The Shuttle Carrier Aircraft carrying space shuttle Discovery backs out of the Shuttle Landing Facility's mate-demate device at NASAâs Kennedy Space Center in Florida. The device, known as the MDD, is a large gantry-like steel structure used to hoist a shuttle off the ground and position it onto the back of the aircraft, or SCA. The SCA is a Boeing 747 jet that was originally manufactured for commercial use and modified by NASA to transport the shuttles between destinations on Earth. This SCA, designated NASA 905, is assigned to the remaining ferry missions, delivering the shuttles to their permanent public display sites. NASA 905 is scheduled to ferry Discovery to the Washington Dulles International Airport in Virginia on April 17, after which the shuttle will be placed on display in the Smithsonian's National Air and Space Museum Steven F. Udvar-Hazy Center. For more information on the SCA, visit www.nasa.gov/centers/dryden/news/FactSheets/FS-013-DFRC.html. For more information on shuttle transition and retirement activities, visit www.nasa.gov/transition. Photo credit: (NASA/Kim Shiflett)
