Updated (11:29 EST): The Atlantis has now blasted off from the Kennedy Space Center launch pad, watch below.

Original Post:

The Atlantis is scheduled to blast off from the Kennedy Space Center in Florida at 11:26 EST. NASA had previously estimated that there's a 70 percent chance that weather may delay the launch, but the official Twitter account of the Kennedy Center now relays: "Weather is now 'green'. Let's go Atlantis!"  NASA's launch coverage adds:

Weather across Kennedy Space Center is observed 'go,' and hopefully conditions will remain that way for the next 40 minutes or so -- long enough for space shuttle Atlantis and a crew of four astronauts to launch on the STS-135 mission.

The live-feed is below, where you'll be able to watch the final launch of the space shuttle era: