U.S. officials say video images taken during the liftoff of the Space Shuttle Discovery show that up to five pieces of debris fell off the craft's external fuel tank during Tuesday's ascent.
Officials from the U.S. space agency NASA said Tuesday that it is too early to determine exactly what the debris was or whether it damaged the shuttle.
The Discovery lifted off from Cape Canaveral in the southeastern U.S. state of Florida earlier in the day, bound for the International Space Station.
Discovery's seven astronauts are to deliver supplies to the station and to practice inspection and repair techniques.
The agency had given the final go-ahead for the launch after deciding that a small crack in foam insulation on the shuttle's external fuel tank would not impede the mission.
In recent days, the U.S. space agency has twice delayed Discovery's launch, because of bad weather.
Tuesday's lift-off was the first-ever held on the American Independence Day holiday, and the second since the shuttle Columbia broke apart in 2003, killing seven astronauts.
Columbia's disintegration upon re-entry has been traced back to problems caused by a piece of foam insulation that broke off and hit Columbia's left wing.
A German member of the Discovery crew, Thomas Reiter will remain at the space station, expanding its crew to three for the first time since the Columbia disaster.