Planetary Radio: Space Exploration, Astronomy and Science - The Right Site: Choosing A Landing Spot on Mars

Episode Date: August 25, 2015

The 2020 Mars Rover may be years away, but determining where it will land is already a hot topic among scientists and engineers. Many of the former gathered in early August for a site selection workshop. We talk with Co-Chair and Mars veteran Matt Golombek, JPL astrobiologist Lindsay Hays, and Ken Edgett of Malin Space Science Systems.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

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Clear skies. Keep looking up. Where, oh where, to look for past life on Mars? This week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. The landing of the next big Mars rover is still five years away, but the process of deciding where to put it on the red planet is well underway. We'll talk to three of the people helping to make that momentous decision. First, though, the Planetary Society's senior editor, Emily Lakawala,

considers a neat trick regularly pulled off by a current Mars rover. Emily, I would have wanted to talk to you today about your August 19 piece about how Curiosity takes selfies of itself. Is that redundant? But another issue came up. Before we talk a little bit about the challenge of doing that, I saw this post on Facebook from a friend of mine that had some of the selfies, and there were a lot of comments, and probably 10 to 20 percent of them said, oh, well, this is obviously fake. First of all, it looks like outside Las Vegas. And second, where's the camera?

You couldn't see where the arm was that was taking this shot looking back at the spacecraft. What's going on here? Well, my response to people who say that is to challenge them. Take your phone, go take a self-portrait, and show me where in that picture is your hand in the camera. That's not bad. And there's much more to this. How difficult is it for Curiosity to get one of these shots? Well, there actually is a fair amount of artifice on it,

not, of course, faking the fact that the rover is on Mars, but the fact is that the camera on the end of the arm doesn't have a wide enough field of view in order to get the entire rover and all of Mars around it in a single photo. When you try to take a panoramic picture on Earth, you use the video capture mode in your camera, and you actually sweep the camera around the landscape. And it's shooting many, many photos that in software, it assembles it into a single seamless panorama. And that's more or less what the rover is doing. It takes a single photo and then moves the camera slightly, takes another photo, and then sends nearly 100 distinct photos back to Earth, which are assembled on Earth with software and also a human hand

in order to make a single seamless-looking photo. These images, they have to be very carefully planned, and I guess everything has to be practiced first here on Earth? That's right. There's nothing that they do with the rover's arm on Mars that they don't practice on Earth first with their vehicle system test bed, VSTB. And what that means is that we have some great self-portraits of the VSTB sitting here on Earth with some of the human operators, actually, in the photos, which would be quite a trick if you could manage to do that on Mars, but we'll have to settle for the photos taken on Earth. which would be quite a trick if you could manage to do that on Mars. But we'll have to settle for the photos taken on Earth.

Very briefly, is this just good public relations, or is there good science that comes out of these? You know, it's mostly for public relations. And it's also a matter of documenting, sort of a historical documentation of the place on Mars that Curiosity was when she acquired the samples that she drilled out of the surface. They take these photos primarily where the rover has drilled in order to just kind of say, here I was, here is where I was when I took that precious sample of Martian soil. Wow. Terrific piece, Emily. Thanks very much. And remember to smile for the camera. You're welcome, Matt.

She's our senior editor, the planetary evangelist for the Planetary Society and a contributing editor to Sky and Telescope magazine. How do you pick a spot on Mars to drop a billion-dollar rover? A rover that will look for signs of past life and collect samples of the Martian surface that will someday be brought back to labs on Earth. Matt Golombek of the Jet Propulsion Laboratory knows this process as well as anyone. He has led it before, and he has begun co-leadership of it again as we prepare for a mission in 2020. A big step was taken in early August in a hotel conference room not far from JPL.

More than 100 scientists gathered to learn, argue, and cast informal votes for sites that offer a wide range of science potential and a wide range of danger for the robot that must land and drive safely across them. Matt and I talked in a somewhat noisy lobby right after a session of this second in a series of site selection workshops. Good to get you back on Planetary Radio. Matt, isn't this a great place to be talking? It's super.

