2012-02-08

Spirit Sol 1102

We didn't see the MB's contact switches trip on Puenta Arenas, after not seeing them trip on Mount Darwin a few days ago. This is getting a little worrisome -- it's not too surprising that we had a problem at Mount Darwin, since the target was in the air, but we sort of expected to see contact at Puenta Arenas.

It's remotely possible they're not working any more, which would be awful; the MB contact plate is our only way to reliably sense the soil, so that would take out our ability to IDD soil targets. However, the switches are redundant for this reason, and unless there's a pebble stuck behind the contact plate or something, everything is probably just fine. We'll have to do an experiment on this in the near future.

But not today. Today we're driving.

If you can call it that. We're going to spend most of the day just turning around -- a slow and painful endeavor on a vehicle with a broken wheel. We have to use the fact that the RF wheel is an anchor, by pushing and pulling the whole vehicle around it. It's not precise, and it's not pretty, but it's tested and it works.

And it's slow. Every turn segment -- a single maneuver gets us about 14 degrees or so -- needs a visodom update afterward, and that costs us around 3 minutes. Since we need to turn about 180 degrees, we need about 13 of these, more or less. We'll end up spending 40 minutes or so just turning, out of a total drive time of a little over an hour. Take away the overhead at the beginning and especially the end of every drive, and we'll be lucky if we make any progress at all.

But the right way to drive this vehicle, it seems to me, is to be optimistic. What happens if everything goes right? Well, we might possibly manage to haul ourselves another 3m or so toward where we actually want to go. So Khaled and I add in some commands that will take effect if we actually complete the turn, and we'll see how far she gets. As long as she gets mostly turned around, we'll be happy.

The poor girl. She's so much more agile than this, at least in my memory of her. She's like a dancer way past her prime -- arthritic and broken, but not reconciled to it. Not yet. Maybe never.

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