Endeavour on Saturday prepared for a mission that includes the deployment of a huge inflatable antenna, a test on Coca-Cola in space and the study of tiny sea creatures.
With near-perfect weather forecast and no technical problems, the shuttle was expected to blast off on a 10-day mission at 4:30 a.m. MDT Sunday."The launch countdown status can be summarized in one word: It's great," said Bob Sieck director of shuttle operations at NASA's Kennedy Space Center.
Fueling of the shuttle's giant rust-colored fuel tank with 500,000 gallons of liquid oxygen and liquid hydrogen began Saturday night.
The Air Force forecast a 90 percent chance of acceptable weather for liftoff. The only concern was the slight possibility of showers early Sunday.
About 90 percent of Endeavour's experiments were commercial in nature, said Greg Reck of NASA's Office of Space Access and Technology, in Washington, D.C.