Marc Kaufman
for National Geographic News
Published March 1, 2013

The Mars rover Curiosity experienced its first significant malfunction on Wednesday, when one of its two onboard computers became corrupted and failed to turn off and enter "sleep mode" as planned.

The Curiosity team at NASA's Jet Propulsion Laboratory sent up commands to switch all operations from the corrupted A computer to the twin B computer early Thursday morning, according to a Thursday NASA statement.

Most spacecraft have a backup computer to step in if the primary computer fails. (Related: Meet One of Curiosity's Earthbound Twins.)

Richard Cook, project manager for the Curiosity project, said the problem was the most serious experienced by the rover so far in its nearly 7 months on the red planet.

Cook said the team was most concerned Wednesday night, before they got a handle on the nature of the problem. But once they began to understand better, it became clear that switching to the other computer was necessary and unlikely to have long-term consequences.

He said he hoped Curiosity would resume science work in about a week.