NASA astronaut Rex Walheim checks out the Dragon spacecraft und

HAWTHORNE, Calif. -- NASA astronaut Rex Walheim checks out the Dragon spacecraft under development by Space Exploration Technologies SpaceX of Hawthorne, Calif., for the agency's Commercial Crew Program. In 2011, NASA selected SpaceX during Commercial Crew Development Round 2 CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Six other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. ATK, The Boeing Co., Excalibur Almaz Inc., Blue Origin, Sierra Nevada, and United Launch Alliance ULA. For more information, visit www.nasa.gov/commercialcrew. Image credit: Space Exploration Technologies

S135-E-009344 (18 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, takes an opportunity to get the best view of Earth from aboard the International Space Station as he moves inside the Cupola. Walheim and three crewmates were in the last hours of their stay of over one week onboard the orbiting complex. Photo credit: NASA

Walheim in the Cupola

Walheim during EVA 3

ISS016-E-029502 (15 Feb. 2008) --- Astronaut Rex Walheim, mission specialist, holds onto a handrail and spreads his arms at the Columbus laboratory, the newest piece of hardware on the International Space Station. On this the final spacewalk for the STS-122 Atlantis crew, Walheim's pose is reminiscent of that of a musical conductor who has just completed leading a successful concert. Stanley Love (out of frame), mission specialist, shared this extravehicular activity with Walheim.

S122-E-008923 (15 Feb. 2008) --- Astronaut Rex Walheim, mission specialist, performs work on the outside of the Columbus laboratory, the newest piece of hardware on the International Space Station. Astronaut Stanley Love (out of frame), mission specialist, shared this final period of STS-122 extravehicular activity with Walheim.

Schlegel, Frick and Walheim in the A/L

S122-E-008288 (13 Feb. 2008) --- Attired in their Extravehicular Mobility Unit (EMU) spacesuits, European Space Agency (ESA) astronaut Hans Schlegel (left) and NASA astronaut Rex Walheim, both STS-122 mission specialists, are pictured in the Quest Airlock of the International Space Station as the mission's second spacewalk draws to a close. NASA astronaut Steve Frick, commander, assisted Schlegel and Walheim.

Walheim, Frick and Whitson in the A/L

S122-E-009094 (15 Feb. 2008) --- Commanders of the STS-122 Atlantis crew and the International Space Station's expedition, respectively, astronauts Steve Frick and Peggy Whitson, assist astronaut Rex Walheim as he ingresses the station following the third and final extravehicular activity during a week in which the Atlantis was docked to the orbital outpost. Astronaut Stanley Love (out of frame), mission specialist, shared this extravehicular activity with Walheim.

Walheim during EVA 3

S122-E-008913 (15 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, holds onto a handrail on the Columbus laboratory, the newest piece of hardware on the International Space Station. In his helmet visor is mirrored the forward section of the Space Shuttle Atlantis, to which the station is docked. Astronaut Stanley Love (out of frame), mission specialist, shared this final period of STS-122 extravehicular activity (EVA) with Walheim.

Walheim during EVA 2

S122-E-008323 (13 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and European Space Agency (ESA) astronaut Hans Schlegel (out of frame), mission specialist, worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.

S122-E-009101 (15 Feb. 2008) --- Astronaut Alan Poindexter, STS-122 pilot, inspects the gloves of astronaut Rex Walheim, mission specialist, following the ingress of astronauts Walheim and Stanley Love (partially out of frame at left) following the final space walk of a busy week. Astronaut Peggy Whitson, the International Space Station's Expedition 16 commander, checks Love's gloves.

Whitson, Poindexter and Walheim in the A/L

Walheim during EVA 2

S122-E-008395 (13 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and European Space Agency (ESA) astronaut Hans Schlegel (out of frame), mission specialist, worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.

Schlegel, Whitson and Walheim in the A/L

S122-E-008297 (13 Feb. 2008) --- Attired in their Extravehicular Mobility Unit (EMU) spacesuits, European Space Agency (ESA) astronaut Hans Schlegel (left) and NASA astronaut Rex Walheim, both STS-122 mission specialists, are pictured in the Quest Airlock of the International Space Station as the mission's second spacewalk draws to a close. NASA astronaut Peggy Whitson, Expedition 16 commander, assisted Schlegel and Walheim.

S122-E-009541 (16 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, is pictured on the middeck of Space Shuttle Atlantis while docked with the International Space Station.

