U.S. Air Force engineering technicians from the 8th Civil Engineer Squadron, replace the battery of a quadcopter at Kunsan Air Base, Republic of Korea, Nov. 2, 2018. The 8th CES is piloting a Rapid Airfield Damage Assessment System program to see how viable utilizing small unmanned aerial systems will be, instead of sending personnel into potentially hazardous environments to survey damage to the base. (U.S. Air Force photo by Senior Airman Stefan Alvarez)