EIELSON AIR FORCE BASE, Alaska -- Airman 1st Class Zachary Garretson, 57th Aircraft Maintenance Squadron, Nellis Air Force Base, Nev., services the liquid oxygen system of an F-15C Aggressor on the flight line here July 9. Airman Garretson is a part of Red Flag-Alaska 07-3, a multi-service, multi-platform coordinated combat operations exercise, which runs through July 27. (U.S. Air Force photo by Airman 1st Class Christopher Griffin)