[meteorite-list] Mars Exploration Rover Update - July 30, 2004

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Aug 2 11:29:30 2004
Message-ID: <200408021529.IAA08123_at_zagami.jpl.nasa.gov>

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

OPPORTUNITY UPDATE: Opportunity Sees Double. - sol 177-180,
July 30, 2004

Opportunity marked its 180th sol on Mars without pausing to celebrate.
Originally slated for missions of 90 sols each, both Spirit and
Opportunity have passed the double-mission milestone and are continuing
their phenomenal journeys of discovery.

On sol 177 Opportunity performed a two-hour rock abrasion tool grind on
the target "Diamond Jenness," then took the resulting hole's picture
with the microscopic imager. Surface debris and the bumpy shape of the
rock apparently contributed to a shallow and irregular hole, only about
2 millimeters or .08 inches deep, not enough to take out all the bumps
and leave a neat hole with a smooth floor. The alpha particle X-ray
spectrometer examined the rock's composition in the abraded area during
early morning of sol 178.

The team decided that sol 178 would be used to grind into "Diamond
Jenness" again in hopes of deepening the hole. The sequence went
extremely well with the rock abrasion tool grinding almost an additional
5 millimeters (about 0.2 inches). The rover then started a M?ssbauer
spectrometer reading of the deepened hole.

On sol 179 the rover completed the M?ssbauer integration, gathered some
remote-sensing data, then positioned the alpha particle X-ray
spectrometer on the abraded hole for an early-morning integration at
cold temperature on sol 180. This double integration of the hole (once
on sol 178 at an intermediate depth and then a second one at full depth)
will give the science team a unique opportunity to evaluate how the
composition changes with depth.

On sol 180, which ended on July 27, the rover stowed its arm and drove
back up the slope about 1.5 meters (about 5 feet), then turned a little
to the right to go back down about 0.5 meters (about 1.6 feet). The
drive up was to gain a vantage point from which to image the abraded
hole in "Diamond Jenness" with the panoramic camera and to evaluate
characteristics of the driving on this particular terrain. The drive
back down and to the right served to position the rover for potentially
proceeding farther into the crater (avoiding a sandy patch to its left).
It also left the rover at a better angle for communications in the
afternoon. The drive went well, with less slip that anticipated,
reinforcing the team's confidence in driving back up out of the crater
on some future sol.

In general, the rover continues to perform well, benefiting from a
predominantly northward tilt and the greater solar-array energy that
affords. The Mars Odyssey orbiter continues to perform as the rover's
primary source of data return. The location on the slope of "Endurance
Crater" and intensive use of the instrument arm hinder rover drivers
from orienting Opportunity optimally for the radio relays to Odyssey.
The level of communication is acceptable for now and the team expects
that, some sol, Opportunity will venture back out of the crater to
explore to new places. When the rover is on flatter ground, the team can
optimize communications with Odyssey more often.
Received on Mon 02 Aug 2004 11:29:25 AM PDT