CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Christopher Cassidy checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Tim Kopra checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Tim Kopra puts on the helmet for his launch-and-entry suit. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Pilot Doug Hurley checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Tom Marshburn puts on his launch-and-entry suit. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Pilot Doug Hurley puts on his launch-and-entry suit. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Julie Payette is helped with her launch-and-entry suit. She and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Julie Payette checks the communication system in her helmet. She and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Dave Wolf checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Commander Mark Polansky checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Christopher Cassidy puts on his launch-and-entry suit. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Tom Marshburn checks the communication system in his helmet. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Dave Wolf puts on his launch-and-entry suit. He and other crew members will be heading for Launch Pad 39A for a simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Kim Shiflett