Astronaut Pam Melroy presents a commemorative collage of photos and items flown aboard space shuttle Discovery to Bob Cabana, director of NASA's Stennis Space Center in South Mississippi. Melroy commanded NASA's space shuttle mission STS-120. She and fellow crewmembers (from left) Doug Wheelock, Stephanie Wilson, George Zamka, Scott Parazynski and Paolo Nespoli visited Stennis Dec. 13, 2007, to thank employees for the reliability and safe performance of the space shuttle's main engines, which on Oct. 23 launched them aboard Discovery on their mission to the International Space Station.

JSC2007-E-06538 (2 Feb. 2007) --- Astronaut Scott E. Parazynski, STS-120 mission specialist, attired in a training version of the Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a training session in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center.

JSC2007-E-06545 (2 Feb. 2007) --- Attired in a training version of the Extravehicular Mobility Unit (EMU) spacesuit, astronaut Douglas H. Wheelock, STS-120 mission specialist, awaits the start of a training session in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center.

JSC2007-E-06537 (2 Feb. 2007) --- Astronaut Scott E. Parazynski, STS-120 mission specialist, attired in a training version of the Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a training session in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center.

JSC2007-E-06532 (2 Feb. 2007) --- Astronaut Scott E. Parazynski, STS-120 mission specialist, attired in a training version of the Extravehicular Mobility Unit (EMU) spacesuit, awaits the start of a training session in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center.

JSC2007-E-06548 (2 Feb. 2007) --- Astronauts Douglas H. Wheelock and Scott E. Parazynski (partially obscured), both STS-120 mission specialists, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center. Wheelock and Parazynski are attired in training versions of the Extravehicular Mobility Unit (EMU) spacesuit. SCUBA-equipped divers are in the water to assist the crewmembers in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.

JSC2007-E-06549 (2 Feb. 2007) --- Astronauts Douglas H. Wheelock and Scott E. Parazynski (partially obscured), both STS-120 mission specialists, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center. Wheelock and Parazynski are attired in training versions of the Extravehicular Mobility Unit (EMU) spacesuit. SCUBA-equipped divers (out of frame) are in the water to assist the crewmembers in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.

JSC2007-E-06550 (2 Feb. 2007) --- Astronauts Douglas H. Wheelock and Scott E. Parazynski (partially obscured), both STS-120 mission specialists, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near Johnson Space Center. Wheelock and Parazynski are attired in training versions of the Extravehicular Mobility Unit (EMU) spacesuit. SCUBA-equipped divers (out of frame) are in the water to assist the crewmembers in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.

NASA astronaut Doug Wheelock leaves his STS-120 mission patch at the memorial for the Space Shuttle Challenger crew during National Wreaths Across America Day at Arlington National Cemetery, Sat., Dec. 14, 2019 in Arlington, Va. National Wreaths Across America Day is held annually to celebrate the lives of military veterans and wreaths are placed at the foot of every headstone. Wheelock honored those who lost their lives in the quest for space exploration as well as fellow service members. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Doug Wheelock leaves his STS-120 mission patch at the gravesite of former astronaut and U.S. Senator John Glenn during National Wreaths Across America Day at Arlington National Cemetery, Sat., Dec. 14, 2019 in Arlington, Va. National Wreaths Across America Day is held annually to celebrate the lives of military veterans and wreaths are placed at the foot of every headstone. Wheelock honored those who lost their lives in the quest for space exploration as well as fellow service members. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Doug Wheelock takes a moment after leaving his STS-120 mission patch at the memorial for the Space Shuttle Columbia crew during National Wreaths Across America Day at Arlington National Cemetery, Sat., Dec. 14, 2019 in Arlington, Va. National Wreaths Across America Day is held annually to celebrate the lives of military veterans and wreaths are placed at the foot of every headstone. Wheelock honored those who lost their lives in the quest for space exploration as well as fellow service members. Photo Credit: (NASA/Aubrey Gemignani)

