November 10, 2008 PASADENA, Calif. -- A dust storm on Mars has
cut into the amount of sunlight reaching the solar array on
NASA's Mars Exploration Rover Spirit, leaving the rover in a
vulnerable state. Spirit's solar array produced only 89 watt
hours of energy during the rover's 1,725th Martian day, which
ended on Nov. 9. This is the lowest output by either Spirit or
its twin, Opportunity, in their nearly five years on Mars, and
much less energy than Spirit needs each day. The charge level of
Spirit's batteries is dropping so low, it risks triggering an
automated response of the rover trying to protect itself. "The
best chance for survival for Spirit is for us to maintain
sequence control of the rover, as opposed to it going into
automated fault protection," said John Callas of NASA's Jet
Propulsion Laboratory, Pasadena, Calif., project manager for
Spirit and Opportunity. Mission controllers are commanding
Spirit to turn off some heaters, including one that protects a
science instrument, the miniature thermal