Mars Exploration Rover Update - July 14, 2005

http://marsrovers.jpl.nasa.gov/mission/status.html

SPIRIT UPDATE: Spirit Investigating 'Independence' - sol 538-545,
July 14, 2005

Spirit is healthy. On sol 538 (July 8, 2005), Spirit attempted its rock
abrasion tool to brush the rock called "Independence." The tool's
contact switches did not engage the rock face, and the brushing did not
occur. A safety check precluded further use of the robotic arm. The
prescribed operation should have been:

* brush with rock abrasion tool;
* place the alpha particle X-ray spectrometer;
* observe with the microscopic imager;
* place the Moessbauer spectrometer.

From this particular down position for the rock abrasion tool (and the
fact that use of the arm was precluded), the rover would not have been
able to switch to the Moessbauer spectrometer. The entire weekend's
worth
data collection by the Moessbauer spectrometer would have been lost.
However, the arm preclusion was discovered Friday evening and the team
had enough time to modify the robotic arm sequence and recover the
weekend's Moessbauer integration time. The sequence of events became:

* enable robotic arm activity
* move the joint angles to avoid an arm position that would prompt
collision-avoidance software to halt to arm movements;
* observe with the microscopic imager;
* place the Moessbauer spectrometer.

The recovery plan ran well. The Moessbauer spectrometer was placed and
it
collected data all weekend.

On later sols the tool turret on the arm was rotated to the alpha
particle X-ray spectrometer. That instrument examined the same target
for about 17 hours, recovering the alpha particle X-ray spectrometer
integration time lost on July 8 (sol 538). Spirit also found time
during
the weekend to fill in the remaining panoramic camera images for an
"Independence" color panorama.

Sol-by-sol summaries:

Sols 538 and 539 (July 8 and 9): The rover team recovered a long
reading
with Spirit's Moessbauer spectrometer after a planned brushing with the
rock abrasion tool did not occur. The rover also took images of the
target rock, "Independence" with the microscopic imager and continued
taking component images for a large color panorama of the
"Independence"
scene.

Sols 540 and 541 (July 10 and 11): Spirit continued collecting data
with
the Moessbauer spectrometer and taking images for the "Independence"
panorama.

Sols 542 and 543 (July 12 and 13): Spirit continued the Moessbauer
spectrometer integration, then changed the tool to the alpha particle
X-ray spectrometer late in the afternoon and collected data with that
instrument overnight. In the morning of sol 543, Spirit changed back to
the Moessbauer spectrometer for its final few hours of integration.
Spirit stowed the robotic arm and bumped back about 80 centimeters (2.6
feet) to a good position for observing "Independence" with the
miniature
thermal emission spectrometer, now back in use.

Sols 544 and 545 (July 14 and 15): The plans for these sols are for a
25-meter (82-foot) drive followed by a sol of remote-sensing
observations from the new location.