First Lt. Chris Sexton, 37th Bomb Squadron weapons system officer, performs an equipment check of his flight helmet at Ellsworth Air Force Base, S.D., April 29, 2015. Sexton is one of approximately 37 aircrew members from Ellsworth who participated in the Green Flag 15-07 exercise at the U.S. Army National Training Center at Fort Irwin, Calif. (U.S. Air Force photo by Senior Airman Anania Tekurio/Released)