Space Shuttle Discovery’s move from the Vehicle Assembly Building to the mate-demate device, or MDD, at the Shuttle Landing Facility, or SLF, is complete as the sun rises over NASA’s Kennedy Space Center in Florida. At the SLF, Discovery will be secured on the back of a Shuttle Carrier Aircraft, or SCA. The MDD is a large gantry-like steel structure used to hoist a shuttle off the ground and position it atop an SCA. The SCA is a Boeing 747 jet, originally manufactured for commercial use, which was modified by NASA to transport the shuttles between destinations on Earth. Discovery’s new home will be the Smithsonian National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Va.