S120-E-007608 (31 Oct. 2007) --- STS-120 and Expedition 16 crewmembers pose for a group photo following a joint news conference in the Harmony node of the International Space Station while Space Shuttle Discovery is docked with the station. From the left (bottom) are astronauts Clayton Anderson, STS-120 mission specialist; Peggy A. Whitson, Expedition 16 commander; cosmonaut Yuri I. Malenchenko, Expedition 16 flight engineer representing Russia's Federal Space Agency; and George Zamka, STS-120 pilot. From the left (center) are astronauts Stephanie Wilson, STS-120 mission specialist; Pam Melroy, STS-120 commander; and Paolo Nespoli, mission specialist representing the European Space Agency (ESA). From the left (top) are astronauts Daniel Tani, Expedition 16 flight engineer; Scott Parazynski and Doug Wheelock, both STS-120 mission specialists.

ISS016-E-006669 (25 Oct. 2007) --- Expedition 16 and STS-120 crewmembers gather in the Destiny laboratory of the International Space Station shortly after Space Shuttle Discovery docked with the station. Pictured (clockwise) are European Space Agency (ESA) astronaut Paolo Nespoli (foreground), NASA astronauts Stephanie Wilson, both STS-120 mission specialists; George Zamka, STS-120 pilot; Doug Wheelock, mission specialist; Pam Melroy, STS-120 commander; Daniel Tani, Expedition 16 flight engineer; and cosmonaut Yuri I. Malenchenko, flight engineer representing Russia's Federal Space Agency.

S120-E-007617 (31 Oct. 2007) --- STS-120 and Expedition 16 crewmembers pose for a group photo following a joint news conference in the Harmony node of the International Space Station while Space Shuttle Discovery is docked with the station. Astronaut Pam Melroy, STS-120 commander, is at center. Pictured clockwise are astronauts Peggy A. Whitson (bottom left), Expedition 16 commander; Clayton Anderson and Stephanie Wilson, both STS-120 mission specialists; Daniel Tani, Expedition 16 flight engineer; Scott Parazynski, Doug Wheelock, European Space Agency's (ESA) Paolo Nespoli, all STS-120 mission specialists; George Zamka, STS-120 pilot; and cosmonaut Yuri I. Malenchenko, Expedition 16 flight engineer representing Russia's Federal Space Agency.

JSC2007-E-18096 (9 April 2007) --- Astronauts Pamela A. Melroy (left), STS-120 commander; Daniel M. Tani, Expedition 16 flight engineer; and George D. Zamka, STS-120 pilot, enjoy a light moment as they await the start of a training session in the Space Vehicle Mockup Facility at Johnson Space Center. Tani is scheduled to join Expedition 16 as flight engineer after launching to the International Space Station on mission STS-120 and is scheduled to return home on mission STS-122.

View of Astronauts George Zamka (red shirt),STS-120 pilot, Stephanie Wilson, STS-120 Mission specialist, and Paolo Nespoli, STS-120 Mission specialist representing the European Space Agency (ESA), as they pose for a photo on the flight deck of Space Shuttle Discovery during flight day eight activities while docked with the International Space Station.

S120-E-008356 (4 Nov. 2007) --- Astronauts Pam Melroy (left), STS-120 commander; and Peggy Whitson, Expedition 16 commander, pose for a photo after placing the STS-120 crew patch in the Harmony node -- newest addition to the International Space Station -- while Space Shuttle Discovery is docked with the station.

Donned in a training version of her shuttle launch and entry suit, astronaut Pamela A. Melroy, STS-120 commander, awaits the start of a training session in the Space Vehicle Mockup Facility at Johnson Space Center. Melroy and her crew were preparing for their STS-120 mission duties. Launch occurred on October 23, 2007.

S120-E-008339 (4 Nov. 2007) --- Astronauts Pam Melroy (left), STS-120 commander; Peggy Whitson, Expedition 16 commander; and Stephanie Wilson, STS-120 mission specialist, pose for a photo in the Zvezda Service Module of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-008337 (4 Nov. 2007) --- Astronauts Pam Melroy (left), STS-120 commander; Peggy Whitson, Expedition 16 commander; and Stephanie Wilson, STS-120 mission specialist, pose for a photo in the Zvezda Service Module of the International Space Station while Space Shuttle Discovery is docked with the station.

