CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Karen Nyberg is ready to begin driving practice in the M113 armored personnel carrier, part of emergency training. Behind her is Pilot Ken Ham. She and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Karen Nyberg waits to begin training on the M113 armored personnel carrier on Launch Pad 39B. She and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Mike Fossum stands ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Ron Garan is pleased with his driving practice in the M113 armored personnel carrier, part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Ron Garan is ready to drive the M113 armored personnel carrier as part of emergency training. Behind him is Pilot Ken Ham. They and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Pilot Ken Ham stands ready to practice driving the M113 armored personnel carrier as part of emergency training. Behind him is Mission Specialist Karen Nyberg. Ham and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Commander Mark Kelly is ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Greg Chamitoff stands ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Akihiko Hoshide takes his place in the M113 armored personnel carrier, to practice driving as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Mike Fossum drives the M113 armored personnel carrier as part of emergency training. Behind him at left is Mission Specialist Greg Chamitoff. At center is Battalion Chief George Hoggard providing supervision. Fossum and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- After completing M113 driving practice, the STS-124 crew stands in front of the armored personnel carrier for a photo. From left are Commander Mark Kelly, Mission Specialists Mike Fossum, Karen Nyberg and Ron Garan, Pilot Ken Ham, and Mission Specialists Akihiko Hoshide and Greg Chamitoff. They are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Ron Garan practices driving the M113 armored personnel carrier as part of emergency training. At center is the Battalion Chief George Hoggard, providing instruction. Behind Garan is Pilot Ken Ham. They and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Greg Chamitoff drives the M113 armored personnel carrier as part of emergency training. Behind him Commander Mark Kelly. At center is Battalion Chief George Hoggard providing supervision. Chamitoff and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- With Launch Pad 39B in the background, STS-124 Pilot Ken Ham drives the M113 armored personnel carrier as part of emergency training. Behind him at right is Mission Specialist Karen Nyberg. At center is Battalion Chief George Hoggard providing supervision. Ham and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 crew members get instructions inside an M113 armored personnel carrier about emergency procedures. Clockwise from left are Mission Specialists Greg Chamitoff and Akihiko Hoshide, Commander Mark Kelly, Mission Specialist Ron Garan, instructor Battalion Chief George Hoggard, Pilot Ken Ham and Mission Specialists Karen Nyberg and Mike Fossum. They are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Akihiko Hoshide drives the M113 armored personnel carrier as part of emergency training. Battalion Chief George Hoggard provides supervision. Behind them are Mission Specialist Ron Garan and Pilot Ken Ham. Hoshide and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Under the supervision of Battalion Chief George Hoggard, STS-124 Mission Specialist Karen Nyberg takes her turn (right) driving the armored personnel carrier, part of emergency training. At left are Mission Specialists Ron Garan and Akihiko Hoshide, who represents the Japan Aerospace Exploration Agency. They and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialists Greg Chamitoff (left) and Akihiko Hoshide (center) and Commander Mark Kelly take part in M113 training on Launch Pad 39A. They and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - At NASA's Kennedy Space Center in Florida, STS-134 Mission Specialist Greg Chamitoff prepares to drive an M113 armored personnel carrier. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Mission Specialist Andrew Feustel listens intently to instruction during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Commander Mark Kelly listens intently to instruction during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Pilot Greg H. Johnson listens intently to instruction during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Roberto Vittori, European Space Agency astronaut listens intently to instruction during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mission Specialist Rex Walheim affixes his mission's logo on an M113 armored personnel carrier during training at NASA's Kennedy Space Center in Florida . It's tradition for crew members during TCDT to put their mission logo sticker on the M113 they train in. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mission Specialist Rex Walheim holds several of his mission's logos after affixing one on an M113 armored personnel carrier during training at NASA's Kennedy Space Center in Florida . It's tradition for crew members during TCDT to put their mission logo sticker on the M113 they train in. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

STS-106 Mission Specialist Boris V. Morukov, eager to start Terminal Countdown Demonstration Test (TCDT)activities, arrives at the KSC Shuttle Landing Facility aboard a T-38 jet aircraft. As part of TCDT, he and the rest of the crew will practice emergency egress from the Fixed Service Structure and driving the M113 armored carrier, plus take part in a dress rehearsal for launch with a simulated countdown. STS-106 is scheduled to launch Sept. 8, 2000, at 8:31 a.m. EDT from Launch Pad 39B. On the 11-day mission, the seven-member crew will perform support tasks on orbit, transfer supplies and prepare the living quarters in the newly arrived Zvezda Service Module. The first long-duration crew, dubbed “Expedition One,” is due to arrive at the Station in late fall

STS-106 Mission Specialist Boris V. Morukov, eager to start Terminal Countdown Demonstration Test (TCDT)activities, arrives at the KSC Shuttle Landing Facility aboard a T-38 jet aircraft. As part of TCDT, he and the rest of the crew will practice emergency egress from the Fixed Service Structure and driving the M113 armored carrier, plus take part in a dress rehearsal for launch with a simulated countdown. STS-106 is scheduled to launch Sept. 8, 2000, at 8:31 a.m. EDT from Launch Pad 39B. On the 11-day mission, the seven-member crew will perform support tasks on orbit, transfer supplies and prepare the living quarters in the newly arrived Zvezda Service Module. The first long-duration crew, dubbed “Expedition One,” is due to arrive at the Station in late fall

