From CNN.com

NASA grounds shuttle fleet

NASA today grounded the space shuttle program while engineers determine the effects of debris falling from Discovery during blastoff, the agency said. It is not clear whether any debris actually hit Discovery or the extent of any impact. Discovery took off Tuesday — the first shuttle launch since the 2003 Columbia disaster — with a battery of cameras installed watching for falling debris, the cause of Columbia’s disintegration on re-entry into the Earth’s atmosphere.