STS120-S-092 (7 Nov. 2007) --- Astronaut Scott Parazynski, STS-120 mission specialist, touches the nose cone of Space Shuttle Discovery after its landing at NASA's Kennedy Space Center. At far right is astronaut George Zamka, STS-120 pilot, and at center is astronaut Jose Hernandez. The crew is taking part in the traditional walkdown to look at the state of the shuttle after a launch and landing. The Discovery crew completed the 15-day STS-120 mission, with an on-time landing at 1:01:16 p.m. (EST). Wheel stop was at 1:02:07 p.m. Mission elapsed time was 15 days, 2 hours, 24 minutes and 2 seconds. The STS-120 crew continued the construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss.

S120-E-008834 (4 Nov. 2007) --- The STS-120 and Expedition 16 crewmembers gather for a farewell ceremony in the Destiny laboratory of the International Space Station (ISS). Pictured hugging are astronauts Pam Melroy (right center), STS-120 commander; and Peggy Whitson, Expedition 16 commander. Also pictured are astronauts Clay Anderson (foreground), STS-120 mission specialist; Daniel Tani (background), ISS flight engineer; Scott Parazynski, mission specialist; and cosmonaut Yuri I. Malenchenko, ISS flight engineer representing Russia's Federal Space Agency. Hatches were closed between the station and Space Shuttle Discovery at 2:03 p.m. (CST) on Nov. 4.

JSC2007-E-18090 (9 April 2007) --- Attired in training versions of their shuttle launch and entry suits, the STS-120 crewmembers await the start of a training session in the Space Vehicle Mockup Facility at Johnson Space Center. From the left are astronauts Pamela A. Melroy, STS-120 commander; Daniel M. Tani, Expedition 16 flight engineer; George D. Zamka, STS-120 pilot; Douglas H. Wheelock, Scott E. Parazynski, Stephanie D. Wilson and European Space Agency's (ESA) Paolo Nespoli, all mission specialists. Tani is scheduled to join Expedition 16 as flight engineer after launching to the International Space Station on mission STS-120 and is scheduled to return home on mission STS-122.

JSC2007-E-46535 (18 Sept. 2007) --- Astronaut Daniel M. Tani, Expedition 16 flight engineer, dons a training version of the Extravehicular Mobility Unit (EMU) spacesuit prior to being submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near the Johnson Space Center. European Space Agency (ESA) astronaut Paolo Nespoli, STS-120 mission specialist, assisted Tani who is scheduled to join Expedition 16 after launching to the International Space Station on mission STS-120.

JSC2007-E-46533 (18 Sept. 2007) --- Astronaut Daniel M. Tani, Expedition 16 flight engineer, dons a training version of the Extravehicular Mobility Unit (EMU) spacesuit prior to being submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near the Johnson Space Center. European Space Agency (ESA) astronaut Paolo Nespoli (left), STS-120 mission specialist, assisted Tani who is scheduled to join Expedition 16 after launching to the International Space Station on mission STS-120.

S120-E-008849 (4 Nov. 2007) --- Astronauts Peggy Whitson, Expedition 16 commander, and Clay Anderson, STS-120 mission specialist, exchange hugs during a farewell ceremony in the Destiny laboratory of the International Space Station (ISS). Also pictured are astronauts Doug Wheelock (right foreground), STS-120 mission specialist; George Zamka (partially obscured), pilot; and Daniel Tani, ISS flight engineer. Hatches were closed between the station and Space Shuttle Discovery at 2:03 p.m. (CST) on Nov. 4.

JSC2007-E-46540 (18 Sept. 2007) --- Astronaut Daniel M. Tani, Expedition 16 flight engineer, dons a training version of the Extravehicular Mobility Unit (EMU) spacesuit prior to being submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near the Johnson Space Center. European Space Agency (ESA) astronaut Paolo Nespoli, STS-120 mission specialist, assisted Tani who is scheduled to join Expedition 16 after launching to the International Space Station on mission STS-120.

