Planetary Radio: Space Exploration, Astronomy and Science - Phoenix Mars Lander Principal Investigator Peter Smith

Episode Date: July 30, 2007

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A phoenix rises from fire for its flight to an icy red planet, this week on Planetary Radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan. This particular phoenix may head for Mars as soon as this week. With the countdown underway, we'll talk to Principal Investigator Peter Smith about what it will accomplish when it touches down much farther north than any previous Mars lander and digs down to a layer of ice. All the regulars check in this week with Emily Lakdawalla's Q&A just seconds away.

Bruce Betts will tell us about the night sky and a very busy week in space history, just before he gives away another stylish Planetary Radio t-shirt. With any luck, Phoenix will start its journey to Mars just before Space Shuttle Endeavour lifts off for the International Space Station on August 7. A crew of six under Commander Scott Kelly have planned an 11-day mission. It has been four and a half years since Endeavour's last passage into the void. The July 26 accident at Burt Rutan's Scaled Composites facility in California's Mojave Desert is still being investigated. The explosion that killed three workers reportedly took place as a propellant

test was being conducted on Spaceship Two, the company's passenger-carrying follow-up to record-breaking Spaceship One. Want to see how bad the Martian dust storm is? Watch the sun disappear in a series of images on Emily Lakdawalla's blog at planetary.org. Spirit and opportunity are still doing fine. I'll be right back with Peter Smith of the Phoenix Mission. Hi, I'm Emily Lactowalla with questions and answers. A listener asked, How do they determine the zero meridian on an extraterrestrial body?

In order to map the planets, moons, and asteroids, cartographers need to fix a geometric reference frame on the body's surface. It's easy to pick the poles and equator, because every body in the solar system rotates about a spin axis. But how do they choose the zero longitude mark? For planets with solid surfaces, the zero longitude line is usually chosen arbitrarily to pass through some reference point. For example, on Earth, zero longitude passes through the Royal Observatory in Greenwich, England. On Mars, it passes through a small crater named Airy Zero. For most of the moons in the solar system, there is actually a logical longitude to choose, because most moons keep

one face pointed at the planet at all times. The point on the moon that's closest to the planet is defined as zero longitude. Once you've chosen your zero, however, you need to choose which way longitude is measured, positive to the east or positive to the west, and how to make that choice is the subject of a surprising amount of contention. Stay tuned to Planetary Radio to find out more. You might think that the head of a mission about to leave for Mars wouldn't have time to go on the radio. We're sure Peter Smith had plenty on his mind. He nevertheless took time to give us an update on the Phoenix lander.

Peter is the University of Arizona planetary scientist who serves as principal investigator for this aptly named voyage to the red planet. Peter, I don't even know if you remember the last time you were on planetary radio, but it was when the Phoenix mission was still a candidate, and you were waiting to hear if you would be selected to head to the Red Planet. And here you are, less than a week away from the launch of this lander. You know, our launch date next August 3rd is the four-year anniversary of being selected. So it's been precisely four years.

I did not know that. That's great. Well, congratulations, of course. This has got to be an incredibly exciting and busy time. Both, yes. Of course, your window opens on August 3rd, and then I guess you've got, what, about three weeks to get this spacecraft on its way? That's correct, and we could probably even limp along for another week, which would shorten the mission day by day.

But for the first two weeks, we actually land on the same day, May 25, 2008. You pretty much know where you're going now, or do you still have some flexibility in the landing site? Well, we have a box that we've identified, and we'll land in that box. And the box is about 400 kilometers square. It's an area we can shift our landing uncertainty ellipses around in and find just the best place and safest place, and of course the most scientifically interesting place within our box. Now, anywhere in that box is going to be, I assume, interesting place within our box. Now, anywhere in that box is going to be, I assume, much farther north on Mars than we've ever visited before. You're correct. This is really like northern

Alaska on the Earth or the Siberian permafrost. It's a unique part of Mars and represents almost 25 percent of its surface area because it's found not only in the north but in the south. And your spacecraft is certainly designed to take advantage of this location and really dig into some science. I won't even refer to a pun there. Thank you. Yes, you're exactly right. Our entire mission consists of gathering samples from the subsurface and analyzing them,

and eventually we expect to dig down to an icy layer, and this has been discovered by the Odyssey orbiter and verified by other instruments on, I think it was MRO and MGS. So we really have an opportunity to actually follow the water, which is NASA's motto. The nature of this mission, the fact that you will be so far north in itself, puts sort of a time limit on Phoenix that, for example, the rovers don't have. That's exactly correct. We have three months to do our primary science

and then probably another three or four months to monitor the polar weather, which is bound to be exciting, especially as winter starts to approach. We cannot last through the northern winter. It freezes our spacecraft down to a temperature below which it's capable of surviving. You know, as you look at the spacecraft, I would guess most people would agree with me that the most interesting physical feature about it is that robotic arm that's going to allow you to dig down below the surface.

