This week the Opportunity Instrument Arm Anomaly Team continued investigating the safety of different arm positions. The intent is to determine the safest position to leave the arm while the vehicle drives to new locations.
The original position for the arm while driving was to tuck it underneath the rover, hooked on a small pin. This leaves the partially failed shoulder azimuth joint at 90 degrees to the direction of travel. If the arm stuck in this position we would be unable to use the arm.
The current plan is to investigate different versions of driving with the instrument arm's "elbow" sticking out towards the front of the vehicle, with the arm's instrument cluster above the solar panels. From that position the instrument arm could still be used without using the suspect azimuth joint. The variations include leaving the instrument cluster in mid air, or resting one or another instrument on different portions of the rover for stability.
These different positions are being evaluated on the test rover at the Jet Propulsion Laboratory in Pasadena, Calif. Meanwhile, on Mars, Opportunity is continuing to use the arm and its instruments to investigate rocks within its reach. The rover has also been acquiring images for a 360-degree, multi-filter panorama of "Erebus Crater."
Sol-by-sol summaries: