[meteorite-list] Mars Exploration Rover Update - January 11, 2005

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Jan 12 11:36:27 2005
Message-ID: <200501121636.IAA13077_at_zagami.jpl.nasa.gov>

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

SPIRIT UPDATE: Spirit Continues Climbing 'Husband Hill' - sol 353-359,
January 11, 2005

With one eye on the weather, Spirit continued work on "Husband Hill,"
making detailed observations of a rock called "Champagne," using the
full suite of instruments.

Engineers continue to have difficulty getting the rover to make
significant progress toward a ridgeline destination due to high slippage
that Spirit experiences on the sandy, sloped terrain. Spirit has been in
roughly the same spot for the past 30 sols. Since temporarily getting a
potato-sized rock caught in the right rear wheel on sol 339, engineers
have been careful to monitor the slip as Spirit drives. If the wheels
slip too much, engineers stop the drive to avoid the possibility of
picking up another rock as Spirit spins and digs with its wheels.

The opacity of the sky -- or how much light does not shine through the
atmosphere -- has been higher than normal in the past week due to local
dust disturbances. Higher opacity means less energy for the
solar-powered rover. However, despite the recent increase in opacity,
Spirit has had adequate energy (with a safe margin) to continue normal
operations.

The rover's power bus return is a collection of wires designed to carry
current back to the rover power source (battery or solar array).
Electrical current between Spirit's chassis and the power bus return
changed on sol 342 from zero volts to 0.1 volts. The small change in
voltage coincided with powering of heater circuits on the instrument
deployment device (or rover arm). This confirms that there is a short
(unexpected metal-to-metal contact) between the power bus return and the
chassis, as had been suspected since October. The short is somewhere on
the return side of the rover arm heater circuits. The presence of this
short does not affect daily operations. It does, however, take away one
layer of protection should Spirit have a short to the chassis somewhere
else on Spirit.

Sol Summaries:

On sol 353, Spirit continued inspecting the rock "Champagne" and
performed a Mossbauer spectrometer integration on two Champagne targets.

On sol 354, Spirit used its rock abrasion tool to brush the dust off a
target on Champagne, then used the microscopic imager and the alpha
particle X-ray spectrometer to analyze the dust-free spot.

On sol 355, Spirit used the rock abrasion tool to grind into Champagne,
then placed the alpha particle X-ray spectrometer in the hole for an
overnight observation.

On sol 356, Spirit continued using its alpha particle X-ray spectrometer
on the hole drilled by the rock abrasion tool hole.

On sol 357, Spirit changed tools to the Mossbauer spectrometer and
placed it in the rock abrasion tool hole for a long integration.

On sol 358, Spirit took microscopic images of the rock abrasion tool
hole, then stowed the rover arm. Engineers then attempted a short drive
that would have allowed Spirit to image the rock abrasion tool hole from
a distance. The drive did not reach the intended position because of
slippage.

Sol 359 was a "restricted" sol, meaning that engineers had to plan this
sol without knowing the results of the sol 358 sequence. Consequently,
it was a relatively simple day that included routine atmospheric science
and miniature thermal emission spectrometer observations. Sol 359 ended
on Jan. 6.
Received on Wed 12 Jan 2005 11:36:16 AM PST