U.S. Soldiers assigned to 2nd Battalion, 150th Field Artillery Regiment, Indiana Army National Guard, fire a round from an M777 towed 155 mm howitzer during Northern Strike 2013 at Camp Atterbury, near Edinburgh, Ind., Aug. 14, 2013. Northern Strike is an Air National Guard-sponsored training exercise emphasizing air-to-ground operations intended to prepare personnel to conduct direct combat operations. (U.S. Army National Guard photo by John Crosby/Released)