JSC2011-E-068761 (22 July 2011) --- A small portion of a large Ellington Field crowd is seen on July 22, 2011 through a door bearing a STS-135 sticker on its window. A short while later the crew of the space shuttle Atlantis' mission used this door for its entrance during a welcome home ceremony. STS-135 is the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040206 (10 March 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, sits in a hyperbaric chamber as he undergoes high altitude training March 10, 2011 at the Sonny Carter Training Facility near the Johnson Space Center in Houston. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060138 (29 June 2011) --- NASA astronaut Chris Ferguson crawls out of the Crew Compartment Trainer (CCT-2) as the crew of STS-135 trains at NASA?s Johnson Space Center June 29, 2011. The training marked the crew's final scheduled session in the Space Vehicle Mock-up Facility. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

NASA astronaut Rex Walheim is lowered into the water to train for spacewalk in the Neutral Buoyancy Laboratory (NBL) on Tuesday, March 22, 2011, in Houston. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-060794 (30 June 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, points to acknowledge a reporter while greeting the media along with NASA astronauts Doug Hurley, pilot, and Sandy Magnus and Rex Walheim, both mission specialists, during the STS-135 crew media briefing at NASA?s Johnson Space Center June 30, 2011. The press conference provided the last scheduled opportunity for a large group of press to speak with the crew before the final launch on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040220 (10 March 2011) --- NASA astronaut Rex Walheim (left), STS-135 mission specialist, and astronaut Mike Fossum are aided by divers as they work in a mock-up of the space shuttle's payload bay as the crew of STS-135 trains for a spacewalk in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center on March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-068773 (22 July 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, listens as a crewmate addresses the crowd during a July 22 welcome home ceremony for the crew of the space shuttle Atlantis at Ellington Field in Houston. STS-135 is the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060132 (29 June 2011) --- NASA astronaut Doug Hurley crawls out of the Crew Compartment Trainer (CCT-2) mock-up while Rex Walheim waits as the crew of STS-135 trains in the Space Vehicle Mock-up Facility (SVMF) at NASA?s Johnson Space Center June 29, 2011. The training marked the crew's final scheduled session in JSC's Shuttle Vehicle Mock-up Facility. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060797 (30 June 2011) --- Commander Chris Ferguson, pilot Doug Hurley, mission specialist Sandy Magnus and mission specialist Rex Walheim participate in the STS-135 crew media briefing at NASA?s Johnson Space Center June 30, 2011. The press conference provided the last scheduled opportunity for a large group of press to speak with the crew before the final launch on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040269 (24 March 2011) --- The crew members of STS-135 are briefed by trainers before they participate in a post-insertion training session in the Full-Fuselage Trainer in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060793 (30 June 2011) --- The crew of STS-135, from left, pilot Doug Hurley, mission specialists Rex Walheim and Sandy Magnus, and commander Chris Ferguson pose for a group photo following the crew media briefing at the Johnson Space Center in Houston on June 30, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-205596 (2 Nov. 2011) --- The current and former astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo at the Johnson Space Center in Houston on Nov. 2, 2011. They are, from left, John Young, STS-1 commander, Robert Crippen, STS-1 pilot, with the STS-135 crew of commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067680 (12 July 2011) --- This is an overall view of the wiring for the simulated shuttle payload bay in the Shuttle Avionics Integration Laboratory (SAIL) at the Johnson Space Center in Houston on July 12, 2011. The laboratory is a skeletal avionics version of the shuttle that uses actual orbiter hardware and flight software. The facility even carries the official orbiter designation as Orbiter Vehicle 095. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-205613 (2 Nov. 2011) --- The current and former astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo at the Johnson Space Center in Houston on Nov. 2, 2011. They are, from left, Doug Hurley, STS-135 pilot, Robert Crippen, STS-1 pilot, John Young, STS-1 commander, with STS-135 commander Chris Ferguson, and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040211 (10 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, prepares to train in the Neutral Buoyancy Laboratory (NBL) near NASA?s Johnson Space Center in Houston March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040273 (24 March 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, is reflected in a mirror before participating in a post-insertion training session in the Full-Fuselage Trainer in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040335 (4 April 2011) --- NASA astronauts Rex Walheim, right, Sandy Magnus, foreground, both mission specialists, and Doug Hurley, pilot, work on the flight deck as the crew of STS-135 trains in the Fixed Base Simulator at NASA?s Johnson Space Center in Houston April 4, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040284 (24 March 2011) --- NASA astronauts Doug Hurley and Sandy Magnus set up the middeck in the Full-Fuselage Trainer as the crew of STS-135 participates in a post insertion training session March 24, 2011 in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston. Hurley is the pilot and Magnus is one of two mission specialists assigned to the flight. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040267 (23 March 2011) --- NASA astronauts Chris Ferguson, STS-135 commander; Sandy Magnus, mission specialist; and Doug Hurley, pilot, are interviewed by a crowd of media in the Systems Engineering Simulator at NASA?s Johnson Space Center on March 23, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040218 (10 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is aided by divers as he works with astronaut Mike Fossum in a mock-up of the space shuttle's payload bay as the crew of STS-135 trains for a spacewalk in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center on March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040209 (10 March 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, takes a photo of himself with astronaut Mike Fossum before the crew of the final shuttle mission trains March 10, 2011 in the Neutral Buoyancy Laboratory near the Johnson Space Center in Houston. Fossum will fly to the International Space Station aboard a Russian Soyuz spacecraft scheduled for launch in May and will serve as flight engineer for Expedition 28 and as commander for Expedition 29. Since the crew of the final shuttle mission will consist of only four astronauts, the ISS crew will perform the mission's single scheduled spacewalk, and the crew of STS-135 will function in support of the EVA, with Rex Walheim serving as the internally-based 'quarterback' for the spacewalk. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

