Cape Canaveral: The shuttle Discovery blasted off on a mission to fit the International Space Station with a final pair of solar wings ahead of the arrival in a few weeks of an expanded space crew.
The spacecraft launched from the Kennedy Space Centre in Florida. Just over eight minutes later, the shuttle entered orbit and was soaring at 28,000 kilometres per hour.
The journey was expected to take two days to reach the ISS, where the seven-member crew was to deliver and install the fourth and final pair of solar wings on the orbiting ISS.
Mike Leinbach, launch director for the mission, said the lift-off was picture perfect.
"I have seen a lot of launches and this was the most visually beautiful," he told reporters in a briefing.
"It was just spectacular. When the orbiter and the tank, booster got up in the sun light it was just gorgeous."
The mission, one of the last major tasks of the more than decade-long effort to construct the station, has been shortened by one day after a hydrogen leak last week led to a scrub of an earlier launch date.
But NASA officials said that the problem had been cleared up and that there has been no recurrence of the malfunction.
The leak was discovered Wednesday, when the external tank was 98 percent full of liquid hydrogen prompting it to be emptied for the checks.