Curiosity driving again after bungled software upgrade
BY STEPHEN CLARK
Posted: November 13, 2013
NASA's Curiosity Mars rover is hitting the road again Thursday, setting its sights on arriving at the base of a 3.4-mile-high Martian mountain next spring after recovering from a software fault that halted science observations for nearly a week.
Thursday's drive is the first since Curiosity went into safe mode Nov. 7 when the rover's computer froze up as ground controllers tried to switch over to new upgraded software.
Engineers at NASA's Jet Propulsion Laboratory in California radioed the fresh software to the rover last week when it was parked at the Cooperstown outcrop.
But there was a discrepancy between a data file and a catalog file inside the rover's computer. Running on the new R11 software, Curiosity's catalog file, which functions like a folder on a personal computer, showed one particular piece of data was still written in the computer's memory, according to Jim Erickson, Curiosity's project manager at JPL.
When the rover's computer tried to access the data, it was not there. The rover's older R10 software handled data differently.
"[The rover] basically said, 'OK, I'm trying to pull this one data product to send it because it says it's ready, but since it's an old software-generated product, it had the file cleared out but not the catalog pointing to the file,'" Erickson said. "So R11 believed the product was there, opened up that memory space, and said, 'Oh, this doesn't look right at all. We obviously have some kind of a memory corruption,' and asked for a reset."
The rover did a warm reset, a less invasive type of reboot than a cold reset.
"It is sort of like the difference between turning your computer off and unplugging it and telling the Mac OS to just do a reset," Erickson said.
Erickson said the rover will stay on the old software for now while engineers amend the R11 software. Officials aim to uplink the new R11 version to the rover in early December.
"Unfortunately, the handover didn't work well," Erickson said. "It was a transition problem. We can easily fix this now that we know what the issue is by clearing out the ready-to-send catalog before we switch to R11."
The R11 software is the 11th incarnation of software developed for the rover since the program began. It is the third software upgrade to be uplinked to Curiosity since landing and expands the rover's autonomy and extends capabilities for using the robot arm while parked on slopes, an improvement scientists expect will come in handy once the rover arrives at Mount Sharp, according to a NASA press release.
Ground teams restored the rover to normal operations Sunday, according to a NASA press release.
Curiosity's departure from the Cooperstown outcrop Thursday begins the next phase of the rover's journey to Mount Sharp.
The rover spent much of the first year of its mission on Mars investigating a region named Yellowknife Bay. Believed to be part of an ancient river system, Yellowknife Bay once held all the ingredients required to support microbial life, according to data collected by Curiosity's soil-analyzing instruments.
Mount Sharp may hold even stronger clues of a former habitable environment on Mars, and layered terrain in the mountain's foothills may contain organic signatures of ancient life.
Erickson said Curiosity should reach the edge of Mount Sharp some time between May and July 2014.
Cooperstown was the second of four "waypoints" identified on the route to Mount Sharp. Officials selected the waypoints from orbital imagery, providing opportunities to do science on the way to the rover's next big destination.
According to Erickson, Curiosity has completed more than one-third of its approximately 5.6-mile drive to Mount Sharp. The rover's next waypoint should be reached by January.
Follow Stephen Clark on Twitter: @StephenClark1.
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