Conventional maintenance crew members assigned to the 28th Munitions Squadron assemble inert guided bomb units during the Phase II portion of an operational readiness exercise at Ellsworth Air Force Base, S.D., July 10, 2013. The 28th MUNS Airmen are responsible for 1,707 munitions line items, 86 facilities and a 647-acre munitions storage area to support B-1 bomber operations. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)