CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Commander Chris Ferguson checks out shuttle Atlantis' cockpit. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Pilot Doug Hurley checks out shuttle Atlantis' cockpit. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, the STS-135 crew inspects shuttle Atlantis' payload bay. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Commander Chris Ferguson checks out shuttle Atlantis' cockpit. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Working behind the table are Mission Specialists Sandy Magnus, left, and Rex Walheim. Commander Chris Ferguson observes from the front of the table, as do technicians. STS-135 will carry the Raffaello multi-purpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Mission Specialist Sandy Magnus performs some hands-on tasks while Mission Specialist Rex Walheim, left, Commander Chris Ferguson, right, and technicians observe. STS-135 will carry the Raffaello multi-purpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Here, the four-member crew and technicians perform a walk down in the Raffaello multi-purpose logistics module, which will be packed with supplies, logistics and spare parts, bound for the International Space Station. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Standing in front of the Raffaello multi-purpose logistics module, which will be packed with supplies, logistics and spare parts for their mission to the International Space Station, are, from left, Pilot Doug Hurley, Mission Specialists Rex Walheim and Sandy Magnus, and Commander Chris Ferguson. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Standing in front of the Raffaello multi-purpose logistics module, which will be packed with supplies, logistics and spare parts for their mission to the International Space Station, are, from left, Commander Chris Ferguson, Mission Specialists Sandy Magnus and Rex Walheim, and Pilot Doug Hurley. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The purpose of CEIT is for flight crew members to become familiar with the hardware and tools they will work with in space. Here, a technician shows Mission Specialist Rex Walheim the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, which will be used to return a failed ammonia pump module from the International Space Station. Crews on Earth will examine the failure mechanism to help NASA improve pump designs for future systems. STS-135 also will carry the Raffaello multi-purpose logistics module packed with supplies, logistics and spare parts. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, the STS-135 crew inspect shuttle Atlantis' payload bay. From left are Mission Specialists Sandy Magnus and Rex Walheim; Pilot Doug Hurley and Commander Chris Ferguson. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialist Sandy Magnus along with technicians are inspecting the mid-deck of shuttle Atlantis. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the spacecraft and familiarization of the payload they'll deliver to the International Space Station. Atlantis and its payload is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialists Sandy Magnus and Rex Walheim, along with Pilot Doug Hurley (turned away from the camera), inspect shuttle Atlantis' payload bay. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialist Sandy Magnus inspects a tool she'll use in space. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use and familiarization of shuttle Atlantis' payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the STS-135 crew members inspect the cargo that will be loaded into shuttle Atlantis' payload bay. From left are Mission Specialists Rex Walheim and Sandy Magnus; and Commander Chris Ferguson. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialists Sandy Magnus and Rex Walheim check out equipment they'll work with on their upcoming mission. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use and familiarization of shuttle Atlantis' payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Commander Chris Ferguson checks out shuttle Atlantis' cockpit. Behind him is Pilot Doug Hurley. The four-member crew is at Kennedy to participate in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the tools and equipment they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Atlantis is being prepared for the STS-135 mission, which will deliver Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialist Sandy Magnus is inspecting the mid-deck of shuttle Atlantis. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the spacecraft and familiarization of the payload they'll deliver to the International Space Station. Atlantis and its payload is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialist Sandy Magnus crawls through a hatch with the aid of technicians while inspecting the mid-deck of shuttle Atlantis. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with the spacecraft and familiarization of the payload they'll deliver to the International Space Station. Atlantis and its payload is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Frankie Martin

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialist Rex Walheim takes a close look at a camera he'll work with while in space. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the STS-135 crew inspects the Raffaello multi-purpose logistics module with the carrier's technician. From left are Pilot Doug Hurley, Mission Specialist Sandy Magnus, Commander Chris Ferguson (upper level), a carrier technician and Mission Specialist Rex Walheim. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the STS-135 crew inspects the Raffaello multi-purpose logistics module with the carrier's technician. From left are Pilot Doug Hurley, Mission Specialist Sandy Magnus, Commander Chris Ferguson (upper level), a carrier technician and Mission Specialist Rex Walheim. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the STS-135 crew inspects the Raffaello multi-purpose logistics module with the carrier's technician. From left are Pilot Doug Hurley, Mission Specialist Sandy Magnus, Commander Chris Ferguson (upper level), a carrier technician and Mission Specialist Rex Walheim. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the STS-135 crew members enjoy a light moment while they inspect the equipment they'll work with while in space. From left are Mission Specialists Sandy Magnus and Rex Walheim; Pilot Doug Hurley and Commander Chris Ferguson (rear). The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, STS-135 Mission Specialists Sandy Magnus and Rex Walheim check out the equipment they'll work with while in space. The four-member crew is at Kennedy participating in the Crew Equipment Interface Test (CEIT), which gives them an opportunity for hands-on training with tools they'll use in space and familiarization of the payload they'll deliver to the International Space Station. Shuttle Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts to the station. Atlantis is targeted to launch June 28, and will be the last shuttle flight for the Space Shuttle Program. For more information visit, http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

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-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-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

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-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

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. Standing inside the Raffaello multi-purpose logistics module, which will be packed with supplies, logistics and spare parts for their mission to the International Space Station, are Mission Specialist Sandy Magnus (left), Commander Chris Ferguson, Mission Specialist Rex Walheim and Pilot Doug Hurley. The purpose of CEIT is for flight crew members to become familiar with the payload they will be working with and delivering to the station. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis' STS-135 crew participates in a crew equipment interface test, or CEIT, in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. Standing in front of the Raffaello multi-purpose logistics module, which will be packed with supplies, logistics and spare parts for their mission to the International Space Station, are, Pilot Doug Hurley (in profile left), and Commander Chris Ferguson (in profile right). The purpose of CEIT is for flight crew members to become familiar with the payload they will be working with and delivering to the station. STS-135 also will return a failed ammonia pump module on the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135, targeted to launch June 28, will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information visit, www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts135_index.html. Photo credit: NASA_Jim Grossmann

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

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-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

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-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