Opportunity Sol 403 (Spirit Sol 423)

Yesterday we planned sols 402 and 403 (which executes today); today we plan the weekend sols, 404 and 405. Khaled could use the experience, so I have him do the bulk of the RP-1 work today.Which is easy, since he already did most of it yesterday. I spend most of the day struggling with a tricky m4 problem. Don't get me started. But he calls me over to help out with something weird: the INCONs file ("INCONs" is short for "initial conditions" -- it specifies the rover's last known position, which is how it will start the day) shows the rover with the APXS in the wrong position. Instead of being directly on the target, the instrument is laterally offset by about 3.4cm.On comparing the numbers from that file to the numbers we expected, we find it's offset by the right amount to be an MI poker offset. This term takes some explanation. When we're trying to get good MI images of a rock surface, often we first touch it with the MI's poker, a small, thin, steel rod affixed near the MI's lens. When it senses contact, we back off a known amount, and we can trust that the ...