2009-02-11

Spirit Sol 39

Today I try to learn yesterday's lesson about the importance of not being seen. I catch up on my email -- in my office.

The story today is not great. We didn't drive yesterday -- apparently, the HGA calibration failed because the actuators, shadowed by the PMA, were too cold. But the vehicle is healthy, and we'll drive tomorrow.

And we got a lot of data back. Mark is displaying an RSVP animation showing our total driving since sol 1 (total mileage: 33.4m). This is very cool, but even better is the full astrobot picture. We got it!




Courtesy Cornell/NASA/JPL-Caltech. Our full-color drive-by image of the LEGO astrobot; the astrobot is mounted on the lander, in the dead center of this image, ringed by three modified LEGO bricks. Also see LEGO's press release for more info.



The scientists are a little frustrated by yesterday's failure to accomplish anything. At the start of the downlink assessment meeting, one of them asks, a little testily, whether we can't get runout-type science when these things happen, rather than losing the whole day. The short answer is no: when we don't know exactly what's wrong, we don't want to command the vehicle unnecessarily.[1]

And we can't stay long enough to do much science tomorrow. In general, there's not enough time for "good" IDD science and a long drive in the same sol. We can do short touch-and-go days, but we can't get lengthy MB or APXS integrations. We'll probably do one of those short touch-and-gos tomorrow, deploying the IDD, briefly investigating one of the nearby duneforms with the MI, then stowing the IDD and moving on. Our next target is a location dubbed "Stone Council," about another 50-60m out. It will probably take two or three days to get there, meaning I'll get to do at least some of the driving.

Today should be an easy day all around, since it's mostly a replay of yesterday. There's some unhappiness about this, but it's generally accepted.

One of the LTP guys, Dave Des Marais, points out that we've got enough data volume that we can afford to do more remote sensing. We've pretty much sucked the flash dry. So we have some options -- including taking more images, and compressing them less. (Less compression will also save some CPU time, though it's not clear that's enough to reduce our power or time constraints significantly.)

The last topic for the meeting is the daily picture. PIO asks if we should use the PANCAM of White Boat as our daily photo. Mike Carr thinks it's a good idea, and calls for someone to help them write the caption. When no volunteers are forthcoming, and the silence starts becoming awkward, someone suggests, "What about Alian? White Boat was her baby." (Alian Wang was one of the stronger proponents of the White Boat drive.) "OK," Mike Carr says, "how about it, Alian?" But she was wrapped up in something else and has missed the whole discussion. She looks up, blinking. "How about what?" The room laughs. "We've got a volunteer!" says Mike, and that's the end of the planning.

But there are still the science talks, and since I'm not on shift, I have time to stay for them. My favorite is the MTES White Boat results. I was really worried about this one -- I literally woke up in the middle of the night fretting about it -- since it came at the end of the White Boat drive, and we were very uncertain about exactly where we'd end up, or if we'd even be able to face the rock. To get the best position and angle for the MTES, they needed us to get the front wheels 1.5m from White Boat, plus or minus 0.1m (10cm), and because of the interaction between the canned parts of the drive and the autonav behavior, it was hard to coax the simulation into doing just the right thing. So there was a lot of careful, detailed work involved in planning the drive just right. As you already know, we nailed it -- by the most pessimistic estimate, we were only 3cm from our target, well within the MTES error margin. So they got their results thanks to yours truly. (But do they thank me? They do not. They probably won't even list me as a co-author on the paper.)

Anyway, White Boat's surface is just above freezing, or was when they looked at it in the late afternoon. Spectrally, it's equivalent to the dusty part of Adirondack, plus even more dust. The conclusion is that it's a dustier version of Adirondack, possibly with less olivine. (This, incidentally, is exactly what Ray Arvidson predicted, when he scowled that they were wasting time by going to White Boat. "It's just another damned volcanic rock," he muttered.) I ask them later why some of the rocks in the scene are so much dustier than others. The answer -- the tentative answer -- is that some of the rock faces are easier for the wind to scour clean. A low, flat rock like White Boat presents a different kind of surface to the wind than a taller, more angular rock like Adirondack. Over a few million years, the difference adds up. But there are other possible explanations, cautions the scientist I'm talking to. We'll have to see whether the hypothesis holds up.

I've got a list of stuff I need to do, and I've decided to try to knock one thing off the list every day. Today's item is a script Sharon Laubach needs me to write, to save the Opportunity SIEs some error-prone work. The script turns out to be more involved than I originally thought, and I end up hacking out something ugly but functional, just so I can be done with it. By the time I'm finished, it's 3AM -- I was hoping to be home by midnight -- and I need to be back for an 8AM interview with the AP. I'm irritable and frustrated from the unexpected complexity of the script, and because I'm hungry and forgot to bring any food. But there's not much point in going home, and not really time to go out for food and also get meaningful work done. I decide to stick around and knock a few other items off the list.

Which, in the way of to-do lists, only lengthens as I try to shorten it. Chris Leger has a good suggestion for a RoSE macro that would simplify our Bonneville traverse planning (hiding out in my office didn't help after all), and implementing this macro takes most of my remaining time. But when it's done, it's pretty damn slick, if I do say so myself. So at least I've done some work I can be proud of today.

I finish the macro with about 5 minutes to spare before the AP interview. There's not time to set up a workstation with something visually interesting before the interview -- which I've learned I should do, because it's too distracting to try to do this during the interview itself -- so I just go meet the guy. He has a photographer with him, and someone from the media office accompanies us, so we're a bit too much for the Spirit sequencing MSA. Instead we go upstairs to the Opportunity sequencing MSA, which is empty at the moment. I'm tired, frustrated, hungry, and distracted, but the interview goes OK anyway -- not great, but OK. I don't know if I'm any good at this press stuff at all, but I'm better at it when I'm happy, alert, and fed. It's over by about 9:30 -- nine and a half hours after I originally wanted to be home. Bleah. Maybe tomorrow I'll try hiding in my house instead of in my office. What's the point of paying for DSL if you never work from home?

I leave the damn place, get some food, and go home.




Footnotes:

[1] But this was a good idea, and we ended up doing it after we had a little more experience with the rovers.

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