U.S. Air Force Senior Airman Jack Cortez, a vehicle operator with the 374th Logistics Readiness Squadron, drives a bus at Osan Air Base, South Korea, Aug. 26, 2014, during Ulchi Freedom Guardian 2014. Cortez, one of six vehicle operators, transported more than 200 military members to various locations around the base as part of his four-hour shift during the exercise. Ulchi-Freedom Guardian is an annual joint/combined command post exercise designed to ensure U.S.-South Korean ability to maintain stability on the Korean Peninsula.