ISS016-E-007813 (28 Oct. 2007) --- European Space Agency (ESA) astronaut Paolo Nespoli (center), STS-120 mission specialist, turns a flip for astronauts Scott Parazynski (right), STS-120 mission specialist, and Daniel Tani, Expedition 16 flight engineer, as they prepare for the mission's second session of extravehicular activity (EVA) in the Quest Airlock of the International Space Station while Space Shuttle Discovery is docked with the station. Parazynski and Tani are attired in their Extravehicular Mobility Unit (EMU) spacesuits.

ISS016-E-009233 (3 Nov. 2007) --- Attired in their Extravehicular Mobility Unit (EMU) spacesuits, astronauts Scott Parazynski (left) and Doug Wheelock, STS-120 mission specialists; are pictured in the Quest Airlock of the International Space Station as the mission's fourth spacewalk draws to a close. Also pictured are astronauts Pam Melroy (center foreground), STS-120 commander, and Peggy Whitson, Expedition 16 commander.

JSC2007-E-098007 (8 Nov. 2007) --- The crew of the STS-120 mission was welcomed home to Houston Nov. 8, following the landing of Space Shuttle Discovery in Florida on Nov. 7. Astronaut Doug Wheelock, mission specialist, addresses the crowd on hand at Ellington Field. Also seen are astronauts Stephanie Wilson and Scott Parazynski, mission specialists. Not pictured are STS-120 commander Pam Melroy, pilot George Zamka and mission specialists Paolo Nespoli (ESA) and Clay Anderson.

S120-E-006963 (27 Oct. 2007) --- Astronauts Daniel Tani (bottom), Expedition 16 flight engineer; Stephanie Wilson, and Doug Wheelock (second left), both STS-120 mission specialists; cosmonaut Yuri I. Malenchenko, flight engineer representing Russia's Federal Space Agency; and astronaut George Zamka (right), STS-120 pilot, take a moment for a photo on the middeck of Space Shuttle Discovery while docked with the International Space Station.

JSC2007-E-46530 (18 Sept. 2007) --- Astronaut Daniel M. Tani, Expedition 16 flight engineer, dons a training version of the Extravehicular Mobility Unit (EMU) spacesuit prior to being submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near the Johnson Space Center. European Space Agency (ESA) astronaut Paolo Nespoli, STS-120 mission specialist, assisted Tani who is scheduled to join Expedition 16 after launching to the International Space Station on mission STS-120.

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here is Mission Specialist Scott Parazynski. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. The T-38 jet aircraft on which Mission Specialist Doug Wheelock arrived is shown here. Wheelock will be making his first shuttle flight and will perform three spacewalks during the STS-120 mission. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

JSC2007-E-098006 (8 Nov. 2007) --- The crew of the STS-120 mission was welcomed home to Houston Nov. 8, following the landing of Space Shuttle Discovery in Florida on Nov. 7. Astronaut Scott Parazynski, who participated in all four STS-120 spacewalks, addresses well-wishers. Astronaut George Zamka, pilot, looks on. Not pictured are astronaut Pam Melroy, commander, and mission specialists Scott Parazynski, Stephanie Wilson, Doug Wheelock, Paolo Nespoli (ESA) and Clay Anderson (all out of frame). The astronauts were welcomed by family and friends during an afternoon ceremony at Houston's Ellington Field.

S120-E-008853 (4 Nov. 2007) --- Astronauts Peggy Whitson (left), Expedition 16 commander, and Pam Melroy, STS-120 commander, exchange handshakes in the Pressurized Mating Adapter (PMA-2) of the International Space Station as the STS-120 crewmembers exit the station to board Space Shuttle Discovery for their return trip home. Hatches were closed between the station and the shuttle at 2:03 p.m. (CST) on Nov. 4.

S120-E-006970 (27 Oct. 2007) --- STS-120 and Expedition 16 crewmembers share a meal on the middeck of Space Shuttle Discovery while docked with the International Space Station. Pictured are astronauts Daniel Tani (foreground), Expedition 16 flight engineer; Doug Wheelock, STS-120 mission specialist; and cosmonaut Yuri I. Malenchenko (right background), Expedition 16 flight engineer representing Russia's Federal Space Agency.

