LOS ANGELES, Dec. 9 (Xinhua) -- NASA's Mars Odyssey¹ orbiter will have worked longer at Mars than any other spacecraft in history, the Jet Propulsion Laboratory (JPL喷气推进实验室) announced on Thursday.

On Dec. 15, the 3,340th day since that arrival, Odyssey will pass the Martian career longevity² record set by its predecessor³, Mars Global Surveyor, which operated in orbit from Sept. 11, 1997 to Nov. 2, 2006, according to JPL in Pasadena, Los Angeles.

After entering orbit around Mars on Oct. 24, 2001, Odyssey made its most famous discovery -- evidence for copious⁴（丰富的，很多的） water ice just below the dry surface of Mars -- during its first few months, JPL said.

After finishing its radiation-safety check for future astronauts before the end of its prime mission in 2004, Odyssey's missions were extended, enabling the spacecraft to achieve many accomplishments⁵ that would not have been possible otherwise, JPL said.

"The extra years have allowed us to build up the highest- resolution maps covering virtually the entire planet," said Odyssey Project Scientist Jeffrey Plaut at JPL.

The orbiter's longevity has given Odyssey scientists the opportunity to monitor seasonal⁶ changes on Mars year-to-year, such as the cycle of carbon-dioxide freezing out of the atmosphere in polar regions during each hemisphere's winter, according to JPL.

"It is remarkable⁷ how consistent（一致的，坚持的） 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's performance has boosted benefits from other missions, too. When NASA's Mars Exploration Rovers, Spirit and Opportunity, far exceeded their own expected lifetimes, Odyssey remained available as the rover's primary communication relay, JPL said.

Nearly all the science data from the rovers（巡游者） and NASA's Phoenix⁸ Mars Lander has reached Earth via Odyssey relay. Odyssey also became the middle segment of continuous observation of Martian weather by a series of NASA orbiters: Mars Global Surveyor, Odyssey, and NASA's Mars Reconnaissance Orbiter, which began its science mission in late 2006, according to JPL.