NASA has extended the mission of the Mars Odyssey orbiter, which has been studying and mapping the Red Planet since early 2002 as well as serving as a relay for data from the surface rovers Spirit and Opportunity.
Odyssey's primary mission, which cost $297 million, ended Tuesday. The $35 million extension will fund operations through September 2006, and NASA noted that the spacecraft has enough fuel left to operate through the rest of the decade and the following decade at the current rate of consumption.
"Odyssey has accomplished all of its mission-success criteria," said Philip Varghese, Odyssey project manager at NASA's Jet Propulsion Laboratory.
The spacecraft's findings include evidence of abundant frozen water under the surface of the south polar region, a widespread mineral indicating the Martian environment has been quite dry, and suggestions that Mars is undergoing climate change. Its instruments have also made the most detailed maps of Mars.
Odyssey also carried the first experiment sent to Mars in preparation for human missions. A detector on the orbiter found that radiation levels around the planet, from solar flares and cosmic rays, are two to three times higher than they are around Earth.
A solar flare knocked out the radiation detector in 2003.
The orbiter also helped planners analyze landing sites for the twin rovers that set down on the planet in January and since then has relayed about 85 percent of images and other data sent by the robot vehicles.
Odyssey is now being used to analyze sites for another mission scheduled to land on Mars in 2008 and is monitoring the planet's atmosphere to plan for the arrival of an orbiter in 2006. That craft will use dips into the atmosphere, a process called aerobraking, to adjust its orbit.
Odyssey was launched April 7, 2001, and reached Mars on Oct. 23, 2001. It also used aerobraking to modify its orbit around the planet.