"We have main engine start. Four, three, two, one, booster ignition and liftoff," an announcer from the space agency's mission control said.
The shuttle basted off at 3:33 am IST on Thursday, in what was the sixth attempt on the heels of a stream of weather woes and technical troubles.
Soaring into the Florida sky, the shuttle accelerated into space faster than the speed of sound, reaching 26,000 kilometers per hour in less than nine minutes.
In the minutes before liftoff when it became clear that weather would not cause another costly delay, NASA's relief was evident.
"Persistence pays off, good luck and God speed," said launch director Pete Nickolenko.
Endeavour's launch has been scrubbed three times since Saturday due to bad weather.
Two earlier attempts in June were aborted after potentially hazardous fuel leaks were discovered, apparently caused by a misaligned plate linking a hydrogen gas vent line with the external fuel tank.
The previous attempts left the cash-strapped US space agency footing 4.5 million dollars in extra costs.
Published 16 July 2009, 05:20 IST