2011-08-31

Opportunity Sol 925 (Spirit Sol 946)

Well, the tests on the IDD have gone well, and yesterday they even did real work with it. Maybe it was just a transient failure, after all.

However, we're still nervous about it, mostly because we're in for pain if it fails while we're trying to stow. During the stow and unstow process, the IDD maneuvers itself through a number of tight spaces, and getting it back out can be a real bitch. And stowing contains several small joint-1 moves, so if we didn't just have a transient failure -- if we have a real, ongoing problem -- then it's possible we'll fault out when that happens.

Fortunately, we can do something a little more active than just cross our fingers. We can walk the IDD partway through the stow process manually, at least as much as is relatively easy to sequence -- and to undo, if we get stuck. That will either build our confidence that the real thing will succeed, or tell us we shouldn't bother trying the real thing.

Happily, Eric Baumgartner left behind excellent documentation, including the exact IDD joint angles we need in order to do this test. So we look those up, put the sequence together -- and get shot down. Well, not permanently, but the SOWG chair's call is that since our doing this would put thisol's MB observation at risk, we should punt. And I can't really disagree, since we have a chance to do it again tomorrow. So we put our nearly complete sequence on the shelf, point the next day's RPs to it, and move on with the rest of the day's IDD sequencing. At least it won't be work wasted.

[Next post: sol 954 (Opportunity sol 931), September 9.]

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