I mean, this is where you start thinking about what your next rover is going to do on the surface of Mars, Thinking about what your next rover is going to do on the surface of Mars, what materials it's going to sample, and what materials might eventually get returned to Earth. So, yeah, it doesn't get much better than this. I walked in this morning, and I was so impressed. It was like, oh, my gosh, there's so-and-so and so-and-so. It's just like, I don't know how many people you've got, over 100, but all Mars all-stars. Yeah, and if you think about it, this is the place where you get real feedback on your hypotheses of what you think is at the surface. Because it matters when the rover actually gets there. And you want that criticality of thought and that discussion and that level of thought on what you think is at the surface to really help drive the site selection.

How long have you been involved in this kind of process for various missions? You're a vet. I think I started this with Pathfinder. Our first workshop was in 1994, maybe. So I guess that's, what are we at, 20 years now. And we had two open landing site workshops for Pathfinder, just, again, to get the community's input and response and thoughts as to where we might go and what we might do. So I'm looking at this incredible wealth of data that you and others have been presenting today.

How does this compare when you look back 20 years to Pathfinder? And it's got to be a somewhat different experience now. You have so much information. Yeah, it's spectacular what you can do now. I'd say with MSL, there were almost no surprises. We had seen so much of the surface in terms of the surface safety and characterization. Everything we saw was what we saw when we got to the ground now there's some different rock types and stuff but that that's

kind of you'd expect that but in comparison to pathfinder we had no new data except viking data from 25 years before and well actually there's some radar data but it wasn't it wasn't much to give you an example we didn't even know what the elevation of the landing site was because there were no accurate measures. We used radar data to estimate the elevation. And radar from Earth. From Earth, yeah, that's right. So we were picking based on 40, this was relatively high resolution Viking images for Pathfinder. They were 40 meters per pixel. So the smallest thing we could see or get resolved was the size of a football stadium. And the things you're worried about landing are rocks that are as big as you.

So how do you fill that gap? Whereas now with HiRISE, we see the shadows directly. We can measure the rocks directly. Yeah. You talked about that. In fact, you talked about the shortage of grad students forced you into developing an automated system. Well, yeah, it wasn't a shortage. It was just you wouldn't want to do that to any grad student. But yeah, that was something where having a machine vision tool became a very good way to do that. Tens of millions of rocks that you've now cataloged? So remember that we first started seeing rocks as individual rocks when HiRISE got to orbit around Mars. The first thing it was supposed to do was to certify the landing sites for Phoenix. And we had picked three areas that we thought were benign with respect to everything we knew at the time. And HiRISE got there and it took pictures of those

three regions and there were rocks all over the place and everybody just freaked out. So in a very short period of time, within months of starting to get high rise, we developed this technique to automatically measure the rocks and in fact, to measure them across every high rise image as it came in to make sure that we could characterize their total size frequency distribution and estimate the risk from it. It was born out of necessity and it was quite a bit. I mean, we were, what, a year from launch at that time. That's unprecedented to have that big a surprise in your site selection activity that late in the process. So we know so much more now about this planet and where to put a lander and how to get a lander down there. But it's still tough. I mean, planning a road trip on Mars is no easy task.

Yeah, there's two parts to this. So very interesting to compare the science data that drove the site selection for Pathfinder versus the science data that's driving the selection now. And that's a great way to look at our advance in knowledge of Mars, because as the science community learns more about the planet, those factors are going to become important. So as an example, Pathfinder was the first small rover with a chemical analysis instrument to roam over 100 meters. And the idea was, let's just see what Mars is made of. We had no idea what Mars is made of. We had no chemical information that told us what the composition of Mars.

We inferred it was basaltic from shield volcanoes and meteorites, but we didn't know, and we didn't know what else was there. So we landed at the mouth of a catastrophic outflow channel, figuring we'd get a grab bag sample of what Mars is made of. That was it. That was the sophistication of the science. Whereas now, we're talking about clay minerals and metamorphic minerals and habitable environment where water has processed those rocks. Much more specific and detailed information about the environments, the geologic evolution of that region, and why it would be a good place to get samples back. So incredibly more sophisticated now than we were 20 years ago.

