Daily Updates - July 7, 2004
Opportunity Status at end of sol 154-158
Sol 154 consisted of Opportunity completing activities on the target "Kettlestone," including a long Moessbauer integration, some microscopic images and placement of the arm for a little early morning alpha particle X-ray spectrometer integration to occur on the morning of Sol 155. The rover then went to sleep.
Sol 155 began with an early morning Mars Odyssey UHF relay of about 60 megabits of data, followed by a completion of the alpha particle X-ray spectrometer integration on Kettlestone. The rover then performed a calibration activity with the arm, consisiting of moving the arm into about 20 different poses and imaging each pose with the front hazard-avoidance cameras. From the stereo images and the reported position of the arm, the rover team will be able to update models and better target the instruments onto surface features in the future. Some miniature thermal emission spectrometer activity was conducted midday, and then the rover drove backwards about 1 meter (3.3 feet). The drive backwards served two purposes: first, it positioned the rover to image the most recent rock abrasion tool holes with the panoramic camera and miniature thermal emission spectrometer; secondly, it gave the team an opportunity to evaluate driving back up over the "curb" that was considered so difficult before traversing on sol 150. The drive back up over the curb went very well. Slip was estimated at around 11 percent, admirable for such a traverse.
On sol 156, due to an incorrect time conversion, the rover team failed to get the intended command load to the spacecraft at the right time. As a result, the spacecraft executed a backup set of minimal activities and returned about 80 megabits of data through Odyssey in the afternoon.
On sol 157 the rover acquired some images of the rock abrasion tool holes from previous sols. Then it drove down the hill to approach the next target. It drove beautifully and achieved its goal location. However, due to the large slopes (final rover tilt was 28.6 degrees), Opportunity ended the drive with the right rear wheel apparently slightly above the terrain (not touching anything). Even in this state the rover appears to be stable, but the team will likely take action on the next sol to get the suspension squared up (six wheels touching) before proceeding with preparations to grind with the rock abrasion tool again. On the night of sol 157 to 158 the rover gave up deep sleep in order to preserve an exceptional morning Odyssey pass.
The very early morning of sol 158, the rover woke up to chat with the Odyssey spacecraft and returned over 100 megabits of data! The rover then started the day's activities early with an attempt to image clouds around 8:30 in the morning. It then went back to sleep until about 10:30. After the morning uplink, it acquired some microscopic images of the new target area, then stowed its arm to allow a small mobility maneuver to get all six wheels squarely planted on the ground. This seemed to go as planned and reduced the total tilt of the vehicle to only 26.4 degrees, but did not appreciably change its position. This left the rover, as desired, in position to perform science investigations on the next targets of interest.