Airman 1st Class Nathaniel Greene, 28th Communications Squadron ground radar maintenance technician, monitors air traffic control, weather, ground aircraft control and warning radar systems at Ellsworth Air Force Base, S.D., April 16, 2013. The central control workstation ensures that proper readings, data collection and efficient communication systems are operating without any malfunctions. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)