KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Mission Specialist Robert L. Behnken looks over the payload in space shuttle Endeavour's payload bay. He and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 crew members look at hardware in space shuttle Endeavour's payload bay. From left are Mission Specialist Garrett Reisman and Robert L. Behnken and Commander Dominic Gorie. The STS-123 crew is at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Mission Specialists Garrett Reisman (left) and Robert L. Behnken look over the payload in space shuttle Endeavour's payload bay. They and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Commander Dominic Gorie takes a close look at the payload in space shuttle Endeavour's payload bay. He and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Mission Specialist Robert L. Behnken (left) and Pilot Gregory Johnson look over the payload in space shuttle Endeavour's payload bay. They and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Mission Specialist Rick Linnehan photographs some of the payload in space shuttle Endeavour's payload bay. He and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Mission Specialist Takao Doi looks over the payload in space shuttle Endeavour's payload bay. Doi represents the Japan Aerospace and Exploration Agency, or JAXA. He and other STS-123 crew members are at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 crew members get a close look at the payload in space shuttle Endeavour's payload bay. At right, Pilot Gregory Johnson photographs the hardware. The STS-123 crew is at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 crew members look up at the docking system in space shuttle Endeavour's payload bay. The STS-123 crew is at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- On NASA Kennedy Space Center's Launch Pad 39A, STS-123 Pilot Gregory H. Johnson is harnessed and tethered while looking at hardware in space shuttle Endeavour's payload bay. The STS-123 crew is at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. The TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Endeavour is targeted to launch March 11 at 2:28 a.m. EDT on the 16-day STS-123 mission to the International Space Station. Endeavour and its crew will deliver the first section of the Japan Aerospace Exploration Agency's Kibo laboratory and the Canadian Space Agency's two-armed robotic system, Dextre. Photo credit: NASA/Kim Shiflett