Walheim on Atlantis MDDK

Walheim during EVA 1

S122-E-007864 (11 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim during EVA 1

S122-E-007797 (11 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim during EVA 1

S122-E-007830 (11 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim during EVA 1

S122-E-007884 (11 Feb.2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim during EVA 1

S122-E-007833 (11 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim during EVA 3

S122-E-008925 (15 Feb. 2008) --- This digital still camera's wide shot affords a panoramic view of STS-122's final leg of work on the International Space Station. With mostly blue skies and some scattered clouds on Earth, solar panels and a station truss in the background, astronaut Rex Walheim, mission specialist, installs handrails on the outside of the Columbus laboratory, the newest piece of hardware on the International Space Station. Astronaut Stanley Love (out of frame), mission specialist, shared this final period of STS-122 extravehicular activity with Walheim.

Walheim during EVA 1

S122-E-007828 (11 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, participates in the first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the almost eight-hour spacewalk, Walheim and astronaut Stanley Love (out of frame), mission specialist, installed a grapple fixture on the Columbus laboratory and prepared electrical and data connections on the module while it rested inside Space Shuttle Atlantis' payload bay. The crewmembers also began work to replace a large nitrogen tank used for pressurizing the station's ammonia cooling system.

Walheim and Schlegel during EVA 2

S122-E-008200 (13 Feb. 2008) --- European Space Agency (ESA) astronaut Hans Schlegel (top) and NASA astronaut Rex Walheim, both STS-122 mission specialists, participate in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and Schlegel worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.

Schlegel and Walheim during EVA 2

S122-E-008187 (13 Feb. 2008) --- European Space Agency (ESA) astronaut Hans Schlegel (left) and NASA astronaut Rex Walheim, both STS-122 mission specialists, participate in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and Schlegel worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.

Walheim and Schlegel during EVA 2

S122-E-008199 (13 Feb. 2008) --- European Space Agency (ESA) astronaut Hans Schlegel (right) and NASA astronaut Rex Walheim, both STS-122 mission specialists, participate in the mission's second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 45-minute spacewalk, among other tasks, Walheim and Schlegel worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.

S135-E-007434 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured in the U.S. lab or Destiny on the International Space Station during the fourth day in space for the Atlantis crew and the second day during which the two spacecraft are docked in Earth orbit. Photo credit: NASA

Walheim in US Lab

S135-E-007457 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured on the flight deck of the space shuttle Atlantis during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

Walheim on Aft Flight Deck

S122-E-007664 (10 Feb. 2008) --- Astronauts Peggy Whitson, Expedition 16 commander; Stanley Love and Rex Walheim (bottom), both STS-122 mission specialists, work in the Quest Airlock of the International Space Station while Space Shuttle Atlantis is docked with the station.

Whitson,Walheim and Love in A/L

S122-E-008521 (14 Feb. 2008) --- Astronauts Stanley Love (left) and Rex Walheim, both STS-122 mission specialists, look over checklists on the middeck of Space Shuttle Atlantis while docked with the International Space Station.

Love and Walheim on MDDK

ISS016-E-028885 (9 Feb. 2008) --- NASA astronaut Rex Walheim (left) and European Space Agency (ESA) astronaut Hans Schlegel, both STS-122 mission specialists, work with Extravehicular Mobility Unit (EMU) spacesuits in the Quest Airlock of the International Space Station while Space Shuttle Atlantis is docked with the station.

Walheim and Schlegel in A/L

S135-E-006320 (9 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, looks through an overhead window on the aft flight deck of the space shuttle Atlantis during the mission's second day of activities in Earth orbit. Photo credit: NASA

Walheim on Aft Flight Deck

S135-E-007696 (13 July 2011) --- On Atlantis' middeck, NASA astronauts Rex Walheim and Sandy Magnus, STS-135 mission specialists, discuss the large tasks of moving supplies on the joint shuttle/International Space Station complex during the sixth day in space for the four shuttle crewmembers. Photo credit: NASA

Walheim and Magnus on Atlantis Middeck

S135-E-007459 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured on the flight deck of the space shuttle Atlantis during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

Walheim on Aft Flight Deck

S135-E-007392 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured on the middeck of the space shuttle Atlantis during the mission's fourth day in space and second day docked with the International Space Station. Photo credit: NASA

Walheim on Atlantis Middeck

JSC2011-E-036274 (11 Feb. 2011) --- NASA astronaut Rex Walheim, mission specialist. Photo credit: NASA

Walheim Official Individual ACES suit photo

JSC2003-E-47248 (13 June 2003) --- Astronaut Rex J. Walheim, mission specialist.

