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, enters the Canister Rotation Facility from the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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 in the Canister Rotation Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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, enters the Canister Rotation Facility from the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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 in the Canister Rotation Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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 in the Canister Rotation Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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, enters the Canister Rotation Facility from the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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 Space Station Processing Facility to the Canister Rotation Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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 Space Station Processing Facility to the Canister Rotation Facility at NASA's Kennedy Space Center in Florida. There, the canister that protects the space-bound payload will be rotated from a horizontal to vertical position so that it can be installed into Endeavour's payload bay. AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, space shuttle Endeavour's STS-134 Commander Mark Kelly speaks to the media before the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, media and the crew of space shuttle Endeavour's STS-134 mission gather on the Shuttle Landing Facility runway to check out the Alpha Magnetic Spectrometer, or AMS, which arrived aboard an Air Force C-5M aircraft from Europe. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A technicians in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, check the progress of the Payload Attach System, or PAS, as it is lifted up to the Alpha Magnetic Spectrometer, or AMS, where it will be attached to the bottom of the AMS. The PAS provides a method of securely connecting the payload to the International Space Station. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a technician monitors the progress of the Payload Attach System, or PAS, as it is lifted up to the Alpha Magnetic Spectrometer, or AMS, where it will be attached to the bottom of the AMS. The PAS provides a method of securely connecting the payload to the International Space Station. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 Mission Specialist Michael Fincke pauses for a photo before the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 Mission Specialist Andrew Feustel looks on as European Space Agency astronaut Roberto Vittori greets the media after the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, media check out the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility's conference room at NASA's Kennedy Space Center in Florida, Ken Bollweg, Alpha Magnetic Spectrometer-2 (AMS) deputy project manager, talks to media about the particle physics detector. AMS is designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, processing continues for the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Professor Sam Ting, Alpha Magnetic Spectrometer-2 (AMS) principal investigator at the Massachusetts Institute of Technology, checks out the particle physics detector. AMS is designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, media check out and learn more about the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- Technicians in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, monitor the guide wires of the overhead crane as it lifts the Payload Attach System, or PAS, up to the Alpha Magnetic Spectrometer, or AMS, for installation. The PAS provides a method of securely connecting the payload to the International Space Station. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Technicians in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, check the progress of the Payload Attach System, or PAS, as it is lifted up to the Alpha Magnetic Spectrometer, where it will be attached to the bottom of the AMS. The PAS provides a method of securely connecting the payload to the International Space Station. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, processing continues for the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, media check out the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, processing continues for the Alpha Magnetic Spectrometer-2 (AMS). AMS is a particle physics detector, designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida Professor Sam Ting, Alpha Magnetic Spectrometer-2 (AMS) principal investigator at the Massachusetts Institute of Technology, talks to media about the particle physics detector. AMS is designed to operate as an external experiment on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS-2 will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Glenn Benson

