Mobility Ship-based and highly mobile
Targets Short-, medium-, and intermediate-range ballistic missiles
Role Sea-based variant of the Aegis BMD designed to provide both regional and homeland missile defense and surveillance
Interceptors Standard Missile-2 (SM-2)–approx. 75-165 km range; Standard Missile-3 (SM-3)–approx. 700 km (Block IA/IB) and approx. 1,500 km (Block IIA); Standard Missile-6 (SM-6)–approx. 240-370 km
Status Deployed in U.S. fleets in the Pacific and Atlantic; Japan has four KONGO Class Destroyers and South Korea has three Sejong the Great Class Destroyers with Aegis BMD capabilities
Producer Lockheed Martin (Standard Missiles produced by Raytheon)



Aegis Afloat is the sea-based component of the Missile Defense Agency’s Ballistic Missile Defense System (BMDS). Aegis BMD builds upon the Aegis Weapon System, Standard Missile, and Navy and joint forces’ Command, Control and Communication systems. The U.S. deploys Aegis BMD to provide both regional and homeland missile defense. In recognition of its scalability, Aegis BMD/SM-3 system is a keystone of the European Phased Adaptive Approach (EPAA).

The sea-based component of Aegis BMD employs Aegis-equipped cruisers and destroyers to intercept short-, medium-, and intermediate-range ballistic missiles in the midcourse and terminal phases of flight using hit-to-kill technology. Aegis vessels are also able to identify, track, and intercept low-flying cruise missiles. In addition to shorter range threats, Aegis BMD is employed to identify and track long-range ballistic missiles that—once identified—can subsequently be engaged by the Ground-based Midcourse Defense (GMD) system. Components of Aegis BMD include AN/SPY-1 radar fielded aboard Aegis vessels, the MK 41 Vertical Launching System, Command and Decision System, Global Command and Control System, Aegis Display System, and Standard Missile-2 (SM-2), Standard Missile-3 (SM-3), and Standard Missile-6 (SM-6) interceptors. [1] In addition to SPY-1 radar, Aegis BMD can also coordinate with the land-based Army/Navy Transportable Surveillance (AN/TPY-2) radar. As mandated by the EPAA, Aegis BMD has also been modified for use on land. Called Aegis Ashore, this land-based component of Aegis BMD is currently operationally deployed in Romania, with a corresponding test site in Kauai, Hawaii and plans to operationally deploy another system in Poland in 2018. Future capabilities of Aegis BMD include engagement of longer-range ballistic missiles, improving existing early intercept capability, enhancing terminal capability against short- and medium-range ballistic missiles, increased number of ships and missiles, and more maritime ally involvement.

Aegis Ballistic Missile Defense Interceptors

Interceptor Role Missile Targets
Standard Missile-2 (SM-2) Endoatmospheric ballistic missile defense and air defense Short-range ballistic missiles and cruise missiles
Standard Missile-6 (SM-6) Endoatmospheric ballistic missile defense, air defense, and capable of striking land targets Short-range ballistic missiles and cruise missiles
Standard Missile-3 (SM-3) Exoatmospheric kinetic ballistic missile defense Short- to intermediate-range ballistic missiles

Aegis Air Defense Interceptors

Interceptor Targets
Standard Missile-2 (SM-2) Cruise missiles; aircraft; unmanned aerial vehicles; short-range ballistic missiles in the terminal phase
Standard Missile-6 (SM-6) Cruise missiles; aircraft; unmanned aerial vehicles; short-range ballistic missiles in the terminal phase
Sea Sparrow Missile High-Speed, Low-Altitude Anti-Ship Cruise Missiles; Helicopters; UAS; other low-velocity air-threats
Evolved Sea Sparrow Missile (ESSM) High-Speed, Low-Altitude Anti-Ship Cruise Missiles; Helicopters; UAS; other low-velocity air-threats; High-Speed Maneuverable Surface Threats

Software Aegis BMD systems are programmed with highly sophisticated software to help identify, track, target, and intercept missile threats. This advanced software has resulted in a very successful test record—85% intercept success rate—and has established Aegis BMD as one of the most successful missile defense systems employed by the United States. Over time, Aegis BMD software has been incrementally modernized and improved. Software version 3.6 is the earliest form of Aegis BMD software that is still employed, and is used by around 17 deployed Aegis vessels. Aegis BMD 3.6 configuration allowed for Long Range Surveillance and Track (LRS&T) of ICBMs and intercept—using SM-3 Block IA interceptors—of short- to intermediate-range ballistic missiles in the midcourse and terminal phases. Aegis BMD 4.0 is the second generation of Aegis BMD software and—in accordance with the SM-3 Block IB—allows for the engagement of increasingly longer range and more sophisticated ballistic missiles. Nearly 9 deployed Aegis BMD vessels are equipped with the 4.0 software.

