An AH-64 Apache helicopter from the First Battalion,

An AH-64 Apache helicopter from the First Battalion, 104th Aviation Regiment, Pennsylvania National Guard fires an M271 rocket at the Grayling Air Gunnery Range on Camp Grayling, Mich., during Northern Strike 15, July 28, 2015. Northern Strike combines ground and air capabilities and brings together aircraft from more than a dozen units, and service members from more than 20 states and four coalition countries from July 13 to Aug. 1 on Camp Grayling, Alpena and in Rogers City. Northern Strike is the only exercise of this size and scope for the Michigan Guard and integrates ground-based mortars and artillery weapon systems with attack aircraft to support maneuver forces on the ground. (Army National Guard photo by Master Sgt. Ron Raflik/Released)