Mars Exploration Rover Update - October 25, 2004

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

SPIRIT UPDATE: Spirit's been mulling over 'Uchben' - sol 279-284,
October 25, 2004

Spirit is healthy and currently investigating a layered rock called
"Uchben." Spirit is farther from the equator than its twin, Opportunity
is, and it has much less available solar energy. Spirit's solar panels
are pointed to the northern Sun, but Spirit is still only getting about
400 watt-hours of energy per day - enough to run a 100-watt bulb for
four hours. Opportunity has been getting more than 700 watt-hours a day.
The lower power supply for Spirit limits the rover's daily activities.

On sol 279, Spirit was parked at the location where a second occurrence
of a problem with the rover's dynamic brake relay anomaly had halted a
planned drive on sol 277. Scientists took the opportunity to analyze
disturbed soil in front of the rover. Spirit deployed its robotic arm,
acquired images of the soil with the microscopic imager, and placed the
alpha particle X-ray spectrometer on a new target, named "TakeABreak,"
for an overnight integration.

Sols 280, 281, and 282 were built as a single three-sol plan to execute
over Earth's weekend. On sol 280, Spirit acquired morning observations
of sky and ground with its miniature thermal emission spectrometer, took
a panoramic camera image to assess atmospheric quality, and completed
the overnight alpha particle X-ray spectrometer measurement. After a
midday nap, Spirit did a tool change from the alpha particle X-ray
spectrometer to the Mossbauer spectrometer and began an overnight
integration on the same soil patch.

On sol 281, Spirit completed the Mossbauer spectrometer measurement,
took a midday nap, acquired three images of a nearby target called
"Coffee" with the microscopic imager, and stowed the robotic arm. Spirit
then successfully drove about 4 meters (13 feet) backwards, putting the
target "Uchben" into the workspace of the robotic arm. The drive
included straightening the right front and left rear steering wheels,
which are the two impacted by a problem with the relay that is used in
turning the steering motors on and off. The drive also successfully
tested driving without use of the right front and left rear steering
wheels to limit use of these motors while investigation of the
malfunction continues.

On sol 282, Spirit acquired measurements of the sky and ground in the
morning with the miniature thermal emission spectrometer, took the usual
midday nap, and then made remote-sensing observations in the afternoon,
including some navigation camera images for use in planning of future
driving.

On sol 283, after receiving its daily commands and acquiring a panoramic
camera assessment of atmospheric quality and miniature thermal emission
spectrometer measurements of the sky and ground, Spirit took a midday
nap. In the afternoon, Spirit deployed the robotic arm and acquired 20
images of a target region called "Koolik" on Uchben with the microscopic
imager. Spirit then deployed the alpha particle X-ray spectrometer for
an overnight integration.

On sol 284, which ended on Oct. 25, Spirit completed the alpha particle
X-ray spectrometer measurement and then did a tool change to the
Mossbauer spectrometer for a nighttime integration on Koolik.