The main room of the aircraft engine test cell located in Bldg. 1500 on Ellsworth Air Force Base, S.D., July 19, 2012. B-1 engines are mounted inside the room using two overhead cranes and activated from a nearby control hub to ensure they are operationally ready, or to pinpoint the cause of a malfunction. (U.S. Air Force photo by Airman Ashley J. Cass/Released)