Spirit Sol 69

I wake up about an hour early so I can deal with the paperwork for my SpaceOps paper. It turns out there are no problems: the JPL guy faxed me the forms I need to sign, just as I'd asked, so all I have to do is sign them and fax them to the SpaceOps people. (Oh, yeah, and send them the paper itself.) But as a result, I'm about an hour early. So I go ahead and go to work -- and catch up on the latest images before my shift even starts.

Ahhhh, that's better.

Moreover, they're on a new schedule -- the meetings start 90 minutes later now, so I could have come in that much later. They were testing this schedule a few days back, and it looks like it's going to be permanent. And, as it turns out, we're sitting still for at least one more sol -- no driving, no IDD. So I have practically nothing to do today, except hang around and catch up on work.

Now that we've gotten a better look at the backshell, it doesn't look like the backshell any more. Whatever it is, it's angular, not round. It might be a broken chunk; they're going to take more images to find out for sure. In the meantime, there's a lot of joking about our having found an alien artifact -- job security, here we come!

75% of the legacy panorama is now on the ground -- good news, since they've got another one coming (just in time for their conference, of course). And they're showing a movie of the Deimos transit: eight frames, ten seconds apart. (It's not clear to me whether this is the movie Opportunity took, or whether we got our own; it sounds like the latter.) The PUL says that the transit was a little earlier, and a little closer to the center of the sun, than was expected. There's some uncertainty about Phobos's and Deimos's orbits -- because they're so small, they're hard to observe -- which our observations will help to eliminate.

And our odometer is practically a blur: we've already gone 402m, total. Someone also discovered that we've been a little wrong about one of the mission success criteria. With a tau (atmospheric opacity) of over 0.5, we have to operate the rover for only 60 sols, not 90, to declare success. The time we spent sitting at Adirondack doesn't count, so we reach the minimum success level in only 3 more sols -- not 21 more sols, as we had all thought. Our thanks go out to the global dust storm that preceded our arrival.

The dark deposit we see inside Bonneville crater is of uncertain composition. Its spectral characteristics seem to be more like Gusev-area rock than soil, but no rocks are visible in the area of the deposit itself. It's just possible we'll have to go down there and see for ourselves, though the default plan is just to crawl along the rim for a while instead.

I do actually have a little bit of work to do, as it turns out. We're trying to characterize how the rover slipped in driving up the last few meters of the crater rim, so that we can do a better job of driving it in this area. To do that, we need to know precisely how far it actually moved, as opposed to what we commanded. And to do that, we need to take pictures of the wheel tracks -- specifically, the locations where the rover started and ended each leg of the traverse.

This is harder than it sounds, because we don't know exactly where those locations are (if we knew that, we wouldn't have to take the pictures). Making matters worse, the rover reset its position -- as commanded -- when it was done with the drive, so the numbers we have for the commanded positions no longer mean what we want them to mean to the rover. The MI PUL (Alex) and I have to fix this by coregistering images by hand. We identify the same rocks in both the pre-drive and post-drive images, compare their positions, and use the difference to compute the actual offsets we need to use to aim the cameras at the drive locations. We must have done a good job, though -- when we check the pointing afterward in RSVP's camera view, it looks like we nailed them. We'll see when we get the actual images. After that, I hack on RoSE for a while -- mainly for fun. I have real work to do, but it can wait a day.

Andy stayed on Mars time longer than I thought, but tonight actually is his last night. Everyone signs the "Now Planning Sol 69" sheet for him, and he gets a round of applause. He's making a big mistake, though -- by which I mean, giving up his best excuse to just let things fall behind.

Courtesy NASA/JPL/Texas A&M/Cornell/SSI. A reduced-size version of Spirit's Deimos transit animation, taken on sol 68.

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