Official Portrait of Astronaut Rex J. Walheim.

Schlegel, Frick and Walheim in the A/L prior to EVA 2

S122-E-008118 (13 Feb. 2008) --- Attired in their Extravehicular Mobility Unit (EMU) spacesuits, European Space Agency (ESA) astronaut Hans Schlegel (left) and NASA astronaut Rex Walheim, both STS-122 mission specialists, prepare for the mission's second session of extravehicular activity (EVA) in the Quest Airlock of the International Space Station while Space Shuttle Atlantis is docked with the station. NASA astronaut Steve Frick, commander, assisted Schlegel and Walheim.

S122-E-006222 (8 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, is pictured between two Extravehicular Mobility Unit (EMU) spacesuits on the middeck of Space Shuttle Atlantis during flight day two activities.

Walheim on MDDK during STS-122

S135-E-010689 (19 July 2011) --- NASA astronauts Doug Hurley (left), pilot for the STS-135 mission and Rex Walheim, mission specialist, are pictured on the flight deck of the space shuttle Atlantis prior to undocking/ separation from the International Space Station. Photo credit: NASA

Hurley and Walheim on Aft Flight Deck

S122-E-006376 (8 Feb. 2008) --- Astronaut Rex Walheim, STS-122 mission specialist, does not have a shortage of windows from which to view Earth's horizon or steal a glance into space from his position on the aft end of Space Shuttle Atlantis' crew cabin.

Walheim on FD during STS-122

S135-E-010692 (19 July 2011) --- NASA astronauts Doug Hurley (left), pilot for the STS-135 mission and Rex Walheim, mission specialist, are pictured on the flight deck of the space shuttle Atlantis prior to undocking/separation from the International Space Station. Photo credit: NASA

Hurley and Walheim on Aft Flight Deck

S135-E-010688 (19 July 2011) --- NASA astronauts Doug Hurley (left), pilot for the STS-135 mission and Rex Walheim, mission specialist, are pictured on the flight deck of the space shuttle Atlantis prior to undocking/ separation from the International Space Station. Photo credit: NASA

Hurley and Walheim on Aft Flight Deck

NASA Day at the Capitol

Astronaut Rex Walheim (center) speaks to members of the Mississippi House of Representatives in chambers during NASA Day at the Capitol in Jackson on Feb. 19. Walheim was joined at the podium by members of the Mississippi House of Representatives Gulf Coast delegation, as well as Stennis Space Center Director Gene Goldman (astronaut's immediate right) and NASA's Shared Services Center Director Rick Arbuthnot and Partners for Stennis Executive Director Tish Williams (astronaut's immediate left).

Walheim and Tani on FD

S122-E-010922 (18 Feb. 2008) --- Astronaut Rex Walheim (right), STS-122 mission specialist, uses a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows on the aft flight deck of Space Shuttle Atlantis after undocking from the International Space Station. Astronaut Daniel Tani, mission specialist, uses a still camera to photograph the station in its new configuration.

Walheim during EVA 2

S122-E-008149 (13 Feb. 2008) --- Anchored to a foot restraint on the station's robotic Canadarm2, astronaut Rex Walheim, STS-122 mission specialist, transfers a large nitrogen tank assembly -- used for pressurizing the station's ammonia cooling system -- during the second scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station.

S122-E-007662 (10 Feb. 2008) --- Astronauts Peggy Whitson, Expedition 16 commander; Stanley Love and Rex Walheim (bottom), both STS-122 mission specialists, work in the Quest Airlock of the International Space Station while Space Shuttle Atlantis is docked with the station. Two Extravehicular Mobility Unit (EMU) spacesuits are visible in the image.

Whitson, Walheim and Love in A/L

Walheim Troubleshoots GPC 3

S135-E-007351 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, watches as astronaut Chris Ferguson (out of frame at right) toggles switches on the overhead panel of the forward flight deck of the space shuttle Atlantis. The action came during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

S122-E-007071 (9 Feb. 2008) --- Astronaut Rex Walheim (left) and European Space Agency astronaut Hans Schlegel prepare to join seven other astronauts and a cosmonaut for a special reunion onboard the International Space Station soon after the hatches were opened between the orbital outpost and the Space Shuttle Atlantis on docking day.

