2011-06-27

Opportunity Sol 863 (Spirit Sol 882)

I'm in a little early and run into Oded Aharonson, whom I haven't seen in -- well, it's been a while. He's been off in Greenland or Iceland or Norway or something, working on Cryobot, some kind of prototype ice driller they might send to Mars someday.

Which is why I haven't seen him around, of course. Being away from MER seems to have given him a certain perspective on what we're doing -- "shepherding the rovers to their death" is how he puts it. He doesn't mean it in a bad way, and I know exactly what he means, but I have to confess I'm still in denial about that. They're gonna live forever, ya know? Just a few aches and pains, is all. They're fine.

Speaking of those aches and pains ... "How are we at five-wheeled driving?" he asks. "Can we get back up onto Home Plate?"

"I doubt it."[X]

"Circumnavigate Home Plate?"

"That's more likely. Since you bring it up, what's the obsession with Home Plate, anyhow?"

Oded's always animated, but a question like that always stirs the pot. "Home Plate," he explains excitedly, "is the first time we've seen a geological feature we have a chance of explaining, a chance of forming testable hypotheses about. It's not water, but it's still interesting." Ah-hah ... looks like even Oded thinks there might be a little life left in this mission.

Though you might not know it so much by today's plan. We didn't receive sol 860's PCAMs, so we're stuck planning a drive in the NCAMs, and that limits us to about 20m. We don't have any significant IDD work, either, though we do have a bit of IDD checkout at -- oddly enough -- the end of the drive. This being Opportunity, we have our normal post-drive unstow. And after that, we stretch the IDD out a little further to check out a problem with the MB's reference channel.

This is a data stream that feeds calibration data from the MB's internal calibration target into the flight software, so that we have calibrated measurements from that instrument. For some reason, we seem to have lost that data entirely -- possibly some kind of cabling problem. All hope is not lost for that instrument, since we still can place the MB on the rover's external calibration target (just above where the IDD is stowed). But it's one more of those little aches and pains.

The rovers are fine, you know. Just fine. And they're going to stay that way, forever.

[Next post: sol 893, July 8.]




Footnotes:

[1] Wrong, of course. Didn't I know better than to bet against Spirit? The next driving season came around, and up onto Home Plate she went.

2011-06-23

Opportunity Sol 857 (Spirit Sol 878)

Sure enough, we got about 40m out of the previous drive -- not yestersol, but the sol before, since we're in restricted sols. We're now about 776m to Victoria, and only 304m to Beagle. Thisol, we're gonna step on the gas a little, and shoot for about 50m.

We've got a guest driver helping us. His name is Kelly Wills. He's spending the summer at JPL, working on an MSL task -- trying to reduce the power requirements of one of their instruments. He's from Ohio, he just graduated from high school, and he's blind.

I try to remember what I was doing the summer after I graduated from high school. I'm pretty sure it wasn't anything like that, though. And I'm not even blind.

Man, do I suck.

This somehow gets Paolo and me talking about our other, non-MER tasks. I remind him that he's not allowed to leave MER, and he assures me there's no danger of that. "There will be four people here to switch off the last workstation," he says. "Mark Maimone, Steve Squyres, you, and me."

I can't speak for the other three, but he's right about me, at least.

Speaking of Steve Squyres ... he's our friendly SOWG chair today, and something happens today that makes me suspect I'm not a complete waste of water and trace chemicals. During the B-833 anomaly investigation, it came to my attention that several of the RPs, particularly newer ones such as Paolo, had trouble standing up to pressure from the science team, particularly Steve. In my new role as the RP team lead, I urged them to stand up to this pressure, pointing out, among other things, that Steve pushes and expects you to push back when he's pushed too far -- and you shouldn't disappoint him.

So, at the APAM, Steve, smelling a long drive, says something about "putting in as many slip checks as duration allows." And Paolo says simply, "I think I will use a different philosophy: we'll use as many slip checks as we need to be safe, and we'll let the distance be what it is."

I coulda kissed him!

Oh, and speaking of water and trace chemicals .... (I really am the King of the Segues!) Steve also relates a recent science find. Concentrated calcium salts, plus zinc, plus hematite, all in one location -- the implication being, maybe, hydrothermal hot springs.

Cooool.

The other news is not so good. Opportunity's MB has lost its reference channel, which carries internal calibration data. That doesn't make the instrument useless, as we can still calibrate it against the external calibration target mounted above the IDD's stowed position. But it raises a disturbing possibility, one that Matt Heverly points out: combined with the recent transient failures we've seen when commanding the MI, it might be that we're seeing a degradation of the flex cabling that carries power and data along the IDD. If that failed, we might lose the IDD a whole lot sooner.

Fortunately, Matt came to JPL from ASI -- the company that built the IDD. And he knows the guy who was in charge of the flex cabling. "I'll shoot him an email," Matt says.

