Space shuttle Atlantis, NASA's final shuttle mission in its 30-year history, returned to earth on July 21, 2011 after a 13-day flight in which it successfully restocked supplies at the International Space Station.
The NASA administrator, Charles Bolden, speaks as the crew of Space Shuttle Atlantis stand near Space Shuttle Atlantis after landing at the Kennedy Space Center at Cape Canaveral, Fla. (July 21, 2011)
Shuttle launch director Mike Leinbach, right, hugs LeRoy Cain, deputy space shuttle program manager, after the space shuttle Atlantis lands at the Kennedy Space Center in Florida completing STS-135, the final mission of the NASA shuttle program. (July 21, 2011)
Commander Chris Ferguson, left, and NASA's deputy administrator, Lori Garver, look at space shuttle Atlantis' landing gear after landing at the Kennedy Space Center at Cape Canaveral, Fla. (July 21, 2011)
This panoramic view provided by NASA was photographed from the International Space Station, looking past the docked space shuttle Atlantis' cargo bay and part of the station including a solar array panel toward Earth, was taken on July 14, 2011 as the joint complex passed over the southern hemisphere. Aurora Australis or the Southern Lights can be seen on Earth's horizon and a number of stars are visible also.
Grace Calhoun, 16, of Nashville, front, screams with joy while watching the Space Shuttle Atlantis land at Space Camp at the U.S. Space and Rocket Center at U.S. Space Camp in Huntsville, Ala. (July 21, 2011)
NASA employee Jerry Davison, center, and his wife, Maureen, right, take photos as they watch at Johnson Space Center in Houston as space shuttle Atlantis approaches for landing at Kennedy Space Center, Fla. (July 21, 2011)
This NASA photo taken by the Expedition 28 crew and released on July 15, 2011 shows the Space Shuttle Atlantis as it approaches the International Space Station. Beneath them all lie the teal-colored shallows around the Bahamas.
A photo made from NASA television shows the Atlantis as it passes under a solar panel on the International Space Station after undocking on Tuesday. (July 19, 2011)
Space shuttle Atlantis STS-135 mission specialists Rex Walheim, left, and Sandra Magnus, pilot Douglas Hurley and commander Christopher Ferguson before boarding the Astrovan and heading to the launch pad for their scheduled blastoff at Kennedy Space Center in Cape Canaveral, Fla. (July 8, 2011)
Space shuttle Atlantis, STS-135 astronauts, left to right, Commander Christopher Ferguson, Pilot Douglas Hurley, Sandra Magnus and Rex Walheim wave American flags after arriving at Kennedy Space Center in Fla. (July 4, 2011)
Launch pad worker Chris Cassidy lays down grease on the tracks of the rotating service structure (RSS) on launch pad 39a prior to the RSS being rolled back to reveal the space shuttle Atlantis at the NASA Kennedy Space Center in Cape Canaveral, Fla. (July 7, 2011)
The crew of STS-135, from left, pilot Doug Hurley, commander Chris Ferguson, mission specialist Sandy Magnus and mission specialist Rex Walheim pose for a group photo following the crew media briefing at the Johnson Space Center, in Houston. (June 30, 2011)
An employee of the Kennedy Space Center Visitor Complex dressed as an astronaut greets children at the center one day before Space shuttle Atlantis is scheduled to launch for the last mission of the space shuttle program in Cape Canaveral, Fla. (July 7, 2011)
President Barack Obama with daughters Malia, left, Sasha, first lady Michelle Obama, right, and her mother Marian Robinson, partially hidden, examine the tiled underbelly and landing gear of Space Shuttle Atlantis as they visit Kennedy Space Center in Cape Canaveral, Fla. (April 29, 2011)
Kelleen Stewart signs a poster that reads, "Best Wishes Atlantis," at the Kennedy Space Center Visitor Complex one day before Space shuttle Atlantis is scheduled to launch for the last mission of the space shuttle program in Cape Canaveral, Florida. (July 7, 2011)
The space shuttle Atlantis on Launch Pad 39A at Kennedy Space Center in Florida. Preparations continue for the launch scheduled July 8 launch of STS-135, the final flight of the shuttle program. (July 7, 2011)
Mark Dojciechowski, left, and Amy Wohlwend from Atlanta, Ga., eat breakfast outside their camper as they wait to watch the launch of Space shuttle Atlantis on the last mission of the space shuttle program in Titusville, Fla. (July 7, 2011)