Walheim and Schlegel in US Lab

Walheim and Tani on FD

S122-E-010920 (18 Feb. 2008) --- Astronaut Rex Walheim (right), STS-122 mission specialist, uses a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows on the aft flight deck of Space Shuttle Atlantis after undocking from the International Space Station. Astronaut Daniel Tani, mission specialist, uses a still camera to photograph the station in its new configuration.

S122-E-009003 (15 Feb. 2008) --- Silhouetted against the starboard solar array of the International Space Station, astronaut Rex Walheim, STS-122 mission specialist, works to install handrails and worksite interface fixtures on the Columbus laboratory during the mission's third session of extravehicular activity (EVA) while Space Shuttle Atlantis is docked with the station.

Walheim during EVA 3

200802200007HQ Space Shuttle Atlantis (STS-122) Lands

STS-122 Mission Specialist, Rex Walheim, left, and Shuttle Launch Director, Michael D. Leinbach take a moment to watch the close out crew work on the space shuttle Atlantis. Atlantis landed at the Shuttle Landing Facility, 9:07a.m., Wednesday, Feb. 20, 2008 at Kennedy Space Center, Fla. completing delivery of the European Space Agency’s (ESA) Columbus laboratory to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

S135-E-007353 (11 July 2011) --- NASA astronauts Rex Walheim (left), STS-135 mission specialist, and Chris Ferguson are pictured on the forward flight deck the space shuttle Atlantis. The photo was taken during the mission's fourth day of activities in Earth orbit and second day while being docked with the International Space Station. Photo credit: NASA

Walheim and Ferguson Troubleshoot GPC 3

S122-E-008583 (14 Feb. 2008) --- Astronauts Steve Frick (second right), STS-122 commander; Leland Melvin (left), Stanley Love (top) and Rex Walheim, all mission specialists, take a moment during flight day eight activities for a photo on the middeck of Space Shuttle Atlantis while docked with the International Space Station.

Melvin, Love, Frick and Walheim on MDDK

S122-E-008586 (14 Feb. 2008) --- Astronauts Rex Walheim (left), STS-122 mission specialist; Steve Frick, commander; Stanley Love, mission specialist; and Alan Poindexter, pilot, take a moment during flight day eight activities for a photo on the middeck of Space Shuttle Atlantis while docked with the International Space Station.

Walheim, Frick, Love and Poindexter on MDDK

S122-E-008585 (14 Feb. 2008) --- Astronauts Rex Walheim (left), STS-122 mission specialist; Steve Frick, commander; Stanley Love, mission specialist; and Alan Poindexter, pilot, take a moment during flight day eight activities for a photo on the middeck of Space Shuttle Atlantis while docked with the International Space Station.

Walheim, Frick, Love and Poindexter on MDDK

S122-E-008750 (15 Feb. 2008) --- Astronaut Rex Walheim (foreground), mission specialist, shares a spacewalk task with astronaut Stanley Love (partially obscured at top of frame), mission specialist. The two astronauts had paired up for the first of three scheduled STS-122 sessions of extravehicular activity earlier in the week and came back out for this final EVA on Feb. 15.

Walheim and Love during EVA 3

S122-E-007162 (9 Feb. 2008) --- Astronauts Steve Frick (left) and Rex Walheim, STS-122 commander and mission specialist, respectively, take a moment for a photo on the aft flight deck of Space Shuttle Atlantis during flight day three activities.

Frick and Walheim on FD during STS-122

S122-E-007099 (9 Feb. 2008) --- Astronauts Steve Frick (left), STS-122 commander; Rex Walheim, mission specialist; and Alan Poindexter, pilot, take a moment for a photo on the flight deck of Space Shuttle Atlantis during flight day three activities.

