A main rocket carries a camera. But the NASA-industry team is confident of success. In September 1999, NASA's Mars Climate Orbiter crashed into the Red Planet because English units were used for critical reorientation rocket firings instead of metric units as required. It was one of NASA's most embarrassing blunders. Three months later a companion spacecraft, the Mars Polar Lander , disappeared without a trace during descent to the surface.
Engineers believe the lander's engines shut down too early because of an electrical glitch.
In the wake of the failures, NASA's Mars exploration program underwent a painful reassessment and restructuring. But getting into the proper orbit will not be easy. The aerobraking procedure must be completed within 90 days to ensure the Odyssey probe ends up in a polar orbit carrying it over the Earth-facing side of the planet at what amounts to mid afternoon local Mars time. That will ensure proper lighting on Odyssey's large solar array and maximize the return from the spacecraft's suite of science instruments. CBS News Space Consultant William Harwood has covered America's space program full time for more than 15 years, focusing on space shuttle operations, planetary exploration and astronomy.