U.S. Air Force Lt. Col. David Knesek returns from his last mission piloting a 307th Bomb Wing B-52H Stratofortress on April 24, 2015, Barksdale Air Force Base, La. Knesek is assigned to the 93rd Bomb Squadron at Barksdale and is retiring from the Air Force Reserve. (U.S. Air Force photo by Master Sgt. Greg Steele/Released)