A B-1 bomber assigned to the 34th Bomb Squadron takes off at Ellsworth Air Force Base, S.D., to participate in a Green Flag exercise at Nellis AFB, Nevada, April 7, 2016. Green Flag provides realistic training with more than 75 aircraft flying in various combat scenarios, preparing U.S. forces to fight in a high-tech combat environment. (U.S. Air Force photo by Airman 1st Class Denise M. Nevins/Released)