[meteorite-list] Mars Exploration Rover Update - April 10-17, 2008

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 25 Apr 2008 10:59:31 -0700 (PDT)
Message-ID: <200804251759.KAA16151_at_zagami.jpl.nasa.gov>

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

OPPORTUNITY UPDATE: Opportunity Reverses Path - sol 1498-1504,
April 10-17, 2008:

During the past week, Opportunity celebrated another major milestone by
reaching 1,500 sols (Martian days) of continuous exploration of the red
planet!

Meanwhile, Opportunity continued to execute a "toe dip" stategy of
driving forward a short distance and backing up again to characterize
the sandy terrain beneath the rover's wheels. While driving toward the
promontory known as "Cape Verde" in the rim of "Victoria Crater,"
Opportunity experienced wheel slippage of more than 90 percent. The
rover also experienced high tilt during the backward part of the drive.
Following a series of adjustments to both slippage and tilt limits,
Opportunity's front wheels had begun to dig into the terrain. At that
point, the rover's handlers decided to concentrate on driving backward
to extract the rover's front wheels and prevent them from digging
further into the sand. Making slow and steady progress, as of sol 1502
(April 15, 2008), Opportunity had driven backward 24 centimeters (9.5
inches) with no errors, giving rover drivers hope that the rover would
soon be out of the sand.

Opportunity's handlers implemented a "Stow/Go/Unstow" strategy of
unstowing the robotic arm after each day's drive to avoid having the arm
in the stow position during thermal cycling (overnight temperature
changes). This freed the arm for full use of its scientific tools in the
event of a cold-induced motor failure. On sol 1502 (April 15, 2008),
while attempting to unstow the arm, Opportunity experienced a stall in
the joint that controls shoulder position. The nature of the stall
appeared to be different from previous stalls in the same joint (known
as Joint 1). On sol 1504 (April 17, 2008), the rover's handlers directed
Opportunity to run a diagnostic test of movement in the robotic arm.
While moving the joint, Opportunity experienced another stall.
Investigation of this anomaly is expected to continue for the remainder
of this week.

Opportunity is healthy and all subsystems are performing as expected,
with the exception of the investigation of the robotic arm. Immediate
plans call for continued focus on getting out of the sand and resolving
the robotic-arm anomaly.

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 1498 (April 10, 2008): Opportunity surveyed the horizon and the sky
and measured atmospheric dust at sunset with the panoramic camera. After
transmitting data to Odyssey, the rover measured atmospheric argon with
the alpha-particle X-ray spectrometer.

Sol 1499: In the early part of the sol, Opportunity took thumbnail
images of the sky with the panoramic camera and shot a 4-frame movie of
potential clouds with the navigation camera. The rover stowed the
robotic arm, drove toward Cape Verde, acquired post-drive images with
the hazard-avoidance cameras, and unstowed the robotic arm.

Sol 1500: Opportunity acquired a full-color, 2-by-1 panel of images of
Cape Verde using all 13 filters of the panoramic camera.

Sol 1501: Opportunity recharged the battery.

Sol 1502: Opportunity started the day by monitoring dust on the
panoramic-camera mast assembly and measuring atmospheric dust. The rover
stowed the robotic arm, drove toward Cape Verde, acquired images of the
wheel cleats in the rover's tracks to assess traction and other
post-drive images with the hazard-avoidance cameras. Opportunity
unstowed the robotic arm before sending data to Odyssey and going to sleep.

Sol 1503: In the morning, Opportunity surveyed the horizon with the
panoramic camera. The rover acquired microscopic images of the robotic
arm to document changes during the diagnostic test of the arm's ability
to move.

Sol 1504 (April 17, 2008): In the morning, Opportunity acquired
full-color images, using all 13 filters of the panoramic camera, of
trenches created by the rover's wheels that have been informally named
"Williams" and "Harland." The rover took spot images of the sky for
calibration purposes with the panoramic camera and ran more diagnostic
tests of the robotic arm. Opportunity took thumbnail images of the sky
with the panoramic camera. After relaying data to Odyssey, the rover
used the alpha-particle X-ray spectrometer to measure argon gas in the
atmosphere. Plans for the next morning called for the rover to take more
thumbnail images of the sky with the panoramic camera.

Odometry:

As of sol 1502 (April 15, 2008), Opportunity's total odometry was
11,691.49 meters (7.26 miles).
Received on Fri 25 Apr 2008 01:59:31 PM PDT