I love that. If you heard a knock coming from under the hood of your car, wouldn't you love to be able to just email the guy who built the engine?

[Next post: sol 882 (Opportunity sol 863), June 27.]

2011-06-20

Opportunity Sol 855 (Spirit Sol 876)

We're continuing to make good progress toward Victoria. Close enough to taste it, or anyway smell it. Or maybe just hear it.

Anyway, we did 40m yestersol, and we'll do 40m again thisol. This one's a little weird; we're driving up onto a sort of curb. We see these once in a while -- abrupt little steps in the terrain, usually, as here, associated with rock.

Why do they happen? I don't know, I just drive over 'em.

But not without some paranoia. The curb is at the limit of our ability to precisely measure, so after some discussion, we end up loosening the suspension limits considerably for driving over the thing. It's not implausible that we'd pop a wheelie going over it -- this happens when one of the bogie wheels (usually the leading wheel) loses purchase but its partner keeps going, as can happen when you're driving over a feature like this. The suspension auto-corrects within a meter or two, and no harm done. We wouldn't want to cut the drive in half if that happened, so we effectively tell Opportunity to just ignore it if it does.

And once again, we're plodding toward Victoria.

[Next post: sol 878 (Opportunity sol 857), June 23.]

2011-06-17

Opportunity Sol 852 (Spirit Sol 873)

Opportunity's entering restricted sols -- "a good thing, for once," as somebody points out, "since we don't have enough power to drive every sol any more anyhow."

We're losing energy, and worse, we're losing Eric Baumgartner. (I am the King of the Segues.) He's heading off to become the Dean of Engineering at Ohio Northern University. I hand him a poster we all signed for him, and shake his hand.

Eric is the kind of genius I can only wish I were. Smarter than hell, a fantastic engineer, but also great with people -- terrific social skills, a top-notch manager. And somehow he finds time to coach his kid's soccer team. It's a real loss to the Lab.

Depressed, I head downstairs to plan thisol's drive, which is a challenge. The trough before us ends in sort of a cul-de-sac about 20m away. Lying across the trough is a sort of "pitcher's mound" -- likely soft material we don't want to drive over -- and a few meters behind that is another one. Paolo wants to stop short of the first pitcher's mound, but I think we can take it, and I manage to convince him of it. Instead, we're going to drive up onto the ripple beside it, nestle in the hollow between mounds, and then scoot off into the next trough to the east. If we make it that far, we'll turn south again and back across a big patch of outcrop.

I'm either insane, or a genius. I mean, not an Eric Baumgartner genius. But a genius, anyway.

Or insane.

[Next post: sol 876 (Opportunity sol 855), June 20.]

2011-06-16

Spirit Sol 872

The bad news is, we're under 300 W-hr for the first time -- 297 is the actual number. 250, of course, is the lower limit of survivability (at least without pulling Opportunity-style Deep Sleep tricks).

The worse news is, they don't need rover drivers today. So I sit down with Tara Estlin, who's had bad luck with missing shadow shifts and stuff lately, and we work through the MI mosaic we sent last time, making sure she knows it like the back of her hand.

I'm going to have her write a simplified version of it herself, when she interrupts me. "I might need to leave a bit later," she says apologetically. "I have a sick cat ...."

Worse than merely sick, as it turns out. Tara's beloved fourteen-year-old Ripley -- the runt of the litter, but as feisty as her namesake from Alien -- is coming to the end of her days. She's got kidney problems, and she's ... she's not well. And Tara's barely keeping it together as the words tumble out of her.

Well, if there's one person around here who's going to understand about that ... I tell her about my own too-recent experiences with Jake and Zenobia, and as gently as I can, I encourage her to go home and spend some time with Ripley. I don't remember much about what I was doing at work the weeks they died, but I remember clearly the time I took off from work to spend with them toward the end. It's like gold in my hand.

"I don't know," she says, "your time is so valuable ...."

"My time is valuable," I agree quietly. "Right now, Ripley's time is even more valuable."

Tara goes home.[1]




[1] This was a hard post to revisit, having just recently lost another cat (Indiana). Life goes on, though, you know: Tara recently got another cat, whom she adores. And I know I will, too. Not yet, though. Not yet.

2011-06-15

Spirit Sol 871

We're continuing the extended RAT-brush campaign on Progress, but it hasn't been going well. For one thing, the RAT stalled again, possibly due to a pebble getting jammed in the works.

At first there's talk of blowing off the IDD work for the sol and just doing remote sensing, but cooler heads prevail. We end up doing an MI of the RAT hole, as much for engineering diagnostics as for science reasons -- if there's a pebble, we want to spot it. Then we'll image the RAT with the PCAM and FHAZ, so that if the putative pebble's lodged in the machinery, we'll have a shot at spotting it.

