Second computer glitch puts Mars rover on 'standby'

NASA's Mars rover Curiosity has gone on a precautionary 'standby mode' after a software glitch hit the robot over the weekend, scientists say.
Curiosity initiated this automated fault-protection action, entering "safe mode" on March 16, while operating on the B-side computer, one of its two main computers that are redundant to each other.
Bringing Curiosity out of safe mode status on the B-side is expected to take a couple of days, scientists said.
It did not switch to the A-side computer, which was restored last week and is available as a back-up if needed.
The rover is stable, healthy and in communication with engineers, NASA's Jet Propulsion Laboratory, Pasadena, California said in a statement.

The safe-mode entry was triggered when a command file failed a size-check by the rover's protective software. Engineers diagnosed a software bug that appended an unrelated file to the file being checked, causing the size mismatch.

"This is a very straightforward matter to deal with. We can just delete that file, which we don't need any more, and we know how to keep this from occurring in the future," said the project manager for Curiosity, Richard Cook from the laboratory.
The mission's science observations have been on hold since a memory glitch on the A-side computer on February 27, which prompted controllers to command a swap from the A-side computer to the B-side computer.

That operator-commanded swap put Curiosity into safe mode for two days. The rover team restored the availability of the A-side as a backup and prepared the B-side to resume full operations.
Before the glitch, the rover had sent its first analysis of rock samples drilled from the inside of a slab of bedrock in the rover's Gale Crater landing site.
Beginning April 4, all commands to the rover will be suspended for four weeks due to solar system geometry of Mars passing nearly directly behind the Sun from Earth's perspective.
The suspension is a precaution against interference by the Sun corrupting a command sent to the rover.