[meteorite-list] Mars Exploration Rover Update - September 20, 2007

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 20 Sep 2007 17:12:19 -0700 (PDT)
Message-ID: <200709210012.RAA14415_at_zagami.jpl.nasa.gov>

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

OPPORTUNITY UPDATE: 'Shaking' Off the Dust and Getting Back to Work -
sol 1274-1281, Sep 20, 2007:

The skies continue to clear over the Opportunity site, and the dust is
falling from both the sky and the rover. The last week was dedicated to
evaluating the payload and assessing dust accumulation on the
instruments. Fortunately, the solar array energy has improved to over
350 Watt-hours for the last four sols. This has given the vehicle enough
power to support two alpha particle X-ray spectrometer integrations and
two Mars Express UHF overflights.

The team began a campaign to recalibrate the panoramic camera tau
observations used to measure the level of atmospheric opacity. The
recalibration sequences are designed to run at various times of day to
get the sun at different angles in the sky. Each sequence has custom
exposure durations and color filters tailored to the intended time of
execution.

As the team saw last week, the instruments on the robotic arm turret
collected a substantial amount of dust during the storm. There are two
main concerns: dust inside the alpha particle X-ray spectrometer and
dust under the microscopic imager dust cover. On Spirit, dust managed to
somehow find its way under the microscopic imager dust cover, so
engineers are handling the dust-covered turret on Opportunity with care.

Twice in six sols, the team used the front hazard avoidance camera (and
the panoramic and navigation cameras) to image the microscopic imager
with the dust cover closed. There were two drives between each set of
imaging and there is noticeable cleaning between the two. The first of
several sky flats images taken with the microscopic imager (dust cover
closed) came down today. Preliminary analysis indicates little to no
dust on the lens or dust cover. Next week, the team will determine if it
is safe to open the dust cover and take images to see if any dust is on
the lens itself.

The first of two alpha particle X-ray spectrometer integrations was
received on the ground today and the initial analysis shows little to no
dust contamination. Argon peaks are just as large as before, but
additional integrations are necessary to complete the analysis. In the
meantime, the team modified the robotic arm ready position to face the
alpha particle X-ray spectrometer in towards the vehicle's warm
electronics box. The hope is that this will prevent any dust from
collecting inside.

Sol-by-sol summary:

Each sol contained: navigation camera tau at the start of the plan and a
Mars Odyssey downlink in the afternoon.

Sol 1274: On this sol, the panoramic camera tau measurements were
recalibrated. The team moved the robotic arm to place the microscopic
imager in view of appropriate cameras for the following images: front
hazard avoidance camera of the microscopic imager bore-sight, panoramic
camera of MI bore-sight, panoramic camera of microscopic imager side
view. Opportunity then finished work with the arm to move to modified
ready position with the alpha particle X-ray spectrometer pointed
towards the rover. More recalibrations of panoramic camera tau
measurements were done before and after the Mars Odyssey pass. Finally,
a panoramic camera image of rock target 'Mango' was shot.

Sol 1275: The vehicle remained in place due to a sequencing error that
precluded the robotic arm from stowing before the planned drive. The
uplink team corrected the logic error, and the rover resumed driving at
the next opportunity on sol 1278. After the Odyssey pass, more tau
recalibrations were conducted. The panoramic camera was also used to
survey the horizon and image the sky.

Sol 1276: This sol was used to recharge. Some panoramic camera
recalibrations were conducted.

Sol 1277: More panoramic camera tau measurement recalibrations began
this sol. Afterwards, the robotic arm was moved into position to take a
panoramic camera image of the microscopic imager from a side view. The
panoramic camera took images of the sky. After the Odyssey pass, a tau
measurement was taken and the alpha particle X-ray spectrometer was
integrated for four hours. There was a Mars Express UHF pass and then
Opportunity took a mini-deep sleep.

Sol 1278: The first part of this sol was used for more panoramic camera
tau recalibrations and panoramic camera mast assembly ("head" and
"neck") dust monitoring. The panoramic camera was also used to image the
sky. Another recalibration took place before the rover stowed its arm
and drove 1.43 meters (4.7 feet) using visodom (visual odometry
software) on its closest approach toward the crater rim. Opportunity
then conducted post-drive navigation camera images. After the Odyssey
pass, more panoramic camera recalibrations were conducted.

Sol 1279: On this sol, the microscopic imager, navigation camera and
panoramic cameras were all used to image the sky. More recalibrations
were conducted before and after the Odyssey pass. The alpha particle
X-ray spectrometer was integrated for 5.5 hours.

Sol 1280: A panoramic camera tau recalibration was conducted in addition
to a panoramic camera tau measurement. The navigation camera took an
image. The panoramic camera used its 13 filters to image a bright
ripple. Before and after the Odyssey pass, more recalibrations took place.

Sol 1281: The first part of this sol was used to conduct a panoramic
camera tau recalibration, to monitor dust on the panoramic camera mast
assembly and to image the sky with the panoramic camera. The panoramic
camera then imaged "Duck Bay." Before and after the Odyssey pass, more
recalibrations were conducted.

Odometry:

As of sol 1279, Opportunity's total odometry is 11,483.39 meters (7.14
miles).
Received on Thu 20 Sep 2007 08:12:19 PM PDT