Basic cadet trainees march to Jacks Valley at the U.S. Air Force Academy, Colo. to begin two weeks of training that will test their stamina and determination. Included will be weapons training, confidence and assault training, drill evaluations, tent inspections and aerobic and physical fitness tests. (U.S. Air Force photo/Danny Meyer)

From cadet to lieutenant
The U.S. Air Force Thunderbirds perform an airshow after the 2007 U.S. Air Force Academy Graduation Ceremony May 30 in Colorado. The ceremony marks the culmination of four years at the academy and their transition from cadet to the Air Force's newest second lieutenants. (U.S. Air Force photo/David Armer)