ELLSWORTH AIR FORCE BASE, S.D. – Airman 1st Class Jordon Powers, 28th Security Forces Squadron patrolman, defends his position during a simulated ground attack of a phase II operational readiness exercise, July 21. Airman Powers, along with other security forces members, work 12-hour shifts during the exercise. (U.S. Air Force photo/Airman 1st Class Matthew Flynn)