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Problems for Mars Global Surveyor orbiter NASA/JPL NEWS RELEASE Posted: November 8, 2006 Engineers are striving to restore full communications with NASA's Mars Global Surveyor on the 10th anniversary of the spacecraft's Nov. 7, 1996, launch.
The orbiter has operated longer than any other spacecraft ever sent to Mars. It has returned more information about Mars than all earlier missions combined and has succeeded far enough beyond its original mission to see two later NASA orbiters arrive: Mars Odyssey and Mars Reconnaissance Orbiter. Among many important accomplishments so far, Mars Global Surveyor has found many young gullies apparently cut by flowing water, discovered water-related mineral deposits that became a destination for NASA's Opportunity rover, mapped the planet topographically and examined many potential landing sites on Mars. On Nov. 2, one orbit after commands were sent for a routine maneuver to move the solar panels, the spacecraft reported that the motor moving one of the arrays had experienced errors. Onboard software responded as programmed, switching the spacecraft to a backup motor controller, then to a backup circuitry connection. Following these indications of difficulty, a two-day lapse in contact occurred on Nov. 3 and 4. The signal from the spacecraft was received on Nov. 5 during four different orbits, but it did not carry any data from the spacecraft. The signal's frequency indicated that the spacecraft had entered safe mode, a pre-programmed state of restricted activity in which 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 additional pre-programmed response, intended to help it survive when it senses that a solar array is stuck. The spacecraft turns that array toward the sun to maintain its power supply and rotates the rest of the spacecraft in the same direction, thereby making communication with Earth less effective. "The spacecraft has many redundant systems that should help us get it back into a stable operation, but first we need to re-establish communications," said Tom Thorpe, project manager for Mars Global Surveyor at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Further information on the recovery of the spacecraft will be released as it comes available. |
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The twin STEREO space observatories designed to change the way we view the sun launch from Cape Canaveral aboard a Boeing Delta 2 rocket.
With launch of the Upper Atmosphere Research Satellite from space shuttle Discovery in September 1991, a new era in studying Earth's environment from space began. The crew of STS-48 describes the mission in this post-flight film, which includes an beautiful nighttime flyover of the United States.
Astronauts, rodents and jellyfish were the subjects during extensive medical tests performed aboard the first Spacelab Life Sciences mission launched in June 1991 aboard shuttle Columbia. A space laboratory module riding in the payload bay housed the experiment facilities. The crew of STS-40 explain the mission in this post-flight film.
A progress report on development of the Orion crew exploration spacecraft and the Ares launch vehicle is given during this briefing held October 18 at the Glenn Research Center in Cleveland.
Some of the initial pictures and data from NASA's Mars Reconnaissance Orbiter since the craft entered its mapping orbit around the Red Planet are presented in this news briefing held October 16 from the Jet Propulsion Laboratory.
Space shuttle Discovery's STS-39 flight, launched in April 1991, served as a research mission for the U.S. Department of Defense. An instrument-laden spacecraft for the Strategic Defense Initiative Organization was released to watch Discovery perform countless rocket firings and maneuvers, as well as canisters releasing clouds of gas. The crew tells the story of the mission in this post-flight film presentation.