CAPE CANAVERAL, Fla. -- A United Space Alliance technician examines one of shuttle Atlantis' thermal protection tiles in Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida. The tile went through a pull test, which measured the force it took to pull it off of the shuttle in order to make sure the bond between the two is strong enough to withstand the force of launch and landing. Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- United Space Alliance technicians gear up for a pull test of shuttle Atlantis' thermal protection tiles in Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida. The pull test measures the force it takes to pull a tile off of the shuttle in order to make sure the bond between the two is strong enough to withstand the force of launch and landing. Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- United Space Alliance technicians perform a pull test on shuttle Atlantis' thermal protection tiles in Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida. The pull test measures the force it takes to pull a tile off of the shuttle in order to make sure the bond between the two is strong enough to withstand the force of launch and landing. Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- United Space Alliance technicians perform a pull test on shuttle Atlantis' thermal protection tiles in Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida. The pull test measures the force it takes to pull a tile off of the shuttle in order to make sure the bond between the two is strong enough to withstand the force of launch and landing. Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis makes its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis slowly backs out of Orbiter Processing Facility-1 during its final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians prepare shuttle Atlantis for its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- STS-135 Pilot Doug Hurley talks with workers in Orbiter Processing Facility-1 during shuttle Atlantis' final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Hurley, along with Commander Chris Ferguson, and Mission Specialists Rex Walheim and Sandra Magnus are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Workers watch as shuttle Atlantis slowly backs out of Orbiter Processing Facility-1 during its final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis slowly backs out of Orbiter Processing Facility-1 during its final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Members of the media and NASA Kennedy Space Center workers snap photos of the STS-135 crew members who are at the center to watch shuttle Atlantis make its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building. From left, are Mission Specialist Rex Walheim, Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Sandra Magnus. The move called "rollover" is a major milestone in processing for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. Targeted to launch in early July, STS-135 also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Workers and the crew of STS-135 hold up a "We're Behind You, Atlantis" banner during the final planned move of shuttle Atlantis from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Members of the media and NASA Kennedy Space Center workers snap photos of the STS-135 crew members who are at the center to watch shuttle Atlantis make its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building. From left, are Mission Specialist Rex Walheim, Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Sandra Magnus. The move called "rollover" is a major milestone in processing for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. Targeted to launch in early July, STS-135 also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis makes its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis slowly backs out of Orbiter Processing Facility-1 during its final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians prepare shuttle Atlantis for its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- STS-135 Mission Specialist Sandra Magnus talks with technicians in Orbiter Processing Facility-1 prior shuttle Atlantis' final planned move to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Magnus, along with Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Shuttle Atlantis makes its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- The STS-135 crew members pose for a photo in front of shuttle Atlantis, which is making its final planned trek from Orbiter Processing Facility-1 to the Vehicle Assembly Building. From left, are Mission Specialist Rex Walheim, Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Sandra Magnus. The move called "rollover" is a major milestone in processing for the STS-135 mission, which will deliver the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts to the International Space Station. Targeted to launch in early July, STS-135 also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians prepare shuttle Atlantis for its final planned move from Orbiter Processing Facility-1 to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- STS-135 Commander Chris Ferguson talks with United Space Alliance tile technician Terry White, left, and NASA Kennedy Space Center Director Bob Cabana, right, in Orbiter Processing Facility-1 during shuttle Atlantis' final planned move to the Vehicle Assembly Building. The move called "rollover" is a major milestone in processing for the STS-135 mission to the International Space Station. Inside the VAB, the shuttle will be attached to its external fuel tank and solid rocket boosters. Ferguson, along with Pilot Doug Hurley and Mission Specialists Rex Walheim and Sandra Magnus are targeted to launch in early July, taking with them the Raffaello multipurpose logistics module packed with supplies, logistics and spare parts. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jack Pfaller