[meteorite-list] Mars Exploration Rovers Update - April 29, 2004

[Ron Baalke]

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

SPIRIT UPDATE: A Drive and a Dig - sol 112-113, Apr 29, 2004

Spirit took it easy the morning of sol 112, which ended at 
8:30 a. m. PDT on April 27, and didn't begin operations 
until 11:45 a.m. Mars Local Solar time, to conserve energy 
for an afternoon drive. Before taking off, Spirit gathered 
some soil and atmospheric observations with the mini 
thermal emission spectrometer and panoramic camera.

Then the drive began. Spirit's updated autonomous navigation 
software proved its worth again this sol.  During a long 
auto-navigation segment, the rover encountered a hazard and 
was able to back up and find a way around it. Spirit 
continued to drive backwards towards its intended goal 
point, using the rear hazard avoidance cameras to navigate 
the way. When the allotted drive time was up, Spirit turned 
back around and made one last short drive to its resting 
place for the night. Spirit's odometer records backwards 
and forwards driving and logged another 88.6 meters (290.7 
feet) for the sol 112 drive. The actual distance covered 
was about 60 meters (197 feet).

On Sol 113, which ended at 9:09 a.m. PDT on April 28, 
Spirit woke up earlier than normal, 9:00 a.m. Mars Local 
Solar time, to do morning atmospheric science. One 
objective of the early sky scan was to image morning 
clouds with the panoramic camera. Spirit then began an 
intense study of a soil spot called "MayFly." During her 
examination of the area, Spirit took panoramic camera and 
mini thermal emission spectrometer images in parallel, 
conducted a two-hour Mössbauer integration and 
finished off with a look through the microscopic imager. 
The rover then stowed the instrument arm to prepare for 
digging a trench.

Rover planners intended for Spirit to use its wheels to 
dig a trench at the MayFly spot, but hazard avoidance
camera images of the area showed a potato-size rock that 
could have potentially fallen into the wheel hollow in the 
process. Rather than take that risk, controllers decided 
to back the rover up 10 centimeters (3.9 inches) to a 
clearer spot. After the final positioning, Spirit used 
its wheels to dig a 6-centimeter (2.4-inch) trench. Spirit 
finished the sol with hazard avoidance camera images of 
the trench, which was used to plan Mössbauer, alpha 
particle X-ray spectrometer and microscopic imager work 
on sol 114.

On sol 114, which ended at 9:49 a.m. PDT on April 29, 
2004 Spirit continued to investigate the trenched area
with the Mössbauer spectrometer, alpha particle X-ray 
spectrometer and the microscopic imager.


OPPORTUNITY UPDATE: Opportunity Edges Its Way Toward 
'Endurance' - sol 92-93, Apr 29, 2004

Opportunity spent sols 92 and 93, which ended at 8:51 p.m. 
PDT on April 27 and 9:30 p.m. PDT on April 28 respectively, 
edging its way closer to "Endurance Crater." A total 
drive of 106 meters (347.8 feet) left the rover just 70 
meters (229.7 feet) from the rim.

The pattern for these two sols has been to take pre- and 
post-drive remote sensing observations and imaging in 
the crater direction between midday energy-conserving 
naps.

By sol 95, Opportunity will make the final approach to 
Endurance Crater.