Competition will speed up timeline to field next-gen homeland missile defense interceptor, MDA director says 3 hours ago A threat-representative ICBM target launches from the Ronald Reagan Ballistic Missile Defense Test Site on Kwajalein Atoll in the Republic of the Marshall Islands March 25, 2019. It was successfully intercepted by two long-range Ground-based Interceptors launched from Vandenberg Air Force Base, Calif., in the first salvo test of GBIs. (Photo courtesy of Missile Defense Agency) WASHINGTON — The Missile Defense Agency is aiming to get its first Next-Generation Interceptors to replace the current Ground-Based Interceptors that make up the United States’ homeland ballistic missile defense system by 2028, but the agency’s director anticipates being able to move more quickly.