Spirit Sol 476

As we work our way back down the ridge to Larry's Lookout, our next stop is Jib Sheet. Thisol we're sequencing a drive to take us most of the way there; wherever we end up, we'll IDD over the weekend, and then complete the Jib Sheet approach early next week.

It's a complex drive. To get there, we'll need to drive in a big "U." It's a total distance of about 25m, a much longer drive than we're normally able to accomplish in this challenging terrain. In our favor, the terrain does flatten out considerably as we go, which will make the vehicle's performance more predictable. But the length of the drive and the nature of the overall terrain will make this a long and difficult plan.

We're not sure for a while exactly where we want the rover to end up, or how it will get there, or even whether we'll drive forward or backward. Dan Moyers sees this and decides to have a little fun with TUL-in-training Rich. "We need the final heading so we can do comm predicts," he says. "Ask the rover planners what our final heading will be."

But Rich is on the ball. "Dan wants to know our final heading."

"Sixty," Chris says without turning around. "Plus or minus 180."

It's mostly Chris's show today. I do the stow and work out the best plan for the first couple of meters of the drive, just enough to get us on the road. Chris does most of the work of planning out the route, though I throw in my opinion now and then. For instance, he's hoping to take a shortcut between two larger rocks, letting autonav find a safe path. I do some analysis to work out that the rover won't be able to find a safe path without loosening the autonav settings, and neither one of us wants to do that. So we take the long path.

Our accidental IDD animation keeps turning up new surprises. I composed and posted the full two-sol version of the animation the other day, and Brenda Franklin's been looking over it carefully. Her scrutiny was rewarded with a neat surprise: in the second-to-last frame on the second sol, a huge gust of wind -- maybe a dust devil -- kicks up a huge cloud of dust on a far hill. "Definitely lemonade with whiskey," she says.

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(I've had trouble with animated GIFs and Blogger. You should be able to see the animation at twitpic.)
Courtesy NASA/JPL-Caltech. The dust devil is in the upper-left corner, near the horizon. Subtle, but it's there.