I return home and get ready to go to JPL for Opportunity's landing. They tell us to dress up a little in case we're on TV, but I decide to wear my "Rover Driver" T-shirt. I'm a rover driver, damn it, whether I've got a rover to drive or not. I turn on NASA TV to see what's up, and it turns out I have a rover to drive after all. Spirit is back!
After the rover boots, it sets up a file system in flash memory. If this doesn't succeed, it reboots and tries again. For some reason -- they still don't know why -- this is what it's been doing. To fix it, they sent it a command that says not to use the flash-memory file system, to use the volatile RAM instead. And it worked!
Pete cautions that Spirit may be stuck here for a few weeks yet, which sounds pessimistic to me -- we'll have a workaround and updated processes before that, surely. But then, it's part of his job to be pessimistic.
More and more, Spirit really does come to resemble a drama queen. In cruise, she scared us by making us think her Moessbauer spectrometer was broken, only to have it turn out fine on the surface. All eyes were on her when she stopped talking to us for ten or twelve heart-stopping minutes during landing -- only to turn out she was fine all along. She does a little pirouette on the lander, glides to the surface, does another little pirouette -- all flawless. But wait! Here comes her twin sister, ready to steal the spotlight. So what does she do? She throws a tantrum. So this is nothing. She'll be fine.
At JPL, Richard Kornfeld asks me to be his cameraman for a story he's filming for Swiss TV. I've never been a cameraman for Swiss TV before, so what the hell. This turns out to entail following Richard around the SMSA with a handheld Sony DV camera while he points at things and talks in German. I tell him I want a cameraman credit. (And I do: I can't wait to tell people that I'm a cameraman for Swiss TV, and when they don't believe me, I haul out the tape .... Damn, I'm weird.) At one point, our roles are partly reversed -- he points the camera at me, and says something in German about how I'm a rover driver. (Or that's what I assume he's saying; maybe all of Switzerland will shortly believe that I'm the official project prostitute, or something.) I can't help wondering if this bit will end up in the final product, which will make my life even weirder.
The CMSA is showing on the TV. Al Gore and Arnold Schwarzenegger are here, though not visible yet -- they'll show up as soon as there's a successful landing to associate themselves with. I wonder if I'll get to meet them and not have my picture taken with them. Wayne Lee is wearing his US flag shirt again.
As we watch, the Mechanisms guys are discussing what Rob Manning's job will be after Opportunity's EDL succeeds.[2] That'll make it three for three, a stunning achievement. Joel [Krajewski] says that after three successful EDLs, you just walk around and they pay you forever. They make you a fellow, give you a robe, and you never have to work again. Well, he's earned it. If this works. We also compare working on MER to working in Vegas: the place is blacked out, we get lots of comps (rooms, ice cream[3], water), and we're spending $4 million a day.[4]
Todd Litwin shows up and starts poring over some code. Todd wrote the file system code for the rovers, which means he's the guy who would know the real story on the failure, as well as anyone does yet. He says he doesn't think the file system was the culprit. It's a pretty simple affair, and the flight software looks for problems and fixes them at startup. It is possible that the file system was corrupted by the continual rebooting, though, and there are more aggressive self-checks he's thinking of enabling. But he doesn't think it's his fault.
At some point in the distant past, Craig Leff used to be a scientist -- a geologist, specifically -- and he's hanging out with us, so I ask him some questions about the rocks in Spirit's vicinity. He tells me that Adirondack and its neighbors look, to him, like pahoehoe, a kind of volcanic rock you find in Hawaii. The rock has quartz embedded in it, and as it weathers the softer rock around the quartz erodes most, leaving the rock with a faceted appearance similar to that caused by impact stress. The same kind of weathering can also produce the grooves we see on Sashimi.
On the TV, Pete is pacing relentlessly. The stress of the situation is written all over his face. Wayne Lee is doing airplane jokes ("If you had looked out the left side of the spacecraft, you would have seen Valles Marineris ... on behalf of the entire EDL team, we'd like to thank you for flying with us ...."), which actually make Pete laugh.
