Senior Airman Joseph Fletcher and Airman 1st Class Christopher Kelly inspect a TPS-75 radar March 13, 2012, in Southwest Asia. The TPS-75 is being replaced by a new Three-Dimensional Long-Range Radar (3DELRR) system that will serve as the Air Force's primary long-range, ground-based sensor for detecting, identifying, tracking and reporting aerial targets. A contract was awarded to Raytheon for the engineering, development and manufacturing of the system, Oct. 6, 2014. (U.S. Air Force photo/Staff Sgt. Nathanael Callon)