Aegis BMD 5.0 is the most modern software upgrade—currently equipped by around two deployed Aegis vessels—and increases the sea-based BMD force structure. The capability of Aegis BMD 5.0 was improved significantly by software upgrade Baseline 9, which integrates Aegis BMD vessels with other missile defense sensors and systems and allows them to engage cruise and ballistic missiles simultaneously. Baseline 9 was first tested in November 2014, when the guided-missile destroyer USS John Paul Jones (DDG 53) successfully intercepted a short-range ballistic missile and two cruise missiles. Around 4 deployed Aegis BMD vessels are equipped with upgraded Aegis 5.0 Baseline 9 software. The Aegis BMD 5.1 was first demonstrated on February 6th, 2017 and will integrate the SM-3 Block IIA interceptor into the combat system to defeat longer-range ballistic missiles and allow the capability to engage on remote.

Regional Defense –Aegis BMD Engagement Capability Aegis BMD 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. Fleet warships conduct flight tests for Aegis BMD and each test increases the operational realism and complexity of targets and scenarios. Aegis BMD-capable vessels are deployed to Europe, Asia, and the Middle East to provide regional missile defense. In Europe, the sea-based Aegis BMD and the land-based Aegis Ashore provide regional missile defense as mandated by the EPAA. Phase I of the EPAA called for deployment of Aegis BMD ships and land-based radar in Europe by the end of 2011. The first phase mandated that four Aegis ships be anchored in Rota, Spain. From there, these vessels deploy throughout the Mediterranean and Persian Gulf to protect southern Europe from ballistic missile attacks coming out of the Middle East. Phase II (2015) and III (2018) of the EPAA mandate interceptor improvements for Aegis-capable ships in Europe and the development of Aegis Ashore sites in Romania and Poland.

Homeland Defense – Aegis BMD Long Range Surveillance and Track Aegis BMD ships patrol, detect, and track ballistic missiles of all ranges – including intercontinental ballistic missiles—and report tracking 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 (GMD) interceptors located at Fort Greely, Alaska and Vandenberg Air Force Base, California. Tracking data is also provided to other elements of the BMDS including land-based firing units—Terminal High Altitude Area Defense, Patriot (PAC-3)—and other Navy BMD ships.

International cooperation Aegis BMD is the first missile defense capability produced by the MDA to be purchased by a military ally, Japan, which deploys four KONGO Class Destroyers that are equipped with Aegis BMD capabilities. In addition, Spain, South Korea, and Australia either operate, are building, or plan to build Aegis BMD ships.

Deployment As of April 2018, there are 36 Aegis BMD combatants (5 cruisers [CGs] and 31 destroyers [DDGs]) in the U.S. Navy. Of the 36 ships, 20 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. As mandated by the EPAA, Aegis BMD vessels have been deployed to Europe, the Mediterranean, and the Persian Gulf since 2011. [2]

Deployed Ships

Hull Number Name Version Homeport
CG-70 Lake Erie 4.0 San Diego, CA
DDG-113 John Finn 5.0 (Baseline 9) San Diego, CA
DDG-73 Decatur 4.0 San Diego, CA
DDG-76 Higgins 3.6 San Diego, CA
DDG-59 Russell 3.6 San Diego, CA
DDG-115 Rafael Peralta 5.0 (Baseline 9) San Diego, CA
DDG-60 Paul Hamilton 3.6 San Diego, CA
DDG-114 Ralph Johnson 5.0 (Baseline 9) Everett, Washington
DDG-53 John Paul Jones 5.0 (Baseline 9) Pearl Harbor, HI
DDG-77 O’Kane 3.6 Pearl Harbor, HI
DDG-73 Port Royal 3.6 Pearl Harbor, HI
DDG-70 Hopper 3.6 Pearl Harbor, HI
DDG-69 Milius 5.0 (Baseline 9 2018) Yokosuka, Japan
DDG-65 Benfold 5.0 (Baseline 9) Yokosuka, Japan
CG-67 Shiloh 4.0 Yokosuka, Japan
DDG-63 Stethem 3.6 Yokosuka, Japan
DDG-52 Barry 5.0 (Baseline 9) Yokosuka, Japan
DDG-54 Curtis Wilbur 4.0 Yokosuka, Japan
DDG-56 John S. McCain 4.0 Yokosuka, Japan
DDG-62 Fitzgerald 3.6 Yokosuka, Japan