Much as happened with Spirit, EDL is upon us before I know it. It's a weird feeling, knowing it's all over, for good or ill, already. Thanks to light-time delays, when we look at Mars, we're looking at ten minutes ago, so the spacecraft is already on the ground -- one way or another -- before we even see it hit the top of the atmosphere. What's odd about EDL this time is that there's no data dropout; we stop bouncing almost immediately after we land, so we don't lose contact. And we hit with very little force, only about 2 or 3 Gs, which means we probably didn't drop from very far up. Good thing they decided to deploy the parachute earlier, I guess.
The place explodes with joy, of course, and just as I predicted, Arnold and Al come out of the woodwork almost as soon as our success is known. The news continues to flow in as the spacecraft rolls (or not -- this turns out to be an artifact of radio self-interference) and lands, once again, base petal down (or not -- turns out we're +Y down, landing on our side for the first time).
Another item in our "how you know you've made it" series: Geraldo is talking about us on Fox News, interviewing some JPLer[5], and when he's done with us he segues into a story about J. Lo.
There's a wait of a couple of hours before the pictures come in. Frank and I talk about how astonishing it is that we work here, that this is what we do for a living. He and John are putting together a proposal to write software to remote-control (from Earth) the bulldozers that will build the President's proposed moon base -- who knows more about it than the guys who drive Mars rovers? The past few years I keep saying I'm living in the future, and it keeps getting more and more true.
This time, I'm actually in the SMSA when the images start flowing. I followed my sneaky plan of stealing in at the last minute, to avoid getting kicked out, and it turns out that probably wasn't necessary. They don't seem to be quite as fascistic this time. Sean O'Keefe is there, and I intend to get my picture taken with him, but in all the confusion that doesn't happen, making me 0 for 3 this evening.
Everyone is learning to cluster around Justin's workstation, since that's where the images appear first, and I get prime real estate. When the pictures do start flowing, Squyres is once more overjoyed. Indeed, he's more excited about Opportunity's landing site than he was about Spirit's, and she's not going to like that. Looks like the scientists who decided to gamble on Opportunity, including Squyres himself, won.
What remains of the evening is almost a formality. Fascinating pictures of a new place, trooping over to von Karman to watch the press conference in person, printing out a few pictures before I leave for the night, that sort of thing. I'm living in the future, and I like it here.
Leo's on Geraldo!
The press conference gears up.
At the press conference, Squyres, Soderblom, and Wallace (among others) discuss the first images from Opportunity. Above their heads is a color image of the soil inside Eagle Crater.
Courtesy NASA/JPL-Caltech. Opportunity opens her eyes on a new world.
Footnotes:
[1] Robin Mitsui, an instructor at the dojo.
[2] Rob Manning was in charge of EDL for Mars Pathfinder, as well as for Spirit and Opportunity. Martian EDL has a high failure rate, but Rob is so far batting 1000.
[3] Oh, yeah, the free ice cream. At a MER All-Hands meeting a while before landing, Elachi asked us if there was anything the Lab could do for us, and someone yelled out "free ice cream!" We got it -- and it was good stuff, too. I'm already thinking about what I'm going to yell out next time Elachi asks that question.
[4] Not intended to be literally true. Someone -- I think it was Jennifer Trosper -- came up with this as a useful way to think about the value of each sol. Here's where that number comes from:
Very roughly, MER cost $800 million for the prime mission -- that's including design, development, testing, launch, cruise, and the first 90 sols of surface ops. So you figure it's about $800 million for about 200 combined sols on the surface; that's about $4 million per sol.
However, ops itself is actually comparatively cheap; most of the mission cost goes into simply getting you to Mars. (Launch costs alone were about $100 million per rover, I believe, a quarter of our total mission budget.) We now run the rovers for something like $20 million per year, total, so the per-sol cost of the mission goes down the longer you last. Now, more than 3500 combined sols into the mission, our comparable amortized per-sol cost over the whole project is merely $285,000 or so -- and still falling.
However, at the time, we very firmly believed MER cost about $4 million per sol (in the above sense). So you didn't want to be the guy responsible for blowing a sol, you really didn't. If you make $100,000 per year for 40 years -- a rather long working lifetime -- that's $4 million. Think about it. In some sense, I believed that something close to all the value I would bring to the Lab in my entire working lifetime could be wiped out by a single mistake.
[5] Leo Bister. Sorry, Leo, I didn't know you then.
Posts
1 comment:
That was me that said "free ice cream". Possibly my second greatest contribution to MER.
Post a Comment