Opportunity Sol 273 (Spirit Sol 294)

I'm not on shift thisol. But when I'm on shift, I can't get any other work done -- not even reading my email, usually -- and now I've got at least two weeks' worth of stuff demanding my immediate attention. So I come in today just to catch up.

Frankly, I don't really want to know how the drive went. If yestersol (272) didn't work, there's no reason to think thisol has a chance. Maybe we'll get lucky and at least make enough distance on the last leg of the drive to be sure we're safe to deploy the IDD, so they can do the magnet observations they had to cancel last week. Still, I don't want to know. I avoid the sequencing rooms altogether.

But I can't escape Jeff's email:

I see we're back on the paving stones - should be smooth
roving from here. Nice driving!

I stare at this for nearly a minute, not really believing it. Then I jump out of my seat and literally run upstairs to the fifth floor. Cooper and Ashitey are wearing the fancy 3-D goggles, looking at the front HAZCAM images. The front HAZCAM shows rocky stuff, not sand.

"We made it," Cooper says. "Great driving!" ("It was a beautiful drive," echoes Art, "and I hate you for it." Art wants out of the crater, and this success means we'll be staying a while. The traverse to Burns Cliff is back on.)

"Did you see that NAVCAM?" Ashitey asks.

One of the NAVCAM images shows where we started yestersol. It's worse than we thought -- at least three of the wheels were dug in, not just the left front wheel. In 3-D, it's a dramatic picture. It's hard to believe we got out.

It's even harder to believe we got all the way uphill. Much as I want to, I can't really take credit for the success. The imagery confirms our suspicions -- there was just a thick band of impassable soft sand, and we spent a couple of weeks getting repeatedly caught up in it. (Where the sand is deep enough to form an opaque layer -- common in the crater -- you can't tell how deep it is until you drive across it. Maybe the sandy layer is a mere 1cm deep, so the rover won't slip at all. Yestersol we got caught in stuff that was more than 25cm deep. It's like crossing a swamp, where at any minute you might plunge in right up to your neck.)

Sol 270's experimental drive worked, right up to the point where we got caught up in the stuff again, which explains why we made no progress on the following sol. Yestersol we happened to get across a shallower layer of sand and onto friendlier terrain -- apparently early on, too, so that the rest of the drive worked and we're way uphill now.

So what changed was maybe 10% a matter of skill (if that) and 90% a matter of what happened to be under the wheels. I can't take credit, but I can sure be happy about the outcome, and you'd better believe I do that for all I'm worth. It takes sustained conscious effort to wipe the dumb grin off my face.

It's still a long way to Burns Cliff. The promised (threatened?) traversability meeting -- which grows every time we hold it, incidentally -- works out a plan for driving there. Optimistically, it might take another two weeks; more likely, longer. There's still a "Bermuda Triangle" of sand along the way, which we're not sure we can pass. The slopes look worrisome.

But at least we're back in the running.

[Next post: sol 297 (Opportunity sol 276), November 2 (at nearly midnight).]

Courtesy NASA/JPL-Caltech. Holy smoke! It worked! ... Uh, I mean, I never had any doubts.

Courtesy NASA/JPL-Caltech. Well, that explains a lot. Two weeks of struggling, encapsulated in a single NAVCAM image -- with Wopmay lurking in the background, and the crater floor beyond.


Rockwolf said...

Scott, I've got a terminal case of professional envy. As a geologist, I see the pictures you're posting and yearn to take a stroll in the red dust of Mars. You guys are the closest thing we (the royal we) have got to boots on the ground.

Thing is, "the ground" happens to be over 3 light-minutes away. I'm jealous mate, I really am.

Take it easy.


Scott Maxwell said...

Glad we can bring you along for the ride, if only virtually. It's great to have you with us.