Hull Number Name Version Homeport
CG-72 Vella Gulf 3.6 Norfolk, VA
CG-61 Monterey 3.6 Norfolk, VA
DDG-61 Ramage 5.0 (Baseline 9) Norfolk, VA
DDG-55 Stout 3.6 Norfolk, VA
DDG-58 Laboon 3.6 Norfolk, VA
DDG-72 Mahan 3.6 Norfolk, VA
DDG-67 Cole 4.0 Norfolk, VA
DDG-74 Mcfaul 4.0 Norfolk, VA
DDG-66 Gonzalez 4.0 Norfolk, VA
DDG-51 Arleigh Burke 5.0 (Baseline 9) Norfolk, VA
DDG-57 Mitscher 5.0 (Baseline 9) Norfolk, VA
DDG-68 The Sullivans 3.6 Mayport, FL
DDG-71 Ross 3.6 Rota, Spain
DDG-64 Carney 4.0 Rota, Spain
DDG-75 Donald Cook 4.0 Rota, Spain
DDG-78 Porter 4.0 Rota, Spain

Strategic Implications

Europe The developing ballistic missile programs of nations like Iran pose a threat to the European allies of the United States. To counter this emerging threat, the Obama Administration announced the EPAA, which called for an improved missile defense capability in Europe to counter any short- to intermediate-range ballistic missile threats coming from the Middle East. The EPAA mandates the deployment of sea- and land-based Aegis BMD systems to protect Europe from ballistic missile attack and assures our European allies of U.S. commitment to their security. This commitment is becoming increasingly important as nations like Iran continue to improve their ballistic missile capabilities and develop weapons that can strike U.S. partners and allies in Europe.

Asia The nuclear and ballistic missile capabilities of North Korea and China pose a threat to U.S. allies in the Asia-Pacific region. U.S. allies most threatened are South Korea and Japan. To strengthen cooperation with these allies and appease their security concerns, the U.S. has deployed six Aegis-capable vessels to Japan and five to Hawaii, with an additional five in San Diego. These Aegis BMD vessels not only defend against a potential ballistic missile attack, but also strengthen the deterrence capability of U.S. allies in the region. Japan’s four KONGO Class Destroyers also bolster the deterrence capabilities of U.S. allies in Asia.

