collision with the 1,300-foot-long near-Earth object. There's much more to come on Planetary Radio, including Bruce Betts and a new trivia contest. I'll be back with Steve Squires right after Emily takes us to the stars. Hi, I'm Emily Lakdawalla with questions and answers. A listener asked, What is the most distant object from the Earth that was built by humans? The Voyager 1 spacecraft is the human-made object that is most distant from her birthplace.

Each year, she adds a third of a billion kilometers to her distance from the Earth. In fact, Voyager 1 is traveling so fast that she will eventually escape the pull of the Sun's gravity entirely. This is very unusual for objects within the Solar System. All of the planets, moons and asteroids, and nearly all of the comets and other spacecraft, orbit the Sun on elliptical paths. These elliptical paths mean that they will circle round and round the Sun forever. But Voyager 1's orbital path is not an ellipse. It is in the shape of a different conic section, a hyperbola.

A hyperbolic orbit is open-ended, so Voyager 1 will never again return to the neighborhood of the Sun. What other spacecraft are on hyperbolic orbits? Stay tuned to Planetary Radio to find out. Cornell Professor of Astronomy Steve Squires has joined us several times. He is Principal Investigator for the Athena Science Payload on both Spirit and Opportunity, the Mars Exploration Rovers. Steve, congratulations on a year of rolling around Mars.

Thank you very much. Quite an accomplishment. You guys must be celebrating, even though we're only celebrating the first complete Earth year, and only for Spirit at this point. Yeah, we're celebrating. We're tired. We're joyful. We're having a heck of a good time.

Has it been a grueling, although exciting, year? I think that describes it well. It's been grueling in the sense that these are very demanding vehicles to operate. You can't just give them a day off. You've got to keep them busy, and that keeps us very busy. But at the same time, it's been an utterly remarkable experience to go exploring around on the surface of Mars. I would not trade it for anything. A year ago at this time,

did you have any thought, really realistic thought, that you would be still so involved with these two rovers? No, I mean, you know, if you had sat me down and given me truth serum and said, okay, Squires, you know, to be honest,

how long do you really think they're going to last? Don't give me this 90-day stuff. How long do you really think they're going to last? Don't give me this 90-day stuff. How long do you really think they're going to last? I would have said, you know, I would have swallowed hard. I would have said, you know, 120, 150, maybe if things really break our way, 180 days on the surface. But a year of operations, you know, four kilometers of driving with spirit, climbing mountain ranges, going down of driving with Spirit, climbing mountain ranges, going down into impact craters.

No, not for a second. Not for a second. And yet here you are, and so much more science than you must have also thought you would be. Yeah, you know, the science, that's one of the things that's really surprised me, is the way the science keeps on coming. What I had not counted on was the diversity, the variety at these landing sites. And you've got to wonder, is all of Mars this good?

I don't think all of Mars is this good, frankly. I think we picked two good landing sites. Just a week ago, we discovered a completely new kind of geologic material that nobody had ever seen on Mars before at the Spirit site, just out of nowhere. And it keeps on coming. And that's been one of the remarkable things to me is that the rovers keep making new discoveries. Now, the downside to that, I've come to realize, is that in a sense, a rover's work is never done. You know, there's always going to be something good over the horizon.

And what I'm starting to try to emotionally come to grips with here is the fact that we'll never be finished. You know, whenever they die, whether it's tomorrow or six months from now, there's always going to be something wonderful just over the horizon out of reach. Your colleagues who are now beginning to put together what will be known, I guess, as the Mars Science Laboratory, Mars Exploration Rover be known, I guess, as the Mars Science Laboratory. Yep. Mars Exploration Rover on steroids, I guess. They must be awfully glad that you guys have been so successful

because now it's not about finding the water anymore. Well, you know, it's funny. They're glad, but we've really kind of raised the bar. Oh. We've raised expectations. You really want and you really expect each mission to make a significant advance over the previous one. And for MSL to make a major advance over our mission gets a little bit harder. Now, I'm involved in MSL too, so I'm kind of in that boat at the same

time. It's a good boat to be in. But, yeah, each day we keep going, it certainly increases the payoff from this mission. But I'm sure that you and they wouldn't have it any other way. No, no, of course not. I mean, this is what you pray for. Yeah, and everybody always wants to run a faster mile than the last one. Yeah. What would you point to over the last year as the greatest discoveries?