S120-E-008866 (4 Nov. 2007) --- Astronaut Pam Melroy (left), STS-120 commander, and Peggy Whitson, Expedition 16 commander, pose for a photo in the Pressurized Mating Adapter (PMA-2) of the International Space Station as the STS-120 crewmembers exit the station to board Space Shuttle Discovery for their return trip home. Hatches were closed between the station and the shuttle at 2:03 p.m. (CST) on Nov. 4.

S120-E-008852 (4 Nov. 2007) --- Astronauts Peggy Whitson (left), Expedition 16 commander, and Pam Melroy, STS-120 commander, exchange handshakes in the Pressurized Mating Adapter (PMA-2) of the International Space Station as the STS-120 crewmembers exit the station to board Space Shuttle Discovery for their return trip home. Hatches were closed between the station and the shuttle at 2:03 p.m. (CST) on Nov. 4.

ISS016-E-009711 (4 Nov. 2007) --- STS-120 and Expedition 16 crewmembers share a meal in the Zvezda Service Module of the International Space Station while Space Shuttle Discovery is docked with the station. Pictured (from the left) are astronauts Daniel Tani, Expedition 16 flight engineer; Pam Melroy, STS-120 commander; George Zamka, pilot; Doug Wheelock, Stephanie Wilson and European Space Agency's (ESA) Paolo Nespoli, all mission specialists.

While seated at the commander's station, astronaut Pamela A. Melroy, STS-120 commander, participates in a training session in the crew compartment trainer (CCT-2) in the Space Vehicle Mockup Facility at Johnson Space Center. Preparing for the STS-120 mission which launched October 23, 2007, Melroy is wearing a training version of her shuttle launch and entry suit.

NASA Deputy Administrator Pam Melroy, right, shows NASA Administrator Bill Nelson the white board created by the families of the astronauts of the STS-120 mission, after a tour of the firing rooms in the Launch Control Center (LCC), Wednesday, July 28, 2021, at NASA’s Kennedy Space Center in Florida. Deputy Administrator Melroy served as commander on STS-120 which was her third and last spaceflight. Photo Credit: (NASA/Aubrey Gemignani)

JSC2007-E-095034 (31 Oct. 2007) --- The members of the STS-120 Orbit 1 flight control team pose for a portrait in the space shuttle flight control room in Houston's Mission Control Center (MCC). Flight director Rick LaBrode (left) and astronaut Chris Ferguson, spacecraft communicator (CAPCOM), hold the STS-120 mission logo.

JSC2007-E-08815 (7 Feb. 2007) --- European Space Agency (ESA) astronaut Paolo Nespoli (left), STS-120 mission specialist, and astronaut Daniel M. Tani, Expedition 16 flight engineer, converse as they await the start of a post insertion/de-orbit training session in one of the full-scale trainers (out of frame) in the Space Vehicle Mockup Facility at Johnson Space Center. Nespoli and Tani are wearing training versions of their shuttle launch and entry suit. Tani will join Expedition 16 as flight engineer after launching to the International Space Station aboard Atlantis on mission STS-120 and is scheduled to return home aboard Discovery on mission STS-122.

STS120-S-095 (7 Nov. 2007) --- Astronaut Pam Melroy, STS-120 commander, talks to media and guests on the Shuttle Landing Facility at NASA's Kennedy Space Center after guiding the landing of Space Shuttle Discovery. Behind Melroy are (from the left) astronauts Stephanie Wilson, mission specialist; George Zamka, pilot; Doug Wheelock and Scott Parazynski, both mission specialists. The Discovery crew completed the 15-day STS-120 mission, with an on-time landing at 1:01:16 p.m. (EST). Wheel stop was at 1:02:07 p.m. Mission elapsed time was 15 days, 2 hours, 24 minutes and 2 seconds. The STS-120 crew continued the construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss.