Some consideration is still the same, right? I mean, does much of this come down to finding the right balance between science and engineering, protecting that rover? If you don't land safely, you don't get any science. It doesn't matter what your aspirations are. But even there, what we're evaluating, remember Pathfinder's ellipse, we didn't even know where Mars was in its orbit. It'd been 20 years since we'd been to Mars. We didn't know its ephemeris.

So our ellipse was 300 kilometers by 100 kilometer. That was as accurately as we could target a lander. Now we're talking about 12 by 18 kilometer ellipses. These are teeny, teeny little spots going to incredibly special regions. Think about an ellipse 130 kilometers across. You can't target a single unit. It's too big. You just need smooth and flat. And so the engineering constraints dominate in ellipses like that, whereas now the science is driving you to these very, very special places. You have an interesting collection of site candidates that are being discussed here already, and there have already been some initial evaluations of which ones may be more practical than others. Is this fairly typical? Are you pleased with the process? Yeah, so what happens in site selection is you become, with time, more and

more specific and precise with your estimates of how safe the site is as you learn more and more specific and precise with your estimates of how safe the site is as you learn more and more about it. And as you map it and try to understand it more, you learn more about what scientific things are there for you to investigate. And those two things go hand in hand. And as you learn more and more and more, there will be distinguishing characteristics that will separate out. And this is the first salvo of that at this level. And this has happened for every site selection. You start out with a large number and you parse them down and you parse them down. Well, this one has better science.

This one really looks terrible to land. And you get down to a smaller number that you study in ever more detail until you come up with a winner. There's an abbreviation that I must have heard over 100 times this morning. And I want you, if you can, to tell us what this is all about. TRN. So it's Terrain Relative Navigation, TRN. And it's effectively how cruise missiles work here on Earth. So the missile has a map in its head of where it wants to go. And it goes, it flies there, and then it collects a map

in real time while it's traveling to correlate with the map it has in its brain from what you told it to do beforehand. And it matches the map that it had pre-programmed with what it collects. And that gets rid of all the uncertainty between the cartographic frame and the inertial frame and the landing and yada, yada, yada. And that allows you to know beforehand where you're coming down in that map and then that allows you to say well i'd want to avoid the bad places if i've determined from orbit that this patch is too rocky or too slopey or has bad things about it, we can divert away from that by 100 meters, 150 meters as we're coming down. So it matches the map. It figures out, oh, my God, I'm coming down to a bad place.

I'm going to just nudge over here. It takes a little extra fuel on the final descent, but it's capable of doing it. So that's what TRN is. So it gives you a little bit of extra flexibility. It could turn a site that doesn't look so great into one that might work. So I think that's the dominant thing you saw from this morning is our estimates of the success probability at many of these sites are dramatically improved if you have that little capability to avoid the bad spots. What's also clear is the incredible variety of factors that need to be considered. Even, and there was a presentation here from someone about not this mission,

but the next mission, the one that will follow up, the one that's going to collect the samples that this one, we hope, is going to, cash is going to leave here and there. I think part of the idea of having an open workshop to help select a landing site is the landing site is more important than just the mission that operates that particular mission. The results that come from that mission have a direct feedback into our understanding of Mars and how we could think about and consider the planet. And wouldn't you want the widest diversity of opinion that's brought to bear on that topic? In this particular case for Mars 2020,

it's even more important because this is collecting samples that could be returned in the future. And the people who are going to be investigating those rocks when they come back to Earth from Mars are none of the people who are sitting in this room. We may be gone, okay, but it will be a group of laboratory people that will take slices of that rock and learn incredibly wondrous things. We have a record of that from the Apollo missions when those samples got returned. That was the vibrant analysis. Heck, it's still going on today. So you want to make sure that you have a wide diversity of opinion that goes into the selection of that site.

