Airmen duck for cover as a non-lethal grenade explodes during a Pre-Ranger Assessment, Feb. 11, 2018, at Moody Air Force Base, Ga. The three-day course is designed to determine whether Airmen are ready to attend the Air Force Ranger Assessment Course held at Fort Bliss Army Post, Texas. (U.S. Air Force photo by Senior Airman Janiqua P. Robinson)