2009-02-28

Spirit Sol 55

On my way in I find myself reflecting that driving the Mars rover has become almost routine. I should have known better. Today's plan is something we've never done before, a RAT mosaic. Even the RAT guys have never done this in their labs; we'll try it for the first time ever by trying it on Mars. I'm surprised at this, but one of the RAT guys explains it to me this way: "It's getting late in the mission, and they're letting us go nuts."

The idea is to use the RAT to brush the dust off of three spots located next to each other on the rock we just drove up to ("Humphrey," or "Humphreys," or "Humphries," depending on who's spelling it), which will give a nice broad area for the MTES to investigate. It will also look like Mickey Mouse.

When I come in there's no data yet from last night, and to make matters worse I'm a little late. I start off behind for the day and pretty much stay that way, which is not good because it's going to be a complex sol. The slide that describes it at the downlink assessment meeting calls it "Albert's Folly" -- after Albert Yen, who I suppose came up with the idea. It looks like this:

1. Do a short APXS on the unbrushed face, just enough to establish sulfur abundance.

2. MI series.

3. Close the APXS doors.

4. Do the RAT mosaic. (Place RAT, establish ~30N preload, brush surface, repeat.)

5. Stow the arm.

6. Back up 85cm.

7. PANCAM, NAVCAM, and MTES the brushed area.

8. Drive 85cm forward, back to where we started.

9. Take documentation images to establish a new terrain mesh for the next sol.

On the next sol, we'll deploy the arm and examine the brushed areas. We'll also grind the rock -- maybe in one of the brushed areas, maybe somewhere else; they haven't decided yet.

They argue about whether to APXS or MI first. The argument for doing the APXS first is that the APXS gathers better data when it's cold; heat makes their data noisy. The argument for MIing first is that they want to see the undisturbed surface. The APXS wins.

Another sign that it's getting late in the mission is that they break the naming rules. There are a couple of high school students visiting us -- I don't think they're part of the Red Rover program -- and the scientists name the three brushing targets after them and their teacher. Naming targets and features after people is supposed to be a no-no. I don't care what they name the things, but there's some griping about it from several of the scientists and engineers. I think breaking that rule is a mistake: once you've opened that door, everyone wants to go through.

Despite the complexity of their plan, I'm calm and ready, not stressed at all. I've handled worse than this. But it doesn't want to go well, because I'm just that little bit behind and can't catch up. It's one of those days when everyone needs to interrupt me for a "quick question." Nobody's wrong to do it, but the result is that I can't get any traction.

And then it gets worse. Because we got the downlink so late, we didn't have accurate terrain meshes to plan with, so we couldn't create accurate targets, so we couldn't do critical portions of the sequencing. By the time we get targets we can sequence with, it's very late, and it turns out that the targets are going to be unusually hard to reach.

Which makes me feel stupid. All along I've been telling people that yeah, the work is practically done already, we're just waiting for the targets and it will all be over. Now I'm warning them that we might have to start over and select alternates, and it's pretty damn late in the day to do that. I can't help but feel like Stuart Smalley: "This was not ... my best ... sol."

I end up finding ways to reach the targets, but it's slow going. So it's not done when Bob comes in, and I stick him with more work than I usually do: he'll finish the IDD sequencing, I'll take the drive. I apologize for leaving him so much IDD work, but Bob -- the IDD expert -- laughs and says, "Yeah, you know how much I hate that!" So it's okay.

Don't get me wrong, I still feel like a moron. But it's okay.




Courtesy NASA/JPL-Caltech. Humphrey dares us to IDD it.

No comments: