Airmen from the 6th and 9th Air Refueling Squadrons, Travis Air Force Base, Calif., use a KC-10 Extender to refuel an F-15C Eagle, during exercise Northern Edge, May 14, 2019, at Joint Base Elmendorf-Richardson, Alaska. Units participating in Northern Edge have access to the Joint Pacific Alaska Range Complex, one of the largest training ranges in the world with approximately 65,000 square miles of available airspace; 2,500 square miles of land and 42,000 square nautical miles of surface, subsurfaces and overlying airspace. (U.S. Air Force photo by Master Sgt. Nathan Lipscomb)