NASA probing trouble with long-running Mars rover

Computerworld - NASA scientists are putting together diagnostic tests to find out why one of the space agency's two Mars rovers began failing to respond to instructions over the weekend.

The Mars rover Spirit started acting erratically early this week, according to NASA late on Wednesday afternoon. Spirit and its Mars rover companion, Opportunity, have been working on the red planet for five years despite initially being given an on-planet life span of three months.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said Sharon Laubach, a team chief at NASA's Jet Propulsion Laboratory. "Our next steps will be diagnostic activities."

NASA said that on Sunday, Spirit sent information back to Earth indicating that it had received its driving commands for the day, but it did not move. And on the same day, the rover failed to record its activities, as it normally does, into its own memory.

Then on Monday, the rover's controllers sent the robotic machine instructions to find the sun with its camera, in the hopes that that would enable Spirit to reorient itself. The rover reported back that it was unable to find the sun.

Engineers and scientists at NASA say that cosmic rays hitting the electronics onboard the rover could be causing the trouble.

The two rovers are among the best pieces of technology that the Jet Propulsion Lab has ever built, said Bruce Banerdt, project scientist for the Mars Exploration Rovers, in a previous interview.

The rovers, which are working on the Mars equator but on different sides of the planet, had their five-year anniversary on Mars this month. The machines have been sending and receiving information from Earth every day, with a team of about two-dozen programmers and engineers uploading code to guide the rovers' movements and aim their cameras. All of that information travels about 200 million miles one way, taking anywhere from five to 21 minutes to travel from one planet to the other.

NASA scientists have been working to to launch an SUV-size rover to Mars next year later this year. However, the space agency announced just last month that testing and hardware problems are pushing back the launch of NASA's $2.3 billion Mars Science Laboratory from next fall to 2011. NASA has been putting a lot of focus on Mars.

This past November, NASA's Phoenix Mars Lander went dark after five months of digging up and analyzing soil samples on Mars, verifying the existence of ice and noting that snow falls from Martian skies.

The lander's robotic arm worked for months, digging up samples and delivering them to the various pieces of scientific equipment onboard the machine.

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