Spirit Sol 76

Our downlink data is delayed by some kind of ground system glitch. The glitch clears up to show us a flattish, whitish rock just in front of us, and a much more interesting fishlike rock a few meters away. It reminds me of a coelacanth or something. So we're going to MI the nearby whitish rock, then drive to the coelacanth. This all fits neatly into one of the scientists' sol templates (a "D-type," or "dirt-type," sol).

The "coelacanth's" name is Mazatzal, which is the name of a group of mountains in Arizona. Nobody can get this name straight; all night, people keep calling it "Mazatlan," "Marzipan," etc., until it becomes a running joke. I really wanted them to call it "Coelacanth," but that would have been worse. I end up attaching a picture of a coelacanth to my uplink report anyway.

Our odometry total is 459m, plus the 25m or so we traversed today. Added to Opportunity's 115m, we are just under 600m combined.

The time the scientists save planning by using the new sol templates gives them a lot of time to sit around arguing. They must love them.

To kick off the discussion, Jeff Johnson shows a PANCAM spectrum of Bear Claw, the scuff I helped make when I was last on shift. It's a beautiful, beautiful picture, and the science information revealed by the scuff is no less interesting. The small rocks we see around us seem to be made mostly of the same stuff as Adirondack. The material inside the Serpent drift, the stuff revealed by the scuff, is something different -- they don't know what yet -- and the dark deposit on the far wall of the crater, with its "mystery feature," is something in between. That's surprising, since they expected Serpent's insides to look the same as the crater deposit. They haven't yet compared the data to the trench results -- "but that's a good idea," Jeff muses, "we should do that."

The scar, however, does show some evidence of the mystery feature, which is also surprising: why would the stuff (whatever it is) be in some of these identical-seeming drifts and not in others? At this point, there's no answer.

At the SOWG meeting, Art has some bad news: the rover appears to have lost one of its PRTs (a temperature sensor). But he compensates with good news. No, it's not that he just saved a bunch of money by switching his auto insurance to GEICO. It's that the ICFA is at 90% capacity. The ICFA, he explains, is the Ice Cream Freezer Assembly.

Today's IDD work is straightforward; it's the drive that's going to be a pain. Mazatzal is only a few meters away, but we have to do a little zig-zagging in order to get there from here. But that's not such a big deal; what makes this drive difficult is that we don't yet know how we're slipping in this terrain. So we can't be sure whether the drive will overshoot, and overshooting will be a problem, because the rock we're driving to is obstacle-sized: it wouldn't be safe to drive over it. And, because they naturally want to IDD the rock when we get there, we have to end up in a fairly narrow range: close enough to reach a range of targets with the arm, not so close that we can't even safely unstow the arm without whacking the rock -- or, worse, not so close that we actually drive onto the rock. Even if we had a good slip analysis, there would still be significant uncertainty, because that's just a probability; it changes based on how rocky the terrain is, for instance. We do the best we can.

On my way out I run into Ted Specht, who wrote some software we ended up not using. Back when that used to happen to me, I always used to wonder why. Why would people ask for things and then not use them once I delivered them? Now I know: on a flight project, things move so fast that you've got to keep moving with them. Ted's a multimission guy; if he'd been 100% on MER, we probably would have ended up using his stuff. But he had other obligations, and by the time he delivered his solution, we had other solutions in place. Fortunately, he's still glowing from his honeymoon in Croatia. I don't think he minds at all that we didn't end up using his code. Or even notices.

Courtesy NASA/JPL-Caltech. Mazatzal (above) totally looks like a coelacanth (below, c/o Wikimedia).

Courtesy Alberto Fernandez Fernandez. Image licensed under a Creative Commons Attribution ShareAlike 2.5 license.

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