29 April 2008
Hey folks, I’m on downlink duty again this week, once again working with Opportunity. When I last posted an update, Opportunity was making her way to the tantalizing layers in the Cape Verde cliff face. Unfortunately, we’ve made little progress since then. First a small sand trap held us in place for a week or so, but we escaped that. Now we’re sitting still for something more serious: arthritis.
Opportunity’s “shoulder” joint has locked up, preventing her from extending her arm. The motor for this joint has had problems in the past, and now Oppy’s age is catching up to her. You can’t blame her, she’s lived nearly seventeen times her life expectancy and things are bound to wear out.
So, for now, Opportunity is sitting on the slope of Duck Bay and the rover drivers are executing a series of very careful tests to see if they can get Opportunity’s arm to move again. Right now it is almost, but not quite in its “stowed” position. If they can get her arm to move enough so that it is pointing away from the rover, they may keep it that way, held out in front as she drives like she’s Rosie the Riveter. It would be awkward, but that would mean that we still might be able to use all the valuable instruments on the arm, at least until the other joints wear out from holding it such in an awkward position.
An unpleasant alternative to that might be to eke the last bit of motion out of the motor and stow the arm. That would mean no more microscopic imager, no more mossbauer spectrometer, no more alpha particle x-ray spectrometer, and no more rock abrasion tool. Combined with the loss of the Mini-TES instrument earlier this year, this scenario would leave only the cameras working. To paraphrase Steve Squyres, Oppy would become the first Martian tourist, doing nothing but driving around and snapping pictures.
It’s pretty clear that we will be sitting still for quite a while, while we work out the arm problems. I will keep you posted throughout the week as we do more tests and figure out what is going to happen.