Spirit is approaching the 4km mark; they might make it as early as today. It's a shame I won't get to do that drive, but I've contributed my share toward this achievement. It's OK if somebody else has a little glory.
It turns out that there's a logic behind the fact that some Opportunists want out of Endurance Crater and some don't care. Field geologists, Brenda Franklin explains to me, want out. They want to see new rocks. The spectroscopy folks don't care -- they're hunched over their instrument data, and any rock is as exciting as any other because what they really care about is not the rocks but the instruments themselves.
I say that I think I'm the only Opportunist who's happy either way. "So you don't care whether you get to do a three-hundred-meter drive?" one of the scientists asks teasingly. (This is obviously possible only on the plains outside the crater, not inside the crater itself.) Well, maybe I do care, at that.
Thisol we're redoing the RAT on Wharenhui, making it another easy sol. The exciting stuff -- the egress drive -- will happen later in the week. We should know by 15:15 Sunday whether we've egressed, and I volunteer to come in and help assess the drive result. (Like they could keep me away.) It's a bit of a shame that I won't get to do the drive, but as I've said, I'd rather that honor went to someone who badly wants out. There's no shortage of those folks anyway.
Since most of the cost of the mission was up-front costs -- development, hardware, launch, and so on -- the sols are getting cheaper. We originally figured about $4 million per sol -- that's assuming about 200 sols of combined operations and an overall mission cost of about $800 million. But now we've had about 600 sols of operations, with only a modest cost increase. As Art points out, that means sols now cost about $1.3 million each. (And since that's amortized over the life of the mission, they're actually cheaper than that.) "Pretty soon they'll be so cheap we can all afford 'em," he says. "Maybe we should start auctioning them on eBay." 
[Next post: sol 337, December 14.]
 Since I know you're wondering ... I don't have exact numbers, but they're now well under a quarter-million apiece. And still falling.