Spirit Sol 655

The plan is to drive 17m at an azimuth of 130deg. But I have a better idea. We're perched at the top of a local hillock, and spread out below us is Haskin Ridge. We've got a beautiful view of it, a superb terrain mesh -- and, best of all, three hours of driving in the plan.

I think we can do more like 100m.

And it should be fairly simple. The hillock itself is pretty steep -- we might see 22deg tilt on the way down it -- but that's only for the first 15m or so. After that, the terrain quickly shallows out, so that we're in a far more forgiving 8-10deg of tilt all the way down. We can do 50m blind, and the terrain beyond looks decent for autonav. We don't get opportunities like this so often that we can just throw them away.

The day has its ups and downs. It turns out they forgot about a coordinated observation with HST, so they have to completely swap the plan around, but we still end up with about three hours of driving time. And Squyres decides they'd rather we drove at an azimuth of more like 100deg than 130deg, so that they can do a long-baseline stereo observation along the ridge. But at the end of the day, we've got a 110m drive planned, and a real shot at making it to the end -- or at least breaking 100m.

I expect to have real problems selling this to management, but everyone's pretty enthusiastic. When I tell Jim how far we're driving, he says, "I'd kill to get that on Opportunity right now." Then he reconsiders. "Well ... I'd wound," he amends.

Not surprisingly, John Wright -- one of the more aggressive drivers, and RP-2 today -- is fully up for this. "Throw caution to the wind!" he says.

"It's thrown!" I answer.

"Damn the torpedoes!"



That was Thursday. We were planning well ahead, for a drive to execute Saturday. And Friday, Chris and Ashitey look at the drive and decide to raise some objections.

Their basic argument is reasonable enough: we're driving into terrain that looks benign enough, but in the hills we've found that we can get bogged down even at relatively low tilts and in terrain that looks benign from a distance. So we should add slip checks to the sequence.

John and I don't really agree, and I don't want to call in the uplink team on a day they'd been promised off, but I can't say they're being unreasonable. And our general approach is that if an RP has a reasonable concern, we take it seriously. So I call in Jake Matijevic and Beth Dewell, and they agree that we should act on Chris's concerns.

The required sequencing is easy enough. I simply break up the final waypoint into 15m segments, adding a slip check between segments. Voila.

John complains bitterly about this: "They're just trying to see to it that we don't get our hundred meters."

"Look," I tell him, "they've got a reasonable concern and we've agreed to act on it, so there's no use arguing about it now."

"I agree," he nods. "But I never said I wouldn't bitch about it."

Good point.


94 meters. It doesn't quite have the cachet of 100m, but who cares? It feels gooood.

[Next post: sol 658 (Opportunity sol 637), November 8.]


Anonymous said...

Timed out, or did the extra slip checks fail just before the finish line?

Scott Maxwell said...

We ran out of time thanks to that extra slip check. Without it, we'd have had 100 meters spot on. sigh