NASA fixes bug that put Curiosity Mars rover on standby

The Curiosity rover is getting back to business after NASA solved the bug that had hit its B-side computer.

NASA has taken the Mars rover Curiosity out of a two-day "safe mode" standby after resolving a software bug that affected the robotic vehicle's B-side computer.

The sample analysis work done by Curiosity, which landed on Mars last August, has been hampered over the last month by two glitches affecting its two main computers.

Since late February, Curiosity's computing needs have been served by its B-side computer after a memory issue affecting the A-side computer prompted NASA engineers to 'flip' active computers.

On Sunday 16 March Curiosity went into a precautionary standby status after a "command file failed a size-check by the rover's protective software", allowing it to append an unrelated file which then caused a file size mismatch, according to NASA.

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Curiosity's 'self portrait'. Credit: NASA.

"Curiosity initiated this automated fault-protection action, entering 'safe mode' at about 8 pm PDT (11 pm EDT) on March 16, while operating on the B-side computer, one of its two main computers that are redundant to each other. It did not switch to the A-side computer, which was restored last week and is available as a back-up if needed," NASA said on Monday.

NASA wrote on the Curiosity's Twitter account on Tuesday that it was now "out of safe mode & ready to resume science operations [mission status]."

"We expect to get back to sample-analysis science by the end of the week," Curiosity mission manager Jennifer Trosper of NASA's Jet Propulsion Laboratory said on Tuesday.

The latest glitch was resolved as NASA prepares to place a one month "moratorium" on sending commands to the Curiosity from 4 April when Mars will be obscured from earth by the sun. It is concerned that the sun may corrupt messages sent to the vehicle.