Discovery Mission STS-120

Space Shuttle Discovery deploys a parachute as it touches down at the shuttle landing facility at Kennedy Space Center Wednesday, Nov. 7, 2007, in Cape Canaveral, Fla. Discovery successfully completed its 15-day build and repair mission to the International Space Station.

The space shuttle Discovery glides over the Banana River before landing Wednesday, Nov. 7, 2007, at the Kennedy Space Center in Cape Canaveral, Fla.

The Space Shuttle Discovery flies around the international space station Monday, Nov. 5, 2007. The Discovery undocked from the space station in preparation for its return to earth.

Astronaut Scott Parazynski, anchored to a foot restraint on the end of the Orbiter Boom Sensor System, assesses his repair work as the solar array is fully deployed during the mission's fourth session of extravehicular activity while Space Shuttle Discovery is docked with the International Space Station Saturday, Nov. 3, 2007.

In this image taken from NASA television, a rip is seen in a second solar panel as it was unfurled after it was installed Tuesday, Oct. 30, 2007, by spacewalking astronauts Scott Parazynski and Douglas Wheelock. The astronauts abruptly stopped the unfurling of the second panel, however, as soon as they spotted the rip.

In this image made available by NASA, astronaut Scott Parazynski, STS-120 mission specialist, participates in the second of five scheduled sessions of extravehicular activity (EVA) as construction continues on the International Space Station, Sunday, Oct. 28, 2007.

In this image made available by NASA, astronaut Daniel Tani, Expedition 16 flight engineer, participates in the second of five scheduled sessions of extravehicular activity (EVA) as construction continues on the International Space Station, Sunday, Oct. 28, 2007.

In this image made available by NASA, the Space Shuttle Discovery is docked to the Pressurized Mating Adapter (PMA-2) on the International Space Station during the second session of extravehicular activity (EVA) for the STS-120 mission, Sunday, Oct. 28, 2007.

In this image made available by NASA, astronaut Peggy A. Whitson, left, Expedition 16 commander, and Pam Melroy, STS-120 commander, take a moment for a photo Saturday, Oct. 27, 2007 in the Unity node of the International Space Station while Space Shuttle Discovery is docked with the station. The joint mission of the two marks the first time both spacecraft have been commanded by females simultaneously.

In this image taken from NASA TV, space station Commander Peggy Whitson, left, welcomes space shuttle Discovery commander Pamela Melroy aboard the international space station Thursday, Oct. 25. 2007. Discovery docked with the international space station, and its crew prepared to embark on the most challenging construction work ever attempted in a single mission.

The space shuttle Discovery arches into orbit after launching off pad 39A, Tuesday, Oct. 23, 2007, at the Kennedy Space Center, Fla. Discovery blasted off successfully at 11:38 a.m. on a key mission to the international space station.

The space shuttle Discovery launches off pad 39A Tuesday, Oct. 23, 2007, at the Kennedy Space Center, Fla. Discovery is carrying a seven-person crew on a 14-day mission to the international space station. Discovery blasted off successfully at 11:38 a.m. ET.

Ponds surrounding the launchpad for space shuttle Discovery reflect the orbiter's flame during liftoff Tuesday Oct. 23, 2007, at the Kennedy Space Center in Cape Canaveral, Fla.

The space shuttle Discovery crew leaves the Crew and Check-Out building at the Kennedy Space Center, in Cape Canaveral, Fla. Tuesday, Oct. 23, 2007. Clockwise from front right: Commander Pamela Melroy, Pilot George Zamka, Mission Specialist Stephanie Wilson, Astronaut Daniel Tani, Astronaut Scott Parazynski, European Space Agency astronaut Paolo Nespoli, and Douglas Wheelock.

The Rotating Service Structure pulls away revealing the Space Shuttle Discovery Monday afternoon Oct. 22, 2007 at the Kennedy Space Center in Cape Canaveral, Fla.

A rainbow arcs past the space shuttle Discovery as it sits on launch pad 39A at the Kennedy Space Center in Cape Canaveral, Fla., Monday, Oct. 22, 2007. Discovery is scheduled to launch Oct. 23 to deliver the Harmony module to the International Space Station. The module will provide attachment points for European and Japanese laboratory modules.

The crew of the space shuttle Discovery, left to right, Commander Pam Melroy, Pilot George Zamka, Mission Specialists Scott Parazynski, Stephanie Wilson, Douglas Wheelock, Paolo Nespoli of the European Space Agency and Daniel Tani leave a shuttle training aircraft Friday, Oct. 19, 2007, upon their arrival at Kennedy Space Center, Cape Canaveral, Fla.

The space shuttle Discovery leaves the Vertical Assembly Building early Sunday, Sept. 30, 2007, at Kennedy Space Center, in Cape Canaveral, Fla., heading for launch pad 39A (background).

Space shuttle Discovery rolls out of the Vehicle Assembly Building atop the crawler transporter en route to launch pad 39A at Kennedy Kennedy Space Center Sunday, Sept. 30, 2007, in Cape Canaveral, Fla.

The space shuttle Discovery leaves the Vertical Assembly Building early Sunday, Sept. 30, 2007, at Kennedy Space Center, in Cape Canaveral, Fla., heading for launch pad 39A in preparation for a scheduled Oct. 23 launch.