I mean, we've already talked about, you know, the question of was there water on Mars? That's old hat. That's so a year ago. Yeah. It's a hard question to answer because it's still going on. You know, I mean, we discovered something today. So, you know, it's hard to really put all of it in context, but I've got to say I think probably when we really sit back and look at all this, that the most significant discovery will be the evidence for water on the surface at the Opportunity Landing site.

And not just that there was water on the surface, but we really picked up a lot of information about the details of what that environment was like. The water was salty. The conditions were arid, dry much of the time. The water sort of came and went. The water was probably very acidic. It was acid. It was sulfuric acid. It was a strange environment. We also learned that the rocks there are the kinds of rocks that are very good

at preserving evidence of whatever was in the water. I think the rocks there would be wonderful targets for a sample return mission. It's hard to say, but at this point in time, I think I'd have to guess that's going to turn out to be our most important scientific legacy. If you had to go one down from now, what would be number two? Oh, wow. What would be number two? I think number two is going to turn out to be a story that's still emerging. Over at the

Spirit Landing site, the first 160 days of the Spirit Landing site, we were driving around on dry old basaltic lava. There was some dust and there was a little salt here and there. There was some interesting stuff going on, but it wasn't what we went for.

And then around the 160th day of our 90-day mission, we crossed over into a mountain range called the Columbia Hills. And we've been in the Columbia Hills ever since. There's a story that's still emerging there, and we get new clues daily. And it's a story of explosive rocks, rocks that were formed by some violent event, either a volcanic explosion or an impact, a meteorite impact of some sort. But then after that, these rocks got wet. They were altered by water. We see minerals in the rocks that can only form in the presence of water.

We see patterns in their elemental chemistry that point to water. And, you know, we're still piecing that story together because you sort of get it a clue at a time. Each rock has its own little thing that it adds to the story, and gradually the evidence builds up and builds up, and it's still building there. We're still piecing that story together. And I think once all is said and done, that's going to be our second most important finding, but it's still coming together. And it ain't over yet. No, it ain't over by a long shot.

Let's bring it back home, and I mean home to Cornell. You got to head this team for the Athena Science Payload on both rovers. Pretty amazing opportunity, I think, considering that I think more typical is what's going to happen with Mars Science Laboratory. A lot of great investigations, but provided by a lot of sources. You guys are responsible for all of these. Yeah, it was done a little bit differently, and it worked out well for us. The thing that I liked was that we were able to design all the pieces so that they worked together from the start in a very complementary fashion.

so that they worked together from the start in a very complementary fashion. I mean, when we first picked the instruments, we picked them so that when you got to a given rock, when you got to a given outcrop, each individual instrument, each individual tool, would provide a different complementary piece of the puzzle. And, you know, any one of them individually will sort of give you a very incomplete picture of what's going on. But if you look at them together, they really work nicely as an ensemble.

And being able to take that basic concept and then craft it into a set of tools that really work together well was a real interesting scientific and engineering challenge. And drop them on a pretty cool rover. Oh, these are great rovers. We didn't... Fantastic machines. We're just about out of time. We didn't get a chance to combine you in the same conversation with Jim Erickson,

but on this anniversary, any message for that manager and his team of engineers at JPL? Thank you, thank you. A thousand times. These guys built the most wonderful machines I've ever seen. Those of us who were in the Pasadena Convention Center, me and, what, 1,200 other people and a whole bunch of people on the Web, will always remember your face and your reaction on that day a year ago. And thank you for that, Steve, and thank you for a tremendous success on planet Mars.

It was a pleasure. Steve Squires is the principal investigator for the Athena science payload on both Mars exploration rovers. for the Athena science payload on both Mars exploration rovers. And still, still, a year later, moving around Mars, making discoveries. He is also a professor of astronomy at Cornell University, his alma mater. And we'll be back right after this. This is Buzz Aldrin. When I walked on the moon, I knew it was just the beginning of humankind's great adventure in the solar system. That's why I'm a member of the Planetary Society, the world's largest space interest group.

The Planetary Society is helping to explore Mars. We're tracking near-Earth asteroids and comets. We sponsor the search for life on other worlds. And we're building the first-ever solar sail. You can learn about these adventures and exciting new discoveries from space exploration in the Planetary Report. The Planetary Report is the Society's full-color magazine. It's just one of many member benefits. You can learn more by calling 1-877-PLANETS.

