spacetoday.net: MGS failure caused by software glitch

Posted: Sat, Apr 14, 2007, 9:25 AM ET (1325 GMT)
MGS illustration (NASA/JPL)

A software glitch, undetected in testing on the ground, caused the demise of NASA's Mars Global Surveyor (MGS) spacecraft last November, an investigation board concluded Friday. In a preliminary report, members of an internal review board determined that a problem in software uploaded to the spacecraft earlier last year caused the spacecraft to misorient itself after a solar panel adjustment. The incorrect orientation exposed one of the spacecraft's batteries to direct sunlight, causing it to overhead and draining the charge in all the spacecraft's batteries. The spacecraft was unable to relay data back to Earth during this time because its antenna was mispointed. The panel concluded that the project team did follow procedures, but that the procedures were not good enough to catch the errors that caused the loss of the spacecraft; NASA plans to reevaluate its procedures for other missions to prevent a similar incident in the future. MGS, launched in 1996, had exceeded its planned lifetime by a factor of four and was continuing to return observations of the planet when it was lost.