An artist's rendition of the Mars Odyssey spacecraft in orbit above Mars.
A NASA spacecraft is coming up on a record-breaking milestone: Next week, the space agency's Mars Odyssey orbiter will have worked longer at Mars than any other spacecraft in history.
Odyssey entered orbit around Mars on Oct. 24, 2001. On Dec. 15 the 3,340th Earth day since that arrival Odyssey will break the record for the longest mission to Mars, overtaking its predecessor, NASA's Mars Global Surveyor, which operated in orbit from Sept. 11, 1997 to Nov. 2, 2006.
Odyssey has made some notable discoveries over the past nine years around the Red Planet. During its first few months, for example, the orbiter found evidence that lots of water ice lurks just below the dry surface of Mars. That evidence was later confirmed by NASA's Phoenix lander in 2008.
Odyssey also completed a radiation-safety study, vital information for any future astronauts visiting the Red Planet.
The spacecraft's primary mission ended in 2004, but NASA has given Odyssey several life extensions that have kept the spacecraft busy mapping the Martian surface and doing a variety of other things.
The probe has accomplished a great deal, and it's not done yet, mission researchers said.
"The extra years have allowed us to build up the highest-resolution maps covering virtually the entire planet," Odyssey project scientist Jeffrey Plaut of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement.
The Odyssey orbiter's longevity has also given scientists the opportunity to monitor seasonal changes on Mars year-to-year, scientists added. For example, they've been able to track the cycle of carbon dioxide freezing out of the atmosphere in polar regions during each Martian hemisphere's winter.
"It is remarkable how consistent the patterns have been from year to year, and that's a comparison that wouldn't have been possible without our mission extensions," Plaut said.
Odyssey has helped out several other missions, too, serving as a key communications link for NASA's Mars surface craft. Nearly all the science data from the Spirit and Opportunity rovers and the Phoenix lander has reached Earth via Odyssey relay, researchers said.
Odyssey also became the middle segment in the set of continuous observations of Martian weather made by a series of NASA orbiters: Mars Global Surveyor, Odyssey and NASA's Mars Reconnaissance Orbiter, which began its science mission in late 2006.
NASA plans to keep Odyssey busy with science and communication-relay duties for the near future, officials said. And, if required, controllers will adjust Odyssey's orbit so the spacecraft is in a favorable position to help relay data during the August 2012 landing of NASA's next Mars rover Curiosity.
A continuing partnership between JPL and Lockheed Martin Space Systems operates Odyssey. The spacecraft and its mission have engaged many science partners over the years, including Arizona State University, the University of Arizona, the Russian Aviation and Space Agency and Los Alamos National Laboratory, officials said.
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