U.S. Department of Defense - Missile Defense Agency

U.S. Department of Defense - Missile Defense Agency

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Sea-Based Weapons Systems

Aegis Ballistic Missile Defense (BMD) is the naval component of the Missile Defense Agency's Ballistic Missile Defense System (BMDS). Aegis BMD builds upon the Aegis Weapon System, Standard Missile, Navy and joint forces' Command, Control and Communication systems. The Commander, Operational Test and Evaluation Force, formally found Aegis BMD to be operationally effective and suitable. The Navy embraces BMD as a core mission. In recognition of its scalability, Aegis BMD/SM-3 system is a keystone in the Phased Adaptive Approach (PAA) for missile defense in Europe.

Regional Defense – Aegis BMD Engagement Capability

  • Defeats short- to intermediate-range, unitary and separating, midcourse-phase, ballistic missile threats with the Standard Missile-3 (SM-3), as well as short-range ballistic missiles in the terminal phase with the SM-2.
  • Flight tests are conducted by Fleet warships. Each test increases the operational realism and complexity of targets and scenarios and is witnessed by Navy and Defense Department testing evaluators.

Homeland Defense – Aegis BMD Long Range Surveillance and Track

  • Aegis BMD ships on Ballistic Missile Defense patrol, detect and track ballistic missiles of all ranges — including Intercontinental Ballistic Missiles and report track data to the missile defense system. This capability shares tracking data to cue other missile defense sensors and provides fire control data to Ground-based Midcourse Defense interceptors located at Fort Greely, Alaska and Vandenberg Air Force Base, California and other elements of the BMDS including land-based firing units (Terminal High Altitude Area Defense, Patriot) and other Navy BMD ships.


  • As of October 2017, there are 33 Aegis BMD combatants (5 cruisers [CGs] and 28 destroyers [DDGs] in the U.S. Navy. Of the 33 ships, 17 are assigned to the Pacific Fleet and 16 to the Atlantic Fleet. In response to the increasing demand for Aegis BMD capability from the Combatant Commanders, the MDA and Navy are working together to increase the number of Aegis BMD capable ships. Such efforts consist of upgrading Aegis DDGs to the BMD capability, incorporating Aegis BMD into the Aegis Modernization Program and new construction of Aegis BMD DDGs.
  • The first deployment of European PAA Phase I capabilities came on March 7, 2011, when the Aegis BMD cruiser, USS MONTEREY (CG-61), armed with SM-3 Block IA missiles, deployed to Europe.

International Efforts

  • SM-3 Cooperative Development Program is the joint U.S.-Japan development of a 21-inch diameter variant of the SM-3 missile, designated SM-3 Block IIA, to defeat longer range ballistic missiles. Deployment begins in 2018.
  • Japan has four KONGO Class Destroyers that have been upgraded with Aegis BMD operational capabilities.

Aegis Ashore

  • Aegis Ashore is the land-based component of the Aegis BMD system. The deckhouse and launchers – designed to be nearly identical to the version installed aboard U.S. Navy destroyers and cruisers – are equipped with the Aegis BMD weapon system and the SM-3.
  • Aegis Ashore is part of the European Phased Adaptive Approach (EPAA). The Aegis Ashore site in Romania was certified operational in 2016 as part of the EPAA Phase II. In 2018, Aegis Ashore will be installed in Poland as part of EPAA Phase III.
  • The Aegis Ashore Missile Defense Test Complex (AAMDTC) at the Pacific Missile Range Facility, Kauai, Hawaii, is a test and evaluation center used in the development of Aegis Ashore.

Future Capabilities

  • Engagement of longer range ballistic missiles.
  • Enhanced terminal capability against short and medium range ballistic missiles.
  • Increased number of ships and missiles.
  • More maritime ally involvement.