And I have to tell you that at least in Earth terms, it looks kind of spindly, but there I am thinking as an Earthling. Well, if you had your feet braced on rocks and were trying to pull that arm and keep it from moving, you couldn't stop it. Really? It's quite a strong and dependable digging tool. Now, that doesn't mean it can go through solid ice at very cold temperatures. And we have an actual power tool on the end of the arm

for gathering samples inside the hardest of the ice. And you've got a camera right out there on the end too, right? We sure do. And we have one on the deck. And so it's kind of a camera-controlled robotics. We get pictures back at the Earth, we do a 3D terrain model, and then we tell the arm where to dig inside of that model. Talk about the other instruments that Phoenix is carrying to the Red Planet. Yeah, we have the themes of fire and water. And one instrument accepts samples into its ovens.

It has eight separate ovens, each used once. And it heats the soil very slowly up to 1,000 degrees centigrade. And at those high temperatures or on the process of getting to those high temperatures, you decompose all kinds of minerals that are formed through the action of water on soil. And so we can tell precisely what minerals have been formed and try and determine if that ice melted and created those minerals. And so we're looking for clays and carbonates and things of that nature. And then as gases are cooked out of this material,

and you might think of your oven at home, if you leave the oven on too high a temperature, you start to see smoke come out. And that's what happens with these materials. You can actually detect complex organic compounds by the smoke coming out of those little ovens. And we analyze that smoke, and we understand exactly what was in those ovens. You know, it occurred to me recently, reading about this mission, which will be the first since Viking to make a soft landing via retro rockets on the surface. I think you're also the first since those missions 30 years ago

that they will have sort of these little reaction chambers that you'll be able to dump these samples of Mars into. Oh, yeah, that's right. And, in fact, the other type of sample chamber we have is when we actually add water. We simulate what happens to the soil when the ice melts by adding water. Otherwise, we'd have to wait 50,000 years for that ice to melt or lager. And so we are going to look at what goes in the solution, and in particular the salts, you know, like the Great Salt Lake and the evaporates.

You know, by looking at the nature of the wet soil and looking at what happens when we cook the soils, we can tell if that ice has ever melted. I've read that this is basically a geological mission, but here you're mentioning the fact that you'll be able to detect organics, at least certain organics. Do you have any thought in the back of your mind of being able to find some interesting chemistry there that might go beyond geology on Mars? I think you know what I'm getting at.

Right, and what we say we're doing is looking for a habitable zone. We're looking for food sources, for the presence of liquid water. We're looking for the building blocks of life as we know it, and that's not just carbon, hydrogen, and oxygen, but also nitrogen and phosphorus and sulfur. And by really finding all the ingredients necessary for life, we would call this a habitable zone. Now, what are the chances, without any previous indication from remote sensing, that we would be lucky enough to land in some biological oasis on the northern plains? I think this is something that would have to be searched for. So we're just looking for the ingredients for life and the possibility that

life could exist somewhere in that region. That's Peter Smith, Principal Investigator for the Phoenix Mission to the Martian Arctic. We'll hear more in a minute. This is Planetary Radio. I'm Robert Picardo. I traveled across the galaxy as the doctor in Star Trek Voyager. Then I joined the Planetary Society to become part of the real adventure of space exploration. The Society fights for missions that unveil the secrets of the solar system. It searches for other intelligences in the universe, and it built the first solar sail. It also shares the wonder through this radio show, its website, and other exciting projects that reach around the globe.