Recent News


  • October 15, 2017  – During the 2017 Formidable Shield Exercise, the U.S. guided-missile destroyer USS Donald Cook successfully detected, tracked and intercepted a medium-range ballistic missile target with a Standard Missile-3 Block IB guided missile.
  • October 7, 2017 – The Arleigh Burke-class guided-missile destroyer USS Mitscher (DDG 57) fired Standard Missiles-2 at the incoming Mirach and Firejet anti-ship cruise missiles as part of a no-notice launch of anti-ship cruise missiles in the IAMD exercise scenario.
  • August 29, 2017 – This test marked the second time the SM-6 Dual 1 intercepted a complicated medium range ballistic missile target and was the third successful test of the SM-6. This also marked the seventh successful test of the Aegis Baseline 9.0 software.
  • June 22, 2017: The USS John Paul Jones (DDG 53) unsuccessfully conducted an intercept test using the SM-3 Block IIA interceptor, which is cooperatively developed by the United States and Japan. A medium-range ballistic missile target was launched from the Pacific Missile Range Facility at Kauai, Hawaii. The USS John Paul Jones detected and tracked the missile target with its onboard AN/SPY-1 radar and Aegis Baseline 9 C2 weapon system. The ship launched an SM-3 Block IIA missile, but the missile did not intercept the target.
  • June 2, 2017: The U.S. Navy commissioned the USS John Finn (DDG 113) built by Ingalls Shipbuilding. The USS John Finn is an Arleigh-Burke class guided missile destroyer, equipped with Baseline 9 software, enabling the vessel to conduct integrated air and missile defense missions. The USS John Finn is fitted with Aegis Ballistic Missile Defense version 5.0 software and Naval Integrated Fire Control-Counter Air (NIFC-CA). The ship is scheduled to join the U.S. 3rd fleet and U.S. Naval Surface Forces.
  • February 3, 2017: The USS John Paul Jones (DDG 53) successfully conducted an intercept test using the SM-3 Block IIA interceptor, which is cooperatively developed by the United States and Japan. The test, which occurred in the Pacific Ocean near Hawaii, marked the first successful intercept test using the SM-3 Block IIA. Intercepted during the test was a medium-range ballistic missile target, which fired from the Pacific Missile Range Facility in Kauai, Hawaii.
  • August 2016: Aegis fleet in the U.S., Japan, and the Republic of Korea are bringing Integrated Air and Missile Defense (IAMD) capabilities to new Destroyers. The ships will be equipped with the latest Aegis system, Baseline 9, which is capable of IAMD. Japan will add two more Aegis capable ships to their fleet. South Korea will add 3 KDX-III Destroyers equipped with Aegis.
  • May 2016: The USS JOHN PAUL JONES used Aegis Baseline 9 terminal engagement capability to detect and track a medium range ballistic missile (MRBM) target. This exercise marked the first demonstration of Aegis’s ability to conduct a complicated tracking exercise against a MRBM during its endo phase of flight.
  • December 2015: The Japan Ministry of Defense (MOD) Acquisition, Technology and Logistics Agency (ATLA), and the MDA—in cooperation with the U.S. Navy—successfully conducted an SM-3 Block IIA flight Test from Point Mugu Sea Range, San Nicolas Island, California. The missile successfully demonstrated flyout through kinetic warhead ejection. No intercept was planned and no target missile was launched.
  • November 2015: The MDA, BMDS Operational Test Agency, Joint Functional Component Command for Integrated Missile Defense, U.S. European Command, and the U.S. Pacific Command conducted a complex operational flight test of the Ballistic Missile Defense System, demonstrating a layered defense architecture. The test stressed the ability of Aegis BMD and Terminal High Altitutde Area Defense (THAAD) weapon systems to negate two ballistic missiles threats while Aegis BMD simultaneously conducted an anti-air warfare operation.
  • October 2015: The U.S. Navy and eight other countries successfully conducted a detect-to-engage integrated air and missile defense exercise in the North Sea, during which the coalition simultaneously intercepted a ballistic missile in space and an anti-ship cruise missile target. This was the first missile defense test of its kind in Europe.
  • August 2015: The MDA, U.S. Pacific Command, and U.S. Navy successfully conducted a series of four flight test events at Kauai, Hawaii demonstrating successful intercepts of short-range ballistic missiles and cruise missiles with SM-6 Dual I and SM-2 Block IV interceptors. This was the first live fire event of the SM-6 Dual I missile.
  • June 2015: The U.S. and Japan announced the successful completion of a SM-3 Block IIA flight test from the Point Mugu Sea Range, San Nicolas Island, California. This was the first flight test of the SM-3 Block IIA, which is an interceptor variant designed to intercept medium- and intermediate-range ballistic missiles. Deployment of the SM-3 Block IIA is scheduled to begin in 2018.