ISS016-E-007838 (28 Oct. 2007) --- Attired in their Extravehicular Mobility Unit (EMU) spacesuits, astronauts Daniel Tani (left), Expedition 16 flight engineer, and Scott Parazynski, STS-120 mission specialist, prepare for the mission's second session of extravehicular activity (EVA) in the Quest Airlock of the International Space Station while Space Shuttle Discovery is docked with the station. European Space Agency (ESA) astronaut Paolo Nespoli (center bottom), STS-120 mission specialist, assisted Tani and Parazynski, while astronaut Doug Wheelock, mission specialist, photographs the event.

S120-E-006051 (24 Oct. 2007) --- Astronaut Pam Melroy, STS-120 commander, photographed on the middeck of Space Shuttle Discovery during flight day two activities

ISS016-E-009301 (4 Nov. 2007) --- Astronaut Clay Anderson, STS-120 mission specialist, uses a computer in the Destiny laboratory of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-006887 (26 Oct. 2007) --- Astronaut Scott Parazynski, STS-120 mission specialist, uses a computer on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S120-E-006219 (25 Oct. 2007) --- Astronaut Scott Parazynski, STS-120 mission specialist, looks out an overhead window on the aft flight deck of Space Shuttle Discovery during flight day three activities.

S120-E-007204 (29 Oct. 2007) --- A model of the Harmony node floats freely near astronaut Stephanie Wilson, STS-120 mission specialist, on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S120-E-007537 (30 Oct. 2007) --- Astronaut George Zamka, STS-120 pilot, works on the flight deck of Space Shuttle Discovery during flight day eight activities while docked with the International Space Station.

S120-E-006405 (25 Oct. 2007) --- Astronaut Pam Melroy, STS-120 commander, floats in the Orbiter Docking Compartment (ODS) after hatch opening between the International Space Station and Space Shuttle Discovery.

S120-E-006428 (25 Oct. 2007) --- Astronaut George Zamka, STS-120 pilot, floats into the Unity node of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-007903 (1 Nov. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, uses a computer on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S120-E-006433 (25 Oct. 2007) --- Astronaut Pam Melroy, STS-120 commander, floats into the Unity node of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-006047 (24 Oct. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, photographed on the middeck of Space Shuttle Discovery during flight day two activities.

S120-E-006035 (24 Oct. 2007) --- Astronaut George Zamka, STS-120 pilot, photographed on the flight deck of Space Shuttle Discovery during flight day two activities.

S120-E-007216 (29 Oct. 2007) --- Astronaut Stephanie Wilson, STS-120 mission specialist, and a model of the Harmony node float freely on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S120-E-007899 (1 Nov. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, uses a computer on the middeck of Space Shuttle Discovery while docked with the International Space Station.

S120-E-007028 (28 Oct. 2007) --- Astronaut Stephanie Wilson, STS-120 mission specialist, poses for a photo as a procedures handbook floats freely nearby in the Destiny laboratory of the International Space Station.

S120-E-006425 (25 Oct. 2007) --- Astronaut George Zamka, STS-120 pilot, floats into the Unity node of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-006738 (25 Oct. 2007) --- Astronaut George Zamka, STS-120 pilot, seated at the pilot's station on the forward flight deck of the Space Shuttle Discovery during rendezvous and docking operations.

S120-E-007025 (28 Oct. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, poses for a photo as a procedures handbook floats freely nearby in the Destiny laboratory of the International Space Station.

S120-E-006435 (25 Oct. 2007) --- Astronaut Doug Wheelock, STS-120 mission specialist, floats into the Unity node of the International Space Station while Space Shuttle Discovery is docked with the station.

S120-E-006068 (24 Oct. 2007) --- Astronaut Stephanie Wilson, STS-120 mission specialist, photographed on the aft flight deck of Space Shuttle Discovery during flight day two activities.