I'm proud to be part of this greatest of all voyages, and i hope you'll consider joining us you can learn more about the planetary society at our website planetary.org slash radio or by calling 1-800-9-WORLDS planetary radio listeners who aren't yet members can join and receive a planetary radio t-shirt our nearly 100,000 members receive the internationally acclaimed planetary report magazine that's planetary.org slash radio. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. I'm Matt Kaplan. Phoenix Mission Principal Investigator Peter Smith

of the University of Arizona is our guest. His lander may already be in space as you hear this, headed for the frozen northern reaches of the red planet. How does Phoenix fit into the constellation of both orbiters and, well, the rovers that we now have on Mars? Well, I'll tell you, we had a plan starting 10 years ago to send first an orbiter and a lander to Mars at every opportunity. And then that's every 26 months you can actually launch to Mars. For two opportunities, we did that. And then with the failures of Polar Lander and the Mars Climate Orbiter, we kind of went back to another less ambitious method, and that is having an orbiter and then a lander and an orbiter and a lander.

And the idea is that the landers follow up on the discoveries of the orbiters. And Phoenix is a perfect example of that because we are following up on the discovery of ice in the northern plains by the Odyssey spacecraft. For those people who didn't hear that show that we did something like four years ago where we talked about the genesis of the Phoenix mission, like four years ago where we talked about the genesis of the Phoenix mission. Can you talk a little bit about why that name, Phoenix, is so appropriate for this lander? Yeah, the Phoenix is the mythological bird that lives 500 years and then dies in flames, and out of the ashes from that fire comes the new Phoenix bird.

And so we think of it sort of as a rebirth or a resurrection in some sense. We are trying to recover the investment into Mars landers made over the last 15 years with Polar Lander, with the 2001 lander that was mothballed after it was canceled. And so all of this equipment was available, and we were allowed to propose it for a scout mission. And by gosh, you know, I participated in all those missions, and I was really anxious to find a really important science task for this equipment to do so we could actually realize on NASA's investment over the last 15 years, and of course my investment too. So we called it Phoenix. But of course, Phoenix has an Arizona connotation, too.

Has spoken like a proud Arizonian. The landing system that you'll be using, which was, you know, developed a while back as well, is the only place where I've heard comments about this mission and concern that because you do come down on these rockets that by necessity use toxic materials, that you might be affecting the landing spot that you'll be looking at. And I wonder what your thoughts are about that and whether you have any concerns. Well, as you might suspect, the landing is the riskiest part of the whole mission, and we've put a great deal of effort into it. And we are using thrusters because this class of spacecraft was developed before airbags had actually successfully landed on Mars,

and we inherited this, so that's part of the Phoenix inheritance. So we're going to use them, by gosh, and we're going to make sure they work properly. Now, as far as damaging the landing site, of course, that's a concern we've faced all along. Since we're looking for organic materials, we've been very careful to find hydrazine, which is our fuel, that has no organics as a contaminant. Therefore, as it combusts, while it puts ammonia and water down on the surface, it doesn't put organic contaminants on the surface. And of course, the thrusters can also blow soil away. And that's something we're just going to have to live with and find places in our digging area, which is

quite large. It's about eight square yards where the soil hasn't been disturbed. And of course, you have this advantage of being able to dig down, what, pretty far. Is it a half meter or so that you're hoping? We can reliably dig to half a meter, and if we find the digging fairly easy, we could finally probably go to a meter. But we know we can get to half a meter. So your window opens on August 3rd. Will you be at the Kennedy Space Center for the launch?

I don't imagine you'd want to be anywhere else. I sure will, and I'll be in the control room, actually. And then you've got to... No, I don't have the red button. No. Well, I think that's appropriate. Of course, I'd be in trouble if I didn't mention the 250,000 or so passengers that you're bringing along on this spacecraft on the Visions of Mars DVD. This is really an exciting thing we're doing with the Planetary Society.

We've taken all the Planetary Society membership, and we've put their names on a DVD, and we've also put some of the literature that a lot of us have loved growing up and as science fiction fans, from Arthur C. Clarke, from Carl Sagan, from many of the great science fiction writers of the last 50 or 75 years. And we've thought of this as the first library on Mars. Now, you might think, well, who needs a library on Mars? But in my introduction, I talk about what if in 10,000 years we've gone through another dark age on this planet, through some sort of third world war or who knows what, or global warming or any of the threats it faces as a human species. And what if in 10,000 years we get back to a space-faring society and we've lost all knowledge of what was happening in the 20th century? We would have a library on Mars that future astronauts could return and could be, you know, really a treasure for them.