That's toll-free, 1-877-752-6387. And you can catch up on space exploration news and developments at our exciting and informative website, PlanetarySociety.org. The Planetary Society, exploring new worlds. We heard about the science side of the Mars Exploration Rover one-year anniversary from Steve Squires. Let's go to the fellow who leads the team of engineers Steve appreciates so much. Jim Erickson of the Jet Propulsion Lab near Pasadena, California, is the project manager.

Jim Erickson, thanks very much for taking some time out of your vacation to join us on Planetary Radio. Well, any time. I appreciate it. I like to spread the word out to the public. Congratulations on the completion of one year of rovers, Spirits specifically, on Mars, one Earth year. And we got another one coming up on the 24th. So with two anniversaries under our belt, it'll be nice to look forward to a couple more months, maybe longer, of action. What are the right superlatives to use? You've got two spacecraft that have done incredible science, made amazing discoveries,

and they really probably should have been dead nine months ago, and they're still going strong. And we hope to keep them running a little bit longer, too. But I would like to point out that Steve Squires is congratulating us, but it's really all of us, including the science community, that's been assisting us on the mission. It's been one real big team, and we've really pulled it off to a large extent because of how well we've worked together. That was a theme that we covered on this show early on, that the level of cooperation between the science side and the engineering side has really been a model, and you're saying that's held up?

It's still continuing to this day. We're really, really happy to see them when we get to see them. Right now we get a lot more video conferences with them to do the daily in-and-out sequencing of what the rovers are going to be doing. But we're going to actually have them, as many as we can, come out here on the 24th, and they're going to have a project science group meeting, and afterwards we're probably going to go out a little bit and celebrate. So you're going to celebrate that opportunity. I think so.

In the back of your mind, were you saying, well, yeah, the warranty is three months, but I'll bet you we're going to last longer? Actually, when we first started thinking about doing better than 90 days was probably about two weeks after landing when we actually knew what the power production out of the solar panels were. Now, we still had a lot of doubts that we'd get through the winter, primarily because we were expecting to have sort of a linear deposition of dust on the solar panels. We wouldn't get as much energy as we might. Well, a couple of things have happened.

One, there was a possibility pre-launch and pre-landing that the dust deposition wasn't linear, that it would tail off exponentially at some value based on some just end-of-the-mission observations with the Sojourner rover on Pathfinder. That turned out to hold up. In other words, you would get the dust piling up to a certain point, and then you just wouldn't see it arriving get the dust piling up to a certain point, and then you just wouldn't see it arriving at the same rate and sticking to those panels? Right. It looks like it falls off at about the same rate as it gets deposited, so everything was in good shape.

What we actually saw was probably about a maximum of 25 to 28 percent loss in the energy from the solar panels, and that's it, which meant we were in much better shape than we could have been, and we made it through the winter. The shortest day of the year, everything went fine. We had enough power to keep everything up to temperature and healthy. And after that, spring's coming. It's only going to get better. What else can you point to that would explain why these rovers have been so amazingly hardy?

Well, in general, I'd have to say that there's a great design team that put them together. You can't say enough about the people, what the plans were. We had to take into account worst-case analysis, what's the worst thing that Mars could throw at us. And so far, we're seeing a lot of breaks in our favor in terms of the amount of driving we can do. We've got more energy, so we get farther per day as an option. We also do other things with that energy. So we're sort of living the good life right now and probably for the future in terms of power. And that was the biggest constraint that we had to face. Motors, wheel bearings, we got what we could. The designs are beefier than you would expect to last for only three months.

But you can't really make them much weaker than they actually are. So it really was the power constraint that was going to do us in. And once we got past that, we're still looking to see what might be the problem that we're going to come up with next. But so far, everything looks like it's a long ways off. I think it's probably going to be something like a random part failure in electronics that's going to cause some kind of a problem. But until that happens, and there's no way really to model that or predict that, an indefinite future, an indefinite horizon for these rovers? Well, every time we get close to the shortest day of winter, we're going to go through, oh, I don't want to say a crisis,

but we're certainly going to have a crisis of conscience anyway as to whether we're going to survive that one. And we'll just have to wait and see each time. And the Martian year is just about two years, two Earth years. So think about that when you're talking about 06 in the summer, and we'll see what happens. You guys started out on such a crazy schedule, Mars time. That at least mercifully ended.

But it's still a pretty grueling schedule, isn't it? We actually still work as sort of a modified Mars time. On Monday, we'll start at 8 o'clock. Tuesday, 8.40. Wednesday, 9.20. Thursday, we're at 10 o'clock in the morning for the start time. On Thursday, we're at 10 o'clock in the morning for the start time. But when we roll to the point where we're going to end our operations day at 11 p.m. at night, we stop.

