On sol 215 Opportunity completed a reading with its Mossbauer spectrometer of a target called "Kirchner," where a wire brush on the rover's rock abrasion tool had scrubbed a circular patch on the surface of a rock called "Escher." The rover also made some remote-sensing observations then then set up for using its alpha particle X-ray spectrometer on Kirchner early the following morning. However, an image from the rover's hazard-avoidance camera revealed that the doors of the alpha particle X-ray spectrometer had not completely opened. The door is a tricky mechanism; incomplete openings and closings have occurred before, and the team continues to work on approaches to more reliably maneuver the door.
On sol 216 the rover successfully acquired early morning alpha particle X-ray spectrometer data on Kirchner. Despite the incomplete opening of the instrument's dust doors, the spectra look good. No repeat of the integration will be necessary. The rover also used the Mossbauer spectrometer to examine another brushed target, "EmilNolde," on Escher. This reading was planned to run into the evening then later, following a deep sleep, to resume in the early morning of sol 217. The Mossbauer placement went fine. The rover was commanded to close and reopen the alpha particle X-ray spectrometer doors and this went well. The doors are now properly open and ready for action on sol 217.
On sol 217, which ended on Sept. 3, Opportunity used its rock abrasion tool to brush a target called "Otto Dix," and used its microscopic imager to look at the brushed area. Then the rover was commanded to place the alpha particle X-ray spectrometer on EmilNolde, precisely on a "dirty" portion of that target (an area that was not very well cleared away by the brush action a few sols ago). The plan was to collect data with the alpha particle X-ray spectrometer in the evening, perform a move in the middle of the night to a cleanly brushed portion of EmilNolde and integrate again until morning. These two integrations will be used to discern the differences between the "clean" and "dirty" portions of the target. A 100-megabit afternoon downlink through Mars Odyssey on sol 217 showed that all activities went well through the placement of the alpha particle X-ray spectrometer on the "dirty" part of EmilNolde.