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour provides supervision while space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Driving the M113 is Mission Specialist Sandy Magnus while Pilot Doug Hurley looks on. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour provides supervision while space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Driving the M113 is Mission Specialist Sandy Magnus while Pilot Doug Hurley looks on. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour provides supervision while space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Driving the M113 is Pilot Doug Hurley; seated are Mission Specialist Sandy Magnus (background right) and Commander Chris Ferguson. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour provides supervision while space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Driving the M113 is Mission Specialist Sandy Magnus while Commander Chris Ferguson looks on. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew sign their names to an Atlantis flag at the conclusion of their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialist Sandy Magnus (right) and Commander Chris Ferguson. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Pilot Greg H. Johnson takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Commander Chris Ferguson pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew pause for a photo at the conclusion of their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialist Rex Walheim (left), Pilot Doug Hurley, Mission Specialist Sandy Magnus and Commander Chris Ferguson. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - Space shuttle Endeavour's STS-134 crew members pose for a group photo in front of an M113 armored personnel carrier at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. From left, are Mission Specialists Greg Chamitoff, European Space Agency astronaut Roberto Vittori and Andrew Feustel, Pilot Greg H. Johnson, Mission Specialist Michael Fincke, and Commander Mark Kelly. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour provides supervision while space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training near Launch Pad 39B at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour stops for a photo opportunity with space shuttle Endeavour's STS-134 crew members as they participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - At NASA's Kennedy Space Center in Florida, STS-134 Mission Specialist Greg Chamitoff, left, and Commander Mark Kelly take a break from training on the M113 armored personnel carrier at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour provides supervision while space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mission Specialist Sandy Magnus pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Pilot Doug Hurley pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Mission Specialist Mike Fincke takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew pause for a photo at the conclusion of their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialist Rex Walheim (left), Pilot Doug Hurley, Mission Specialist Sandy Magnus and Commander Chris Ferguson. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Pilot Greg H. Johnson takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. With Johnson is Commander Mark Kelly (left) and European Space Agency astronaut Roberto Vittori. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - At NASA's Kennedy Space Center in Florida, the crew members of space shuttle Endeavour's STS-134 mission experience the interior of an M113 armored personnel carrier. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. From left is Pilot Greg H. Johnson, Mission Specialist Greg Chamitoff, Battalion Chief David Seymour (partially obscured), Commander Mark Kelly, Mission Specialists Mike Fincke and European Space Agency astronaut Roberto Vittori. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew pause for a photo during their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Commander Chris Ferguson (front), Mission Specialists Sandy Magnus, Rex Walheim and Pilot Doug Hurley (red cap). An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Mission Specialist Greg Chamitoff takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour provides supervision while space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training near Launch Pad 39B at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mission Specialist Rex Walheim pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Behind Walheim is Pilot Doug Hurley. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Pilot Doug Hurley pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- The STS-135 crew pause for a photo during their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Commander Chris Ferguson (front), Mission Specialists Sandy Magnus, Rex Walheim and Pilot Doug Hurley (red cap). An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-134 Mission Specialist Andrew Feustel takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CACAPE CANAVERAL, Fla. -- Commander Chris Ferguson pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Mission Specialist Sandy Magnus (left) and Commander Chris Ferguson. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - At NASA's Kennedy Space Center in Florida, STS-134 Mission Specialist Greg Chamitoff practices driving an M113 armored personnel carrier. Mission Specialist Mike Fincke (left), astronaut Roberto Vittori with the European Space Agency and Pilot Greg H. Johnson enjoy the ride. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour provides supervision while space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour provides supervision while space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Media snap photos of the STS-135 crew (out of frame) during their M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. Seen here are Battalion Chief David Seymour (right) and Carmel Shearer, pad rescue team driver. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour and space shuttle Atlantis' STS-135 crew members enjoy a light moment as they participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. From left are Mission Specialist Sandy Magnus, Pilot Doug Hurley, Commander Chris Ferguson (obscured) and Mission Specialist Rex Walheim. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour instructs space shuttle Atlantis' STS-135 crew members as they participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. From left are Mission Specialist Sandy Magnus, Pilot Doug Hurley, Commander Chris Ferguson (partially obscured) and Mission Specialist Rex Walheim. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - Battalion Chief David Seymour provides supervision while space shuttle Endeavour's STS-134 crew members participate in M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This is the final scheduled spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Astronaut and Mission Specialist Roberto Vittori with the European Space Agency takes time out from driving practice of the M113 armored personnel carrier to pose for a photo at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Space shuttle Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mission Specialist Rex Walheim pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Commander Chris Ferguson pauses for a photo during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Commander Chris Ferguson speaks with media at the conclusion of the crew's M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. - At NASA's Kennedy Space Center in Florida, STS-134 Commander Mark Kelly jokes around with his crew mates while trying to figure out where to affix his mission's logo on an M113 armored personnel carrier. An M113 is kept at the foot of the launch pad in case an emergency exit from the pad is needed and every shuttle crew is trained on driving the vehicle before launch. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Battalion Chief David Seymour (center) and Carmel Shearer, pad rescue team driver, join in as space shuttle Atlantis' STS-135 crew members share a light moment during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. From left are Mission Specialist Sandy Magnus, Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialist Rex Walheim. An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- Media snap photos while Battalion Chief David Seymour (left) and Carmel Shearer, pad rescue team driver, instruct shuttle Atlantis' STS-135 crew members during M113 armored personnel carrier training at NASA's Kennedy Space Center in Florida. From left are Pilot Doug Hurley (red cap), Mission Specialist Rex Walheim, Commander Chris Ferguson, Mission Specialist Sandy Magnus (blue cap). An M113 is kept at the foot of the launch pad in case an emergency exit from the launch pad is needed and every shuttle crew is trained on driving the vehicle before launch. The STS-135 crew is at Kennedy to participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Atlantis and its crew are targeted to lift off July 8, taking with them the Raffaello multi-purpose logistics module packed with supplies and spare parts to the International Space Station. The STS-135 mission also will fly a system to investigate the potential for robotically refueling existing satellites 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/Kim Shiflett