SPACE NASA tries to revive Mars rover

If the software is flawed, a fix can be done remotely.
PASADENA, Calif. (AP) -- Anxious NASA engineers were trying to diagnose and possibly patch up their ailing robotic patient after the Spirit rover stopped transmitting data from Mars.
NASA hoped communication with the six-wheeled rover would resume this morning after two days without receiving any significant data -- a potentially calamitous turn that project manager Pete Theisinger called "a very serious anomaly."
Since Wednesday, its 19th day on Mars, the Spirit has sent back to Earth only meaningless radio noise or simple beeps acknowledging receipt of commands.
Among the possible causes: a corruption of its software or computer memory. If the software is awry, NASA can fix it from Earth by beaming patches across more than 100 million miles of space or by rebooting the rover's computer. But if the problem lies with the rover's hardware, the situation would be far more grave -- perhaps beyond repair.
Baffled scientists struggled to pinpoint the trouble.
"It is precisely like trying to diagnose a patient with different symptoms that don't corroborate," said Firouz Naderi, manager of NASA's Jet Propulsion Laboratory Mars exploration program.
Officials said the next best opportunity for actual data to come from the rover was between 6 a.m. and noon EST Friday.
Twin rover
Spirit is one-half of an $820 million mission. Its twin, Opportunity, is expected to land on Mars late Saturday. The twin rovers are supposed to examine the Red Planet's dry rocks and soil for evidence that it was once wetter and more hospitable to life.
Until Wednesday, Spirit had functioned almost flawlessly and NASA scientists and engineers had been jubilant.
Steven Squyres of Cornell University, the mission's main scientist, cautioned that communications problems are common on spacecraft.