Spirit is on the east side of Home Plate, which is this raised platform-like structure that we're trying to understand. It could be some kind of volcanic structure, possibly formed by hot lava inteacting with groundwater, and it would be the first volcanic feature either rovers or landers have gotten to investigate. Because the surface of Mars is largely volcanic, it's important for us to understand the processes of volcanism and so we're trying to do a really full-up investigation of Home Plate.
Our next target is called Madeleine_English (the team is informally naming targets after deceased members of the All-American Girls Professional Baseball League, complementing the names from the Negro Leagues on HP's west side last fall) and is a really interesting target for understanding Home Plate. It is pretty obviously a layer of rock, near the bottom of the stack of layers that make up Home Plate. We'd really like to understand what the different layers are made of and how they are put together. We got to take a look at Madeleine_English a couple of days ago in all 13 glorious Pancam filters (you can see the pictures filter by filter, like here, or combined to make the true-color filter combination at left) and the results are intriguing, showing a very interesting texture in the rock.
So all this week, Spirit and her handlers tried valiantly to approach Madeleine_English so we could deploy the arm instruments. Unfortunately, we're really feeling the effects of having a gimpy wheel. During these short drives over rough terrain angling for a precise approach, the rover has to strain against the wheel, because the wheel doesn't rotate freely. But as I've said here before, the rover drivers are amazing at coaxing the rover into places to wring more science out of this planet. Here's their summary of the driving maneuver to get to this target: "The route involves driving backward, turning around, backing up, parking in parallel between two sizable rocks flanking the target, pivoting clockwise on the stuck right front wheel, and finally "crabbing" forward to the target. Spirit performs crabbing by steering the two rear wheels toward the stuck right front wheel, thus opposing resistance from the right front wheel and keeping yawing (swinging from side to side) to a minimum." (You can see weekly summaries of rover activities in the JPL Mission Manager reports)
Whew! Check out where Spirit ended up (through her front hazcam). Sweet! That's the target rock right in front of us! Can't wait to have a closer look!