And at some point, that those people that, okay, maybe it's not them, but people like them would be analyzing these rocks when they came back, have a chance to enumerate what their greatest interests and concerns are about the process. What is the timeline? We still have five years roughly until this mission heads out to the red planet. So every site selection takes between three and five or even longer numbers of years. It has to be done as the project is being designed and worked as a feedback between what we think the lander can accept and take, what it can land on safely,

and every spacecraft is different. So even though this is like MSL, it's a little more massive, it already has new safety criteria that are coming up. So you can't do it beforehand because you don't know how the system is going to be evolving with regard to the hazards until it gets pretty close. So yeah, we have a bunch of time, and that's the idea, is to use that time to investigate these sites and understand them better. And the requirement is that we select, oh, sometime before launch. Now, this particular project would prefer to select a little bit earlier if they could,

and we're on track to try to do that. So a year or two before launch, we'll probably have a pretty good idea. Best of luck with that, Matt. It's great to talk to you, and I sure look forward to following this process. And we hope you will. Matt Gollenbeck of JPL, co-chair of the Mars 2020 Landing Site Steering Committee. Stay with us to hear from two prominent participants in the site selection workshop. This is Planetary Radio.

Hey, Bill Nye here. I'd like to introduce you to Merck Boyan. Hello. He's been making all those fabulous videos, which hundreds of thousands of you have been watching. That's right. We're going to put all the videos in one place, Merck. Is that right? Planetary TV. So I can watch them on my television? No. So wait a minute. of you have been watching. That's right. We're going to put all the videos in one place, Merc. Is that right?

Planetary TV. So I can watch them on my television? No. So wait a minute. Planetary TV's not on TV? That's the best thing about it. They're all going to be online. You can watch them anytime you want.

Where do I watch Planetary TV then, Merc? Well, you can watch it all at planetary.org slash TV. Random Space Fact! Nothing new about that for you, Planetary Radio fans.org slash TV. I really wouldn't. A new random space fact video is released each Friday at youtube.com slash planetary society. You can subscribe to join our growing community and you'll never miss a fact. Can I go back to my radio now? Welcome back to Planetary Radio. I'm Matt Kaplan. This week, bringing you conversations with three of the over 100 scientists who participated in an early August workshop.

They narrowed the choices for a 2020 Mars rover landing site to eight locations. They were told to consider only science in this gathering, and that's what I discussed with Lindsay Hayes. Lindsay is a space systems engineer and astrobiologist with JPL's Mars Program Office. I jokingly asked her how one studies alien life that, so far, no one has found. Ah, the old astrobiology is a science without a subject question. As astrobiologists, we like to think of it as a little bit different. We have a lot of things to study, and actually, astrobiology is the intersection of a lot

of different fields. It's organic geochemists who want to look at lipids, and it's astronomers who look at extrasolar planets, and it's a whole bunch of people who look at Mars and icy worlds in this solar system and all that kind of thing. Instead of having no subject, we actually have an overabundance of subjects in a way. The really exciting thing about Mars 2020 is that it's our first opportunity to pick out which samples we want to return from Mars. The point of visiting the Meteoritical Society group, those are people who study meteorites. So we do have rocks from Mars. We just haven't been able to pick which ones we want yet.

And so the exciting thing about Mars 2020 is we'll get to return samples that we pick and we'll get to say we want that kind of sample or this kind of sample. We want one that we know has evidence of having been in a wet environment or we know is related to this particular lava flow or something, as opposed to sort of, well, it's something from a lava flow or it's something that saw water at some point. We can put all of that context into it, which allows for the results that we get to have that much more of an impact.

Obviously, we've been able to do some incredibly wonderful research in situ, sitting on Mars, particularly with MSL. Why this holy grail of sample return? Well, sample return allows us to take that science that we do from the in situ science and be able to then apply the instrumentation that we have in our labs on Earth. This is a terrible analogy, but it's the best one I like to use because it makes a lot of sense. You know, when you think about your travel size, you know, the things you have at home, you have the big hair dryer that can really do a great job.

