Paratroopers assigned to the 1st Battalion (Airborne), 501st Infantry Regiment, 4th Infantry Brigade Combat Team (Airborne), 25th Infantry Division, U.S. Army Alaska, fire a 120 mm mortar on Joint Base Elmendorf-Richardson, Alaska, Friday, April 3, 2015. The indirect-fire infantrymen directed accurate mortar fire on simulated hostile targets under stressed conditions testing reaction times and their mastery with the crew-served weapons. (U.S. Air Force photo/Justin Connaher)