Thursday, January 29, 2004

Holy Cow! We have a robot on another planet!
A report from the Geological Society of Washington

by Callan Bentley

This will not be a scientific post. Though I am a scientist, I'd like to share today a sense of my own wonder at universe we inhabit. I'll also get a little bit political in the fourth paragraph.

I attend regular meetings of the Geological Society of Washington, an earth-sciences group in Washington, DC. We meet once a month or so in the yellow faux-marble John Wesley Powell Room at Dupont Circle's Cosmos Club, on the corner of Florida and Massachusetts, Northwest. (Powell, the man for whom the room is named, was a former president of the Society, and the man to lead the first descent of the entire Grand Canyon in a series of wooden dories, a few years after the conclusion of the U.S. Civil War.)

Each G.S.W. meeting consists of (a) some beer, (b) some pretzels, (c) some parliamentary proceedings (reading the minutes of the last meeting, banging of the gavel, etc.), and then (d) a series of three geological talks. Each talk last 20 minutes, followed by a period of time where Society members may ask questions. Yesterday's meeting began with two boring talks, the second one painfully so. I was mulling over leaving early, when the third speaker took the podium and showed his first slide: an image of the robotic Mars surveyor, portrayed in situ on the red planet.

Mars has been in the news a lot recently. Like anyone who pays a bit of attention to current events, I was aware that the U.S. and European space agencies were landing vehicles on Mars this past month. I knew it, but hadn't really paid much attention to it. I am also aware of the recent suggestion by George Bush that the U.S. send a manned mission to Mars, a lofty goal towards which he has put forward additional money to the equivalent sum of a large Hollywood blockbuster: 200 million dollars. As the excellent "Talk of the Town" essay in this week's New Yorker noted, they spent that much on "Waterworld." It certainly won't be enough to get a human to Mars, even if they eviserate the current NASA budget as well. (The fiduciary disembowelment has already begun, by the way -- with the result that maintainence on the Hubble Space Telescope has been cancelled. The telescope, one of the most fruitful scientific tools ever deployed, will deteriorate, wind down, and die within 3 years.) Now, I'm no fan of Bush to start with, but this scheme strikes me as (a) unlikely to succeed without an incredible influx of cash, (b) a shame since it has already killed Hubble, and (c) merely a pump-up-the-voters election strategy that Bush doesn't really care about. For instance, he didn't mention it once in his State of the Union address last week. Grrrr.

The speaker was a tall, white-haired gentleman with an even beard: Jim Zimbelman, of the National Air and Space Museum. Over the ensuing twenty minutes, he treated us to an amazing series of images of the Surveyor robots and the terrain they find themselves in.

Sitting in that darkened hall, I found myself in shock at the amazing feat that had been accomplished. As Zimbelman pointed out, when we see pictures in the news of NASA scientists cheering, it is because they have worked for three to ten years on a project that either proves itself or fails in a few crucial minutes. As you may be aware, the European attempt at a Mars landing have failed: they haven't heard from their device since Chirstmas. The NASA project, though, featured a back-up: they sent two rovers to Mars, and by some miracle, both seem to be working okay. There was a software problem with the first one, but Zimbelman assured the geologist crowd that the issue was on the verge of being resolved. They just had to reboot the robot.

Again, the shock hits me: We put a robot on another planet.

On what appears to be an otherwise lifeless planet, there are two La-Z-Boy-sized robots rolling around, taking pictures, taking samples, doing analyses. Mars is seeing more activity this month than it has seen in a long time.

This little robo-buggies are equipped with stereo vision that can resolve up to 100 micro-meters in size. That's one-tenth of a millimeter, a pretty small particle. They were dropped to the Martian surface from space, protected by a sheath of balloons which allowed them to bounce and roll to a still position. The initial bounce sent them up about 50 meters into the air! And they're full of delicate cameras, locomotion devices, and scientific equipment that all still works after a trip of a gazillion miles across space and then a drop from the height of a 15-story building! That's incredible.

In the pictures Zimbelman showed us, we saw ventifacts -- wind-sculpted rock nubbins. There was also a tantalizing scene of a rock imbued with many parallel lines: layers of some sort. These layers may have been formed by volcanism, or they may have been formed by sedimentary processes. If the latter, that implies water must have been present. If water was present, there may have been life there. If there was life there, then how are we going to deal with that?

What is the Pope going to say, if we find irrefutable evidence of life on Mars? How will that change our religions, our society, our sense of who we are in this universe? Did God create life in multiple locations in the Universe? Did life evolve in multiple locations in the universe? Did life start one place (either by being Created or by who-knows-what) and then spread elsewhere? If so, did it start on Mars, or on Earth, or on some third (unknown) location? These are big questions.

I asked him how this thing moved: was there a scientist in Pasadena steering it around by remote control? Did he have a joystick, like he was playing Pole Position?

No, Zimbelman told me. The Mars rovers steer themselves. The scientists say "Go to that rock," but the rover makes decisions about how best to get there. It proceeds very cautiously. Remote control wouldn't work because the radio signal takes too long to travel between the two planets. If the rover were operated by remote control, it might be heading towards a cliff, and the video of that approach would take 24 minutes to reach Pasadena, whereupon the decision to brake would be made, and the radio signal instructing the rover to brake would be sent back to Mars, taking an additional 24 minutes in transit. The signal would arrive, of course, 48 minutes after the rover rolled off the cliff and crashed. So the scientists stay out of it, and this little robot rover actually decides itself what the best way is to get from Point A to Point B.

The Mars rovers have a 90-day planned lifespan. The only issue is power, and they are powered by solar panels. The problems is dust, which is slowly but surely settling on the robots' solar panels. Once a certain load of dust builds up, there won't be enough sunlight getting through to power the vehicle, and it will shut down. It occurs to me that this is pretty short-sighted. If you can get a machine safely from one planet to another and give it all kinds of techinical ability, then how much trouble would it have been to equip its solar panels with a pair of windshield wipers to keep them clean? Or a blower device? Nonetheless, the rovers are experiencing less dust than predicted, and NASA hopes to have them operational until November.

I was really impressed with NASA's achievement with getting these functional devices to Mars. They deserve our unqualified kudos. As a geologist, it makes me giddy to think of a whole new planet to explore, learn from, and appreciate. On a small budget, and with no risk to humans, NASA has acheived something wonderful.

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