Frick, Walheim and Poindexter on FD during STS-122

S135-E-012383 (21 July 2011) --- Astronaut Rex Walheim, STS-135 mission specialist, makes preparations on space shuttle Atlantis' aft flight deck for the mission's re-entry phase and the final landing of a NASA space shuttle. Photo credit: NASA

Walheim on Aft Flight Deck during Deorbit Preparations

Astronaut Rex Walheim spoke at the USA Science and Engineering Festival on April 25, 2014 at the NASA Stage. The festival was open to the public on April 26 and 27, 2014 and was held at the Washington Convention Center in Washington, DC. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

Astronaut Rex Walheim spoke at the USA Science and Engineering Festival on April 25, 2014. The festival was open to the public on April 26 and 27, 2014 and was held at the Washington Convention Center in Washington, DC. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

S135-E-007204 (10 July 2011) –-- NASA astronauts Chris Ferguson (left), STS-135 commander, and Rex Walheim, mission specialist, are pictured on the aft flight deck of the space shuttle Atlantis prior to docking with the International Space Station during the mission’s third day in space. Walheim uses a range finder in support of the rendezvous and docking operations. Photo credit: NASA

Ferguson and Walheim on Atlantis Aft Flight Deck during Rendezvous OPS

STS110-E-5006 (8 April 2002) --- Astronaut Rex J. Walheim, STS-110 mission specialist, works on the mid deck of the Space Shuttle Atlantis. The image was taken with at digital still camera.

MS Walheim poses with an WVS equipment on the middeck of Atlantis during STS-110

STS-335 (135) crew members Rex Walheim and Sandy Magnus

JSC2010-E-181483 (27 Oct. 2010) --- Attired in a training version of his Extravehicular Mobility Unit (EMU) spacesuit, NASA astronaut Rex Walheim, STS-135 mission specialist, participates in a spacewalk training session in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Divers are in the water to assist Walheim in his rehearsal, which is intended to help prepare him for work on the exterior of the International Space Station. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-335 (135) crew members Rex Walheim and Sandy Magnus

JSC2010-E-181470 (27 Oct. 2010) --- Attired in a training version of his Extravehicular Mobility Unit (EMU) spacesuit, NASA astronaut Rex Walheim, STS-135 mission specialist, is about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Divers (out of frame) are in the water to assist Walheim in his rehearsal, which is intended to help prepare him for work on the exterior of the International Space Station. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

Love, Melvin and Walheim in the A/L prior to EVA 3

S122-E-008896 (15 Feb. 2008) --- Astronaut Leland Melvin, STS-122 mission specialist, lends his intravehicular support to the two STS-122 mission specialists assigned to the mission's final spacewalk to perform work on the International Space Station. Equipped with their extravehicular mobility units (EMU) and other gear and just about ready to egress the station and begin the day's external tasks are astronauts Stanley Love (left) and Rex Walheim.

Love, Poindexter and Walheim in the A/L prior to EVA 3

S122-E-008894 (15 Feb. 2008) --- Astronaut Alan Poindexter, STS-122 pilot, lends his intravehicular support to the two STS-122 mission specialists assigned to the mission's final spacewalk to perform work on the International Space Station. Equipped with their extravehicular mobility units (EMU) and other gear and just about ready to egress the station and begin the day's external tasks are astronauts Stanley Love (left) and Rex Walheim.

Love, Frick and Walheim in the A/L prior to EVA 3

S122-E-008897 (15 Feb. 2008) --- Astronaut Steve Frick, STS-122 commander, shares his enthusiasm and support with the two STS-122 mission specialists assigned to the mission's final spacewalk to perform work on the International Space Station. Equipped with their extravehicular mobility units (EMU) and other gear and just about ready to egress the station and begin the day's external tasks are astronauts Stanley Love (left) and Rex Walheim.

STS-135 Launch Day

James Branson of United Space Alliance, far left; Sandra Magnus, STS-135 mission specialist and Rex Walheim, STS-135 mission specialist, far right, are seen in the Astrovan as they ride to launch pad 39A to board space shuttle Atlantis on Friday, July 8, 2011, at the Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

S135-E-007160 (10 July 2011) –-- NASA astronauts Chris Ferguson (left), STS-135 commander, and Rex Walheim, mission specialist, are pictured on the aft flight deck of the space shuttle Atlantis prior to docking with the International Space Station during the mission’s third day in space. Photo credit: NASA

Ferguson and Walheim on Atlantis Aft Flight Deck during Rendezvous OPS

S135-E-007117 (10 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured at a control panel on the aft flight deck of the space shuttle Atlantis during rendezvous and docking operations with the International Space Station. Photo credit: NASA

Walheim on Atlantis Aft Flight Deck during Rendezvous OPS

S135-E-010699 (19 July 2011) --- NASA astronauts Doug Hurley (left), pilot for the STS-135 mission and Rex Walheim, mission specialist, are pictured on the flight deck of the space shuttle Atlantis prior to undocking/ separation from the International Space Station. Photo credit: NASA

