Spirit Sol 138

We're planning sol 138, even though sol 137 hasn't started yet. More precisely, it's sol 137 on Mars, but it's too early for Spirit to operate -- she's still sleeping. Jeng has generated initial conditions files that show what the rover's state should be after sol 137, and we'll base the sequences on those. In a little while, Spirit will awake, and they'll uplink the sol 137 sequences. If anything goes wrong, we'll have to adapt on the fly.

Confused yet? You're in good company.

Jeng's back from Montreal, and he tells me my presentation nearly got canceled. Apparently, someone didn't get the word that John was going to present it for me -- they just saw that I wasn't there, and they canceled it. Fortunately, Jeng found out about this and straightened it out.

"How was the conference?" I ask.

"Eh, okay. It was mostly about satellite operations and stuff," he says. "I liked Montreal, but technically speaking, you didn't miss much. The next one is in Rome, though."

Rome? They do SpaceOps every two years; given two years, I'm sure I can come up with something to present, even if it's just to update the presentations they just finished giving in Montreal. "I wouldn't mind going to Rome in two years. Let's see, if I start on the paperwork now ...." Then again, maybe I won't.[1]

Thisol's plan is to finish poking at the trench, then stow the IDD and back up 85cm to MTES it. Chris is working on the IDD stuff and asks me if I'd mind sequencing the drive.

"What, the 85cm backup?" This is one command, plus some boilerplate. I grimace with mock concern as he laughs. "Well, I'll see if I can handle it."

It does turn out to be a little more interesting than that. Our downlink hasn't been very good the last few sols -- when we're working in a trench, we've got to face the trench; we're not free to turn to the best comm direction. But we're finishing up at the trench, leaving us free to turn at the end of thisol. Julie asks if we'd mind building a second simple drive sequence to do the turn, with the idea that they'll run this turn sequence after the backup and the MTES. That's trivial to do, but it seems like needless complexity to me. We can just do the turn immediately after the backup, all in the same sequence, and then do the MTES -- as long as the rover's own body won't obscure the trench when we turn. I simulate it quickly in RSVP, and it looks to me like we're clear. Laura Mehall, thisol's MTES PUL, agrees with me, so we go with that.

So the big drive sequence turned out to be two commands plus boilerplate. Hey, I just doubled my productivity. W00t.

Meanwhile, Julie's stressing because we don't have a Sequence Integration Engineer in yet. The SIE needs to be here to build the sol's master and submaster sequences for the nominal case, so they usually sit in on the Activity Plan Approval Meeting to see the sol's structure. We'll also need an SIE to help build the sequences we'll use to diagnose problems if our downlink shows there's something wrong with the rover. (Not likely, of course, but there's a little extra concern about that today because we didn't get yesterday's afternoon Odyssey pass. Which might be because Odyssey was low on the horizon from the rover's perspective, and we just got too much terrain interference -- or might be because we have a problem and don't know it yet.) She calls the SIE on duty (Marc Pack) but gets no answer, then calls Arthur Amador to alert him to the potential problem.

When she hangs up with Arthur, she talks it over with Scott Doudrick. "We don't really need him until we don't get the comm beep," she says.

"Yeah, but I don't want to get caught with my pants down," Scott says.

"Good point ... well, Opportunity's team should be here; maybe we can steal their SIE in an emergency."

The Activity Plan Approval meeting starts right on schedule -- and moments later, Marc walks in nonchalantly. So much for that problem.

Chris leaves, and I start doing my usual RP-2 thing, polishing the IDD sequences and whatnot. I must be having fun, because time flies -- next thing I know, we're starting the master/submaster walkthrough. This is where we walk through the penultimate versions of the master/submaster sequences, as well as the rover planner sequences, making it Marc's and my show. Marc starts leading the team through the day's master sequence, and it's maybe thirty seconds later when Scott Doudrick comes in with a deeply worried expression.

"We didn't get the comm beep," he says. They uplinked the sol 137 sequences anyway (sometimes failing to receive the comm beep just means there's a minor problem at the DSN, and we'll be able to salvage the sol), but the odds are, this means tomorrow's off. They'll probably have to spend the sol trying to debug the problem and getting the rover back up to snuff. Assuming it's even alive, which we can't prove at the moment. So Julie calls a halt to the meeting.

"Damn," says Marc, "just as I was really starting to build up some steam."

The news goes from bad to worse. Sol 137 was not received on the rover (we would have gotten acknowledgment of this) and so its sequences did not execute. At best, this means we'll delay everything one sol. None of the expected comm sequences appears to have executed on the rover, either. The working assumption is that a sequencing error of some kind caused all of the sequences to be killed, including the ones that set up the comm sequences for the sol. The next thing they try is "pinging" the rover at every valid comm rate, to figure out whether it's listening at all. With a 20-minute light-time delay, this means it's 40 minutes before we can know anything new.

I'm not the only one who's become more relaxed about these problems. In fact, looking around, I see that people are tense, but the responses are healthy: there's more laughter than panic. Jason Fox "confesses" that it's all his fault: he jinxed the sol by planning to go to the beach this afternoon.

A little while later, Scott Doudrick comes back in, looking a little better now. "Carrier in lock," he says, "we got the first beep."

"That's the fault rate?" Julie asks.

"That's the fault rate," he nods. "We're in some fault state -- but we're alive."

Good old Spirit. Drama queen.

"All right," Julie says briskly, all business. "We have a fault state of some sort, so stop planning. Science, you may go home: we're not planning any science on sol 138."

She tells me I can go home, too. "Thanks, but I've got other work to do, so I'm going to stick around a while and do it. Besides, I can't leave without finding out what the problem is."

"Yeah, I know," she grins. "It's like walking out of a mystery movie."

"Besides," I continue, "some part of me imagines I'll actually be able to help. Like, 'Oh, we could drive our way out of this fault, if only we had a rover driver around.'"

I'm not the only one with that irrational response. Everyone has it; it's natural. When a problem like this occurs, people start accreting, like worried family outside an operating room. Mostly, we stand around with worried expressions, continuously rehashing what we know and trying to work out what the problem might be.

Andy does it, too. Julie brings him up to speed.

"It could be another one of those one-time things," Andy says. He doesn't sound hopeful, and I don't blame him: we just had "one of those one-time things" the other day, the race condition that interrupted our backward drive. Strictly speaking, that doesn't have any bearing on the odds that we're seeing one today, but it doesn't feel right.

Just then I'm about to send out some email, and I notice the quote the system has randomly chosen for my email signature: "If [space travel] were [risk-free], it wouldn't be glorious." That's William Gibson, writing on the Columbia disaster. I'm not sure whether, if I were superstitious, I'd see that as a bad omen or a good one.

The SMSA is the place to be when these things are happening, so I give up on trying to get work done and go hang out there. They've already got a working theory: the spacecraft fataled for some reason during the sol. When this happens, the spacecraft considers the state of the HGA encoders unknown and switches to a low data rate -- which is what we see. We should get downlink in 13 minutes with EVRs saying what happened to the vehicle.

Mark Maimone walks through, trailing a couple of visitors -- his parents, I think. He sees right away that something's wrong. "Were we driving?" he asks me, sotto voce. "No," I tell him, "it's not your fault." He looks relieved and moves on.

The time for the expected downlink comes and goes. This is not encouraging. We'll learn nothing more today. Not quite what I was expecting at the end of this particular mystery movie: a big placard reading, "To be continued ...."

[Next post: sol 142, May 27.]


[1] Yeah. Didn't. Sigh.

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