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http://www.jpl.nasa.gov/news/features.cfm?feature=1226Ground Team Stays Busy on 10th Anniversary of NASA Mars LaunchMedia contact: Guy Webster (818) 354-6278/JPLJet Propulsion LaboratoryNovember 07, 2006Engineers are striving to restore full communications with NASA's MarsGlobal Surveyor on the 10th anniversary of the spacecraft's Nov. 7,1996, launch.The orbiter is the oldest of five NASA spacecraft currently active atthe red planet. Its original mission was to examine Mars for a fullMartian year, roughly two Earth years. Once that period elapsed,considering the string of discoveries, NASA extended the missionrepeatedly, most recently on Oct. 1 of this year.The orbiter has operated longer than any other spacecraft ever sent toMars. It has returned more information about Mars than all earliermissions combined and has succeeded far enough beyond its originalmission to see two later NASA orbiters arrive: Mars Odyssey and MarsReconnaissance Orbiter. Among many important accomplishments so far,Mars Global Surveyor has found many young gullies apparently cut byflowing water, discovered water-related mineral deposits that became adestination for NASA's Opportunity rover, mapped the planettopographically and examined many potential landing sites on Mars.On Nov. 2, one orbit after commands were sent for a routine maneuver tomove the solar panels, the spacecraft reported that the motor movingoneof the arrays had experienced errors. Onboard software responded asprogrammed, switching the spacecraft to a backup motor controller, thento a backup circuitry connection.Following these indications of difficulty, a two-day lapse in contactoccurred on Nov. 3 and 4. The signal from the spacecraft was receivedonNov. 5 during four different orbits, but it did not carry any data fromthe spacecraft. The signal's frequency indicated that the spacecrafthadentered safe mode, a pre-programmed state of restricted activity inwhich it awaits instructions from Earth.No further signal was heard during subsequent orbits on Nov. 5 and Nov.6. Engineers concluded that the spacecraft had made an additionalpre-programmed response, intended to help it survive when it sensesthata solar array is stuck. The spacecraft turns that array toward the sunto maintain its power supply and rotates the rest of the spacecraft inthe same direction, thereby making communication with Earth lesseffective."The spacecraft has many redundant systems that should help us get itback into a stable operation, but first we need to re-establishcommunications," said Tom Thorpe, project manager for Mars GlobalSurveyor at NASA's Jet Propulsion Laboratory, Pasadena, Calif.Further information on the recovery of the spacecraft will be releasedas it comes available.