In this image provided by NASA, the space shuttle Atlantis is seen shortly after the rotating service structure (RSS) was rolled back at launch pad 39a, Thursday, July 7, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. Atlantis is set to liftoff Friday on the final flight of the shuttle program, STS-135, a 12-day mission to the International Space Station. NASA decided to start the fueling operations early Friday morning. (AP Photo/NASA, Bill Ingalls)

Space Shuttle Atlantis is seen on the pad at the Kennedy Space Center at Cape Canaveral, Fla. , Thursday July 7, 2011. Atlantis and a crew of four are scheduled to launch on Friday, July 8, on the 135th and final space shuttle launch for NASA. (AP Photo/Stan Honda, Pool)

Rain storms in the area of pad 39a Thursday night July 7, 2011 forms puddles as the Space Shuttle Atlantis gets ready for its final launch Friday afternoon from the Kennedy Space Center. Atlantis is set to liftoff Friday on the final flight of the shuttle program, STS-135, a 12-day mission to the International Space Station. NASA decided to start the fueling operations early Friday morning. (AP Photo/Craig Rubadoux - Florida Today)

The nose and crew quarters of Space Shuttle Atlantis is seen at the Kennedy Space Center at Cape Canaveral, Fla. , Thursday July 7, 2011. Atlantis and a crew of four are scheduled to launch on Friday, July 8, on the 135th and final space shuttle launch for NASA. (AP Photo/Stan Honda, Pool)

Sarah Paschall, of Jacksonville, Fla., looks out from her tent as she waits for the launch of space shuttle Atlantis Friday, July 8, 2011, in Titusville, Fla. Atlantis is scheduled to liftoff Friday on the final space shuttle mission. (AP Photo/David J. Phillip)

Vincentzo DiMartino sells drinks to spectators along the Max Brewer Bridge as they wait for the final launch of space shuttle Atlantis Friday, July 8, 2011, in Titusville, Fla. Atlantis is scheduled to liftoff Friday on the final space shuttle mission. (AP Photo/David J. Phillip)

The space shuttle Atlantis astronauts left to right, pilot Doug Hurley, mission specialist Sandra Mangus, commander Chris Ferguson and missions specialist Rex Walheim, leave the operations and check out building on their way to the pad at the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/John Raoux)

The space shuttle Atlantis astronauts left to right, mission specialists Rex Walheim, Sandy Magnus, pilot Doug Hurley and commander Chris Ferguson wave after leaving the operations and check-out building on their way to the pad at the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Chris O'Meara)

Joshua and Orlando Perez, of Orlando, Fla., sleep on a dock while they await the final launch of space shuttle Atlantis in Titusville, Fla., Friday, July 8, 2011. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/Gerry Broome)

The Howard family from Huddersfield, England, walk along the Max Brewer Bridge before space shuttle Atlantis lifts off Friday, July 8, 2011, in Titusville, Fla. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/David J. Phillip)

Spectators cheer as space shuttle Atlantis lifts off Friday, July 8, 2011, in Titusville, Fla. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/David J. Phillip)

NASA employee Robin Allen of Huntsville, Ala., helps her husband launch his kite on Cocoa Beach, Fla., on Friday, July 8, 2011. The 29-year employee will be leaving her job shortly as the shuttle Atlantis is the final mission before the fleet is retired. (AP Photo/Dave Martin)

The space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Chris O'Meara)

The space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/John Raoux)

In this photo provided by NASA, space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft as it lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/NASA, Dick Clark)

Spectators watch and take photographs as space shuttle Atlantis lifts off Friday, July 8, 2011, in Titusville, Fla. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/David J. Phillip)

The space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Tim Donnelly)

An aerial view of the Space Shuttle Atlantis as it roars into space over Cape Canaveral Fla., on Friday, July 8, 2011. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/Reinhold Matay)

Doug Chambers raises his arms as space shuttle Atlantis lifts off Friday, July 8, 2011, in Titusville, Fla. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/David J. Phillip)

The space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Dave Martin)

Ron Stillman, left, and Tara Reece of Cocoa Beach, Fla., watch from their sufboards as the space shuttle Atlantis lifts off on STS-135 in Cocoa Beach, Fla., on Friday, July 8, 2011. The space shuttle Atlantis is the final shuttle mission before the fleet is retired. (AP Photo/Dave Martin)

The space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Terry Renna)

Mary Lamb, left, of Ocala, Fla., points out the space shuttle Atlantis to granddaughters Delaney Reed, 7, Sabrina Sena, 10, and Simone Sena, 12, as they watch the last shuttle launch from Daytona Beach Friday July 8, 2011. (AP Photo/Daytona Beach News-Journal, Jim Tiller )

Space shuttle Atlantis lifts off from Pad 39A at the Kennedy Space Center in Cape Canaveral, Fla., Friday, July 8, 2011. The STS135 mission, the final shuttle flight, will bring supplies to the international space station. (AP Photo/John Raoux)

Spectators watch the final launch of space shuttle Atlantis in Titusville, Fla., Friday, July 8, 2011. Four astronauts are taking space shuttle Atlantis for one last ride, the very last one of the 30-year space shuttle era. (AP Photo/Gerry Broome)

Phil Norfleet, from Tennessee, cheers while watching the space shuttle Atlantis launch from the Max Brewer Memorial Parkway in Titusville, Fla. on Friday, July 8, 2011. Norfleet drove 12 hours with friends to watch the last shuttle liftoff. (AP Photo/The Gainesville Sun, Matt Stamey)

Spectators watch the space shuttle Atlantis lift off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Terry Renna)

Former Apollo astronaut Tom Stafford reacts after the space shuttle Atlantis lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. (AP Photo/Terry Renna)

Space Shuttle Launch Director, Mike Leinbach, waves the Atlantis flag as he enters the press site auditorium following the launch of Space Shuttle Atlantis at the Kennedy Space Center at Cape Canaveral Fla. Friday July 8, 2011. Atlantis and a crew of four are on a mission to the International Space Station. This is the 135th and final space shuttle launch for NASA. (AP Photo/John Raoux)

Thousands gather in the surf and on the beach in Cocoa Beach, Fla., Friday, July 8, 2011 to watch the launch of the space shuttle Atlantis on STS-135. The space shuttle Atlantis is the final shuttle mission before the fleet is retired. (AP Photo/Dave Martin)