The launch of the two-ton Mars Reconnaissance Orbiter on top of a Lockheed Martin Atlas V rocket from Cape Canaveral Air Force Station in Florida will be postponed for at least 24 hours, said spokesman George Diller.
Engineers found a failure in the navigational controls of a similar Atlas V launch vehicle and need to make sure the problem does not affect the one being used for the Mars spacecraft, NASA said.
The orbiter's mission, now due to launch at the earliest between 7:50 a.m. and 9:35 a.m. EDT Thursday, will be to learnlong enough to . Previous Mars missions have shown that water once flowed across the planet's surface.
The 21-foot Mars Reconnaissance Orbiter is scheduled to reach the planet in March 2006.
It will use an array of scientific instruments to zoom in for close-up photos of the Martian surface, analyze mineral deposits, search for subsurface water and shorelines of ancient seas, trace dust and water distribution in the atmosphere, and monitor the weather through a full cycle of Martian seasons.