A large crowd of supporters welcomes home the crew of STS-135 during a ceremony for the crew of the space shuttle Atlantis, the final mission of the NASA shuttle program, at Ellington Field in Houston on Friday, July 22, 2011. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-059397 (13 May 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, simulates a spacewalk in the Virtual Reality Laboratory at NASA?s Johnson Space Center May 13, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059386 (11 May 2011) --- In this high-angle wide shot, STS-135 flight director Kwatsi Alibaruho, (center with back toward camera), and astronaut Steve Robinson (center, facing camera), CAPCOM, work in the Mission Control Center at NASA?s Johnson Space Center during a simulation exercise with the crew on May 11, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040286 (24 March 2011) --- NASA astronauts Sandy Magnus, STS-135 mission specialist, and Chris Ferguson, commander, are seen through a hatch as the crew of STS-135 debriefs after a post-insertion training session in the Full-Fuselage Trainer in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center on March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-205619 (2 Nov. 2011) --- The current and former astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo at the Johnson Space Center in Houston on Nov. 2, 2011. They are, from left, Doug Hurley, STS-135 pilot, Robert Crippen, STS-1 pilot, John Young, STS-1 commander, with STS-135 commander Chris Ferguson, and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040270 (24 March 2011) --- NASA astronaut Chris Ferguson, left, STS-135 commander, dons his training version of a shuttle launch and entry suit before participating in a post-insertion training session with NASA astronauts Doug Hurley, pilot, and Sandy Magnus, mission specialist, March 24, 2011, in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston. Hurley and Magnus are wearing their liquid-cooled undergarments for the orange suit. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The crew of STS-135, from left, Doug Hurley, Chris Ferguson, Sandy Magnus and Rex Walheim walk between buildings at the Johnson Space Center after a simulation in the motion based simulator on Friday, May 6, 2011, in Houston. ( NASA Photo / Houston Chronicle, Smiley N. Pool ).

