2009-11-09

Spirit Sol 303

I'm back in the Spirit World, and today's my first chance in a long time to work with Jeff Biesiadecki. Jeff's one of the other rover drivers, a smart and easy-going guy who wrote large chunks of the mobility flight software. He's also the guy who recommended me to Cooper in the first place (Jeff and I had worked together briefly in the Operations Engineering Laboratory, when I started at JPL), thus setting me on the path that eventually led to this, my dream job from childhood.

So I like working with Jeff.

It's an easy sol. Yestersol they did some IDD work and inadvertently closed the APXS doors just before placing it. It's easier to make this mistake than you might think. You close the doors simply by rotating the turret to a certain position. If you're trying to approach a certain target and the only way to get there is to rotate the turret to that point, well, then, the doors close. (Just to make the point: if this were software, they'd call that a bug. When it happens with hardware, everybody just shrugs.) Back when we worked together practically every sol, Bob Bonitz drilled into me the importance of watching out for this, and indeed it's part of my personal checklist.

So thisol we'll just reopen the doors and re-place the IDD. As it happens, the doors closed when the IDD was switching from the MB to the APXS, so it's not an inevitable consequence of measuring this target; we just need skip the usual preceding MB touch. Since the MB touch itself worked fine yestersol, we just need to get the recorded joint angles out of the downlink. After that, writing the sequence itself is something we could do with our eyes closed.

Apropos of nothing, we've known for some time that Opportunity started showing a sudden power boost recently. The reason is something of a mystery, but the likely cause is simply that Opportunity happened to be in the path of a dust devil, which blew some dust off its solar panels. (Badly power-deprived Spirit could use some of that dust devilly goodness, but no such luck.) The MI images Opportunity took of her magnets show that they've been cleaned off as well, which is consistent with the dust-devil explanation.

My favorite explanation involves a homeless Martian with a squeegee and a bottle of Windex. Mark Maimone points us to another possible explanation: a cartoon showing the solar panels with "WASH ME" finger-written in the dust.

2 comments:

Hank Roberts said...

http://www.sciencenews.org/view/generic/id/49504/title/Unsticking_Spirit

Posted a pointer to you over there; this is pointing you back to them.

Hard to read both side by side and be sure I know what's being talked about; can you connect the two stories?

A. Karley FGS, BSc said...

"Mark Maimone points us to another possible explanation: a cartoon showing the solar panels with "WASH ME" finger-written in the dust. "

Come on, you know you want to put it through the scanner and post it. C'mon!

http://adesignmafia.com/wp-content/uploads/2009/04/clean-me.jpg

http://dirtyvan.com/