Opportunity Sol 785 (Spirit Sol 805)

Our previous drive went splendidly, gaining us about 57m toward Vickie (my little nickname for Victoria Crater). This leaves us an estimated 1603m from Victoria. During the SOWG meeting, I do the math, and am able to announce a milestone. A literal one, at that: "We're about 1603m from Victoria Crater, and a mile is 1609m -- so we're less than a mile away!"

Applause, applause.

(Speaking of the SOWG meeting, our SOWG chair today is none other than Steve Squyres himself. The last time Squyres was SOWG chair on this rover was somewhere in the 400s, back when we were in Endurance. I will try not to interpret this as some kind of hint that he lacks faith in Spirit.)

The big question of the day is just how far we're going to go. The next trough over (to the east) is more appealing than the one we're in, so we'll hop into it. Well along it -- 45m from our starting point -- is a small patch of outcrop. We can reach that without much trouble, and we can do so with considerable time to spare.

Then what? The most appealing option is another patch of outcrop 20m beyond that (65m from here), but I don't think we can reach it. There's a big mound -- a transverse ripple, I think -- just past the 45m outcrop. It's too big for us to go over and wide enough that we don't have room to go around.

Off to the other side -- to the east -- is another patch of outcrop. This one's only 58m from our starting point, so it's less appealing than the 65m patch (though it does let us go a bit eastward, which is something we try to do when we can, since Vickie's a bit east of south). However, between us and it is a bit of a step, or a slope.

The likely reason for that, judging by what we've always seen in this terrain, is simply that it's a perfectly safe, shallow slope that we can't quite see from here. However, we can't prove it's not a dangerous step.

Now, as it happens, we have a tool in our toolbox for just such occasions -- autonav! We haven't used autonav on this rover much since Purgatory. Frank and I had just reintroduced it and used it for a few drives, when Opportunity's IDD started failing. Since then, it hasn't been used at all.

But Frank and I are on shift together today, and, well ... autonav it is!

I honestly don't care whether we make a whole lot of distance on the autonav segment. What really matters is that we will have done it, and can start incorporating it into Opportunity's drives again. If she even takes a step or two on autonav, that will be a roaring success.

I also introduce another innovation today. For a long time, we've wanted RoSE to indent IF statements in our sequences, so that you could see the sequence structure more clearly as you wrote and walked through them. I got around to writing this code at last, figured out a way to backport it from the development branch to the installed branch, and took advantage of a scheme I worked out some time ago to dynamically apply the patch to the running (installed) version. I do that for the first time today, and wait to see how long it takes Frank to notice.

It takes him about, oh, I'd say, all of five seconds. Then we get another idea: we decide to have him running with that patch during the walkthrough, and we'll see if anyone notices.

Frank loves this idea, so we do it. All I can think about during the walkthrough is when somebody will notice -- but nobody says anything. I'm quite disappointed. But then, as Frank's wrapping up, Saina says, "Is this the first day using the new RoSE?" From the reactions around the room, it's clear she's not the only one who noticed. (But, amusingly, Julie didn't, and Frank comically refuses to point it out to her. "You've got to see it for yourself," he shrugs.)

"Yeah, this is the first time we've used it."

"Is it tested?" she asks.

In unison, Frank and I answer, "It is now!"

"Back when Jim was mission manager, you think he woulda let us get away with that?" Frank asks me rhetorically. "Times have changed."

They sure have. Back then, we wouldn't have tried to get away with that.

[Next post: sol 807 (Opportunity Sol 787), April 11.]


Ed Davies said...

O/T by 5 years but if there had been a federal government shutdown would that have affected Rover operations? I realise that JPL is not NASA and so you wouldn't have been directly affected (the contract's already signed) and that the DSN belongs to JPL but I wonder if, for example, communication with the DSN ground stations goes through NASA facilities (GSFC?) or anything like that?

g said...

You spent 804 sols reviewing sequences without indentation? Ouch.

Scott Maxwell said...

@Ed All I know is that we've been told JPL -- since we're technically a contractor and not a government center per se -- would be largely unaffected by a government shutdown, at least in the short term. Obviously, nearly all of our money comes from the government eventually, so sooner or later we'd feel the hit, but possibly not for months.

We operate the DSN ourselves, so we wouldn't get hit there, either.

@g Yeah, no kidding. And it was one of those things where, as soon as it existed, I could no longer imagine how we'd lived without it.

Tellingly, we almost immediately started moving to more complicated sequence structures -- this tool meant we quickly started spending our "complexity resource" differently.