Hurley and Walheim on Aft Flight Deck during Undocking OPS

S135-E-010702 (19 July 2011) --- NASA astronauts Doug Hurley (left), pilot for the STS-135 mission and Rex Walheim, mission specialist, are pictured on the flight deck of the space shuttle Atlantis prior to undocking/separation from the International Space Station. Photo credit: NASA

Hurley and Walheim on Aft Flight Deck during Undocking OPS

S135-E-007284 (10 July 2011) – From left, NASA astronauts Chris Ferguson, Sandy Magnus and Rex Walheim are pictured on the flight deck of the space shuttle Atlantis during rendezvous and docking operations with the International Space Station. Photo credit: NASA

Ferguson, Magnus and Walheim on Atlantis Aft Flight Deck during Docking OPS

JSC2007-E-27720 (6 June 2007) --- Astronaut Rex J. Walheim, STS-122 mission specialist, dons a training version of the Extravehicular Mobility Unit (EMU) spacesuit in preparation for a training session in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center.

STS-122 crew member Rex Walheim suiting up

S122-E-007945 (12 Feb.2008) --- Astronaut Rex Walheim, STS-122 mission specialist, is pictured on the aft flight deck of Space Shuttle Atlantis during flight day six activities while docked with the International Space Station.

Walheim on FD during Expedition 16/STS-122 Joint Operations

JSC2011-E-024208 (1 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured in the rear station of a NASA T-38 trainer jet prior to a flight at Ellington Field near NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crewmembers Chris Ferguson, Doug Hurley and Rex Walheim

JSC2011-E-024222 (1 March 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured in the rear station of a NASA T-38 trainer jet prior to a flight at Ellington Field near NASA's Johnson Space Center. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crewmembers Chris Ferguson, Doug Hurley and Rex Walheim

S135-E-007118 (10 July 2011) ? NASA astronaut Sandy Magnus, STS-135 mission specialist, is pictured at controls on the flight deck of the space shuttle Atlantis during rendezvous and docking operations with the International Space Station. NASA astronaut Rex Walheim, mission specialist, is at right. Photo credit: NASA

Magnus and Walheim on Atlantis Aft Flight Deck during Rendezvous OPS

S135-E-007155 (10 July 2011) –-- NASA astronauts Chris Ferguson (left), STS-135 commander, and Rex Walheim, mission specialist, are pictured on the aft flight deck of the space shuttle Atlantis prior to docking with the International Space Station during the mission’s third day in space. Photo credit: NASA

Ferguson and Walheim on Atlantis Aft Flight Deck during Rendezvous OPS

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029011 (21 March 2011) --- NASA astronauts Rex Walheim (left) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructor Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029017 (21 March 2011) --- NASA astronauts Rex Walheim (center) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructor Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029013 (21 March 2011) --- NASA astronauts Rex Walheim (left) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructor Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029056 (21 March 2011) --- NASA astronauts Rex Walheim (right) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructors John Ray (left foreground) and Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029042 (21 March 2011) --- NASA astronauts Rex Walheim (second left) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructors John Ray (left foreground) and Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029044 (21 March 2011) --- NASA astronauts Rex Walheim (left) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructors John Ray (right background) and Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029041 (21 March 2011) --- NASA astronauts Rex Walheim (right) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructors John Ray (left foreground) and Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029027 (21 March 2011) --- NASA astronauts Rex Walheim (center) and Sandy Magnus, both STS-135 mission specialists, participate in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructor Art Thomason assisted Walheim and Magnus. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

STS-135 crew members Rex Walheim and Sandra Magnus during EVA TPS OPS at 1G Trainer at the NBL.

JSC2011-E-029049 (21 March 2011) --- NASA astronaut Rex Walheim (foreground), STS-135 mission specialist, participates in an extravehicular activity (EVA) hardware training session in the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. EVA instructor Art Thomason assisted Walheim. STS-135 is planned to be the final mission of the space shuttle program. Photo credit: NASA or National Aeronautics and Space Administration

ISS004-E-10100 (16 April 2002) --- Astronaut Rex J. Walheim, STS-110 mission specialist, looks out a window in the Zvezda Service Module on the International Space Station (ISS).

STS-110 MS Walheim looks through a window in the Zvezda SM during Expedition Four