NASA ispreparing to revive the dormant Cassini spacecraft in orbit aroundSaturn,which ceased science operations three weeks ago due to a computerglitch.
Cassinimission controllers plan to reawaken the Saturn probe tomorrow (Nov.24). Thespacecraft has been operating in a protectivestandby mode ? called "safe mode" ? sinceNov. 2 because of anill-timed flip of a data bit in Cassini's command and data systemcomputer.
"Thebit flip happened in exactly the wrong location ? almostanyplace else wouldhave merely resulted in a rejected command ? but the spacecraftrespondedexactly as programmed," Cassini program manager Bob Mitchell, of NASA'sJet Propulsion Laboratory (JPL) in Pasadena, Calif., said in an updatethismonth. "Cassini is in excellent shape, and we are looking forward tothenext seven years of this mission." [Cassini'sGreatest Hits: Photos of Saturn]
This latestcomputer hiccup marked the sixth time since Cassini's launch in 1997that thespacecraft went into safe mode. During that time, the probe beamedengineeringand spacecraft health data to its mission operations center at JPL, butcouldnot perform science observations.
The glitchforced mission planners to skip planned observations of Saturn'slargest moon Titan during a Nov. 11 flyby of thecloud-covered satellite.
Over thelast week, Cassini engineers commanded the probe to reset its sickcomputer tofix the bit flip problem. Science instruments were also slowlyreactivated andmission managers hope to recover data lost during the initialmalfunction, JPLofficials said.
"Playbackfrom the computer's memory is enabling engineers to extract sciencedatacollected before the spacecraft entered safe mode," JPL officials said.
The Cassinispacecraft arrived in 2004 to study Saturnand its rings, and to deliver the European-built Huygensprobe to land onTitan. Cassini completed its primary mission in 2008 and is now in itssecondextended phase that extends through May 2017.
The missionis a collaborative effort between NASA, the European Space Agency andtheItalian Space Agency.
- Gallery:The Rings and Moons of Saturn
- Cassini'sGreatest Hits: Photos of Saturn
- 30-YearSaturn Odyssey: From NASA's Voyagers to Cassini Today