Space shuttle Discovery attached to a purge unit that pumps conditioned air into the shuttle.

Space shuttle Discovery, attached to a purge unit that pumps conditioned air into the shuttle while it is towed, rolls along the towway from the Shuttle Landing Facility to Orbiter Processing Facility-2 at NASA's Kennedy Space Center in Florida. In the distance at left is the 525-foot-tall Vehicle Assembly Building. Discovery touched down on Runway 15 at 11:57 a.m., bringing an end to its 39th and final spaceflight mission, STS-133. Discovery and its six-member STS-133 crew delivered the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station.

Inside the processing facility, Discovery will be prepared for future public display. Photo credit: NASA/Kim Shiflett