The same week its Opportunity rover was declared dead, NASA has revealed it came close to losing its more advanced Mars visitor, Curiosity.
A "hiccup during boot-up" sent the US$1.5 billion robot into a "protective safe mode" on February 15, scientists at NASA's Jet Propulsion Laboratory said.
It was successfully revived a few days later.
"We're still not sure of its exact cause and are gathering the relevant data for analysis," said Steven Lee, Curiosity's deputy project manager.
"The rover experienced a one-time computer reset but has operated normally ever since, which is a good sign. We're currently working to take a snapshot of its memory to better understand what might have happened."
For now, its work has been postponed.
"In the short-term, we are limiting commands to the vehicle to minimize changes to its memory," said Mr Lee. "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."
"Did you ever have a case of the Mondays on a Friday? Blerg," the rover's account tweeted.
"I'm taking a little science hiatus while the team diagnoses a computer reset."
Curiosity landed on Mars in 2012 on a two-year mission, but is now in its sixth year of operation.
Opportunity landed in 2004 on a 90-day mission which lasted until 2018, when it stopped communicating following a dust storm. Its mission was declared over earlier this month, NASA unable to get in touch with the 185kg rover.