U.S. Air Force crew chiefs, assigned to the 509th Aircraft Maintenance Squadron, talk with pilots during pre-flight operations at Global Thunder 17, Whiteman Air Force Base, Mo., Oct. 27, 2016. Exercise Global Thunder is U.S. Strategic Command’s annual field training and battle staff exercise to train Department of Defense forces and assess joint operational readiness. GT17 will provide training opportunities to and exercise scenarios for all USSTRATCOM mission areas, with a specific focus on nuclear readiness. (U.S. Air Force photo by Tech. Sgt. Andy Kin)