CAPE CANAVERAL, Fla. -- Technicians in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, check the progress of the Payload Attach System, or PAS, as it is lifted up to the Alpha Magnetic Spectrometer, where it will be attached to the bottom of the AMS. The PAS provides a method of securely connecting the payload to the International Space Station. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, space shuttle Endeavour's STS-134 crew members pause for a photo prior to the arrival of the Alpha Magnetic Spectrometer, or AMS. From left to right are Commander Mark Kelly, Mission Specialists Greg Chamitoff, Andrew Feustel European Space Agency astronaut Roberto Vittori, Mission Specialist Michael Fincke and Pilot Gregory H. Johnson. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, space shuttle Endeavour's STS-134 crew is on hand for the arrival of the Alpha Magnetic Spectrometer, or AMS. From left to right are Mission Specialists Greg Chamitoff, Andrew Feustel, European Space Agency astronaut Roberto Vittori, Mission Specialist Michael Fincke and Pilot Gregory H. Johnson. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Inside the C-5M aircraft that delivered the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 Mission Specialists Greg Chamitoff and Andrew Feustel take a walk around the AMS still secured in the aircraft's cargo bay. In the background is European Space Agency astronaut Roberto Vittori. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, Professor Sam Ting, AMS Principal Investigator from the Massachusetts Institute of Technology listens intently as Professor Manuel Aguilar, AMS Spanish Coordinator, speaks to the media before the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Inside the C-5M aircraft that delivered the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 Commander Mark Kelly, Mission Specialist Greg Chamitoff, European Space Agency astronaut Roberto Vittori and Mission Specialist Andrew Feustel speak with a member of the C-5M flight crew. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 Commander Mark Kelly, European Space Agency astronaut Roberto Vittori (left) and Mission Specialist Andrew Feustel get a close look at the Alpha Magnetic Spectrometer, or AMS, inside the C-5M aircraft. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-134 Mission Specialists Michael Fincke, Andrew Fuestel, Pilot Gregory C. Johnson, Commander Mark Kelly and Mission Specialist Greg Chamitoff (in blue flight suits) join the Air Force C-5M flight crew that delivered the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility, in a group photo opportunity. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-134 European Space Agency astronaut Roberto Vittori is accompanied by Pilot Gregory H. Johnson and Commander Mark Kelly on the tarmac where the C-5M aircraft is parked after the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, Prof. Jean Pierre Vialle, AMS French Coordinator, addresses the media before the arrival of the Alpha Magnetic Spectrometer, or AMS. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Prior to the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, Professor Sam Ting, AMS Principal Investigator from the Massachusetts Institute of Technology speaks to the media. AMS,a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a crane lifts a section of the Alpha Magnetic Spectrometer, or AMS, toward a tractor-trailer which will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Prior to the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, Prof. S.C. Lee, AMS Taiwanese Coordinator, speaks to the media. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a crane moves the next section of the Alpha Magnetic Spectrometer, or AMS, toward a tractor-trailer which will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- Before the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, Professor Maurice Bourquin, AMS Swiss Coordinator, speaks to the media. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a crane lifts the next section of the Alpha Magnetic Spectrometer, or AMS, toward a tractor-trailer which will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a crane lowers the next section of the Alpha Magnetic Spectrometer, or AMS, onto a tractor-trailer which will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a crane lowers a section of the Alpha Magnetic Spectrometer, or AMS, onto a tractor-trailer which will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a tractor-trailer carrying the Alpha Magnetic Spectrometer, or AMS, at the Space Station Processing Facility, where it will be processed for launch. AMS arrived on Kennedy's Shuttle Landing Facility aboard an Air Force C-5M aircraft from Europe. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour is ready for its slow move from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. This is the final scheduled rollout for Endeavour, which is attached to its external fuel tank and solid rocket boosters atop a crawler-transporter. Endeavour and its six STS-134 crew members 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 International Space Station on the shuttle's final spaceflight. Launch is targeted for April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour is ready for its slow move from High Bay 3 in the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. This is the final scheduled rollout for Endeavour, which is attached to its external fuel tank and solid rocket boosters atop a crawler-transporter. Endeavour and its six STS-134 crew members 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 International Space Station on the shuttle's final spaceflight. Launch is targeted for April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the protective panels that covered the Alpha Magnetic Spectrometer, or AMS, have been removed so that the technicians can begin preparing it for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- Before the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, European Space Agency Director of Human Spaceflight, Simonetta Di Pippo addresses the media. AMS,a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Workers in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, monitor the progress of an overhead crane as it moves the Alpha Magnetic Spectrometer, or AMS, to an area for technicians to prepare it for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a tractor-trailer carrying the Alpha Magnetic Spectrometer, or AMS, arrives at the Space Station Processing Facility, where it will be prepared for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, technicians remove a side panel that protected the Alpha Magnetic Spectrometer, or AMS, during shipment. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, media are on hand as the Alpha Magnetic Spectrometer, or AMS, is delivered to the Space Station Processing Facility, where it will be prepared for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- Prior to the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, European Space Agency Director of Human Spaceflight, Simonetta Di Pippo addresses the media. AMS,a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida an overhead crane lowers the Alpha Magnetic Spectrometer, or AMS, onto to floor for technicians to prepare it for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida an overhead crane is poised above the floor of the Space Station Processing Facility to lift the Alpha Magnetic Spectrometer, or AMS, from the tractor-trailer that delivered it. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida an overhead crane moves the Alpha Magnetic Spectrometer, or AMS, to an area for technicians to prepare it for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida an overhead crane lifts the Alpha Magnetic Spectrometer, or AMS, off of the tractor-trailer that delivered it. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- Workers and media at NASA's Kennedy Space Center in Florida, monitor the arrival of a tractor-trailer carrying the Alpha Magnetic Spectrometer, or AMS, to the Space Station Processing Facility, where it will be prepared for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- Mark Sistilli, AMS Program Manager from NASA Headquarters speaks to the media before the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, while Trent Martin, AMS Project Manager from NASA's Johnson Space Center in Houston looks on. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Mark Sistilli, AMS Program Manager from NASA Headquarters looks on as Trent Martin, AMS Project Manager from NASA's Johnson Space Center in Houston speaks to the media prior to the arrival of the Alpha Magnetic Spectrometer, or AMS, to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, workers begin to offload an Alpha Magnetic Spectrometer, or AMS, section from an Air Force C-5M aircraft. A tractor-trailer will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a technician releases the bolts on a panel that protected the Alpha Magnetic Spectrometer, or AMS, during shipment. The Air Force C-5M flight crew that delivered AMS to Kennedy's Shuttle Landing Facility left their signatures and good wishes for the success of the mission on the panel. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, workers begin to offload the next section of the Alpha Magnetic Spectrometer, or AMS, from an Air Force C-5M aircraft. A tractor-trailer will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a tractor-trailer carrying the Alpha Magnetic Spectrometer, or AMS, is on its way to the Space Station Processing Facility, where it will be processed for launch. AMS arrived on Kennedy's Shuttle Landing Facility aboard an Air Force C-5M aircraft from Europe. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, workers begin to offload a section of the Alpha Magnetic Spectrometer, or AMS, from an Air Force C-5M aircraft. A tractor-trailer will transport the AMS from the Shuttle Landing Facility runway to the Space Station Processing Facility, where it will be processed for launch. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. AMS will fly to the International Space Station aboard space shuttle Endeavour's STS-134 mission, targeted to launch Feb. 26, 2011. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- The International Space Station Science and Technology Briefing was held in the Press Site auditorium at NASA's Kennedy Space Center in Florida. Speaking to media about the Alpha Magnetic Spectrometer-2 (AMS) are Mark Sistilli, NASA program manager (left); Saul Gonzales, AMS program manager from the U.S. Department of Energy and Professor Sam Ting, AMS-2 principal investigator at the Massachusetts Institute of Technology. Endeavour and its crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Launch is scheduled for April 29 at 3:47 p.m. EDT. 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 International Space Station Science and Technology Briefing was held in the Press Site auditorium at NASA's Kennedy Space Center in Florida. Speaking to media about the Alpha Magnetic Spectrometer-2 (AMS) is Professor Sam Ting, AMS-2 principal investigator at the Massachusetts Institute of Technology. Endeavour and its crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Launch is scheduled for April 29 at 3:47 p.m. EDT. 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 International Space Station Science and Technology Briefing was held in the Press Site auditorium at NASA's Kennedy Space Center in Florida. Speaking to media about the Alpha Magnetic Spectrometer-2 (AMS) are Mark Sistilli, NASA program manager (left); Saul Gonzales, AMS program manager from the U.S. Department of Energy and Professor Sam Ting, AMS-2 principal investigator at the Massachusetts Institute of Technology.Endeavour and its crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Launch is scheduled for April 29 at 3:47 p.m. EDT. 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 International Space Station Science and Technology Briefing was held in the Press Site auditorium at NASA's Kennedy Space Center in Florida. Speaking to media about the Alpha Magnetic Spectrometer-2 (AMS) is Saul Gonzales, AMS program manager from the U.S. Department of Energy. Endeavour and its crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Launch is scheduled for April 29 at 3:47 p.m. EDT. 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