Reminds me of an Isaac Asimov story I read once many, many years ago. It is in the world of science fiction. It's not something you do, you know, as a major part of your mission, but we were able to do this just as kind of a wonderful side event, you know, something we're really kind of having fun with. But it certainly adds another note of romance to this mission, and it's really hard to talk about any mission to the Red Planet without feeling the romance. I think that's right. There's a certain virtual human presence as you send a robot down to the surface of an alien planet.

And we think of that as our lander, you know, having eyes and ears and an arm and so forth. It really is a virtual human on Mars. And this reminds me that 100 years ago, humans were exploring the south polar region of Antarctica for the very first time, Amundsen and Scott racing to the pole, only 100 years ago. And so now, 100 years later, we are sending a virtual explorer

to the polar region of Mars. I find this very intriguing, and I really wonder what we'll be doing 100 years from now. Very exciting. And I hope that you're getting some sleep in these days leading up to the launch. Yes, I am. Thank you. Peter, thanks so much, and I hope that we can check back with you. Of course, we have been covering the Phoenix mission, and we will continue to do so.

And I am willing to bet people will be able to look to Planetary Radio for special coverage when that landing comes, if all goes well, in late May. I'd be pleased to join you again. Thank you so much. Planetary scientist Peter Smith of the University of Arizona is the principal investigator for the Phoenix mission, leaving shortly for a red planet near you. We will return with Bruce Betts, yet another planetary scientist, for this week's edition of What's Up, right after this return visit from Emily.

I'm Emily Lakdawalla, back with Q&A. There's quite a debate over which direction longitude should be measured on planets and moons east or west. Longitude on other planets was first defined by astronomers. As a planet rotates, they define the longitude so that it increases with time when observed from a distance. Thus, if the planet rotates in the same sense as the planets motion around the Sun, as with Mercury and Mars, longitude is measured positive to the west. If the rotation is retrograde or backwards, as with Venus, longitude is measured positive to the east. Unfortunately, tradition had this backwards for Earth. Longitudes on Earth

are measured positive to the east, so that an astronomer observing Earth from a distance would see the longitude decrease with time as we rotate. This difference in convention from planet to planet has resulted in a lot of confusion, and it's only gotten worse as scientists have started to create digital maps of the planets. To deal with this confusion, in 2002, the International Astronomical Union formally recommended that the Mars Convention be changed so that longitude is now measured positive east, the same as it is on Earth. The same may eventually be applied to all the other planets. It may lead to less confusion in the long term, but in the short term, the flip-flopping of longitude is a huge headache for planetary mappers.

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 with Bruce Betts, the Director of Projects for the Planetary Society, back to tell us more about the night sky and something really cool. Perseid meteor shower. Very, very cool this year. Perseids are traditionally the second most powerful shower, no, the most meteors per minute on average of the year in a normal year when you don't have a freak shower. But it's good because at least for us

northern hemisphere people, it actually comes in the summertime. And it is peaking on August 13th, before I forget to mention that date. But it is kind of a slow peak usually, so you can get away with going out a few days before, a few days after. There's a new moon on the 12th, so it's going to be a really, really dark sky. Well, you know, unless you're in L.A. But if you go somewhere dark, then you'll hopefully see a lot. This is, you know, something like one a minute is what we're looking for here.

Wow. And it's going to be better later in the evening. But if you go out after 10, midnight, something like that, then the so-called radiant will be up and you'll see more. I've heard that there are places, even on this planet, that become dark when the sun is facing the other side of the planet. Yeah, I've always wondered about that, because I think physics would indicate it would. It sounds, well, yeah, but, you know, it'd be nice to have it backed up by reality, too. I know. I just thought that maybe I didn't understand something, because it's always light here.

Anyway, that's not important right now. I hear some of our listeners are able to see. And even in a light sky. I mean, the Perseids really, if you're patient, hang out for a half hour, an hour, you will see some. Total lunar eclipse, August 27th or 28th, depending on where you are. Visible from throughout most of Eastern Asia, Australia, and the Americas. Oh, yes. So count on free clouds in Southern California.

