[meteorite-list] Mars Exploration Rovers Update - April 3-16, 2008

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 21 Apr 2008 16:23:26 -0700 (PDT)
Message-ID: <200804212323.QAA13192_at_zagami.jpl.nasa.gov>

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

SPIRIT UPDATE: Spirit Still "Sitting Pretty" for This Time of Year -
sol 1517-1524, April 09-16, 2008:

Despite a slight increase in atmospheric opacity caused by dust, Spirit
is still enjoying higher-than-expected energy levels for this time of
year. Solar array input has been approximately 240 watt-hours per
Martian day, or sol (100 watt-hours is the amount of energy needed to
light a 100-watt bulb for one hour).

Clear skies have had the unfavorable effect, however, of causing a drop
in temperatures at the surface of Mars, increasing the bitter cold
experienced by Spirit's rover electronics module. Nighttime temperatures
are creeping closer to the point where they will trigger the survival
heaters, which draw a large amount of power. A much more desirable
strategy is to keep Spirit awake long enough each day to keep the
electronics module sufficiently warm with heat from normal operations,
providing more time for science observations. "Awake time" vs. heating
time is just one of the many trade-offs the team makes each day to keep
Spirit going through the Martian winter.

Sol-by-sol summary:

In addition to daily communications that include direct-from-Earth
instructions via the rover's high-gain antenna and, as power permits,
data relays to Earth via the Odyssey orbiter, Spirit continues to
monitor atmospheric dust levels each day with the panoramic camera. In
addition, during the past week, Spirit completed the following activities:

Sol 1517 (April 9, 2008): Spirit completed a mini-survey of the sky and
ground with the miniature thermal emission spectrometer; acquired column
8, part 3 of the full-color "Bonestell Panorama" using all 13 filters of
the panoramic camera; and shot movie frames in search of clouds with the
navigation camera.

Sol 1518: Spirit completed a mini-survey of the sky and ground with the
miniature thermal emission spectrometer; acquired a 2-by-1-by-1 stack of
microscopic images of the rover's solar array; acquired column 9, part 1
of the Bonestell panorama; and took spot images of the sky for
calibration purposes with the panoramic camera.

Sol 1519: Spirit surveyed the rover's external calibration target with
the miniature thermal emission spectrometer and acquired column 9, part
2 of the Bonestell panorama. To conserve energy, the rover did not relay
data to Odyssey.

Sol 1520: Spirit completed a mini-survey of the sky and ground with the
miniature thermal emission spectrometer; measured atmospheric opacity
caused by dust with the navigation camera (as well as the panoramic
camera); and acquired movie frames in search of clouds with the
navigation camera. The rover took spot images of the sky and surveyed
the horizon with the panoramic camera. Spirit did not relay data to
Odyssey.

Sol 1521: Spirit completed a mini-survey of the sky and ground with the
miniature thermal emission spectrometer; calibrated the elevation of the
miniature thermal emission spectrometer; and acquired column 9, part 3
of the Bonestell panorama.

Sol 1522: Spirit completed a mini-survey of the sky and ground with the
miniature thermal emission spectrometer; took thumbnail images of the
sky and surveyed the horizon with the panoramic camera; and acquired
lossless-compression images of wind-blown deposits next to the rover
with the hazard-avoidance cameras. Spirit did not relay data to Odyssesy.

Sol 1523: Spirit recharged the battery and did not relay data to Odyssey.

Sol 1524: (April 16, 2008): Spirit recharged the battery.

Odometry:

As of sol 1524 (April 16, 2008), Spirit's total odometry remained at
7,528.07 meters (4.68 miles).

------------------------------------------------------------------------

OPPORTUNITY UPDATE: Driving on Mars Is Hard - sol 1491-1497, April
03-09, 2008:

This week Opportunity demonstrated the challenges of operating a vehicle
on the surface of another planet. The rover is en route to Cape Verde to
acquire high-resolution images of the layering in the rocks. To get
there, Opportunity must cross some sandy stretches. Before entering the
sandy areas, Opportunity will need to stop and take a "toe dip'' -- that
is, drive forward a short distance and back out again -- to characterize
the terrain.

On Sol 1491 (April 3, 2008), Opportunity performed a 4-wheel toe dip,
driving forward until the front four wheels were on the sand and backing
up again.

As part of ensuring vehicle safety, rover drivers set conservative
limits on what the rover may do. For example, if Opportunity exceeds the
maximum amount of wheel slippage or the maximum amount of tilt allowed,
the rover must abort the drive. This gives the rover's handlers a chance
to further evaluate the situation and make changes to the drive plan on
subsequent sols (Martian days). The toe dips provide valuable insight
into the nature of the terrain Opportunity is likely to encounter on the
way to Cape Verde.

Opportunity is healthy and all subsystems are performing as expected.

Sol-by-sol summary:

In addition to receiving morning instructions directly from Earth via
the rover's high-gain antenna, sending data back to Earth via the UHF
antenna on the Mars Odyssey orbiter, and measuring atmospheric dust with
the panoramic camera, Opportunity completed the following activities:

Sol 1491 (April 3, 2008): Before the day's drive, Opportunity took
panoramic-camera and navigation-camera images of a previously made wheel
scuff. The rover stowed the robotic arm and drove toward Cape Verde,
taking hazard avoidance-camera images before and after ending the drive.
Opportunity unstowed the robotic arm and acquired post-drive images with
the navigation and panoramic cameras.

Sol 1492: In the early part of the sol, Opportunity took spot images of
the sky for calibration purposes and surveyed the horizon with the
panoramic camera.

Sol 1493: Opportunity monitored dust on the panoramic-camera mast
assembly, stowed the robotic arm, and continued driving toward Cape
Verde. Just before and after ending the drive, Opportunity took images
of the area close to the rover with the hazard-avoidance cameras. The
rover unstowed the robotic arm, took post-drive images with the
navigation camera, and after communicating with Odyssey, obtained
measurements of argon gas in the Martian atmosphere using the
alpha-particle X-ray spectrometer.

Sol 1494: Opportunity took thumbnail images of the sky with the
panoramic camera and six movie frames in search of clouds with the
navigation camera.

Sol 1495: Opportunity took spot images of the sky for calibration
purposes with the panoramic camera, stowed the robotic arm, and drove
toward Cape Verde. Before and after ending the drive, the rover took
images with the hazard-avoidance cameras. Opportunity unstowed the
robotic arm (known to engineers as the instrument deployment device) and
acquired post-drive images with the navigation camera.

Sol 1496: In the morning, Opportunity took spot images of the sky for
calibration purposes with the panoramic camera and shot a 4-frame movie
in search of clouds with the navigation camera. Opportunity stowed the
robotic arm and drove backward onto bedrock to extract its wheels from
the sand before proceeding toward Cape Verde. Before and after ending
the day's drive, the rover took images with the hazard-avoidance
cameras. The rover then unstowed the robotic arm.

Sol 1497 (April 9, 2008): In the morning, Opportunity took thumbnail
images of the sky with the panoramic camera and shot another 4-frame
movie in search of clouds with the navigation camera. The rover acquired
diagnostic images with the hazard-avoidance cameras and a mosaic of
images of the work volume reachable by the robotic arm with the
panoramic camera. When the evening Sun was low, Opportunity surveyed the
sky with the panoramic camera. Plans transmitted to the rover for the
following morning called for another 6-frame movie of potential clouds
in the Martian sky.

Odometry:

As of sol 1497 (April 9, 2008), Opportunity's total odometry was
11,689.21 meters (7.26 miles).
Received on Mon 21 Apr 2008 07:23:26 PM PDT