Mars rover could be in trouble|
By Dan Vergano, USA TODAY
PASADENA, Calif. — Anxious NASA engineers sent more signals Friday as they tried 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 Friday morning after two days without receiving any significant data — a potentially calamitous turn that project manager Pete Theisinger called "a very serious anomaly."
After acknowledging instructions sent early Wednesday, Theisinger says, the rover sent only random noise instead of data that night.
However, a "beep" indicating that the rover's computer was in a safety mode arrived Thursday morning. That's "good news," Theisinger says, indicating that power, antennas and at least some of the rover's software are working. An attempted data transmission early Friday should provide more clues.
The signal means it's less likely that Spirit had a power failure, which could be "very serious" and could doom the rover. JPL officials said a software glitch would be a fixable problem unlikely to shorten the 90-day design life of the rover.
JPL chief Charles Elachi compared the situation to the Voyager and Magellan probes, which overcame software setbacks to become very successful missions.
Because Mars rotates, Spirit faces away from Earth and is out of radio range for much of the day.
Spirit had paused Wednesday before a rock nicknamed "Adirondack." The last instructions directed Spirit to collect scientific measurements of the rock and use a grinder to get beneath its surface.
For now, Spirit, which is one-half of NASA's $820 million Mars mission, is just parked. NASA had planned to rest the rover after its investigation of the rock for three days while scientists turn their attention to the landing of its twin rover, Opportunity, early Sunday.
Cook said radio interference caused by storms in Australia might have confused the rover's computer. Also, cosmic rays could have zapped Spirit's computer memory. Unlike Earth, Mars lacks a strong magnetic field to shield its surface from such rays.
Mars has a history of failed missions. There have been only four fully successful landings out of 14 attempts since 1971, counting Spirit. The Soviet Union's Mars 3, the first lander to make it to the surface, failed in 20 seconds. Britain's Beagle 2 failed to respond after its scheduled landing Dec. 25.
Contributing: The Associated Press