The WC-135 Constant Phoenix sits on the runway at Patrick AFB, Fla., during a visit to the base where its main mission headquarters, the Air Force Technical Applications Center, is located. The specially-configured aircraft is equipped with external flow devices that allow special equipment operators to collect airborne particulates in support of the U.S. Atomic Energy Detection System in the event of a nuclear detonation. (U.S. Air Force photo by Susan A. Romano)