We start building two plans at a time, do less on each of those plans so we can accomplish it one day. And then the second day is just an update of the first one and a building of the second one. So we sort of begin to get ahead and are able to keep those two plans rolling. Then what happens is eventually we roll around to where we can come in at 8 o'clock again, we jump back to 8 o'clock in the morning, and we start the day over again. Now, in addition to that, keeping our activities between 8 a.m. and 11 p.m., we've also begun trying to actually have weekends off. What a concept. Most normal people.

And it's worked okay. We get less done over the weekend days, and it really makes Friday kind of an ugly day. But everybody would rather have an ugly Friday than get Saturday and Sunday off fairly reliably. It's nice to see the family every once in a while, and weekends are a good thing. So we're doing okay. This human side here and what you've learned on the planet about making a rover do what it needs to do for a long time, I assume this is part of the legacy of the Mars Exploration Rovers, particularly as excitement starts to build about the next step, the Mars Science Laboratory.

There's a couple of things that we probably ought to talk about at this point. One is the fact that when the team was running on Mars time, and I do mean running on Mars time, the science community had a component that was actually monitoring our sleep habits, logging some of our activities. And we're seeing some of that research coming out, but there's probably going to be more in the future. And they're still continuing to watch us.

It's probably going to be a long-term activity for them to monitor us and write papers on how people struggle with being on one planet and working on another. That's the human side. We're almost out of time. What advice are you giving to the MSL guys about how to build a rover that is up to the challenge on the red planet? It's interesting. We've got a whole series of lesson learned meetings that we're having with them. We've gone through probably 18 of them already, you know, three or four hours each. Different types of subjects, whether it's how the ground systems work, how the vehicle worked, how EDL worked.

We're actually even trying to find out how well the heat shield on reentry worked on Opportunity. That you crawled over to. And we'll see what the results are from that, whether we can get good pictures, good science out of what's left of that heat shield. Could you imagine three rovers active on the surface of Mars? Could I imagine it? Yeah.

But 2009, that's a long ways. We'll have to wait and see. I certainly will do my best to make sure we're there, but no promises. Things can break. Awfully nice work so far. No fault. And so, Jim Erickson, we'll simply say thank you very much. And once again, congratulations on a year on Mars. Thank you. I'll pass it on to the team. And we'll be right back after this. I'm Emily Lakdawalla, back with Q&A. Voyager 1 and 2 and Pioneer 10 and 11 are all on hyperbolic orbits, meaning that they will never circle around

to return to the neighborhood of our sun. Instead, they will travel forever. Eventually, long after the spacecraft have all ceased working, and possibly long after human civilization ceases working, they will visit other star systems. In 40,000 years, Voyager 1 will drift reasonably close to the star known as AC 793888 and the constellation of Camelopardalis. 300,000 years from now, Voyager 2 will pass distantly by Sirius, the brightest star in the sky. Pioneer 10 is perhaps the loneliest spacecraft of all. She will take more than 2 million years to pass Aldebaran, the nearest star on her trajectory.

These intrepid explorers are the first human-made objects to escape the clutches of the sun's gravity. Hopefully, there will soon be more such spacecraft, perhaps even carrying humans, to explore other stars. Got a question about the universe? Send it to us at planetaryradio at planetary.org. And now here's Matt with more Planetary Radio. Time for What's Up on Planetary Radio with Dr. Bruce Betts, the Director of Projects for the Planetary Society. Bruce,

Happy New Year, and in keeping with our theme, Happy One Year of Rovers on Mars. Happy New Year, Happy One Year of Rovers on Mars, and Happy New Year, and in keeping with our theme, happy one year of rovers on Mars. Happy New Year, happy one year of rovers on Mars, and happy one year of Mars Express in orbit around Mars as well. Lest we forget. That started a little bit earlier, still carrying out a successful mission under the European Space Agency. Those two rovers both working much longer than expected, as you've been talking about. It's pretty exciting. Bruce, what else is up? as you've been talking about.

It's pretty exciting. Bruce, what else is up? Well, we've got those festive and fun naked-eye planets all playing and partying in the night sky before dawn. It's a really rare thing. Well, at least it's kind of rare. It'll be a few years before you can see all five at one time easily. Right now you can if you get up before dawn, which I don't consider easy, but some people do.

