[meteorite-list] Mars and Earth Activities Aim to Get Spirit Rolling Again

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 19 May 2009 14:10:09 -0700 (PDT)
Message-ID: <200905192110.OAA02953_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2009-087

Mars and Earth Activities Aim to Get Spirit Rolling Again
Jet Propulsion Laboratory
May 18, 2009

Mars Exploration Rover Mission Status Report

PASADENA, Calif. -- NASA's rover project team is using the Spirit rover
and other spacecraft at Mars to begin developing the best maneuvers for
extracting Spirit from the soft Martian ground where it has become
embedded.

A diagnostic test on May 16 provided favorable indications about
Spirit's left middle wheel. The possibility of the wheel being jammed
was one factor in the rover team's May 7 decision to temporarily suspend
driving Spirit after that wheel stalled and other wheels had dug
themselves about hub-deep into the soil. The test over the weekend
showed electrical resistance in the left middle wheel is within the
expected range for a motor that has not failed.

"This is not a full exoneration of the wheel, but it is encouraging,"
said John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif.,
project manager for Spirit and its twin rover, Opportunity. "We're
taking incremental steps. Next, we'll command that wheel to rotate a
degree or two. The other wheels will be kept motionless, so this is not
expected to alter the position of the vehicle."

Another reason to suspend driving is the possibility that the wheels'
digging into the soil may have lowered the body of the rover enough for
its belly pan to be in contact with a small mound of rocks. The rover
team is using Opportunity to test a procedure for possible use by
Spirit: looking underneath the rover with the microscopic imager camera
that is mounted on the end of the rover's arm. This might be a way to
see whether Spirit is, in fact, touching the rocks beneath it.

NASA's Mars Odyssey orbiter is also aiding in the Spirit recovery plan.
As a result of winds blowing dust off Spirit's solar panel four times in
the past month, Spirit now has enough power to add an extra
communication session each day. The Odyssey project has made the orbiter
available for receiving extra transmissions from Spirit. The
transmissions include imaging data from Spirit's examinations of soil
properties and ground geometry.

Rover team members are using that data and other information to
construct a simulation of Spirit's situation in a rover testing facility
at JPL. The team is testing different materials to use as soil that will
mimic the physical properties of the Martian soil where Spirit is
embedded. Later, the team will test maneuvers to get the rover free.
Weeks of testing are anticipated before any attempt to move Spirit.

JPL, a division of the California Institute of Technology in Pasadena,
manages the Mars Exploration Rover project for NASA???s Science Mission
Directorate, Washington.

Media contact: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

2009-087
Received on Tue 19 May 2009 05:10:09 PM PDT