Discovery is set to blast off April 5 with a load of science experiments. It will be the next-to-last flight for Discovery. Only four shuttle missions remain. Discovery is slated to make the final shuttle flight in September.
The seven-member crew includes three women, one of them African-American and another Japanese, both rarities in space. The astronauts are at Florida's Kennedy Space Center for countdown practice.
Liftoff is scheduled for 6:26 a.m. -- right before sunrise.