US Air Force (USAF) SENIOR AIRMAN (SRA) Andrea Howard, Food Service Chefs assigned to the 21st Space Wing (SW), Peterson Air Force Base (AFB), Colorado (CO), fires her 5.56mm M16A2 rifle from the prone position during the marksmanship competition conducted at Vandenberg Air Force Base (AFB) California (CA), during Exercise GUARDIAN CHALLENGE 2002. Guardian Challenge, a four-day space and missile competition, is hosted annually at Vandenberg AFB, CA to test the wartime readiness of Air Force Space Command (AFSPC) professionals