Pilot Greg Johnson and Mission Specialist Mike Fincke of Space Shuttle Endeavour's final mission STS-134 come to Ames Research Center to share their experiences, answer questions and sign autographs during a afternoon with the staff.

Pilot Greg Johnson and Mission Specialist Mike Fincke of Space Shuttle Endeavour's final mission STS-134 come to Ames Research Center to share their experiences, answer questions and sign autographs during a afternoon with the staff.

Pilot Greg Johnson and Mission Specialist Mike Fincke of Space Shuttle Endeavour's final mission STS-134 come to Ames Research Center to share their experiences, answer questions and sign autographs during a afternoon with the staff. Astronauts Johnson and Fincke present photo to Ames Associate Director Steve Zornetzer.

STS-134 mission Commander Mark Kelly is seen preparing to enter space shuttle Endeavour on a monitor in Firing Room Four of the Launch Control Center (LCC), Monday, May 16, 2011, at the Kennedy Space Center in Cape Canaveral, Fla. During the mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Photo Credit: (NASA/Bill Ingalls)

The press site at the NASA Kennedy Space Center is seen as the sun rises a few hours prior to the launch of the space shuttle Endeavour with the STS-134 crew, Monday, May 16, 2011, in Cape Canaveral, Fla. During the mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. -- STS-134 Mission Specialists Mike Fincke, left, chats with STS-134 Assistant Launch Director Pete Nickolenko following the successful return of space shuttle Endeavour to NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The crew of space shuttle Endeavour's STS-134 mission to the International Space Station participates in a news conference in the Press Site auditorium at NASA's Kennedy Space Center in Florida on landing day. From left are Public Affairs Officer Candrea Thomas, STS-134 Commander Mark Kelly, Pilot Greg H. Johnson; Mission Specialists Michael Finke, Roberto Vittori, astronaut with the European Space Agency and Andrew Feustel. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Endeavour and its crew delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- The crew of space shuttle Endeavour's STS-134 mission to the International Space Station participates in a news conference in the Press Site auditorium at NASA's Kennedy Space Center in Florida on landing day. From left are STS-134 Commander Mark Kelly, Pilot Greg H. Johnson, Mission Specialists Michael Finke, Roberto Vittori, astronaut with the European Space Agency and Andrew Feustel. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. Endeavour and its crew delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Media snap photos and record the arrival of space shuttle Endeavour's STS-134 crew members on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. While at Kennedy, Endeavour's crew will participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training in preparation for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 19 at 7:48 p.m. EDT. 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 Greg Chamitoff greets Dana Hutcherson, space shuttle Endeavour's NASA flow manager, after arriving on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida aboard a T-38 jet. While at Kennedy, Endeavour's crew will participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training in preparation for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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. -- STS-134 Pilot Greg H. Johnson performs a walkdown of space shuttle Endeavour's payload bay. The Express Logistics Carrier-3 packed with spare parts and the Alpha Magnetic Spectrometer-2 (AMS) are inside the bay for the STS-134 mission to the International Space Station. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Endeavour is targeted to launch April 19 at 7:48 p.m. EDT on its final spaceflight mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