You have that sort of thing. But the version you take with you on vacation is never quite as good. But being able to take those samples, bring them back to our lab, we can get much higher resolution measurements. We can do a lot of different kinds of measurements. The big problem with in situ science is sometimes we don't know what we want to measure until we get there. And when you have those samples back on earth, we say we want to study this thing. Okay, great. But now we also want to apply this other instrument and that kind of thing. So it allows you to do that iterative process that is science,

and as soon as you learn one thing, then apply the next thing. Okay, well, what's the next question we want to answer? And with the instruments on the Earth, you can do that. So here's the $64 or 100 million mile question. If you didn't have to consider engineering, if you didn't have to consider making sure your rover survives to do the work, and looking at it just from the astrobiological viewpoint, where would you want to plop this lander on Mars? From my own personal perspective, and this is not NASA, this is not JPL, this is Lindsay Hayes,

I've done a lot of work in hydrothermal Hayes. I've done a lot of work in hydrothermal environments. So I've done a lot of work in Yellowstone and that kind of thing. And there's a combination of factors there. There's water and there's, you know, the right kind of temperature, but most important, there's energy. And so we always want to look for that combination of three things, you know, water, food, and energy to allow you to sort of to grow and live. And then on top of that, you need preservation. The two things that I presented here were this combination of either a sedimentary environment, the kind of thing that you would see at the bottom of a lake or, you know, at an ocean or a hydrothermal environment that you get

good preservation for. I think those are going to be our best bets for looking for biosignatures. good preservation for. I think those are going to be our best bets for looking for biosignatures. Lindsay Hayes of JPL, also at the second Mars 2020 rover site selection workshop, was Ken Edgett of Malin Space Science Systems. Malin is the legendary builder of cameras that are on and above Mars, as well as other places around the solar system. I asked Ken if he has a favorite in the site selection race. I frankly don't know where to go with this mission because of the competing interests of what you would want to do with samples you bring back from Mars. There's not any one single magic bullet site

that you can get to all the things you wish you could study at one place. So I don't really know where to go. But I did want to reserve the idea that, you know, if one of the rovers stumbles upon the most important thing ever, we ought to consider going back to those places. This is not the first of these meetings, meetings like this that you've been to, right? Yeah, I didn't come to the first of this, for this mission, but I had been to the whole series for MSL for Curiosity and watched, for example, Gale Crater on the list, come off the list, get back on the list.

So those things do happen. What do you think of the process? I mean, there are so many people in there who are going to be contributing to this. It's a tough process. in there who are going to be contributing to this? It's a tough process. You're trying to keep each other honest and be realistic about what these sites all offer. But, you know, this is a great list of sites. And it really is. I rack my brain every day. Is there something we're missing? Is there a site that's accessible, to this landing system this thermal system etc that would be better than anything on this list and i still rack my brain i hope to you know keep

doing that until i either decide nope these are good or holy cow everybody's forgot about this place i thought maybe you'd just be partial to places that are going to make pretty pictures. Arguably, we got that in Gale. So, no, really, this is all about the science. And, you know, if it turns out to be the flattest, boringest place, but it has all the magic bullets, man, then that's where we should go. Ken Edgett of Malin Space Science Systems. Ken Edgett of Malin Space Science Systems. More on the 2020 Mars rover next week when we'll talk with Jim Bell about Mastcam-Z, the powerful stereoscopic eyes planned for that robot.

Our mission coverage will continue right through the celebration when it touches down and begins its journey across the red planet. Bruce Betts is the Director of Science and Technology for the Planetary Society. He has joined us again for our weekly dose of What's Up in the Night Sky. Welcome. Before we get into What's Up, you were at that site selection meeting that we were just talking to people about. What did you think of it? I thought it was interesting. Most people probably have no concept of how many hours, how much time, how much work goes in by a lot of people to figure out where you put your billion or two billion dollar rover to try to get the most benefit and science out of it.

