Posted: Fri, Jul 8, 2011, 2:08 PM ET (1808 GMT)

The space shuttle Atlantis lifted off Friday morning on the 135th and final mission of the 30-year program. Atlantis lifted off on mission STS-135 at 11:29 am EDT (1529 GMT) from the Kennedy Space Center in Florida. The countdown was halted at the T-31 second mark for about two and a half minutes in order to ensure that the the gaseous oxygen vent arm had fully retracted. Earlier in the day it appeared weather would prevent a launch attempt, but skies cleared enough to permit a launch. Atlantis is on a 12-day mission to eliver supplies to the International Space Station. It is currently scheduled to land, and thus close out the shuttle program, on the morning of July 20.