Crews Prepare Cranes For Discovery's Arrival

Workers use two cranes to position the sling that will be used to demate the space shuttle Discovery, Monday, April 16, 2012, at the Apron W area of Washington Dulles international Airport in Sterling, Va. The sling will be used to demate the space shuttle Discovery from the 747 Shuttle Carrier Aircraft (SCA) once it arrives. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)