  • July 2013: FTG-07 used Aegis BMD to identify and track a ballistic missile target that was intercepted by the GMD system. The Ground-Based Interceptor was fired based on tracking data supplied by the USS LAKE ERIE (CG 70), the first use of an Aegis BMD ship as a launch-on-sensor in a Ground-based Midcourse Defense test. [3]
  • May 2012: Flight Test Mission 16 Event 2a was conducted. This flight test was the first successful live fire intercept test of the second generation Aegis BMD Weapon System, BMD 4.0.1, and the SM-3 Block IB missile. In May 2012, the USS LAKE ERIE (CG 70) successfully intercepted a short-range ballistic missile target over the Pacific Ocean. Aegis BMD 4.0.1 and the SM-3 Block IB missile enable the engagement of increasingly longer range and more sophisticated ballistic missiles. This was Aegis BMD’s 22nd successful intercept out of 27 missile firings against various targets. [4]
  • October 2011: The U.S., Spain, and NATO jointly announced that the U.S. would forward-deploy four Aegis-capable ships to Rota, Spain as part of the EPAA. These Aegis ships anchored in Rota, Spain deploy throughout the Mediterranean to protect southern Europe against short- and medium-range ballistic missiles coming out of the Middle East.
  • April 2011: The MDA, U.S. Navy, and U.S. Army conducted a successful intercept of an intermediate-range ballistic missile using an SM-3 Block IA interceptor over the Pacific Ocean. Aegis BMD launched an SM-3 Block IA missile using track data from the AN/TPY-2 radar that was passed through the Command and Control Battle Management and Communication system to intercept an IRBM target to demonstrate the EPAA Phase 1 capability. This firing was the first Launch on Remote (LOR) Aegis BMD engagement and intercept of an IRBM. The firing was also outside the original design specifications for the SM-3 Block IA missile. [5]
  • March 2011: During Flight Test Mission 16, Event 1, the USS LAKE ERIE successfully tracked a ballistic missile target. In addition to the BMD mission, the LAKE ERIE also validated the ship’s Anti-Air Warfare (AAW) capability by destroying an incoming anti-ship cruise missile target with an SM-2 Block III missile in a live firing exercise. This was the first event in which a ship used BMD 4.0.1 Weapon System to engage an AAW threat. [6]
  • October 2009: During FTX-06 Events 1 through 4, the guided missile Aegis cruiser USS LAKE ERIE (CG 70), upgraded with the BMD 4.0.1 Weapon System, successfully detected, tracked, and conducted simulated SM-3 Block IB engagements against a variety of different ballistic missile targets during a series of tracking exercises. The targets ranged from simple separating medium-range missiles to sophisticated, separating short-range missiles designed to confuse missile defense systems. All test objectives were met. Also, Japan Flight Test Mission (JFTM) 3 took place, during which the USS LAKE ERIE tracked separating ballistic missile targets with the second generation Aegis BMD Weapon System, BMD 4.0.1. In October 2010, JFTM 4 was carried out and conducted a test similar to JFTM 3. [7]
  • September 2009:Obama announced the EPAA, canceling a Bush Administration plan to place a third Ground-based Midcourse Defense (GMD) system in Poland. The EPAA focused on short- to intermediate-range threats originating from the Middle East and called for sea- and land-based Aegis BMD systems to be deployed incrementally throughout Europe from 2011 to 2018.
  • February 2008: A BMD-capable Aegis cruiser deployed northwest of Hawaii shot down an inoperable U.S. surveillance satellite that was in a deteriorating orbit. [8]
  • December 2007: In a flight test, a BMD-capable Japanese Aegis destroyer used an SM-3 Block IA missile to successfully intercept a ballistic missile target off the coast of Hawaii. This was the first time that a non-U.S. ship had intercepted a ballistic missile using the Aegis BMD system.
  • 2005: In 2005, Aegis BMD’s role evolved to include an engagement capability. Aegis BMD ships armed with the SM-3 Block IA were capable of intercepting short- to intermediate-range ballistic missiles in the midcourse phase of flight. In 2006, Aegis BMD engagement capabilities were expanded to include the terminal intercept capability.


[1] “Aegis Ballistic Missile Defense System,” Lockheed Martin. http://www.lockheedmartin.com/us/products/aegis/aegis-bmd.html

[2] “Aegis Ballistic Missile Defense,” U.S. Department of Defense: Missile Defense Agency. http://www.mda.mil/system/aegis_bmd.html.

[3] “Aegis BMD Evolution,” U.S. Department of Defense: Missile Defense Agency, http://www.mda.mil/system/aegis_evolution.html.

[4] Ibid.

[5] Ibid.

[6] Ibid.

[7] Ibid.

[8] O’Rourke, Ronald. “Navy Aegis Ballistic Missile Defense (BMD) Program: Background and Issues for Congress.” Congressional Research Service. December 11, 2015. https://www.fas.org/sgp/crs/weapons/RL33745.pdf.


Missile Defense


International Cooperation