The U.S.A.F. Airborne Laser aircraft sits on the tarmac at Andrews Air Force Base outside Washington, June 21, 2007.
The modified 747 aircraft uses a high-energy Chemical Oxygen Iodine Laser to generate an energy beam from the aircraft's nose to intercept and
destroy a hostile ballistic missile during the boost phase of its trajectory. REUTERS/Larry Downing (UNITED STATES)