You can see the brightest object in the east is Venus, looking like an incredibly bright star-like object. Near Venus, you will find pesky little Mercury. They're switching places here, but right now you have Venus with Mercury slightly to the lower left. Look to the upper right for dim Mars, slightly reddish. Farther to the upper right, you will see Jupiter, also looking extremely bright, though not as bright as Venus. Whip your head around to the other side of the sky over in the west following the same line and you will find Saturn. You can also see Saturn in the evening sky for those of us for whom pre-dawn

is challenging and you will see it appearing in the east in the evening sky next to Castor and Pollux, the stars. And when you look up at that reddish Mars be sure to wave to Biff Starling and Sandy Moondust, who are up there on the rovers. And happy anniversary, Biff Starling, one year on the surface, and shortly, happy anniversary to Sandy Moondust on the surface. People know from last week's show and the Huygens probe, about to enter the Titan atmosphere on January 14th.

It will enter the Titan atmosphere for a two to three hour descent through the atmosphere down to a hopefully brief few minutes that it will actually live on the surface and collecting data on the way. Those who are in the Pasadena area or interested in coming to the Pasadena area,

the Planetary Society will be having an event about Huygens arriving at Titan, and it will feature a retrospective on Voyager and Cassini and all sorts of good stuff that's happening. So go to our website, planetary.org, for more information or for more information on how to improve your life in general. I like that, and I hope they can. What else have you got for us today?

Random Space Fact! The length of the Mars day actually changes perceptively during its season because of ice sublimating from the poles going into the atmosphere and causing the rotation rate to change just slightly. That is so amazing, And you mentioned this to me just before we started recording. You said it's like an ice skater twirling. They pull their arms in, and, of course, they spin faster. Right, because when you have lots of ice on the pole, you've got all that mass concentrated near the axis rotation, and then the ice skater stretches the arms out as the ice sublimates,

and usually carbon dioxide ice going into the atmosphere, which is mostly carbon dioxide, and it spreads over the planet so it ends up slowing the rotation rate slightly but then it begins depositing at the other pole and you speed up the rotation a little bit. So cool. And isn't that what we're all about here? It really is. That and, you know, truly a random space fact. On to trivia?

On to trivia. Last time around we asked you, how many NASA administrators have there been in the wake of the current administrator, Sean O'Keefe, resigning? And how did we do, Matt? Well, we, or rather our listeners, did well. We got lots of entries, once again, from all over the world and a variety of correct answers. Interesting little variations, even among those who were right, because there were, if you count two acting administrators, or in our terminology, NASA. Acting dudes.

Acting dudes, acting NASA dudes. But really there were ten who were sort of full-time guys in the job, and they were identified by a lot of people. Ah, but it's even more complicated, and we didn't realize that. Well, we hadn't thought that through, or we would have been clearer as to what we were looking for. But James Fletcher was administrator twice, so there are nine separate people serving ten separate terms. We give it to either answer, choosing randomly between those that gave those answers. And here's our random winner, who happens to be one of the people who gave it to us in the most detail,

actually gave the names and tenures of each of the administrators, including the acting administrators, which he duly noted. And the winner is Morris Glover. Morris Glover of Abbotsford, Victoria in Australia. And so we have another of our Australian listeners who won out today. And he's going to take a medium-sized Planetary Radio T-shirt, if you please. Morris, we're going to put that in the international mail to you soon. Congratulations. And if you'd like your chance to win the fabulous Planetary Radio t-shirt,

answer the following question. How many cameras or imagers are on board each of the Mars Exploration rovers? How many cameras on each of the Mars Exploration rovers? Go to planetary.org slash radio to find out how to enter our contest and send us your wonderful answer and try to win that Planetary Radio t-shirt. And get it to us by January 10, 2005. Still sounds strange. Give me a couple of weeks.

January 10, 2005 at noon Pacific time. That's Monday. So that you can get your name in and maybe win that fabulous Planetary Radio t-shirt. All right, everybody, go out there looking up at the night sky and think about who first developed coffee. Thank you, and good night. Coffee, which I bet was a big part of the success of the Mars Exploration Rover teams, as it is for most people.

Undoubtedly, it was also a key component on the spacecraft itself. It's a little-known fact. The little-known percolator. Exactly. Which does not count as one of the cameras, by the way. Say goodnight, Bruce. Goodnight, Bruce. Bruce Betts is the Director of Projects for the Planetary Society.

He joins us each week here on What's Up. Join us next time for a pre-launch look at the Deep Impact mission. Have a great week.