Lt. Col. Hugh St. Martin assumes command of the 2nd Communications Squadron from Col. Craig Harding, 2nd Mission Support Group commander, during a change of command ceremony at Barksdale Air Force Base, La., July 7, 2015. The change of command ceremony is a military tradition that represents a formal transfer of authority and responsibility of a unit from one commanding officer to another. St. Martin has previously served for the Joint Chiefs of Staff as the chief of engineering and integration, directorate for command, control, communications and computers/cyber. (U.S. Air Force photo/Airman 1st Class Curt Beach)