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. -- STS-134 Mission Specialists Drew Feustel, left, and Roberto Vittori with the European Space Agency, right, admire space shuttle Endeavour with NASA astronaut Randy Bresnik at NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-134 Mission Specialist Mike Fincke, left, Pilot Greg H. Johnson and Commander Mark Kelly talk with employees following the successful return of space shuttle Endeavour to NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-134 Commander Mark Kelly, left, and NASA Administrator Charlie Bolden chat with employees following the successful return of space shuttle Endeavour to NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Shuttle Launch Director Mike Leinbach, left, greets space shuttle Endeavour's STS-134 crew members following their successful trip home. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-134 Pilot Greg H. Johnson, left, and Commander Mark Kelly check out the nose of space shuttle Endeavour following the successful return to NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The crew members of space shuttle Endeavour's STS-134 mission undergo brief medical checks in the Crew Transport Vehicle before talking to media gathered on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- NASA Administrator Charlie Bolden, left, and NASA Kennedy Space Center Director Bob Cabana greet space shuttle Endeavour's STS-134 commander and pilot following their successful trip home. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Endeavour's STS-134 crew members talk with employees following their successful trip home. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, media and workers watch as the Alpha Magnetic Spectrometer (AMS) is offloaded from an Air Force C-5M aircraft on the Shuttle Landing Facility runway. One of NASA's T-38 training jets, flown by a member of the STS-134 crew, is in the foreground. The state-of-the-art particle physics detector arrived from Europe and will operate as an external module on the International Space Station to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, three of NASA's T-38 training jets sit on the parking apron of the Shuttle Landing Facility. The STS-134 crew members flew the jets to Kennedy to watch the Alpha Magnetic Spectrometer (AMS) arrive aboard an Air Force C-5M aircraft from Europe. The state-of-the-art particle physics detector will operate as an external module on the International Space Station to study the universe and its origin by searching for dark matter. AMS will fly to the station aboard space shuttle Endeavour's STS-134 mission targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- STS-134 Commander Mark Kelly, lying down, and Professor Sam Ting, Alpha Magnetic Spectrometer-2 (AMS) principal investigator at the Massachusetts Institute of Technology, perform a walkdown of space shuttle Endeavour's payload bay. The Express Logistics Carrier-3 packed with spare parts and the (AMS) are inside the bay for the STS-134 mission to the International Space Station. Endeavour's six crew members are at Kennedy for the launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Endeavour is targeted to launch April 19 at 7:48 p.m. EDT on its final spaceflight mission. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

S134-E-010781 (30 May 2011) --- This image provides a close-up view of the Alpha Magnetic Spectrometer - 2 (AMS-2) photographed from inside the orbiter's cabin shortly after the space shuttle Endeavour undocked from the International Space Station (ISS) at the end of the STS-134 mission. Photo credit: NASA

Pilot Greg Johnson and Mission Specialist Mike Fincke of Space Shuttle Endeavour's final mission STS-134 come to Ames Research Center to share their experiences, answer questions and sign autographs during a afternoon with the staff. With John W. 'Jack' Boyd on right.

CAPE CANAVERAL, Fla. -- Shuttle Launch Director Mike Leinbach, right, greets STS-134 Commander Mark Kelly, who arrived on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida aboard a T-38 jet. While at Kennedy, space shuttle Endeavour's crew will participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training in preparation for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- The American flag sways in the breeze as space shuttle Endeavour launches on the STS-134 mission to the International Space Station. The shuttle and its six-member crew lifted off from Launch Pad 39A at NASA's Kennedy Space Center in Florida on time at 8:56 a.m. EDT on May 16. STS-134 will deliver the Alpha Magnetic Spectrometer-2 (AMS), Express Logistics Carrier-3, a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Endeavour's first launch attempt on April 29 was scrubbed because of an issue associated with a faulty power distribution box called the aft load control assembly-2 (ALCA-2). STS-134 will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Troy Cryder

CAPE CANAVERAL, Fla. -- STS-134 Mission Specialist Michael Fincke prepares to depart the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida aboard a T-38 jet. While at Kennedy, space shuttle Endeavour's crew participated in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training. Fincke will return to NASA's Johnson Space Center in Houston to resume training for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 29 at 3:47 p.m. EDT. 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 stands in front of a T-38 jet on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. While at Kennedy, space shuttle Endeavour's crew will participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training in preparation for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 19 at 7:48 p.m. EDT. 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 arrives on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida aboard a T-38 jet. While at Kennedy, space shuttle Endeavour's crew will participate in a launch countdown dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) and related training in preparation for the upcoming STS-134 mission. Endeavour and its six STS-134 crew members 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 International Space Station. This will be the final spaceflight for Endeavour. Launch is targeted for April 19 at 7:48 p.m. EDT. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett