ShareThisBy JIM ERICKSON
Tuesday, November 21, 2006
NASA has been out of touch with Mars Global Surveyor since the evening of Nov. 5. But engineers said late last week they remain hopeful they'll regain contact with it.
"I certainly wouldn't say the mission is over," said Tom Thorpe, project manager at NASA's Jet Propulsion Laboratory.
"The engineers still have plenty of things they want to try, so I would say we've got a good possibility of getting the spacecraft back."
Global Surveyor was built by Lockheed Martin Space Systems. Engineers are contacting the spacecraft every two hours, commanding it to turn on its transmitters and contact Earth.
So far, no response.
"Two seconds from now we could have the signal," Thorpe said. "The problem is, without any response, it's very hard to know" the probe's condition. The spacecraft could be dead and we'll never hear from it again, or it could be there's just one small, little thing that has to be corrected."
Mars Global Surveyor was launched Nov. 7, 1996. Originally scheduled for a two-year mapping mission, the orbiter has endured for a decade.
Among Global Surveyor's many accomplishments:
_ It has operated longer than any other Mars spacecraft and has returned more information than all previous missions to the Red Planet combined.
_ It found geologically young gullies apparently cut by flowing water, discovered water-formed mineral deposits and scouted landing sites for surface rover missions.
_ The spacecraft's camera sent back more than 240,000 photos.
"Mars Global Surveyor helped rewrite the history books on Mars," said Lockheed Martin spokesman Gary Napier. "The fact that its two-year mission turned into a 10-year mission shows what a magnificent spacecraft it is."
The recent concerns began Nov. 2, when the spacecraft reported problems with the motor that moves one of its two solar arrays.
A two-day lapse in contact occurred Nov. 3 and 4. The craft's radio signal was detected again Sunday, but the weak signal contained no data about the probe's health.
Engineers suspect the solar array problem triggered a protective response on the spacecraft. It may have entered a power-saving "safe mode" by turning one or both of the arrays toward the sun, Thorpe said.
In that orientation, the probe spends most of its time with its antennas pointed away from Earth. Thorpe said the recovery effort "could stretch out for weeks or months."
