Opportunity Sol 270 (Spirit Sol 291)

The test drive is a go for today. Steve Squyres likes our planned drive. He calls it a "mobility potpourri," then "a well-thought-out hodgepodge of mobility commands."

Since I did all the work yesterday, you'd think today would be easy. But I know better, which is why I kicked out a version of the drive yesterday: so we'd have time to do it over today. Because there's always something ....

For one thing, as soon as I look at the drive, I realize we chose one of the switchback angles wrong. One of the pairs of switchback legs has the rover going at 60 degrees to the slip vector, which in the face of the level of slippage we're seeing is almost guaranteed to fail to make any uphill progress. Instead, we make that switchback be 30 degrees from the slip vector, which ends up changing other things -- at that point, the angles to the slip vector are such that we should do all the driving in the same direction (backward), rather than switching between backward and forward driving as a strategy to minimize turns.

Then Squyres raises another problem at the APAM. We're starting the drive against a rock and with the wheels in a self-dug hole, and the wriggles at the start of the drive might not suffice to get us past the rock, which would basically make that part of the test useless. Rather than wriggles followed by switchbacks, he suggests switchbacks followed by wriggles. Frank and I talk it over and agree with Steve, but because it's not as simple as just reordering chunks of commands, we end up having to rewrite almost the entire sequence from scratch.

Well, that's why I made sure there'd be time to do it over. I'm learning.