Air Force Lt. Gen. Henry “Trey” Obering III, U.S. Missile Defense Agency director, said today that the Ground-based Midcourse Defense (GMD) element of the Missile Defense Agency emplaced the eighth interceptor missile designed to intercept and destroy a long-range ballistic missile into its underground silo at Ft. Greely, Alaska on December 17. Two interceptors are emplaced at Vandenberg Air Force Base, Calif.