KENNEDY SPACE CENTER, FLA. -- The STS-120 crew is at NASA's Kennedy Space Center for the pre-launch terminal countdown demonstration test, or TCDT. Practicing to get out of the slidewire basket at the landing site during emergency egress training are Mission Specialists Scott Parazynski, Daniel Tani and Paolo Nespoli, who represents the European Space Agency. After the mission, Tani will remain aboard the International Space Station and return with the STS-122 crew, targeted to launch Dec. 6. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

JSC2007-E-18072 (9 April 2007) --- Astronauts Paolo Nespoli (foreground), STS-120 mission specialist representing the European Space Agency (ESA); Daniel M. Tani, Expedition 16 flight engineer; and Scott E. Parazynski (partially obscured), STS-120 mission specialist, participate in a training session in one of the full-scale trainers in the Space Vehicle Mockup Facility at Johnson Space Center. Attired in training versions of their shuttle launch and entry suits, the three are seated on the middeck for a post insertion/de-orbit training session. Tani is scheduled to join Expedition 16 as flight engineer after launching to the International Space Station on mission STS-120 and is scheduled to return home on mission STS-122. United Space Alliance suit technician John Hazelhurst assisted the crewmembers.

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the orbital docking system. Seen here are Mission Specialists Scott Parazynski (left) and Daniel Tani. After the mission, Tani will remain aboard the International Space Station and return with the STS-122 crew, targeted to launch Dec. 6. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here, from left, are Mission Specialists Stephanie Wilson, Daniel Tani and Scott Parazynski. After the mission, Tani will remain aboard the International Space Station and return with the STS-122 crew, targeted to launch Dec. 6. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Doug Wheelock completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- During emergency egress training as part of the pre-launch terminal countdown demonstration test, or TCDT, STS-120 crew members learn how to get out of the slidewire basket at the landing site. In the basket are Commander Pamela Melroy and Pilot George Zamka. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - The STS-120 crew is at Kennedy for a crew equipment interface test, or CEIT. Inspecting the thermal protection system, or TPS, tiles under space shuttle Discovery in Orbiter Processing Facility bay 3 is Mission Specialist Paolo A. Nespoli, a European Space Agency astronaut from Italy. Among the activities standard to a CEIT are harness training, inspection of the thermal protection system and camera operation for planned extravehicular activities, or EVAs. The STS-120 mission will deliver the Harmony module, christened after a school contest, which will provide attachment points for European and Japanese laboratory modules on the International Space Station. Known in technical circles as Node 2, it is similar to the six-sided Unity module that links the U.S. and Russian sections of the station. Built in Italy for the United States, Harmony will be the first new U.S. pressurized component to be added. The STS-120 mission is targeted to launch on Oct. 20. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Paolo Nespoli completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. Nespoli represents the European Space Agency. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Daniel Tani is fully suited and ready to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. Mission Specialist Doug Wheelock, seen here, will be making his first shuttle flight. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. Mission Specialist Stephanie Wilson, seen here, will be making her second shuttle flight. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

STS120-S-090 (7 Nov. 2007) --- At NASA's Kennedy Space Center, the STS-120 crewmembers exit the crew transport vehicle after their successful landing aboard Space Shuttle Discovery. Leading the way is astronaut Pam Melroy, commander; followed by George Zamka, pilot; and Scott Parazynski, Stephanie Wilson and Doug Wheelock, all mission specialists. The Discovery crew completed the 15-day STS-120 mission, with an on-time landing at 1:01:16 p.m. (EST). Wheel stop was at 1:02:07 p.m. Mission elapsed time was 15 days, 2 hours, 24 minutes and 2 seconds. The STS-120 crew continued the construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss.

