A B-1 bomber taxis to a runway prior to taking off for a training mission at Ellsworth Air Force Base, S.D., Sept. 10, 2013. The B-1 is the backbone of America’s long-range bomber force, providing the ability to rapidly deliver massive quantities of precision and non-precision weapons against enemy forces. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)