JSC2011-E-060141 (29 June 2011) --- NASA astronauts Sandy Magnus and Chris Ferguson practice setup of an exercise ergometer as the crew of STS-135 trains in the Crew Compartment Trainer (CCT) mock-up at NASA?s Johnson Space Center in Houston June 29, 2011. The training marked the crew's final scheduled session in the Space Vehicle Mock-up Facility. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060800 (30 June 2011) --- The STS-135 crew meets with the Johnson Space Center public affairs team before the crew's media briefing at NASA?s Johnson Space Center in Houston on June 30, 2011. The press conference provided the last scheduled opportunity for a large group of press to speak with the crew before the final launch on July 8. Shown, from left, are Rob Navias and James Hartsfield of public affairs, and NASA astronauts Sandy Magnus, Rex Walheim, Chris Ferguson and Doug Hurley. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040215 (10 March 2011) --- A bank of video screens shows the progress of a simulated spacewalk as the crew of STS-135 trains in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center in Houston March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060128 (29 June 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, left, looks out over the Space Vehicle Mock-up Facility (SVMF) after the crew of the final shuttle mission trained in the facility at NASA?s Johnson Space Center in Houston on June 29, 2011. The training marked the crew's final scheduled session in the SVMF. NASA astronaut Sandy Magnus, mission specialist, is in background at center. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067674 (12 July 2011) --- Chris St. Julian, left, a Prairie View A&M electrical engineering major who is interning at NASA for the summer, pilots the shuttle for a simulated landing in the Shuttle Avionics Integration Laboratory (SAIL) at the Johnson Space Center in Houston, July 12, 2011. The laboratory is a skeletal avionics version of the shuttle that uses actual orbiter hardware and flight software. The facility bears the orbiter designation of Orbiter Vehicle 095. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059389 (11 May 2011) --- Astronaut Steve Robinson, STS-135 CAPCOM, works in the Mission Control Center at NASA?s Johnson Space Center during a simulation exercise with the crew on May 11, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060798 (30 June 2011) --- The STS-135 crew, from left, mission specialists Sandy Magnus and Rex Walheim, commander Chris Ferguson and pilot Doug Hurley follow Public Affairs Officer Nicole Cloutier-Lemasters to begin a crew media briefing at NASA?s Johnson Space Center on June 30, 2011. The press conference provided the last scheduled opportunity for a large group of press to speak with the crew before the final launch on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040281 (24 March 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, works on the middeck of the Full-Fuselage Trainer during a post-insertion training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center on March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040272 (24 March 2011) --- Suit technicians assist the crew of STS-135 in donning their training versions of a shuttle launch and entry suit before they participate in a post-insertion training session in the Full-Fuselage Trainer in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston March 24, 2011. From left are NASA astronauts Doug Hurley, pilot, along with Sandy Magnus and Rex Walheim, both mission specialists. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

STS-135 pilot Doug Hurley signs a welcome home banner before a welcome home ceremony for the crew of the space shuttle Atlantis, the final mission of the NASA shuttle program, at Ellington Field in Houston on Friday, July 22, 2011. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-205603 (2 Nov. 2011) --- The current and former astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo at the Johnson Space Center in Houston on Nov. 2, 2011. They are, from left, John Young, STS-1 commander, Robert Crippen, STS-1 pilot, with the STS-135 crew of commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060135 (29 June 2011) --- The crew of STS-135, from left, Chris Ferguson, Rex Walheim, Doug Hurley and Sandy Magnus, review procedures on the middeck of the Crew Compartment Trainer (CCT) mock-up as they train at NASA?s Johnson Space Center in Houston on June 29, 2011. The training marked the crew's final scheduled session in the Space Vehicle Mock-up Facility. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040221 (10 March 2011) --- NASA astronaut Mike Fossum is aided by divers as he trains for a spacewalk with astronaut Rex Walheim, STS-135 mission specialist, in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center on March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

NASA astronauts Rex Walheim, Doug Hurley and Chris Ferguson work on computers in an exercises to overcome a power loss on the International Space Station as the crew of STS-135, the final space shuttle mission, trains in the Space Station Training Facility at the Johnson Space Center on Thursday, May 19, 2011, in Houston. ( NASA Photo / Houston Chronicle, Smiley N. Pool ).

JSC2011-E-205608 (2 Nov. 2011) --- The current and former astronauts who formed the crews of STS-1, the first space shuttle mission, and STS-135, the final shuttle mission, pose for a group photo in a training facility at the Johnson Space Center in Houston on Nov. 2, 2011. They are, from left, Doug Hurley, STS-135 pilot, Robert Crippen, STS-1 pilot, John Young, STS-1 commander, with STS-135 commander Chris Ferguson, and mission specialists Sandy Magnus and Rex Walheim. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059424 (19 May 2011) --- The crew of STS-135, the final space shuttle mission, trains in the Space Station Training Facility at NASA?s Johnson Space Center May 19, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067676 (12 July 2011) --- A close-up view of controls and displays on the forward flight deck of OV-095 in the Shuttle Avionics Integration Laboratory (SAIL) at the Johnson Space Center in Houston, July 12, 2011. The laboratory is a skeletal avionics version of the shuttle that uses actual orbiter hardware and flight software. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

