Mars Exploration Rover Update - March 28, 2006

SPIRIT UPDATE: Flight Team Investigates Right Front Wheel Anomaly -
sol 782-789, Mar 28, 2006:

The flight team continues to investigate the right front wheel anomaly
on Spirit. A diagnostic test conducted at a different temperature than
earlier testing continued to indicate an open circuit condition for the
wheel. Team members are conducting testbed experiments at the Jet
Propulsion Laboratory to understand the new characteristics of
five-wheel driving.

On March 21, 2006, NASA’s Mars Odyssey orbiter went into a
safe mode as a result of action by on-board fault protection. Odyssey
was unavailable for three days to relay data from either Spirit or
Opportunity to Earth. Spirit’s flight team held a special Saturday
planning session to make up for lost sols. Because of the approaching
winter, it is imperative to move Spirit to north-facing slopes to
the rover has adequate power during the deepest part of the winter.

Spirit was in restricted sols, which occur when the timing of downlinks
is too late in the planning day to provide vital location and health
information about the rover after it executes the previous day’s
commands. Therefore, drives could be planned for only every second sol.

Sol-by-sol highlights:

Sol 782 (March 16, 2006): Spirit drove more than 9 meters (30 feet).

Sol 784: Challenged by a mound with a modest slope, Spirit stopped the
drive after only 0.85 meters (2.8 feet) because of excessive slip.

Sol 787: Spirit moved away from the sticky mound with a 4.5-meter
(15-foot) drive.

Sol 788 (March 22, 2006): The flight team planned to have Spirit drive
approximately 11 meters (36 feet) to a new waypoint.


As of sol 787 (March 21, 2006), Spirit’s total odometry was 6,812.16
meters (4.23 miles).