Opportunity Sol 773 (Spirit Sol 794)

Good thing you don't get some kind of Martian jet lag when you head from one side of the planet to another. After my Saturday spent trying to coax Spirit a few more meters toward safety, I'm back on Opportunity today (Monday). I'm still not used to Opportunity's being the rover that's in relatively good shape, but so she is.

And we're going to be making use of it. Opportunity goes into restricted sols next Wednesday, so this week we're driving as much as possible -- seven of the next nine sols will be drive sols, everything but Friday and Sunday.

We've been making good progress so far. It's revealed at the SOWG meeting that we're already 345m south of Olympia, a good chunk of the more than 2km we had to make when we started. Something like 1.8km remains, and today we're going to bite off another hunk of that.

Unless Matt Golombek and Tim Parker talk us out of it, that is. They've apparently been taking another look at the orbital maps and think we should head more east than south at this point. But in a little while, they come by and basically do the scientific equivalent of a shrug. Either path ends up being equally likely to be problematic at some point, they tell us. So we go with the locally easy path, the best choice we can make in a position like that.

This is a slightly zig-zaggy course almost due south -- a total drive distance of about 60m, with about 50m of that being actual progress toward Victoria. If it succeeds, I expect this will be one of the longest single drives we accomplish on the way, unless we think up some new tricks over the next couple of months.

Meanwhile, the news from Spirit is pretty good. She managed to turn herself in the direction of her next waypoint and, as a bonus, made a couple of meters' progress toward it. The only bad thing about that was her reason for stopping: too much slip. We told her to stop if she saw more than 70% slip, and she saw increasing slip values that peaked at 71%, at which point she dutifully stopped.

There's very little mystery about why this happened. When we drag one wheel, it simply digs in and builds up material as we drag it. When the RF wheel was functioning but flaky, we'd use a 90-10 duty cycle -- drag it 90cm, then run it for 10cm to drive it up onto the pile of material it would accumulate. But since we can't drive that wheel at all any more, we can't do that trick. We're going to have to come up with something -- and by "we," I mean Ashitey and Chris, since they're reportedly in the testbed, trying to figure this out.

What can I say? I wish them luck. And I wish I could help in a more tangible way than that. I'll be back on Spirit Wednesday, so I might get the chance. But for now, I've got my own little horsie to worry about.

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