CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media after the successful launch of space shuttle Endeavour on its STS-134 mission. From left are, Associate Administrator for Space Operations Bill Gerstenmaier; Michel Tognini, head of the European Astronaut Center and former ESA astronaut; Space Shuttle Program Launch Integration Manager Mike Moses; and Shuttle Launch Director Mike Leinbach. Endeavour lifted off May 16 at 8:56 a.m. EDT. 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 station. This is the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, staff for U.S. Congresswoman Gabielle Giffords brief media after the successful launch of space shuttle Endeavour on its STS-134 mission. From left are, Pia Carusone Chief of Staff, U.S. Rep. Gabrielle Giffords Office, Mark Kimble Press Advisor, U.S. Rep. Gabrielle Giffords Office and Ashley Nash-Hahn, New Media Strategist, U.S. Rep. Gabrielle Giffords Office. Giffords was on hand to watch her husband, STS-135 Commander Mark Kelly and his crew liftoff from Launch Pad 39A on Endeavour's final spaceflight. Endeavour lifted off May 16 at 8:56 a.m. EDT. 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 station. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- During the L-1 prelaunch news briefing in the Press Site auditorium at NASA's Kennedy Space Center in Florida, STS-134 Payload Mission Manager Joe Delai speaks to media about the processing and readiness of space shuttle Endeavour's payload for flight. 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_Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about their unanimous approval to proceed with space shuttle Endeavour's STS-134 mission. From left are Shuttle Weather Officer Kathy Winters, Shuttle Launch Director Mike Leinbach and Space Shuttle Program Launch Integration Manager Mike Moses. Endeavour's launch is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Ben Smegelsky

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about their unanimous approval to proceed with space shuttle Endeavour's STS-134 mission. From left, are NASA Public Affairs Officer Candrea Thomas, Space Shuttle Program Launch Integration Manager Mike Moses, Shuttle Launch Director Mike Leinbach and Shuttle Weather Officer Kathy Winters. Endeavour's launch is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Ben Smegelsky

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about their unanimous approval to proceed with space shuttle Endeavour's STS-134 mission. From left, are NASA Public Affairs Officer Candrea Thomas, Space Shuttle Program Launch Integration Manager Mike Moses, Shuttle Launch Director Mike Leinbach and Shuttle Weather Officer Kathy Winters. Endeavour's launch is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Ben Smegelsky

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about the launch status of space shuttle Endeavour's STS-134 mission. From left are NASA Public Affairs Officer Candrea Thomas, Space Shuttle Program Launch Integration Manager, Mike Moses, Shuttle Launch Director, Mike Leinbach, and Shuttle Weather Officer, Kathy Winters. 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. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about the launch status of space shuttle Endeavour's STS-134 mission. From left are NASA Public Affairs Officer Candrea Thomas, Space Shuttle Program Launch Integration Manager, Mike Moses, Shuttle Launch Director, Mike Leinbach, and Shuttle Weather Officer, Kathy Winters. 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. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media after space shuttle Endeavour's successful landing and conclusion of its STS-134 and final mission. From left are, Associate Administrator for Space Operations Bill Gerstenmaier, Space Shuttle Program Launch Integration Manager Mike Moses; and Shuttle Launch Director Mike Leinbach. 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/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, NASA managers brief media about the launch status of space shuttle Endeavour's STS-134 mission and announce a new launch date. From left are NASA News Chief Allard Beutel, Space Shuttle Program Launch Integration Manager, Mike Moses and Shuttle Launch Director Mike Leinbach. Technicians replaced and tested the aft load control assembly-2 (ALCA-2) and wiring located in Endeavour's aft avionics bay 5. ALCA-2 distributes power to nine shuttle systems and is believed to have caused fuel line heaters for Endeavour's auxiliary power unit-1 (APU-1) to fail April 29 during the first launch attempt. Launch now is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, Shuttle Launch Director Mike Leinbach briefs media about the launch status of space shuttle Endeavour's STS-134 mission and announces a new launch date. Technicians replaced and tested the aft load control assembly-2 (ALCA-2) and wiring located in Endeavour's aft avionics bay 5. ALCA-2 distributes power to nine shuttle systems and is believed to have caused fuel line heaters for Endeavour's auxiliary power unit-1 (APU-1) to fail April 29 during the first launch attempt. Launch now is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, Space Shuttle Program Launch Integration Manager Mike Moses briefs media about the launch status of space shuttle Endeavour's STS-134 mission and announces a new launch date. Technicians replaced and tested the aft load control assembly-2 (ALCA-2) and wiring located in Endeavour's aft avionics bay 5. ALCA-2 distributes power to nine shuttle systems and is believed to have caused fuel line heaters for Endeavour's auxiliary power unit-1 (APU-1) to fail April 29 during the first launch attempt. Launch now is scheduled for May 16 at 8:56 a.m. EDT. 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 station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller