JSC2011-E-059495 (31 May 2011) --- Thermal protection tiles are seen on the underside of the space shuttle Atlantis on Launch Pad 39A at NASA?s Kennedy Space Center in Florida May 31, 2011. The orbiter is scheduled to fly the final mission of the Space Shuttle Program, launching on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Space shuttle Discovery Commander Pam Melroy talks with NASA Administrator Michael Griffin and his wife, Rebecca Griffin, shortly after Melroy and the crew of STS-120 landed at NASA's Kennedy Space Center in Florida. Discovery landed at 1:02pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

JSC2011-E-067642 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059470 (31 May 2011) --- NASA astronaut Doug Hurley, STS-135 pilot, is seen in a partial silhouette against the space shuttle Atlantis as the spacecraft for the program's final mission moves to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida May 31, 2011. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067588 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-068007 (21 July 2011) --- Green paint marks the location where Atlantis' nose landing gear came to a stop on the runway after the space shuttle landed at the Kennedy Space Center in Florida on July 21, 2011. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067643 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040358 (7 April 2011) --- NASA astronaut Doug Hurley, STS-135 pilot, exits the hatch of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067589 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059409 (17 May 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, watches as the space shuttle Atlantis is moved from the Orbiter Processing Facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067691 (21 July 2011) --- Shuttle launch director Mike Leinbach, facing camera, hugs LeRoy Cain, deputy space shuttle program manager, after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the Space Shuttle Program. Photo credit: NASA/Houston Chronicle, Smiley N. Pool

In the firing room at NASA's Kennedy Space Center, NASA Associate Administrator, Chris Scolese and other managers watch the space shuttle Discovery launch the STS-120 mission, 11:38 a.m. EDT, October 23, 2007. Photo credit: "NASA/Bill Ingalls

JSC2011-E-059493 (31 May 2011) --- The space shuttle Atlantis is seen in the background on Launch Pad 39A at NASA?s Kennedy Space Center in Florida on May 31, 2011. The crawler/transporter is seen slowly driving away from the launch pad after making its final scheduled delivery of a shuttle. The orbiter is scheduled to fly the final mission of the Space Shuttle Program, launching on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040372 (8 April 2011) --- Technicians inspect the payload bay of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at NASA?s Kennedy Space Center, Florida on April 8, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Astronaut Scott Parazynski smiles for a photo while he and the crew of STS-120 walk around and look at the underside of the space shuttle Discovery shortly after their 1:01pm EST landing at NASA's Kennedy Space Center in Florida. Parazynski performed a repair of a damaged solar array during one of his spacewalks at the International Space Station. Photo Credit: "NASA/Bill Ingalls"

JSC2011-E-059478 (31 May 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, is seen in silhouette against the Vehicle Assembly Building as the space shuttle Atlantis moves to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040357 (7 April 2011) --- NASA astronauts Chris Ferguson (right), STS-135 commander; and Doug Hurley, pilot, pose for a photo on the cockpit of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The space shuttle Atlantis moves to Launch Pad 39A during rollout at the Kennedy Space Center on Tuesday, May 31, 2011, in Florida. ( NASA Photo / Houston Chronicle, Smiley N. Pool ).

as the space shuttle Atlantis moves to Launch Pad 39A at the Kennedy Space Center on Tuesday, May 31, 2011, in Florida. ( NASA Photo / Houston Chronicle, Smiley N. Pool ).

JSC2011-E-068002 (21 July 2011) --- Amidst a crowd, NASA astronaut Sandy Magnus, STS-135 mission specialist, is pictured with NASA Administrator Charles Bolden, right, and KSC Director Bob Cabana after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The space shuttle Atlantis moves to Launch Pad 39A during rollout at the Kennedy Space Center on Tuesday, May 31, 2011, in Florida. ( NASA Photo / Houston Chronicle, Smiley N. Pool ).

JSC2011-E-059418 (17 May 2011) --- The crew of STS-135, from right, Sandy Magnus, Doug Hurley, Chris Ferguson and Rex Walheim pose for a group photo as the space shuttle Atlantis (out of frame) is moved from the Orbiter Processing facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center in Florida on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-068008 (21 July 2011) --- Red paint marks the location where Atlantis' main landing gear came to a stop on the runway after the space shuttle landed at the Kennedy Space Center in Florida on July 21, 2011. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040349 (7 April 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, familiarizes himself with a camera he will use in space during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059482 (31 May 2011) --- A Shuttle Training Aircraft (STA) piloted by NASA astronaut Chris Ferguson, STS-135 commander, is seen against the late afternoon sun as the crew of the final space shuttle mission practices landings at NASA?s Kennedy Space Center in Florida May 31. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059634 (21 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, drives the M113 personnel carrier in a safety training exercise during the Terminal Countdown Demonstration Test (TCDT) at NASA?s Kennedy Space Center June 21, 2011. TCDT serves as the prelaunch countdown rehearsal for the final space shuttle mission, which is scheduled for launch on July 8. The M113 would be used in the event of an emergency at the pad forcing the crew to evacuate. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059490 (31 May 2011) --- The space shuttle Atlantis moves away from the Vehicle Assembly Building on its way to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida on May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-068015 (21 July 2011) --- A technician works to secure the space shuttle Atlantis following its landing at the Kennedy Space Center in Florida on July 21, 2011. The landing brought to completion STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

