Marines with Lima Battery, 3rd Battalion, 11th Marine Regiment, fire M777A2 Lightweight Howitzers aboard Marine Corps Air Ground Combat Center Twentynine Palms, Calif., Dec. 11, 2012, during Exercise Steel Knight. Steel Knight is a combined arms exercise conducted by 1st Marine Division Marines and sailors from all elements of the Marine Air Ground Task Force. (U.S. Marine Corps photo by Lance Cpl Jason Morrison)