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. Mission Specialist Doug Wheelock, who will be making his first shuttle flight, is welcomed by Shuttle Launch Director Michael Leinbach, at right. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here are Mission Specialists Daniel Tani (left) and Scott Parazynski, looking over the Italian-built U.S. Node 2, named Harmony. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Pilot George Zamka is donning his launch and entry suit to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Pilot George Zamka completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Daniel Tani is putting on his launch and entry suit for a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here are Mission Specialists Stephanie Wilson and Paolo Nespoli, who represents the European Space Agency. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Scott Parazynski completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- During emergency egress training as part of the pre-launch terminal countdown demonstration test, or TCDT, STS-120 crew members learn how to get out of the slidewire basket at the landing site. In the basket are Mission Specialists Doug Wheelock and Stephanie Wilson. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- During emergency egress training as part of the pre-launch terminal countdown demonstration test, or TCDT, STS-120 crew members practice getting out of the slidewire basket at the landing site. Jumping out is Mission Specialist Stephanie Wilson. Waiting his turn behind her is Mission Specialist Doug Wheelock. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here is Mission Specialist Paolo Nespoli, who represents the European Space Agency, pointing to the Italian-built U.S. Node 2, named Harmony. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here is Mission Specialist Paolo Nespoli, who represents the European Space Agency. He stands on a platform next to the Italian-built U.S. Node 2, named Harmony. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Commander Pamela Melroy completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- In space shuttle Discovery's payload bay, STS-120 crew members get a close look at the equipment and payloads. Seen here stretched out on a platform next to the Italian-built U.S. Node 2, named Harmony, is Mission Specialist Paolo Nespoli, who represents the European Space Agency. The TCDT provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Stephanie Wilson is helped with her boot during suitup for a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. Her name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. Pilot George Zamka, who will be making his first shuttle flight, prepares to exit the plane. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Paolo Nespoli is putting on his launch and entry suit for a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 speak to the media following their arrival at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. From left are Mission Specialists Daniel Tani, Paolo Nespoli, Doug Wheelock, Stephanie Wilson, Scott Parazynski; Pilot George Zamka and Commander Pam Melroy. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of space shuttle mission STS-120 prepare for their return to NASA's Johnson Space Center in Houston following three days of terminal countdown demonstration test, or TCDT, activities. At Kennedy Space Center's Shuttle Landing Facility, Pilot George Zamka, at left, and Mission Specialist Paolo Nespoli are packed and ready to board their aircraft. Nespoli is representing the European Space Agency on STS-120. The TCDT provides astronauts and ground crews with equipment familiarization, emergency egress training and a simulated launch countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station on a 14-day mission. Discovery's launch is targeted for Oct. 23 at 11:38 a.m. EDT. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of space shuttle mission STS-120 prepare for their return to NASA's Johnson Space Center in Houston following three days of terminal countdown demonstration test, or TCDT, activities. At Kennedy Space Center's Shuttle Landing Facility, Pilot George Zamka, in front, and Mission Specialist Paolo Nespoli secure themselves in a T-38 jet aircraft for takeoff. Nespoli is representing the European Space Agency on STS-120. The TCDT provides astronauts and ground crews with equipment familiarization, emergency egress training and a simulated launch countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station on a 14-day mission. Discovery's launch is targeted for Oct. 23 at 11:38 a.m. EDT. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- The crew members of mission STS-120 arrive at NASA's Kennedy Space Center Shuttle Landing Facility aboard T-38 jet aircraft to take part in terminal countdown demonstration test activities. Mission Specialist Paolo Nespoli, representing the European Space Agency on his first shuttle flight, is seen here with the space shuttle mate-demate device in the background. The terminal countdown demonstration test provides astronauts and ground crews an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission to the International Space Station. Photo credit: NASA_Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- STS-120 Mission Specialist Stephanie Wilson completes suiting up to take part in a simulated launch countdown, part of the prelaunch terminal countdown demonstration test, or TCDT. His name patch reflects the nicknames the crew gave each other for the event. The TCDT provides astronauts and ground crews an opportunity to participate in various launch preparation activities, including equipment familiarization, emergency training and the simulated countdown. The STS-120 mission will deliver the U.S. Node 2 module, named Harmony, aboard space shuttle Discovery to the International Space Station. Launch of Discovery on mission STS-120 is targeted for Oct. 23 at 11:38 a.m. EDT on a 14-day mission. Photo credit: NASA/Kim Shiflett

STS120-S-091 (7 Nov. 2007) --- NASA Administrator Mike Griffin and his wife Rebecca Griffin (left) greet astronaut Pam Melroy, STS-120 commander, at NASA's Kennedy Space Center. Behind Griffin is Associate Administrator for NASA Space Operations William Gerstenmaier. Melroy and the Space Shuttle Discovery crew completed the 15-day STS-120 mission, with an on-time landing at 1:01:16 p.m. (EST). Wheel stop was at 1:02:07 p.m. Mission elapsed time was 15 days, 2 hours, 24 minutes and 2 seconds. The STS-120 crew continued the construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss.