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NASA's Curiosity begins to resume operations after glitch

Paul Sutherland, Feature writer
Mar 6, 2013, 8:00 UTC

Sen—A puzzling memory glitch that hit Mars rover Curiosity's main computer last week halting its operations appears to have been overcome, according to NASA.

The ground team for Mars Science Laboratory, as the rover is properly known, put it into so-called safe mode last Thursday, 28 February, as a precaution.

They took prompt action after the A-side computer that Curiosity had been using showed symptoms of a corrupted memory location and refused to send data back to mission control or switch to sleep mode.

Scientific observations had to come to a temporary halt to the disappointment of scientists whose onboard instruments had begun analysing a sample of powder drilled from the inside of a rock on Mars.

The rover's Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM) instruments had been fed portions of the sample on 22 and 23 February for inspection.

But yesterday mission controllers at NASA's Jet Propulsion Laboratory announced they had put Curiosity back into active status on Saturday and begun using its high-gain antenna to transmit information again on Sunday.

Full operations by the rover are expected to be resumed by next week.

Mars Science Laboratory Project Manager Richard Cook, of JPL, said: "We are making good progress in the recovery. One path of progress is evaluating the A-side with intent to recover it as a backup.

"Also, we need to go through a series of steps with the B-side, such as informing the computer about the state of the rover - the position of the arm, the position of the mast, that kind of information."

The rover was switched to begin using a redundant onboard computer, called B-side, that had operated during the spacecraft's flight to Mars, instead while the problem was examined by experts at NASA's Jet Propulsion Laboratory.

They began troubleshooting the condition which seemed to be caused by a glitch in flash memory aboard the main computer. The cause has yet to be determined, but it may possibly have been due to a cosmic ray strike by a subatomic particle from an exploding star deep in the Universe.

Cook said at the time: "We switched computers to get to a standard state from which to begin restoring routine operations."

Curiosity is equipped with two main computers - A-side and B-side - as back-up just in case such a problem occurs, so that a failure does not put the whole mission at risk. Each of the computers has other back-up subsystems linked to it.

The rover began using the A-side computer when it touched down in Gale Crater last August to begin examining the area for clues as to whether it might ever have been a habitable environment for microbial life.