Air traffic control operation specialists from the 28th Operations Support Squadron keep an eye on the horizon for approaching inclement weather as the sun sets on Ellsworth Air Force Base, S.D., June 18, 2012. ATC specialists safely manage the flow of traffic on and around the base flightline and in a 50,000 square-mile air space. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)