[meteorite-list] Mars Exploration Rover Update #2 - August 23, 2004

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Aug 24 11:21:58 2004
Message-ID: <200408241520.IAA19730_at_zagami.jpl.nasa.gov>

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

OPPORTUNITY UPDATE: Opportunity Team Decides Against Dunes - sol 200-203,
August 23, 2004

On sol 200 Opportunity was commanded to perform some remote sensing and
some rock abrasion tool diagnostics in response to an activity that
faulted out on sol 199. During these diagnostics on sol 200, the tool
failed to respond as desired to a command to calibrate the grind motor.
Analysis of this event suggests that there is a piece of debris
(probably a rocky chunk of Mars) trapped between the grind bit and the
brush bit. The rover team believes that it can be freed by turning the
bits in reverse, but they are still evaluating the best approach to
remedy the situation. There are several options available. The team
decided to continue the investigation of this anomaly while pressing on
with other objectives.

On sol 201 the rover was commanded to stow its arm and drive to a
position about 12 meters (about 39 feet) clockwise around the crater.
The intent is to head towards a dune tendril that reaches out of the
bottom of the crater and may be accessible without having to drive into
terrain that is too sandy for the rover to safely traverse. The drive
went very well, and the rover ended up in the expected place.

On sol 202 the rover was commanded to proceed a little ways downslope.
Team members were not able to command the drive the rover as far as they
might have liked because they did not get all the data they hoped to get
in the afternoon downlink pass on sol 201. The terrain around the rover
is heavily coated with sand and dust, so each traverse requires careful
evaluation to make sure there is enough rock material to drive on with
confidence. From the images available, the team determined it could
safely command only about a 1-meter (3.3-foot) drive. This drive
proceeded as expected. At the end of the drive, panoramic camera images
were acquired directly in front of the rover and out to the dune
tendril. These images will be used to assess traversability to this
sandy feature.

On sol 203 the team decided to scratch the approach to the dune tendril
and, instead, headed the rover back towards "Axel Heiberg" and another
target named "Ellesmere" for some soil observations. The terrain between
the rover and the dune tendril did not present clear evidence of rocky
plates to give the rover sufficient traction. Rather than spend more
time in an attempt to scout further for an approach path, the decision
was made to abandon the quest for the dune tendril. A drive of
approximately 14 meters (46 feet) positioned the rover where it will be
able to zero in on Ellesmere next. There was an apparent combination of
slip or induced heading change, or both, due to the sandy terrain, which
resulted in the rover ending up about 3 meters (about 10 feet) farther
left than expected. This also caused Opportunity to unintentionally run
over a patch of fine soil with some small dune-like ripples in it. The
team will be assessing this traverse error, but it is par for the course
when driving this far on such sandy, sloped terrain.
Received on Tue 24 Aug 2004 11:20:56 AM PDT