Opportunity Sol 409 (Spirit Sol 430)

You want the good news first, or the bad news?

The good news is, we set another record: 190m.

The bad news is ... huh, there is no bad news. It's all good news.

Jeff was the first to announce the results. He got up way early (or stayed up way late) and sent out a triumphant email at 5:45. I was up to see it at about 6. And neither of us is exactly a morning person.

To congratulate us, Jeff Favretto -- our mission manager that sol and this -- brings in doughnuts, with a congratulations message hand-written in black marker on the top of the pink box. Charles has the honor of announcing the record as the Spirit SOWG meeting is breaking up to make room for Opportunity, and there is much rejoicing. "So that's where the dust devils are coming from," one of the scientists jokes.

It couldn't be a more appropriate sol for the quote that illustrates our rear-looking track image in the Long-Term Planning report, which (as usual) leads off our SOWG meeting. It's a Dakota proverb: "We will be known by the tracks we leave."

The drive should have left us just next to a crater which, yesterday, Ray dubbed "James Caird Crater." (Caird, a whaler, was an important part of Shackleton's expedition. Caird was a Scotsman, which makes him all right by me.) The problem is, we can't see this crater in the images we have. The minimal downlink only gave us forward-looking images, and the crater would be to the west or southwest of us. That crater was our only landmark, meaning that, in a sense, we have no idea where we are.

Perhaps I shouldn't be so dramatic: we have some idea of where we are. Probably a pretty good idea. We'd just like to be able to prove it.

We took NCAM images after the drive; when they make it to the ground this weekend, we should be able to see James Caird Crater in them. Or so we hope. But it seems a shame to be sitting just a few meters from what looks in the orbital imagery like a pretty darn nifty crater, and not get some good images of it. Plus, solid images with good range data would help localize us really well. So, in the back row, Justin Maki and I start scheming. But to little avail: in the end, we fail to talk the science team into spending the bits on it. They might catch it in a PCAM panorama they're taking before we drive on, but the panorama is probably aimed too high (this one needs to be, for science reasons). So we might never see the crater at all.

Well, that's a shame. But the upside is, if indeed we don't see it, it will be because we drove away. Really, really far away. In order to help avoid a repeat of Spirit's squeaky-wheel problem, we're letting the rover rest Friday (today) and Sunday. But Saturday, we're driving with a vengeance. We would have driven a little farther than 190m on the previous drive, but autonav found some obstacles to avoid early on and lost a little time edging around them. Assuming that doesn't happen again this weekend, we'll break 200m this time for sure.

Once the drive sequence is in the bag, Jeff and I take a little time to brainstorm ways to drive even farther on future sols. We don't see a lot to optimize in the current approach -- all the parameters are cranked up as far as is safe, and the general structure of the drive sequences is about as good as it can get. We blind-drive as far as we safely can given the imagery we've got -- lately, this has been about 100m -- and then we switch to the much slower autonav. So the most obvious way to squeeze more time out of a drive is to extend the length of the blind segment.

But we can't, because we're driving as far as our stereo imaging allows. Unless -- "Hey," I say, "what if we did long-baseline stereo? Take an image-pair in the drive direction, drive laterally a few meters, and take another image-pair." I think this is a great idea, but it doesn't seem to set Jeff afire. Turns out they've done this before on the plains, and it didn't seem to improve the data all that much.

Oh, foo. I thought I was being all creative.

[Next post: sol 433 (Opportunity sol 412), March 22.]


Anonymous said...

This is a nerd moment even among nerds, but I can't help but notice your jargon is evolving. When did PANCAM and NAVCAM become PCAM and NCAM? Does this also happen to the HAZCAMs?

Scott Maxwell said...

Nah, I'm just not terribly consistent about it. Most people say PANCAM and NAVCAM to this day; I often abbreviate these to PCAM and NCAM.

For no readily apparent reason, I consider "HCAM" an abomination, though I use FHAZ and RHAZ all the time.