Spirit Sol 90

I'm putting my stuff away when John Grant knocks on the door. "Did we make it?" he asks. "I don't know," I tell him, "I just got here." We go over to the SMSA, but nobody's there yet. I log in and try to figure out how to run the report script that will show me how far we got -- this is something the subsystem teams normally handle, but they're not in yet. John's got to get back to work on Opportunity, but he asks me to let him know as soon as I know.

I'm still trying to figure it out when Andy walks by and asks me the same question. Then Frank does the same thing, and so does Mark Adler. Andy, thinking ahead as usual, is trying to sweet-talk the scientists into making sol 91 a simple day so that we can have our end-of-nominal-mission celebration.

I figure out how to get the report script running just before the Mobility/IDD guy (Reg, today) shows up. It turns out that the data isn't quite in yet. Reg runs it a few minutes later and the answer pops out.

50.129m. A new single-sol record, and well over the 35m we needed. (Our total odometry now stands at 614m.) Andy and Mark are in a meeting in the SMSA conference room, so I tell them the good news, and everyone breaks into applause. I head over to the science context meeting to tell the scientists the good news. "I think I'll go with you," Andy says, and Mark follows us seconds later.

Hap is giving the LTP report, but Mark whispers the good news to the SOWG chair (Ron Greeley again today). Ron grins and motions Hap to hand us the mike. Hap gives it to me. If I had any class, it would have occurred to me to give the mike to Mark or Andy, since they're the ones who always report the news when it's bad. But I don't think of it in time.

"Fifty point one two nine," I say, and I hand back the mike. I don't even have to say what the number means. Everyone cheers.

"Let's see, that means we need, uh, five more meters?" Hap says. Then I remember that LTP's traverse numbers are always a sol or two behind, because they have to put their report together before the downlink data shows up. And he'd just reported an old number -- 545m -- as the odometry total. The room doesn't know that we made it. "No, no, we only needed 35," I tell him. "We're over the limit! We made it!"

Then they really cheer.

"Nice driving," a couple of people tell me. "Well, I'll tell Chris and John for you," I say.

If I remember.

I need to plan our drive for thisol, but I have a couple of promises to keep first. I go upstairs and tell our good news to John Grant (big grin, handshake) and Frank ("Oh ... you set a new record, huh? We're planning an 80m drive ....").

Then I go back downstairs and start looking at the data. I'm going to need to know the planned drive direction in a few minutes, but my ability to analyze the images is limited by the absence of 3-D glasses -- I can't get a good sense of how the terrain is shaped without them. I look around the room a couple of times and don't see any. And then I remember ... the five-dollar 3-D glasses I bought back on sol 5. I'd totally given up on those damn things, and whaddaya know, they turn out to be exactly what I needed. A few minutes later, I know where we need to aim the rover.

Just in time for the downlink assessment meeting. Where they have some good news. Despite losing an hour of sleep tonight when we change to PDT, our schedule starts two hours later on Monday. So tomorrow (Sunday) will suck, but we'll make up for it the next day.

One of the scientists has a warning. Apparently, we don't have functioning temperature sensors on either NAVCAM on this rover, so we have to rely on the thermal models to keep the cameras safe. We got NAVCAM images of the sky the other day; at the time those images were taken, the temperatures on the other cameras were below the lower limit (-55C). We need to ensure we operate the cameras only when they're in the safe temperature range, or we risk damaging them. Yet another thing to keep in mind when planning.

That's something that wasn't my fault. I think it happened when they were taking pictures of the sky, looking for clouds. They have thumbnails that might show clouds, but they won't know until the full images come down. Our other atmospheric news is good: the tau (atmospheric opacity) is below 0.5 for the first time, as the dust storm that preceded our arrival continues to dissipate. As the atmosphere continues to to clear up, we'll see the Columbia Hills better and better -- and, of course, driving toward them won't hurt.

I'm secretly hoping we'll get a chance to set a new distance record tomorrow. The initial plan has a lot of time allocated to driving -- two full hours. But now that we've made it over the limit, it's back to business as usual: they cut the second hour in order to make room for more remote sensing. Oh, well.

On my way up to the SOWG meeting, I stop by to talk to MIPL about the meshes. One of the MIPL guys, Bob Deen, is the only other person who's worked every day of the nominal mission (well, I skipped one day, so he's one ahead of me). I tell him he's going to get the perfect attendance award.

Mindful of Opportunity's upcoming record-setting drive, Scott Doudrick and I joke about how Spirit can rack up more meters. Here's an easy way: a full turn-in-place puts about 6m on the wheels. If we hadn't made it over the limit today, we could have just planned to turn the rover in place for a few hours and call it a trenching experiment. Even Opportunity isn't going to beat that ....

But meanwhile, I have real driving to do. The scientists would like us to approach a rock called Route66, which is about 20m away. And there's a minor constraint on the drive: for comm reasons, we want to end up heading at 120deg (this will avoid HGA flops during the FSW upload period[1]). This constraint turns out to be relatively easy to satisfy; the straight path to the rock has us approaching it at an angle of about 110deg anyway, so we just have to aim a little high and then turn near the end. Even easier, we don't have to make it all the way to the rock thisol; we just plan to get reasonably near it and then finish up the drive nextersol.

So I get the drive built, hand it over to Bob, and he's finishing it up when the word comes in: the telecom guys say we don't want to be at 120deg during the FSW upload, we want to be at 195deg -- not pointing east, but south. This is a bit more of a pain, as it means we'll have to head to the north of the rock, deliberately overshooting it, then turn south for the final approach. Worse, that means we'll have to replan the post-drive imagery, which was built with certain assumptions about our final orientation that this new plan will invalidate. It's getting late in the process, and there might not be time to redo the imaging sequences. After some debate, we change it a little: we'll shoot for a position a little bit northwest of the rock thisol, and spend the next sol driving to the final position. This will let us use the already-built imaging sequences and still have a fair chance of doing the final approach. Bob and I independently work out where we need to end up in order for this plan to work, we come up with a good agreement, and he redoes the drive accordingly.

We're literally seconds away from delivering the new drive when the plan changes again. While we've been working, the telecom guys have been arguing, and they have what we're now told is the final story: not 120, not 195, but 127.5 (actually, they say "between 125 and 130," and we decide to split the difference). So we have to do it all over again, and of course we now have even less time to do it in. Bob's frustrated by this, but I can't help laughing about it. But what the heck: we get it done. At the Command Approval Meeting (CAM), Bob -- who is notorious for changing sequences late in the game -- announces semi-seriously, "I reserve the right to change the sequence until command uplink." (Mark Adler buries his face in his hands and pretends to sob.) "Oh, just until then?" retorts Kevin Talley. "Is today your birthday or a holiday or something?"

I'm done with sequencing, but I stick around to clear out my email backlog and get ahead on some other work. Kevin, looking over the list of target and feature names the scientists have assigned at our current site, says that they're "Tolkien-challenged." They've chosen Mount Doom and Smaug, but Smaug (the dragon from The Hobbit) wasn't at Mount Doom. He doesn't remember the name of Smaug's mountain, but I Google it as fast as he can ask the question. Lonely Mountain. "We'll bring that up at the CAM," he says (and he does).

When Bob shows the drive animation at the CAM, he shows both the "battlefield view" (overhead) version of the drive and the "image view" version, which shows a 3-D version of the rover driving into the images we took from our present location. Bob's showing this on the projection screen, and something prompts me to ask Mark Adler whether he's ever seen a drive in the true 3-D view, the one where we put on the fancy LCD goggles. He hasn't, so I set it up for him after the meeting. Verdict: "Cooool!"

This makes Bob ask me to describe what I see when I look at the terrain in 3-D. I do so, but -- well, that was an odd request. He explains that he can't see in 3-D -- he's what's called an "alternator." He can see fine with either eye, but his brain decided early on not to fuse the two images into a single 3-D image. So he has no depth perception.[2] It's not really that inconvenient, he explains; human eyes are so close-set that people don't have reliable depth perception out past a few meters anyway -- after that limit, you rely on other clues, such as the relative heights of objects. But he does have trouble parallel parking, or pouring drinks. Of course, a lot of people have trouble pouring drinks even with depth perception, I point out. Especially after they've poured a few.

Courtesy NASA/JPL-Caltech. Somewhere in there, Spirit crossed the finish line ... and, true to form, kept right on going.


[1] That is, the antenna that looks like
a lollipop won't have to flop over from one side to the other in order
to track the Earth through the sky.

[2] Including Bob, I think I've met
three people on MER who either can't see 3-D or have trouble with it.
It's odd -- until that moment, I'd gone through my whole life not even
knowing that it was possible for a person to see otherwise normally
but be unable to process 3-D.

1 comment:

Anonymous said...

I didn't get to five years ago so congrats on nominal mission success!

Now get back to work for another five years!