And so it's this multi-year process. Also, what's interesting to me this time is there's more, because I've been attending landing site workshops since Pathfinder, there's more focus in the way the mission is drawn now on looking for biosignatures for potential signs of past life and, of course, for the first time, on caching samples, trying to figure out samples that you would want to bring back to Earth. Yeah, I was certainly impressed with the process for the morning that I was there. And five years to go before we actually have another rover on its way.

Tell us, what's up in the night sky? Early morning, low in the east, Mars, pretty dim. Venus, lower, but super bright. So both Mars and Venus will be getting easier and easier to see in the pre-dawn east. And then in the evening, we have Saturn still hanging out near Scorpius in the south in the early evening. I've been checking out a few International Space Station flyovers. You should go check them out, but that's regional, so you need to do some homework a couple good ways. Our NASA has a spot the station site that will email you about the best passes, or heavensabove.com. And that's heavens-above.com where you sign in with your location. All right, thank you for that.

Moving on to this week in space history, both of them, Voyager 2. In 1981, it flew past Saturn during this week. And same day, eight years later, it flew past Neptune in 1989, with of course, a Uranus flyby in between. We move on to... Well done. Why, thank you. The distance to the closest star system, which is, of course, Alpha Centauri, is about 270,000 times the distance between the Earth and the sun. Space.

It's still big. It's really big. And as I keep saying, it's really, really empty with a few really cool things filling up not a lot of space. All right, we move on to the trivia contest, and I asked you about how many galaxies, including dwarf galaxies, are in the local group that the Milky Way is part of. And we got some variety in answers, which was expected, because the number is not absolutely pinned down.

But I was looking for ballpark, and I know we did well, Matt. Tell me more. Indeed got somewhat of a range of answers, although all within the same range. And a lot of people talked about how it's very tough to find a precise number, probably because there isn't one. I'm very happy to say, though, that Timothy Gale in Denmark appears to be within the acceptable range. He certainly was accepted by Random.org as this week's winner.

He said that he couldn't find the precise number, as we said, so he went with 54 or more, which you found acceptable. Yeah, anything in kind of the 50-60 ballpark range works, so congratulations. Timothy, we're going to send you a Planetary Radio t-shirt and a light sail patch. I don't know if I would sew it onto the t-shirt, but you probably have something you can do with it, and they're really pretty cool. Nice embroidered patch.

We heard from Ryan Hyken as well. He gave us a little bit more information. from Ryan Hyken as well. He gave us a little bit more information. He said that not only is there the Virgo cluster that we're part of, but there is the Laniakea supercluster that contains our cluster, Virgo, the local group. That's quite a structure you're talking about there. You've got the local group, and then beyond that, the Virgo supergroup, and then Laniakea and

there's yeah various groupings that have occurred over time. I'm a little more doubtful over this question Kevin Hecht in Illinois he said his dad once owned a Ford Galaxy would that be considered part of the local group? Yeah actually no no. Dwarf, but not four galaxies. Finally, this from Martin Hajofsky, who obviously knows how to get mentioned. He said, this was a tough one, as I generally only think of the local group as being Matt Kaplan, Emily Lakdawalla, Bill Nye, Casey Dreyer, and Bruce Betts. Well, we are counted as part of the galaxies. We are stars.

Okay, before anybody thinks about that too deeply, please go on. New question. What Mars lander or landers were imaged under parachute while descending to the Mars surface? So name all of them, one or more, that were successfully imaged by Mars Orbiter while under parachute. Go to planetary.org slash radio contest. The prize will once again be a Planetary Radio t-shirt and a beautiful embroidered light sail patch. All right, everybody, go out there and look up in the night sky and think about integrated circuits.

Thank you and good night. That's Bruce Betts. He doesn't have a chip on his shoulder no matter what it sounds like. He's the Director of Science and Technology for the Planetary Society who joins us every week here for What's Up. Planetary Radio is produced by

the Planetary Society in Pasadena, California and is made possible by its choosy members. Daniel Gunn is our associate producer. Josh Doyle created the theme music. I'm Matt Kaplan. Clear skies.