NASA astronaut Sandy Magnus is helped out of her training EMU after training for spacewalk in the Neutral Buoyancy Laboratory (NBL) on Tuesday, March 22, 2011, in Houston. In the background, a test is performed on the Orion capsule. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-040217 (10 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is aided by divers as he works with astronaut Mike Fossum in a mock-up of the space shuttle's payload bay as the crew of STS-135 trains for a spacewalk in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center on March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-067679 (12 July 2011) --- This is an overall view of the wiring for the simulated shuttle payload bay in the Shuttle Avionics Integration Laboratory (SAIL) at the Johnson Space Center in Houston on July 12, 2011. The laboratory is a skeletal avionics version of the shuttle that uses actual orbiter hardware and flight software. The facility even carries the official orbiter designation as Orbiter Vehicle 095. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040219 (10 March 2011) --- NASA astronaut Rex Walheim (left), STS-135 mission specialist, and astronaut Mike Fossum are aided by divers as they work in a mock-up of the space shuttle's payload bay as the crew of STS-135 trains for a spacewalk in the Neutral Buoyancy Laboratory near NASA?s Johnson Space Center on March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060140 (29 June 2011) --- NASA astronaut Rex Walheim laughs with his crewmates as STS-135 commander Chris Ferguson gets a refresher on the use of the waste management system on the International Space Station as the crew trains at NASA?s Johnson Space Center June 29, 2011. The day's training marked the crew's final scheduled sessions in the Space Vehicle Mock-up Facility at JSC. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

A large crowd of supporters welcomes home the crew of STS-135 during a ceremony for the crew of the space shuttle Atlantis, the final mission of the NASA shuttle program, at Ellington Field in Houston on Friday, July 22, 2011. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-067682 (12 July 2011) --- Chief engineer Frank Svrecek pauses in the Shuttle Avionics Integration Laboratory (SAIL) at the Johnson Space Center in Houston July 12, 2011. The laboratory is a skeletal avionics version of the shuttle that uses actual orbiter hardware and flight software. The facility is referred to as Orbiter Vehicle 095. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059375 (4 May 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, plays the drums with the all-astronaut band known as Max Q as the group performs on Innovation Day at NASA?s Johnson Space Center in Houston May 4, 2011. Vocalist Tracy Caldwell Dyson is at left. Guitarist Drew Feustel is at right. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

NASA astronaut Sandy Magnus waves as she is lowered into the water to train for spacewalk in the Neutral Buoyancy Laboratory (NBL) on Tuesday, March 22, 2011, in Houston. ( NASA Photo / Houston Chronicle, Smiley N. Pool )

JSC2011-E-040278 (24 March 2011) --- Rob Tomaro, crew systems instructor, works with NASA astronaut Sandy Magnus, STS-135 mission specialist, on the middeck of the Full-Fuselage Trainer during a post-insertion training session in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center on March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040265 (23 March 2011) --- A long parade of media is escorted between buildings at NASA?s Johnson Space Center in Houston for a media availability with the crew of STS-135 in the Systems Engineering Simulator March 23, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060133 (29 June 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, walks past the Full Fuselage Trainer (FFT) as the crew of STS-135 trains in the Space Vehicle Mock-up Facility (SVMF) at NASA?s Johnson Space Center in Houston on June 29, 2011. The training marked the crew's final scheduled session in the SVMF. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060796 (30 June 2011) --- Reporter Mark Carreau of Aviation Week takes notes during the STS-135 crew media briefing at NASA?s Johnson Space Center on June 30, 2011. The press conference provided the last scheduled opportunity for a large group of press to speak with the crew before the final launch on July 8. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-040277 (24 March 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, practices the use of a digital camera with a long telephoto lens as she participates in a post-insertion training session in the Full-Fuselage Trainer in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center in Houston March 24, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-059611 (24 June 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, leans out around pilot Doug Hurley, left, to confer with commander Chris Ferguson (out of frame) as the crew of the final space shuttle mission participates in the STS-135 Flight Data File (FDF) review at NASA?s Johnson Space Center June 24, 2011. The review involves examining and annotating more than 200 procedure books and cue cards that comprise all of the detailed technical steps that will be performed during the mission. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060127 (28 June 2011) --- The STS-135 crew practices rendezvous and docking with the International Space Station in the Systems Engineering Simulator at NASA?s Johnson Space Center in Houston June 28, 2011. NASA astronaut Chris Ferguson, commander, is at back left, and astronaut Rex Walheim, mission specialist, is at back right; and astronaut Doug Hurley, pilot, is at center. The session marked the crew's final scheduled training in the "Dome" in preparation for the final mission of the Space Shuttle Program. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool

JSC2011-E-060144 (29 June 2011) --- NASA astronaut Doug Hurley, STS-135 pilot, walks up the stairs to the Crew Compartment Trainer (CCT) mock-up as the crew of STS-135 trains June 29, 2011 at NASA?s Johnson Space Center, Houston. The training marked the crew's final scheduled session in the Space Vehicle Mock-up Facility. Photo credit: NASA photo/Houston Chronicle, Smiley N. Pool