(left to right) NASA Administrator Michael Griffin, NASA Assistant Administrator for Public Affairs David Mould and NASA Space Shuttle Manager Wayne Hale watch as the space shuttle Discovery comes in for landing at NASA's Kennedy Space Center, Fla., completing the 15-day STS-120 mission to the International Space Station. Discovery landed at 1:01pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

In the firing room of the Kennedy Space Center in Florida, NASA Shuttle Launch Director Michael Leinbach (2nd from right) and launch managers watch the 11:38 a.m. EDT launch of Space Shuttle Discovery. Discovery launched Oct. 23 on a 14-day construction mission to the International Space Station. Photo credit: "NASA/Bill Ingalls"

JSC2011-E-067983 (21 July 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, is greeted by a KSC employee after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067611 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The space shuttle Discovery lands at NASA's Kennedy Space Center, Fla., completing the 15-day STS-120 mission to the International Space Station. Discovery landed at 1:01pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

JSC2011-E-067645 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067610 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059419 (17 May 2011) --- Photographers take pictures of the STS-135 crew as the space shuttle Atlantis is moved from the Orbiter Processing Facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067644 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059415 (17 May 2011) --- The space shuttle Atlantis is moved from the Orbiter Processing Facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059632 (21 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, participates in safety training in the M113 personnel carrier during the Terminal Countdown Demonstration Test (TCDT) at NASA?s Kennedy Space Center on June 21, 2011. TCDT serves as the prelaunch countdown rehearsal for the final space shuttle mission, which is scheduled for launch on July 8. The M113 would be used in the event of an emergency at the pad forcing the crew to evacuate. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059494 (31 May 2011) --- The space shuttle Atlantis is seen on Launch Pad 39A at NASA?s Kennedy Space Center on May 31, 2011, in Florida. The orbiter is scheduled to fly the final mission of the Space Shuttle Program, launching on July 8. Photo credit: NASA Photo / Houston Chronicle, Smiley N. Pool

JSC2011-E-067995 (21 July 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, makes a public statement as, from left, NASA Administrator Charles Bolden, along with NASA astronauts Rex Walheim, Sandy Magnus and Doug Hurley look on after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059484 (31 May 2011) --- A Shuttle Training Aircraft (STA) piloted by NASA astronaut Chris Ferguson, STS-135 commander, is seen against the late afternoon sun as the crew of the final space shuttle mission practices landings at NASA?s Kennedy Space Center in Florida May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040337 (7 April 2011) --- The STS-135 crew members participate in the Crew Equipment Interface Test (CEIT) in the Space Station Processing Facility at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040345 (7 April 2011) --- NASA astronauts Rex Walheim and Sandy Magnus, STS-135 mission specialists, inspect the front landing gear of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067997 (21 July 2011) --- NASA flight director Chris Edelen (far left foreground) looks up at the orbiter from under the starboard wing after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059488 (31 May 2011) --- The space shuttle Atlantis moves away from the Vehicle Assembly Building on its way to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida on May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040366 (8 April 2011) --- Close-up photo of tools taken during the STS-135 crew members' inspection of the equipment they will use in space. The inspection was part of the STS-135 Crew Equipment Interface Test (CEIT) conducted April 8, 2011 at NASA?s Kennedy Space Center in Florida. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059480 (31 May 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, is seen on May 31 in the rear station of a T-38 which had been piloted by astronaut Doug Hurley, STS-135 pilot, and is now sitting just off the runway following arrival at NASA?s Kennedy Space Center in Florida. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067612 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067590 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067640 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067976 (21 July 2011) --- The sun rises over the space shuttle Atlantis after landing July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059491 (31 May 2011) --- The space shuttle Atlantis moves to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida on May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040339 (7 April 2011) --- The STS-135 crew members pose for a group photo under the space shuttle Atlantis in the Orbiter Processing Facility during the Crew Equipment Interface Test (CEIT) at the Kennedy Space Center in Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059446 (31 May 2011) --- The crew of the space shuttle Atlantis, from left, commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandy Magnus and Rex Walheim address a news conference as the shuttle moves to Launch Pad 39A during rollout at NASA?s Kennedy Space Center in Florida on May 31, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040371 (8 April 2011) --- NASA astronauts, from left, Rex Walheim, Chris Ferguson and Doug Hurley inspect the middeck of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at the Kennedy Space Center in Florida, April 8, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The space shuttle Discovery lands at NASA's Kennedy Space Center, Fla., completing the 15-day STS-120 mission to the International Space Station. Discovery landed at 1:01pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

JSC2011-E-068012 (21 July 2011) --- Milt Heflin, associate director (technical) of the Johnson Space Center, stands under the wing of the space shuttle Atlantis after it landed on July 21, 2011 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067613 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Space shuttle Discovery Commander Pam Melroy talks with NASA Administrator Michael Griffin and his wife, Rebecca Griffin, shortly after Melroy and the crew of STS-120 landed at NASA's Kennedy Space Center in Florida. Discovery landed at 1:02pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

JSC2011-E-059411 (17 May 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, watches as the space shuttle Atlantis is moved May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

NASA astronaut Chris Ferguson, STS-135 commander, examines the thermal tiles of the orbiter after the space shuttle Atlantis landed at the Kennedy Space Center in Florida completing STS-135, the final mission of the NASA shuttle program, on Thursday, July 21, 2011. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-040348 (7 April 2011) --- A technician uses binoculars to look over the space shuttle Atlantis as the crew of STS-135 uses a basket/carrier to inspect Atlantis' payload bay during the STS-135 Crew Equipment Interface Test (CEIT) at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067609 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059636 (21 June 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, participates in safety training in the M113 personnel carrier during the Terminal Countdown Demonstration Test (TCDT) at NASA?s Kennedy Space Center on June 21, 2011. TCDT serves as the prelaunch countdown rehearsal for the final space shuttle mission, which is scheduled for launch on July 8. The M113 would be used in the event of an emergency at the pad forcing the crew to evacuate. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067975 (21 July 2011) --- The sun rises over the space shuttle Atlantis after landing July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067587 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040343 (7 April 2011) --- NASA astronaut Doug Hurley, STS-135 pilot, looks at the thermal protection system on the underside of the space shuttle Atlantis during the mission's Crew Equipment Interface Test (CEIT) at the Kennedy Space Center in Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040338 (7 April 2011) --- NASA astronauts Sandy Magnus and Rex Walheim, both STS-135 mission specialists, work in the Multi-Purpose Logistics Module in the Space Station Processing Facility during the STS-135 Crew Equipment Interface Test (CEIT) at the Kennedy Space Center in Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059420 (17 May 2011) --- NASA astronauts Chris Ferguson, left, and Rex Walheim walk past the space shuttle Atlantis as it is moved from the Orbiter Processing Facility to the Vehicle Assembly Building at NASA?s Kennedy Space Center on May 17, 2011. The move, known as rollover, is a milestone in the preparation for launch as the orbiter leaves its processing hangar to be prepped for its final flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Astronaut Scott Parazynski smiles for a photo while he and the crew of STS-120 walk around and look at the underside of the space shuttle Discovery shortly after their 1:01pm EST landing at NASA's Kennedy Space Center in Florida. Parazynski performed a repair of a damaged solar array during one of his spacewalks at the International Space Station. Photo Credit: "NASA/Bill Ingalls"

JSC2011-E-040373 (8 April 2011) --- Technicians inspect the payload bay of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) in the Orbiter Processing Facility at NASA?s Kennedy Space Center in Florida on April 8, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040346 (7 April 2011) --- NASA astronauts Chris Ferguson, STS-135 commander; and Doug Hurley, pilot, inspect the front landing gear of the space shuttle Atlantis during the STS-135 Crew Equipment Interface Test (CEIT) at NASA?s Kennedy Space Center, Florida on April 7, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059628 (21 June 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, laughs with his crew members before safety training in the M113 personnel carrier during the Terminal Countdown Demonstration Test (TCDT) at NASA?s Kennedy Space Center on June 21, 2011. TCDT serves as the prelaunch countdown rehearsal for the final space shuttle mission, which is scheduled for launch on July 8. The M113 would be used in the event of an emergency at the pad forcing the crew to evacuate. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

(left to right) NASA Administrator Michael Griffin, NASA Assistant Administrator for Public Affairs David Mould and NASA Space Shuttle Manager Wayne Hale watch as the space shuttle Discovery comes in for landing at NASA's Kennedy Space Center, Fla., completing the 15-day STS-120 mission to the International Space Station. Discovery landed at 1:01pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

JSC2011-E-067608 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067641 (8 July 2011) --- The space shuttle Atlantis launches for the STS-135 mission to the International Space Station in the final mission of the Space Shuttle Program at NASA?s Kennedy Space Center in Florida. Liftoff was at 11:29 a.m. (EDT) on July 8, 2011. Onboard are NASA astronauts Chris Ferguson, STS-135 commander; Doug Hurley, pilot; Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067687 (21 July 2011) --- The drag chute is deployed as the space shuttle Atlantis lands on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-068004 (21 July 2011) --- KSC director Bob Cabana, center frame, congratulates members of the damage assessment team after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing marked the completion of STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool