NASA's Curiosity Rover Entered Safe Mode for Four Days and Scientists Still Don't Know Why

Curiosity rover, Mars
NASA's Curiosity Mars took this image with its Mastcam on February 10. The rover is currently exploring a region of Mount Sharp nicknamed "Glen Torridon" that has lots of clay minerals. NASA/JPL-Caltech/MSSS

On February 15, NASA's Curiosity rover, which is currently climbing a mountain on Mars, unexpectedly entered into a protective "safe mode."

Now the space agency has announced that the rover is operating normally and has successfully booted up more than 30 times without a problem—although operators at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, are still not exactly sure what went wrong.

"We're still not sure of its exact cause and are gathering the relevant data for analysis," Steven Lee, Curiosity's deputy project manager, said in a statement. "The rover experienced a one-time computer reset but has operated normally ever since, which is a good sign," he added. "We're currently working to take a snapshot of its memory to better understand what might have happened."

Since February 19, Curiosity has sent and received various batches of technical data which will help the team's investigations. Until the picture becomes clearer, Lee said that Curiosity's science operations will temporarily be put on hold.

"In the short term, we are limiting commands to the vehicle to minimize changes to its memory," Lee said. "We don't want to destroy any evidence of what might have caused the computer reset. As a result, we expect science operations will be suspended for a short period of time."

The car-sized rover—which landed on the Red Planet in August 2012—has been ascending the slopes of Mount Sharp since 2014. The mountain—an area of great scientific interest—rises 18,000 feet above the floor of the 96-mile-wide Gale crater within which it lies.

One of the goals of the Curiosity mission is to investigate whether areas inside the Gale crater could ever have provided the right environmental conditions to support microbial life.

Currently, the rover is exploring a specific region of the crater known as "Glen Torridon" where NASA has spotted an abundance of clay minerals. These are interesting, because they form in water—which is essential to the development of life as we know it. Before it went into safe mode, Curiosity sent back a number of images of the area while searching for a potential drill site.

"The science team is eager to drill our first sample from this fascinating location," said Ashwin Vasavada, Curiosity project scientist at JPL. "We don't yet understand how this area fits into the overall history of Mount Sharp, so our recent images give us plenty to think about."

Curiosity is not the only NASA craft currently sending data back from Mars. The rover is joined by InSight—a stationary lander which touched down on the planet in November.

Earlier this month the space agency announced—to much fanfare—that its Opportunity rover had finally come to the end of its mission after nearly 15 years exploring the surface of the Red Planet.