Spirit Sol 70

It's starting already: at least temporarily, they're moving the downlink teams to Earth time. Sigh.

I've decided to keep coming in at my regular time, even though I could be coming in 90 minutes later (like everyone else), so that I can get more work done. Sigh. But maybe this will mean I'll be able to work less on my days off. (Fat chance.)

They've taken another image of the backshell -- or whatever it is -- which have failed to fully clarify the situation. There are several Spongebob Squarepants fans on the project, who have decided that that's what it is. I guess that counts as finding life on other planets.

At the downlink assessment meeting, they have a beautiful color image of the color crater panorama on the big screens. I'm really getting spoiled by the big screens. When the project is over, I'm going to have to buy a 3200x1200 projection monitor.

Anyway, the plan from here is to work the rim. We'll be here for about 3 weeks (later they say 18-22 sols), inspecting rocks, soils, ripples, deposits, etc., as we crawl along, and that will take us to the end of the nominal mission. The extended mission will be the drive to Columbia Hills.

The guy defending this plan puts up a presentation with a picture of Opportunity's crater; there's a round of good-natured booing. But the point of showing the image is to set a context: in its crater, Opportunity found the interesting stuff (bedrock) just below the rim. We can expect something similar here -- we may, for example, not need to clamber all the way down to the bottom of the crater; exploring the rim and upper slopes may do everything we need.

At Bonneville, though, there is no evident outcrop (which everyone was hoping for). Still, there's significant value in being here. You tend to get more weathering on slopes, since they present a broad face to the wind and allow the weathered material to "escape" (by running downhill), so we'll see fresh material just beneath us. For the same reason, coatings and non-basalt rock types that don't weather as fast as basalts will also be exposed here. So even though we don't see bedrock, we should see plenty of geologically interesting stuff.

One thing we'll need to do is analyze the crater slopes. The angles we're seeing, 20-25 degrees, are on the edge of what we're able to traverse, but there's a worse problem: on those slopes, we're likely to see 100% slippage. This makes it a rover trap, where we can get in but find ourselves unable to get back out. I have the image of a sort of hungry robotic ant lion, lying patiently in wait at the bottom of Bonneville for millions of years, ready for the moment an unwary robotic explorer from another planet should wander in ....

And Ray notes the other end of it: 100% slippage would mean that we could slide all the way down, unable to brake. "I don't want to try to traverse one meter down and the next thing we see is the dunes at the bottom," he tells me. Just think how I'd feel about it!

Ray also has a more serious, and pointed, question. Suppose remote sensing shows more of the same -- more of what we've already seen here. Do we even have to go in? There's a lot of discussion about this, but I think the short answer is: no.

One other note from Ray: we're big news in Baker, CA -- population 392. Don't ask me what Ray was doing there; maybe it's because Baker is the home of the world's tallest thermometer. But he was, and he tells us that people kept coming up to him and saying, "Hey, I heard you made it to that crater!" So if we're news there, I guess we're news everywhere.

Today's sequencing is just a little IDD work; I could do it in my sleep. I'm done with it and hand off to Bob practically the minute he comes in. Once again, I leave on time. This could become a habit.

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