KENNEDY SPACE CENTER, FLA. - Crawler-transporter No. 2 nears Launch Pad 39B (in the background, right). The tip of the orange external tank can be seen above the rotating service structure surrounding the shuttle. The crawler is being moved nearby in the event the mission management team decides to roll back Space Shuttle Atlantis due to Hurricane Ernesto. The hurricane has been forecast on a heading north and east from Cuba, taking it along the eastern coast of Florida. NASA's lighted launch window extends to Sept. 13, but mission managers are hoping to launch on mission STS-115 by Sept. 7 to avoid a conflict with a Russian Soyuz rocket also bound for the International Space Station. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the crawler-transporter moves Space Shuttle Atlantis along the ramp and away from the rotating and fixed service structures, at right, on its rollback to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - The camera captures an optical illusion of a dragonfly above the reedy water near Launch Pad 39B seems to be heading for Space Shuttle Atlantis. The shuttle, sitting on the mobile launcher platform, is being moved off the pad by the crawler-transporter and rolling back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - From Launch Pad 39B, Space Shuttle Atlantis begins rolling back to the Vehicle Assembly Building. First motion was at 10:04 a.m. EDT. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the crawler-transporter moves Space Shuttle Atlantis away from the rotating and fixed service structures, at right, on its rollback to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - The crawler-transporter underneath Space Shuttle Atlantis and mobile launcher platform begins rolling away from Launch Pad 39B, taking the shuttle back to the Vehicle Assembly Building. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - The massive mobile launcher platform and Space Shuttle Atlantis above it nearly dwarf the crawler-transporter below them. The crawler alone is 20 feet high. The crawler is moving the Space Shuttle Atlantis and mobile launcher platform back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - One of the crawler engineers is seen inside the cab on the corner of the crawler transporter. The crawler is moving the Space Shuttle Atlantis and mobile launcher platform back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis reverses direction and begins rolling back out to Launch Pad 39B. It had been moved off the launch pad due to concerns about the impact of Tropical Storm Ernesto, expected within 24 hours. The forecast of lesser winds expected from Ernesto and its projected direction convinced Launch Integration Manager LeRoy Cain and Shuttle Launch Director Mike Leinbach to return the shuttle to the launch pad Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the crawler-transporter moves Space Shuttle Atlantis along the ramp and away from the rotating and fixed service structures, at right, on its rollback to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis reverses direction and begins rolling back out to Launch Pad 39B. It had been moved off the launch pad due to concerns about the impact of Tropical Storm Ernesto, expected within 24 hours. The forecast of lesser winds expected from Ernesto and its projected direction convinced Launch Integration Manager LeRoy Cain and Shuttle Launch Director Mike Leinbach to return the shuttle to the launch pad. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - Viewed from an upper level of the fixed service structure on Launch Pad 39B, Space Shuttle Atlantis begins rolling back to the Vehicle Assembly Building. First motion was at 10:04 a.m. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - Viewed from the NASA News Center across the turn basin in the Launch Complex 39 Area, Space Shuttle Atlantis continues its slow crawl toward the Vehicle Assembly Building from Launch Pad 39B. After this photo was taken, the decision was made to return the shuttle to the launch pad. The rollback was a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm was forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The revised forecast of lesser winds expected from Ernesto and its projected direction convinced Launch Integration Manager LeRoy Cain and Shuttle Launch Director Mike Leinbach to return the shuttle to the launch pad. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - A serene scene surrounds Space Shuttle Atlantis as it begins rolling off Launch Pad 39B to return to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - Reeds muddle the reflection of Space Shuttle Atlantis in the pond next to Launch Pad 39B. The shuttle is rolling back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the rotating service structure has been rolled away from Space Shuttle Atlantis, sitting on the mobile launcher platform. The crawler-transporter, which has moved underneath, will lift and carry both back to the Vehicle Assembly Building (VAB), approximately 4 miles away. Despite the clear blue skies, the rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the rotating service structure has been rolled away from Space Shuttle Atlantis, sitting on the mobile launcher platform. The crawler-transporter, which has moved underneath, will lift and carry both back to the Vehicle Assembly Building (VAB), approximately 4 miles away. Despite the clear blue skies, the rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - On the crawlerway, Space Shuttle Atlantis reverses direction and begins rolling back out to Launch Pad 39B. It had been moved off the launch pad due to concerns about the impact of Tropical Storm Ernesto, expected within 24 hours. The forecast of lesser winds expected from Ernesto and its projected direction convinced Launch Integration Manager LeRoy Cain and Shuttle Launch Director Mike Leinbach to return the shuttle to the launch pad. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - Crawler-transporter No. 2 makes its way toward Launch Pad 39B (in the background). The crawler is being moved nearby in the event the mission management team decides to roll back Space Shuttle Atlantis due to Hurricane Ernesto. The hurricane has been forecast on a heading north and east from Cuba, taking it along the eastern coast of Florida. NASA's lighted launch window extends to Sept. 13, but mission managers are hoping to launch on mission STS-115 by Sept. 7 to avoid a conflict with a Russian Soyuz rocket also bound for the International Space Station. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - Engineers keep watch on the crawler-transporter as it carries Space Shuttle Atlantis and the mobile launcher platform back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, a worker checks the progress of one of the corner bolts of the crawler-transporter that support the mobile launcher platform during transport. Space Shuttle Atlantis, which sits on top of the mobile launcher platform, will be rolled back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - Viewed from across pond near Launch Pad 39B, Space Shuttle Atlantis is framed by tree limbs as it begins rolling back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - Crawler-transporter No. 2 makes its way toward Launch Pad 39B (in the background). The tip of the orange external tank can be seen above the rotating service structure surrounding the shuttle. The crawler is being moved nearby in the event the mission management team decides to roll back Space Shuttle Atlantis due to Hurricane Ernesto. The hurricane has been forecast on a heading north and east from Cuba, taking it along the eastern coast of Florida. NASA's lighted launch window extends to Sept. 13, but mission managers are hoping to launch on mission STS-115 by Sept. 7 to avoid a conflict with a Russian Soyuz rocket also bound for the International Space Station. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - NASA's Kennedy Space Center has begun making preparations for the arrival of Tropical Storm Ernesto. Here workers are boarding up windows on the Operations and Support Building I in the Launch Complex 39 Area. The center has been in HURCON III status since Aug. 28, which means winds of 58 mph are expected within 48 hours. m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis continues its slow crawl toward the Vehicle Assembly Building from Launch Pad 39B. The rollback was a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm was forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. After this photo was taken, a revised forecast of lesser winds expected from Ernesto and its projected direction convinced Launch Integration Manager LeRoy Cain and Shuttle Launch Director Mike Leinbach to return the shuttle to the launch pad. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - A darkening cloud overhead keeps vigil as Space Shuttle Atlantis moves away from Launch Pad 39B on its rollback to the Vehicle Assembly Building. At right are the rotating and fixed service structures. First motion off the pad was at 10:04 a.m. EDT. The crawler is 131 feet long, 113 feet wide and 20 feet high. It weights 5.5 million pounds unloaded. The combined weight of crawler, mobile launcher platform and a space shuttle is 12 million pounds. Unloaded, the crawler moves at 2 mph. Loaded, the snail's pace slows to 1 mph. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Ken Thornsley

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the crawler-transporter (below) begins rolling away with its cargo above of the Space Shuttle Atlantis and mobile launcher platform. The shuttle is rolling back to the Vehicle Assembly Building. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. - NASA's Kennedy Space Center has begun making preparations for the arrival of Tropical Storm Ernesto. Here workers are boarding up windows on the Operations and Support Building I in the Launch Complex 39 Area. The center has been in HURCON III status since Aug. 28, which means winds of 58 mph are expected within 48 hours. m. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. - Equipment in areas of the Launch Control Center at NASA's Kennedy Space Center are wrapped in protective covers for the arrival of Tropical Storm Ernesto in Central Florida. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. - On Launch Pad 39B, the rotating service structure has been rolled away from Space Shuttle Atlantis, sitting on the mobile launcher platform. The crawler-transporter, which has moved underneath, will lift and carry both back to the Vehicle Assembly Building (VAB), approximately 4 miles away. Despite the clear blue skies, the rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis is reflected in the water near Launch Pad 39B. The rotating service structure has been rolled away in anticipation of the rollback of the shuttle and mobile launcher platform to the Vehicle Assembly Building (VAB), approximately 4 miles away. Despite the clear blue skies, the rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - Moved by the crawler-transporter underneath, Space Shuttle Atlantis inches down the ramp from Launch Pad 39B as it rolls back to the Vehicle Assembly Building. At right is the rotating service structure in its open configuration and the fixed service structure with the 80-foot lightning mast on top. First motion off the pad was at 10:04 a.m. EDT. The rollback is a safety precaution as the area waits for the arrival of Tropical Storm Ernesto. The storm is forecast to be bringing 58-mph to 70-mph winds in the next 24 hours. The shuttle will be moved into high bay 2, on the southwest side of the VAB, for protection from the storm. Photo credit: NASA/Jack Pfaller