U.S. Air Force Lt. Col. Aaron Rigdon, 1st Aircraft Maintenance Squadron commander, secures his chemical mask during a combined Phase I and Phase II Operational Readiness Exercise at Langley Air Force Base, Va., April 19, 2012. The combined ORE tested Airmen’s ability to prepare for and deploy to a simulated combat zone. (National Guard photo by U.S. Air Force Master Sgt. Carlos Claudio/Released)