Seminars

The Mars Exploration Rovers, Spirit and Opportunity, landed on the Martian Surface in January 2004. The twin rovers were designed for a 90 Martian day mission but remarkably, they have far outlived their life expectancy. Spirit explored the surface for six years and Opportunity continues operating over eleven years and one marathon later. Due to the harsh Martian environment, extensive use, and old age of the rover, Opportunity has inevitably experienced hardware and software degradations.

In early 2011, Opportunity began experiencing intermittent errors when writing data to flash memory. Similar errors occurred, with increasing frequency, in early 2013 and again in mid-2014. Analysis resulted in the discovery that all of the flash memory errors were occurring in a single bank of memory: Bank 7. These errors were accompanied by unexpected resets of the rover's flight computer (warm reboots), which caused sequenced activities to be terminated. Depending on timing, these warm reboots also caused communication faults. Faced with these more frequent errors, the MER team decided to reformat Opportunity’s flash memory in part because reformatting the flash memory had succeeded in eliminating similar problems on the Spirit rover.  But warm reboots persisted after two attempts to reformat the Opportunity memory.  

The next step was to mask off Bank 7 entirely. The MER team spent weeks building, testing, and validating a new version of the flight software to recognize the smaller flash memory size, and after extensively vetting the new flight software, the team implemented the masking operation on March 19, 2015. This presentation will discuss the results from the masking operation.

Bekah Sosland received a B.S. in Aerospace Engineering from UT Austin in 2013. She has been with JPL on the Mars Exploration Rover team for almost two years. She is one of the MER flight directors, the MER testbed lead, and the MER Opportunity flash tiger team lead. Bekah also serves on the Longhorn Engineering Advisory Delegationfor the Cockrell School of Engineering.