CAPE CANAVERAL, Fla. -- Space shuttle Atlantis is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. There to welcome Atlantis home are thousands of workers who have processed, launched and landed the shuttles for more than three decades. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Media photograph space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Media photograph space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers prepare space shuttle Atlantis for its trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida the STS-135 crew members express their gratitude to the thousands of workers who have processed, launched and landed the space shuttles for more than three decades during an employee appreciation event. Seen here is Commander Chris Ferguson shaking the hand of Kennedy Space Center Director Bob Cabana. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members pause for a photograph in front of space shuttle Atlantis after an employee appreciation event held at Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Commander Chris Ferguson (left), Mission Specialist Sandy Magnus, Pilot Doug Hurley and Mission Specialist Rex Walheim. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the landing convoy vehicles accompany space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility to an orbiter processing facility. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- It is time for reflection at NASA's Kennedy Space Center in Florida as employees accompany space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility to an orbiter processing facility. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Thousands of workers who have processed, launched and landed space shuttles for more than three decades, gather for an employee appreciation event in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members express their gratitude to the thousands of workers who have processed, launched and landed the space shuttles for more than three decades during an employee appreciation event held in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialists Sandy Magnus and Rex Walheim, Commander Chris Ferguson and Pilot Doug Hurley. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers prepare space shuttle Atlantis for its trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis and its employee entourage saunter along the towway from the Shuttle Landing Facility to the Orbiter Processing Facility at NASA's Kennedy Space Center in Florida. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members stop for a photograph after an employee appreciation event held in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialists Rex Walheim (left) and Sandy Magnus, Commander Chris Ferguson and Pilot Doug Hurley. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Media photograph space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, NASA Administrator Charles Bolden, left, and Kennedy Space Center Director Bob Cabana join Kennedy employees in the Pledge of Allegiance at an employee appreciation event for the thousands of workers who have processed, launched and landed America's space shuttles for more than three decades. Following the successful STS-135 mission, space shuttle Atlantis was parked at the celebration site for photo opportunities. STS-135 secured the space shuttle fleet's place in history and brought a close to NASA's Space Shuttle Program. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members express their gratitude with a banner dedicated to the thousands of workers who have processed, launched and landed the space shuttles for more than three decades during an employee appreciation event held in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialists Rex Walheim and Sandy Magnus, Commander Chris Ferguson and Pilot Doug Hurley. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Thousands of workers who have processed, launched and landed space shuttles for more than three decades, gather in front of space shuttle Atlantis after an employee appreciation event at Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Thousands of workers who have processed, launched and landed space shuttles for more than three decades, gather for an employee appreciation event in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis is reflected in the water along the towway from the Shuttle Landing Facility to the Orbiter Processing Facility at NASA's Kennedy Space Center in Florida. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Thousands of workers who have processed, launched and landed space shuttles for more than three decades, gather for an employee appreciation event in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Employees accompany space shuttle Atlantis as it is slowly towed from the Shuttle Landing Facility to an orbiter processing facility at NASA's Kennedy Space Center in Florida. Looming in the background is the 525-foot-tall Vehicle Assembly Building. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the landing convoy vehicles line up to accompany space shuttle Atlantis from the Shuttle Landing Facility to an orbiter processing facility. Atlantis' final return from space at 5:57 a.m. EDT concluded the STS-135 mission, secured the space shuttle fleet's place in history and brought a close to America's Space Shuttle Program. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members express their gratitude to the thousands of workers who have processed, launched and landed the space shuttles for more than three decades during an employee appreciation event held in front of Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialists Sandy Magnus and Rex Walheim, Commander Chris Ferguson and Pilot Doug Hurley. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers prepare space shuttle Atlantis for its trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers accompany space shuttle Atlantis as it makes its slow trek from the Shuttle Landing Facility to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew members pause for a photograph in front of space shuttle Atlantis after an employee appreciation event held at Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. Seen here are Commander Chris Ferguson (left), Mission Specialist Sandy Magnus, Pilot Doug Hurley and Mission Specialist Rex Walheim. Atlantis' final return to Earth occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- A towback technician is seen through the cockpit windows of space shuttle Atlantis as he safes the vehicle on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida. Atlantis' final landing was the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Main gear touchdown was at 5:57:00 a.m. EDT, followed by nose gear touchdown at 5:57:20 a.m., and wheelstop at 5:57:54 a.m. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, NASA Administrator Charles Bolden thanks the Kennedy work force for their dedication at an employee appreciation event for the thousands of workers who have processed, launched and landed America's space shuttles for more than three decades. Following the successful STS-135 mission, space shuttle Atlantis was parked at the celebration site for photo opportunities. STS-135 secured the space shuttle fleet's place in history and brought a close to NASA's Space Shuttle Program. On board were STS-135 Commander Chris Ferguson, Pilot Doug Hurley, and Mission Specialists Sandra Magnus and Rex Walheim. On the 37th shuttle mission to the International Space Station, STS-135 delivered the Raffaello multi-purpose logistics module filled with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 was the 33rd and final flight for Atlantis, which has spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles, and also the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Employees admire space shuttle Atlantis as the landing convoy crew makes the vehicle safe for towing to Orbiter Processing Facility-2. Atlantis' final return to Earth on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis is slowly towed from the Shuttle Landing Facility runway to Orbiter Processing Facility-2 for the last time. Atlantis' final return to Earth on Runway 15 at NASA's Kennedy Space Center in Florida occurred at 5:57 a.m. EDT July 21, 2011. Securing the space shuttle fleet's place in history, Atlantis marks the 26th nighttime landing of NASA's Space Shuttle Program and the 78th landing at Kennedy. Atlantis and its crew delivered to the International Space Station the Raffaello multi-purpose logistics module packed with more than 9,400 pounds of spare parts, equipment and supplies that will sustain station operations for the next year. STS-135 is the 33rd and final flight for Atlantis and the final mission of the Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett