CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, moves past the Launch Control Center at NASA's Kennedy Space Center in Florida as it rolls out to Launch Pad 39B. First motion was at 11:57 p.m. EDT April 16. The 4.2-mile journey is expected to take approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, moves along the crawlerway at NASA's Kennedy Space Center in Florida as it rolls out to Launch Pad 39B. First motion out of the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. The 4.2-mile journey is expected to take approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, moves out of the Vehicle Assembly Building for rollout to Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion was at 11:57 p.m. EDT April 16. The 4.2-mile journey is expected to take approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, arrives on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion out of the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. The 4.2-mile journey took approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, moves out of the Vehicle Assembly Building for rollout to Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion was at 11:57 p.m. EDT April 16. The 4.2-mile journey is expected to take approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Just before dawn, space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, is on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion out of the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. The shuttle was secure on the pad at 7:17 a.m. EDT April 17. On the left of the shuttle is the White Room at the end of the orbiter access arm, 147 feet above the pad. When in place against the shuttle, the White Room provides access into the crew compartment on the shuttle. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, moves along the crawlerway at NASA's Kennedy Space Center in Florida as it rolls out to Launch Pad 39B. First motion was at 11:57 p.m. EDT April 16. The 4.2-mile journey is expected to take approximately 7 hours. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Dawn's early light reveals space shuttle Endeavour secure on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion of the rollout from the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour stands tall and proud on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion of Endeavour's rollout from the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Surrounding the pad (seen left and right) are the new lightning towers erected for NASA's Constellation Program, which will use the pad for Ares rocket launches. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Just before dawn, space shuttle Endeavour, installed on the mobile launcher platform atop the crawler-transporter, is secure on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion out of the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour stands tall and proud on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion of Endeavour's rollout from the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – The rising sun begins to cast its glow over space shuttle Endeavour on Launch Pad 39B at NASA's Kennedy Space Center in Florida. Behind the shuttle is the new lightning tower erected for NASA's Constellation Program, which will use the pad for Ares rocket launches. First motion of Endeavour's rollout from the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. – Space shuttle Endeavour stands tall and proud on Launch Pad 39B at NASA's Kennedy Space Center in Florida. First motion of Endeavour's rollout from the Vehicle Assembly Building was at 11:57 p.m. EDT April 16. Surrounding the pad (seen left and right) are the new lightning towers erected for NASA's Constellation Program, which will use the pad for Ares rocket launches. Endeavour will be prepared on the pad for liftoff in the unlikely event that a rescue mission is necessary following space shuttle Atlantis' launch on the STS-125 mission to service NASA's Hubble Space Telescope. After Atlantis is cleared to land, Endeavour will move to Launch Pad 39A for its upcoming STS-127 mission to the International Space Station, targeted to launch June 13. Photo credit: NASA/Jack Pfaller