NASA made progress on fixing its malfunctioning Mars rover Spirit by finding a workaround for a balky memory card, mission managers said Saturday.
“We made good progress overnight,” project manager Pete Theisinger said during a news conference at NASA’s Jet Propulsion Laboratory. “The rover has been upgraded from critical to serious.”
NASA said it had received some data from the Spirit rover and had developed a theory about its problem.
Scientists said they managed to reset Spirit’s computer and put the rover into what’s called “cripple” mode to bypass software problems.
Still, the problems may prevent the rover from taking another drive on Mars for as long as three weeks.
Malfunction began Wednesday
Spirit began to malfunction on Wednesday, when it ceased communicating with Earth other than to spew gibberish or beeps to acknowledge commands sent to it.
Engineers brought stability to the rover by disabling its flash memory, which is similar to the memory digital cameras use to store pictures, said Orlando Figueroa, director of NASA’s Mars exploration program.
“We made good progress overnight,” project manager Pete Theisinger said during a news conference at NASA’s Jet Propulsion Laboratory. “The rover has been upgraded from critical to serious.”
Spirit resumed transmitting data Friday, but only in limited batches. Despite its woes, scientists said there is still a chance the rover can fully recover.
JPL Director Charles Elachi said other NASA spacecraft, including Voyager, Magellan and Galileo, have recovered from even graver problems.
“I am completely confident, without any hesitation, that I think we will get that rover back to full operation,” Elachi said.
Mission members were able to stop the rover from rebooting its computer — which it had done roughly 130 times — and bypass the computer chips that make up its flash memory. Instead, Spirit will use its random access memory, which is somewhat less efficient than the flash memory.
"It's like [a patient saying] ‘Doctor, doctor, it hurts when I do this,’” explained Firouz Naderi, Mars program manager at JPL. “And the doctor says, well, don’t do this for a while, until we figure out what's wrong.”
Naderi said the mission team was able to reproduce the flash memory problem in laboratory tests back on Earth.
Engineers also succeeded in commanding the robot to sleep after it stayed up two nights in a row when it should have been turned off to conserve power.
Cause under investigation
The root cause of Spirit’s problems remained elusive. NASA’s inability to reproduce the problem in laboratory software tests suggests that something is awry with the rover’s hardware, Theisinger said.
In the weeks since its Jan. 3 landing in Mars' Gusev Crater, Spirit took thousands of pictures and began its work prospecting the soil and rocks around its landing site.
Engineers worked on the problems with Spirit even as another team dealt with the Saturday night landing of Spirit's twin, Opportunity, in Meridiani Planum, an area 6,600 miles (10,500 kilometers) away.
Not since the 1976 landing of the twin Viking landers has NASA had two working spacecraft on different areas of the surface of Mars. Together, the twin rovers make up a single $820 million mission to determine if Mars ever was a wetter world capable of sustaining life.
NASA launched two rovers to double its chances of successfully landing on Mars. Just one in three international efforts to land on the Red Planet has succeeded.
The list of failures may include the British lander Beagle 2, which has not been heard from since attempting to set down in December.
Three other spacecraft, two from NASA and one from the European Space Agency, remain in orbit around Mars.