Spirit Sol 162

At the end of yestersol's sequence was a simple turn-in-place intended to reposition ourselves so that the rock we've been IDDing (dubbed "End of the Rainbow") would be right in front of us, giving us better access for continued IDD work. This maneuver executed perfectly, so thisol is all about poking at the top and side of this small rock.

Chris has only just gotten started on the sequencing when I arrive, meaning they're running a little late. So he asks me to help out by doing a couple of the instrument placements. This doesn't take much time to whip out, and it's nice to be doing the relatively creative part of the job again.

It turns out that there's a reason they're so interested in this rock. The preliminary MB results show it contains hematite. And hematite means water, baby. Water, at last! We couldn't let Opportunity have all the water, I guess.

Despite, or because of, our late start, we have spare time: the meeting schedule gets delayed. (It ends up being delayed two hours.) Since this leaves me a little time to kill, I check out the most recent downlinked images, including a NAVCAM looking up the spur we've just reached. Jake Matijevic, looking over my shoulder, asks, "What's the slope up those hills?"

I don't know that, and I should. So I work it out quickly. "About ... um, that's in radians ... about 10 degrees from here to the top of the hill."

"Not bad -- that's well within the vehicle limits."

"Yeah. Of course, that's just the overall slope -- the surface isn't uniform, so the instantaneous slope might be worse." I think about it for a second. "But that's probably not a problem. We can still climb. It'll be just like avoiding obstacles, only avoiding slopes."

"That may be bad if we have to drag a dead wheel, though," Jake says.

"Ah, it's nothing. We'll just drive backward uphill. What could be simpler?"

But Jake turns serious. "The tests they did in the ISIL weren't encouraging. Dragging a wheel causes positional error and digs a trench behind us." That was the worst case -- with the wheel totally dead -- which probably won't be our situation. We'll probably be able to feed the wheel enough power that it will turn some. But he's right, it will limit us.

"Last I heard anything on this was about a week ago," I say. "Any new thoughts since then on what's causing the problem?"

"Well, if it were the motors, we'd see inconsistent power delivery, and we're not seeing that. Joe Melko thinks it's lubricant congealing in the gearbox due to the cold."

"So is this something we can work around? Run heaters, park with that wheel in the sun? Maybe after the winter solstice, when Mars warms up again, it will just magically get better?" I'd better face it, I think to myself. I'm in denial.

But Jake is right there with me. "Maybe," he chuckles. "Mobility system, heal thyself!" He turns back to his keyboard. "Well," he adds, "stranger things have happened."

Chris takes some time to finish up the IDD sequence, but when he's done, it's in very good shape. I have to fix up the comments and add a safety-deactivate sequence, but not much else changes. At the CAM, Emily asks for science's opinion on the result. "It's gonna be cool," Ray says.

George Chen is going to be doing the flight director webcast thisol, and he has a question for Ray. "Ray, when are we going to announce this rock has hematite? Is it OK to reveal that?"

"Yeah, go ahead," Ray says. "It's definitely hematite. We discovered it on the recovery sol, so we only have the short -- four-hour -- Moessbauer results. That's why we're redoing the observation thisol with a thirteen-hour integration, to get better results. But it's definitely hematite."

Ray grows animated -- by Ray's laconic standards, at least -- describing the importance of this find, and the current thinking about the composition of the hills we labored so hard to reach. He compares them to Mazatzal, the coelocanth-like rock that so interested the science team back around sol 77. "Our model is that the Columbia Hills are like a giant Mazatzal," he says. "Mazatzal gone wild!"

Courtesy NASA/JPL-Caltech. Spirit centers herself for more work on "End of the Rainbow" (smack dab between the wheels).


Anonymous said...

What's with the sparklies (technical term!) in the right wheel?

Scott Maxwell said...

@Anonymous That's sunlight shining through the right-hand side of the wheel (which is not solid) and reflecting off of the inside bottom of the wheel into the camera. Cool effect, huh? I *totally* planned that. ;-)