Discovery roared into the skies over Florida Tuesday morning as NASA returned to shuttle space flight for the first time since the 2003 Columbia disaster.
Under a blue sky, the spacecraft lifted off at 10:39 a.m. ET, as scheduled.
"Liftoff of space shuttle Discovery, beginning America's new journey to the moon, Mars and beyond," said George Diller, the voice of shuttle launch control.
The launch followed days of troubleshooting to fix a faulty fuel sensor in its external tank that led to cancellation of a planned launch on July 13.
But video of what appeared to be some kind of debris falling off Discovery during launch prompted questions that NASA officials said they couldn't immediately answer.
The NASA video showed the unidentified debris falling and not appearing to hit Discovery. Falling debris that struck the craft during liftoff was blamed for the eventual destruction of Columbia as it re-entered the atmosphere in February 2003.
Since then, NASA has taken steps to minimize the amount and size of debris falling off the shuttle's exterior tank during its ascent. But the space agency has said it's impossible to eliminate falling launch debris. NASA experts said they will analyze liftoff video frame by frame in the coming days.
In a departure from previous shuttle liftoffs, 107 ground and aircraft cameras scrutinized this one to observe possible damage to Discovery from falling debris.
By Sunday, the mission management team will have enough information from the cameras to know whether Discovery is in safe enough condition to return to Earth, a NASA spokesman said before the debris video was released.