CAPE CANAVERAL, Fla. -- Space shuttle Endeavour glistens in the sun on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The massive crawler-transporter that hauled the shuttle, attached to its external fuel tank and solid rocket boosters, to the pad March 10 remains on the crushed crawlerway rocks. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to move the primary payload for Endeavour's STS-134 mission into the pad's structure before installing it into the spacecraft's cargo bay. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frank Michaux

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, moves past the Vehicle Assembly Building on its journey from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour glistens in the sun on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to move the primary payload for Endeavour's STS-134 mission into the pad's structure before installing it into the spacecraft's cargo bay. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frank Michaux

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour glistens in the sun on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to move the primary payload for Endeavour's STS-134 mission into the pad's structure before installing it into the spacecraft's cargo bay. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frank Michaux

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour glistens in the sun on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to move the primary payload for Endeavour's STS-134 mission into the pad's structure before installing it into the spacecraft's cargo bay. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frank Michaux

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, moves past the Vehicle Assembly Building on its journey from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- Boeing Space Operation's STS-134 Payload Flow Manager Bob Hart talks to media with space shuttle Endeavour and its primary payload in the background on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- STS-134 Payloads Mission Manager Joe Delai talks to media with space shuttle Endeavour and its primary payload in the background on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, is moved from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Crews move the primary payload for space shuttle Endeavour's STS-134 mission into the Payload Changeout Room on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to make the vertical move. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, moves past the Vehicle Assembly Building on its journey from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, is prepared for its move from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. Next, crews at the pad will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Cory Huston

CAPE CANAVERAL, Fla. -- Crews move the primary payload for space shuttle Endeavour's STS-134 mission into the Payload Changeout Room on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components is open to allow crews to make the vertical move. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 (ELC-3) for space shuttle Endeavour's STS-134 mission, is prepared for its move from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, is moved from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Crews move the primary payload for space shuttle Endeavour's STS-134 mission into the Payload Changeout Room on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA

CAPE CANAVERAL, Fla. -- A canister, carrying the Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 for space shuttle Endeavour's STS-134 mission, is moved from the Canister Rotation Facility to Launch Pad 39A at NASA's Kennedy Space Center in Florida. At the pad, crews will move the payload into the Payload Ground Handling Mechanism (PGHM), and the rotating service structure (RSS) that protects the shuttle from the elements and provides access to its components will be rotated back into place. The payload is scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- The rotating service structure (RSS) protecting space shuttle Endeavour from the elements and providing access to its components is open to allow crews to move the primary payload for the STS-134 mission into the Payload Changeout Room on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The Alpha Magnetic Spectrometer-2 (AMS) and Express Logistics Carrier-3 are scheduled to be installed into the shuttle's cargo bay March 25. Endeavour and its six-member STS-134 crew are targeted to lift off April 19 at 7:48 p.m. EDT to deliver the payload to the International Space Station. This is Endeavour's final scheduled mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA