KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Pilot Christopher Ferguson checks his helmet during suitup before heading to the launch pad. Ferguson is making his first shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Joseph Tanner dons his launch and re-entry suit before heading to the launch pad. Tanner is making his fourth shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - During suitup in the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Daniel Burbank tests the communication system in his helmet. Burbank is making his second shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Joseph Tanner waits to complete suiting up before heading to the launch pad. Tanner is making his fourth shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Steven MacLean dons his launch and re-entry suit before heading to the launch pad. MacLean is with the Canadian Space Agency. MacLean is making his second shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Pilot Christopher Ferguson dons his launch and re-entry suit before heading to the launch pad. Ferguson is making his first shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Commander Brent Jett dons his launch and re-entry suit before heading to the launch pad. Jett is making his fourth shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Steven MacLean checks his glove during suitup before heading to the launch pad. MacLean is with the Canadian Space Agency. MacLean is making his second shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members stride out of the Operations and Checkout Building eager to get to Launch Pad 39B and the start of their mission to the International Space Station. This is the second attempt at launch after a week's postponement due to weather and technical concerns. On the left side, front to back, are Pilot Christopher Ferguson and Mission Specialists Steven MacLean and Heidemarie Stefanyshyn-Piper. On the right side, front to back, are Commander Brent Jett and Mission Specialists Daniel Burbank and Joseph Tanner. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Commander Brent Jett looks reflective as he suits up for launch before heading to the launch pad. Jett is making his fourth shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - In the Operations and Checkout Building at NASA Kennedy Space Center, STS-115 Mission Specialist Daniel Burbank adjusts his glove during suitup before heading to the launch pad. Burbank is making his second shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members walk toward the Astrovan that will take them to Launch Pad 39B. Seen left to right are Mission Specialists Heidemarie Stefanyshyn-Piper, Steven MacLean, Joseph Tanner and Daniel Burbank; Pilot Christopher Ferguson; and Commander Brent Jett. This is the second attempt at launch after a week's postponement due to weather and technical concerns. Atlantis is scheduled to lift off at 11:41 a.m. EDT on this date from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - STS-115 Mission Specialist Heidemarie Stefanyshyn-Piper waves during suitup in the Operations and Checkout Building at NASA Kennedy Space Center. She is making her first shuttle flight on this mission to the International Space Station aboard Space Shuttle Atlantis. On its second attempt for launch, Atlantis is scheduled to lift off at 11:41 a.m. EDT today from Launch Pad 39B. During the STS-115 mission, Atlantis' astronauts will deliver and install the 17.5-ton, bus-sized P3/P4 integrated truss segment on the station. The girder-like truss includes a set of giant solar arrays, batteries and associated electronics and will provide one-fourth of the total power-generation capability for the completed station. This mission is the 116th space shuttle flight, the 27th flight for orbiter Atlantis, and the 19th U.S. flight to the ISS. STS-115 is scheduled to last 11 days with a planned landing at KSC. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is being helped by the closeout crew is Mission Specialist Heidemarie Stefanyshyn-Piper. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is Mission Specialist Steven MacLean. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is Mission Specialist Daniel Burbank. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is Mission Specialist Joseph Tanner. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is Commander Brent Jett. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here is Pilot Christopher Ferguson. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann

KENNEDY SPACE CENTER, FLA. - The STS-115 crew members complete their suitup in the White Room before entering Space Shuttle Atlantis on Launch Pad 39B for a simulated launch countdown. Shown here are Mission Specialists Daniel Burbank (left) and Steven MacLean. The White Room, which is located at the end of the orbiter access arm, allows entry into the orbiter through the crew access hatch. The mission crew is at KSC for Terminal Countdown Demonstration Test (TCDT) activities that are preparation for launch. Liftoff of Atlantis is scheduled to take place in a window that opens Aug. 27. During their 11-day mission to the International Space Station, the STS-115 crew will continue construction of the station and attach the payload elements, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Jim Grossmann