After a computer glitch sidelined NASA's Mars rover Curiosity late last month, another problem has it down again.
NASA reported that Curiosity put itself into safe mode on Saturday after a software bug caused a command file to fail a size-check.
"This is a very straightforward matter to deal with," said Richard Cook, Curiosity's project manager. "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."
NASA said late on Monday that bringing Curiosity out of safe mode is expected to take a couple of days.
Curiosity's scientific work has been on hold since a memory glitch on its main, or A-side, computer on Feb. 27 derailed the rover's activities. NASA scientists were forced to switch from the rover's A-side computer to its backup system, or B-side.
Curiosity's B-side is now running the rover, and the A-side has been repaired and will act as the new backup system.
NASA is on a deadline to get the rover fully functional before April 4, when communication with all Mars rovers and orbiters will end for about a month.
A solar conjunction -- when the Sun will be in the path between the Earth and Mars -- is fast approaching and will keep NASA engineers from sending daily instructions to the rover, or from receiving data and images in return.
NASA will have to send all operational instructions for that monthlong period to Curiosity before the solar conjunction begins.
The space agency also reported that even though the rover has been having technical trouble, it's also having a lot of success.
A week ago, NASA announced that Curiosity sent home data proving that that the Red Planet could have supported life in the distant past. The evidence came from inside the first rock that the NASA rover drilled on another planet.
Analysis of the mudstone rock sample that Curiosity's robotic arm collected showed that it contained sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon -- key chemical ingredients for life.
NASA said Curiosity also found evidence of water-bearing minerals in other rocks in the same area.
The rover used an infrared-imaging capability in one of its cameras and an instrument that shoots neutrons into the ground to probe for life-sustaining chemicals. The discovery is leading NASA scientists to believe there once was water flowing over that area.