All in all, reasonably routine. The one thing that makes me nervous about this sequence is how close we're getting to the soil. As the RAT hole gets deeper and deeper, we move the MI in closer and closer. But since the MI mosaic that images the RAT hole also moves the MI over portions of the soil outside the RAT hole, we get closer and closer to the soil there as we go.

Our minimum standoff is normally about 17mm, but thisol it's going to be 9.5mm. Later we get updated numbers and find that it's not quite as bad as that, but it's close, at 9.85mm. That's within our 1cm error budget for the instrument positioning system, and I can't help disliking it. If you'd worked with Angry Bob[1], you wouldn't care for this, either. Imaging from the last time, when we were only about 1.5mm higher, shows that we should have acceptable clearance, so ... well ... it's one thing to be nervous, it's another to be unreasonable. I shrug and send the commands.




Footnotes:

[1] The nickname for original rover driver Bob Bonitz. If you're curious, here's the tale of his nickname (see that post's footnote).

2011-06-09

Spirit Sol 865

We're done. Or as near as damn it, anyway. We pretty much just have to pick up the sol A-857 sequence -- the one that did the last brush on our soil target, Progress -- and resend it. As usual, it turns out not to be quite that simple, but it's not much more complex, either. All around, an unusually easy sol.

So when Nicole Spanovich alerts me, I'm able to find time to remotely tell my TiVo to record Steve Squyres on the Stephen Colbert show tonight. (Gotta love that online scheduling. Magic!)

And Matt has started exploring RoSE macros.[1] He cranks out one to do the IDD safety-deactivate sequences, progressively making it more and more elaborate.

Ashley looks at him with mock pity. "He's got macro fever," she mourns.

Good. Our macros are getting a bit long in the tooth, and someone needs to work on 'em. Matt would be a great choice.

If I'm really lucky, macro fever will turn out to be contagious.

[Next post: sol 871, June 15.]




Footnotes:

[1] RoSE -- the Rover Sequence Editor, the part of our rover-commanding toolkit (RSVP) that I wrote -- has a feature called "macros," which let you kick out lots of commands for the rover with just a few clicks. I almost didn't think anyone was going to use this feature, but it turned out to be extraordinarily useful for the rover drivers in particular. Huge swaths of our IDD sequences were semi-automated through the use of macros, and later our drive sequences would be as well.

2011-06-07

Spirit Sol 863

Spirit's easy. No RPs thisol.

Spirit's interesting, too: apparently, a couple of rocks sitting very near us turn out to have a remarkably high iron content. Word on the street is, the most logical explanation is that they're iron meteorites.

Well, Opportunity found the first ever meteorite on another planet -- SpongeBob, back near the heat shield. But it's still a feather in Spirit's cap. One of many.

[Next post: sol 865, June 9.]

2011-06-01

Opportunity Sol 836 (Spirit Sol 857)

Jeng has to leave early for personal reasons. He was RP-1, I was RP-2, and Matt was shadowing, so I step in as RP-1 and Matt as RP-2. It's like a well-oiled machine.

This weekend, we had a little excitement on Opportunity: she got herself embedded in another ripple.[1] It's just like it was back at Purgatory, only not as bad: having learned our lesson from Purgatory, we had a slip check that stopped us before things got too hairy. Nevertheless, we're jammed in there pretty well, and it's going to take a bit of work to get ourselves out.

Today, we're just starting that process, commanding 5m of driving straight ahead. We'll take high-quality before-and-after pictures, along with a whole bunch of lower-res images in between. If we're lucky, we'll make about 1cm of progress. But it'll be just about the best-documented 1cm drive ever.

[Next post: sol 863, June 7.]





Courtesy NASA/JPL-Caltech. Aw, crap. Not this again.




Footnotes:

[1] This ripple was later named "Jammerbugt," after a Danish municipality, for some reason known only to Steve Squyres. I had recently been promoted to the rover driver team lead, and one of my first responsibilities was to lead the anomaly investigation into the Jammerbugt embedding.

I had lots of fun with this assignment -- my final slide included a picture of Captain Kirk ("Risk ... is our business") alongside a quote from Jim Erickson ("What I don't want to see is that we lose our nerve"). But more importantly, the investigation turned up something called the "Sullivan Asymmetry," which we named for Rob Sullivan, the science team member who noticed it and told us about it.

It turns out that the ripples were softer on one side and harder on the other, because as the Martian wind blew across them, almost always in the same direction, it deposited softer material on the leading side and harder material on the trailing side. This knowledge would help us avoid future embedding events because it meant that when in doubt, there was always a harder-packed side we could swerve toward. While that wouldn't have prevented this particular embedding (the root cause was a miscommunication between teams, and we solved that in a different way), it probably did prevent lots of future embeddings.

Oh, and one more thing about Jammerbugt. Rover driver Paolo Bellutta called it "Britney Spears Ripple" -- "Oops, I Did It Again." Funny as hell, but I decreed that we are not naming anything on Mars for that person, and that was that.