Mars Exploration Rover Update - February 6, 2006

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

SPIRIT UPDATE: Spirit Completes Mile No. 4 on Mars - sol 735-742,
Feb 06, 2006:

Spirit is healthy and continues to make progress toward “Home Plate”
after driving more than 150 meters (492 feet), taking images, making
atmospheric observations, and analyzing geology.

Spirit completed two diagnostic tests of the dynamic brakes on sol 735
(Jan. 27, 2006) after the team detected a dynamic brake fault
associated
with the left-front and right-rear steering actuators on Sol 733. The
tests were copies of tests that were run after a similar anomaly on sol
265 for Spirit. Also on sol 735, the rover performed a small wheel
wiggle after its drive to test the dynamic brakes. The wheel wiggle
steered the wheels slightly, then steered them straight. No dynamic
brake warnings were observed. The intermittent behavior of the relay
status that controls the dynamic brakes, as well as the results of the
diagnostic activities, are consistent with the behavior observed after
the sol 265 anomaly. The team continued with the same resolution, which
was to instruct the rover to ignore the dynamic brake error status.
Driving has continued with normal steering function.

Sol-by-sol summaries:

Sol 735 (Jan. 27, 2006): Rover planners had a busy day of preparing and
executing a dynamic brake diagnostic test in addition to a day of
driving. Spirit drove 26.3 meters (86.3 feet) without using the
steering
motors on the left-front and right-rear wheels. Results of the
diagnostic testing were consistent with behavior following an anomaly
on
sol 265 (Oct. 1, 2004). Spirit also acquired panoramic camera images of
“Allegheny Ridge” and “YuGong.”

Sol 736: Rover science team members discovered an interesting rock and
decided to spend a couple of days studying it with instruments on
Spirit’s robotic arm. Spirit collected a mosaic of microscopic images
and collected spectrographic information with the Moessbauer
instrument.
Spirit took panoramic camera images of rock targets called “Xing Tian,”
“GongGong,” “Luo Zu,” “Sui Ren,” “Cang Jie,” and used the miniature
thermal emission spectrometer to examine “Cang Jie,” “Sui Ren,” “Ho
Ji,”
and “Luo Zu.”

Sol 737: Spirit made remote sensing observations of Ho Ji and
atmospheric observations using the rover’s panoramic camera.

Sol 738: Spirit began driving around a rocky ridge that separated the
rover from Home Plate, traveling an additional 33.7 meters (111 feet).
Following a complete analysis of diagnostic tests run on sol 735, rover
drivers decided to follow the same recovery plan used after the sol 265
anomaly, and Spirit continued to drive without incident.

Sol 739: Spirit drove 30.5 meters (100 feet). The rover stopped after 5
meters (49 feet) of autonomous navigation because of a sequencing
error.
Rover drivers added an automated flight check to the sequence to catch
future errors of a similar nature. Spirit was unable to complete most
of
the planned post-drive imaging.

Sol 740: Rather than wait another day for Spirit to take a set of
post-drive images, rover drivers gave Spirit the go-ahead to navigate
independently using onboard instruments. Spirit drove 17 meters (56
feet) autonomously.

Sol 741: Spirit drove 43.5 meters (143 feet) to the top of a gently
sloping ridge, providing an excellent view of the path to Home Plate.

Sol 742 (Feb. 3, 2006): Spirit prepared for a day of driving 30 meters
as directed by rover drivers plus driving 15 meters to 20 meters
autonomously.

Odometry:

As of sol 741 (Feb. 2, 2006), Spirit’s total odometry was 6,430 meters
(exactly 4 miles).