PASADENA, Calif. -- The 2001 Mars Odyssey appears to be on target for a rendezvous with the Red Planet in a mission that officials hope will help erase the stigma of NASA's disastrous Mars failures of 1999.
The 7-foot-long spacecraft has 2 million more miles to go before it fires its main engine to orbit Mars on Tuesday, but so far its navigation has been "flawless," said Bob Mase, Odyssey's lead navigator.
"Mars likes to befuddle us. It is a beguiling world," said Jim Garvin, the Mars program scientist at the National Aeronautics and Space Administration. "There always are unforeseen circumstances that take place when we explore Mars. This is a tremendous challenge and many Mars missions in the past have faced challenges."
The spacecraft has made four major course changes since its April launch, but it now should have clear sailing until it is ready to slip into an orbit 386 miles above the Martian north pole, Mase said.
Odyssey's $297 million mission is to map chemicals and minerals that make up the Martian surface, seek out hidden reservoirs of water and assess radiation risks to future human missions. The spacecraft also will serve as a communications relay satellite for both American and international spacecraft in 2003 and 2004.
Its mission follows losses of NASA's Mars Climate Orbiter and the Mars Polar Lander in 1999. Overall, about 30 spacecraft have been launched to Mars since 1960; more than two-thirds of them have failed.
At a news conference last week at the Jet Propulsion Laboratory, NASA officials declared full confidence that the spacecraft would make orbit successfully.
"We're back," Garvin said, although he framed the assurance in the challenges of getting there.
One potential problem could be a planetwide dust storm now raging. That could affect the density of the Martian atmosphere, which the Odyssey will rub against to slow down and ease into a closer orbit over several months.
However, the storm appears to be easing and is under daily scrutiny by another orbiting spacecraft, the Mars Global Surveyor, Garvin said.
Roger Gibbs, the Odyssey deputy project manager at JPL, said the 1999 failures prompted perhaps unprecedented testing and fault analysis this time.
"Every test, every question has been done and answered," Gibbs said.