We'll remind you of that. In the meantime, check out the Perseids August 13th. While you're out there, of course, well, Venus. Venus is still there if you look over just after sunset, but dropping, dropping, dropping quickly. But Jupiter, Jupiter will be the lovely bright star-like object there in the evening sky hanging out in the south moving towards the west over time and if you look down below jupiter you will see anteres red star in scorpius and in the middle of the night you will check out mars gradually moving up looking kind

of reddish as well you do have a lot going on i do i do but i have to know one thing in this week in space history because you know a great day in space exploration. That's right. The first driving of a vehicle on another body by people. So, yeah, they fired up the lunar module on Apollo 15 back in 1971. We had the Messenger spacecraft launched just three years ago, headed on its journey to Mercury. And this is very exciting. launched just three years ago, headed on its journey to Mercury,

and this is very exciting. January, mid-January, we're finally going to see the half of Mercury we've never seen with cameras. First of three flybys, Mark. I believe three. Mariner 10 had three. Three flybys, and then they go into orbit, I believe, in 2011. It's energetically really tough to get in there and hang out with Mercury. Can we just count that as the random space fact?

If you like. No, I'll give one because I didn't get to say. Random space fact! I'm awake now. Excellent. Speaking of getting awake, hey, we can study people. You know, there are people that study asteroid collisions that's their specialty families of asteroids you know and they're counselors for these things too but

that's a little ahead of its time um they collide asteroids they typically whack into each other or they can add up to up to thousands of miles per hour, kilometers per second. But the really big chunks that come flying off because of that whole momentum energy thing come off at like 100 miles per hour or less. Oh, yeah. Two billiard balls or croquet balls passing in the night, hitting each other. It's all vector stuff, isn't it? All that physics stuff. Yes.

What's your vector, Victor? and all that physics stuff. Yes, what's your vector, Victor? Moving right along to trivia, we asked you, in a fit of bureaucratic madness, brought on by the International Mars Conference, I asked you, what does MEPAG stand for in connection with Mars? M-E-P-A-G. How do we do?

You know, we missed an opportunity here. We should have had listeners make up their own acronym for MEPAG. It's not too late, of course, but keep that in mind while I tell people that our winner this week is Dr. James Bonomo. Lots of long O's there. Dr. James Bonomo of Annandale, Virginia. First time winner, I believe, who said MEPAG is Mars Exploration Program Analysis Group. And he says he listens to the podcast, enjoys and learns from every show. He thanks us.

We thank you, Jim, and we're going to send you a T-shirt. Yes, indeed. MEPAG is one of those groups of, well, you can't say advice because then they'd be an advisory group and subject to so much more bureaucratic congressional stuff. All the things you don't want to learn when you go to NASA headquarters. You're safer if you analyze, but if you advise, you're... The funny thing is that A has actually changed over time.

So you can have analysis, you can have... There was an assessment, but never advising. Interesting. Little tip. There are also other Ags, by the way. There are OPAGs, Outer Planets Assessment Group. VEX AGs, Venus Exploration Analysis

Group, whatever. The A's flip around. You're into this stuff. I had to be into this stuff. They do help figure out, kind of plot the farther direction. The conceptual, where would we like to go with exploration of those bodies? And then bureaucracies take over and do what we actually do, going to those bodies. Someday you'll have to tell us more about why you had to learn all this

stuff. Your time in the capital, but not now. Tell us about the next contest. All right, the next contest, we look back at the first truly successful lander on Mars, Viking 1. Where did Viking 1 land? What area name on Mars did Viking 1 land in in the mid-1970s? Go to planetary.org slash radio and find out how to get us your entry. Compete in the contest. And if you could, do just like our winner this week did and let us know where you listen to us. It helps us out. Yeah, we like that. Gives us more to say anyway.

You need to get that to us, though, by 2 p.m. Pacific time on Monday, August 6th. Incredible. How could it be coming up on August? Anyway, that's the deadline, Monday, 2 p.m., August 6th. All right, everybody, go out there, look up the night sky, and think about whether shipping lanes should have lines painted down the middle. Thank you, and good night. Only if we can put them in space, too.

Didn't the Jetsons have those? I don't know! Bruce Betts is the Director of Projects for the Planetary Society when he's not laying out interstellar freeways. He joins us every week here for What's Up.

Do you know how easy it is to introduce others to our little space show? All it takes is a word or two of listener comment or review. We like to hear from you, too. Write to planetaryradio at planetary.org. Planetary Radio is produced by the Planetary Society in Pasadena, California. Have a great week. Thank you.