Luke AFB hosts its third annual Thunderbolt Cup
Thunderbolt Cup participants climb up an obstacle during a mud run event as part of the third annual Thunderbolt Cup Sept. 27, 2018, at Luke Air Force Base, Ariz. The Thunderbolt Cup is a two-day, olympic-style event that tests Airmen's physical and mental readiness. (U.S. Air Force photo by Senior Airman Alexander Cook)