Japan’s BMD System

Q1 What is Ballistic Missile Defense (BMD) system in Japan?

A1.In the areas surrounding Japan, China and Russia deploy a great number of ballistic missiles which can deliver nuclear weapons. Ballistic missile test launches by North Korea have made the threat of ballistic missiles a reality.

In order to ensure readiness in response to armed attacks by ballistic missiles and other objects, Japan started developing the BMD system in 2004.

As depicted in the figure, Japan’s BMD system consists of:

  1. Aegis destroyers to intercept ballistic missiles at the mid-course phase,
  2. Patriot PAC-3 to intercept ballistic missiles at the terminal phase
  3. Sensor system to detect and track ballistic missiles; and
  4. Command and control, battle management, and communications system to systematically counter ballistic missiles by effectively coordinating the weapon systems and the sensor systems.

BMD Architecture and Concept of Operations (Image)

BMD Architecture and Concept of Operations (Image)

*What is Ballistic missile?
Ballistic missile Ballistic missile is a missile propelled by a rocket engine that flies in a parabolic arc and falls nearly vertically at high speed from a high altitude to reach its target. The ballistic missile can deliver heavy payloads and is used as a delivery vehicle of weapons of mass destruction such as nuclear, biological, and chemical weapons. Ballistic missiles are categorized into three types in terms of range: intercontinental ballistic missiles, medium-range ballistic missiles, and short-range ballistic missiles. The range varies from as short as several tens of kilometers to as long as over 10,000 kilometers. (Note: Distance between Tokyo and the Korean peninsula is approx. 900km; between Tokyo and Hawaii is approx. 6,400km.) Ballistic missiles can be also categorized into liquid propellant type and solid propellant type in terms of fuel. Generally, liquid propellant missiles require fuel to be injected taking an extended period of time prior to the launch. On the other hand, solid propellant missiles are characterized by a capability to be launched immediately because the propellant is pre-loaded.

Characteristics of Ballistic Missiles
Type Range Time Re-entry Speed
Short-range Ballistic Missile Approx. 1,000 km and less Approx. 5-10 min. 1~3 km/second (Approx. Mach 3-9)
Medium-range Ballistic Missile Approx. 1,000-5,500 km Approx. 10-20 min. 3~7 km/second (Approx. Mach 9-21)
Intercontinental Ballistic Missile Approx. 5,500 km- Approx. 20-30 min. 7~8 km/second (Approx. Mach 21-24)

*1. Medium-range Ballistic Missile can be categorized into intermediate class.
  2. (Ref.) The maximum speed of F-15 is Approx. Mach 2.5(Approx.0.85km/second).

Challenges to Interception of Ballistic Missiles
High speed Intercept speeds far exceed hitting a bullet with another bullet
Short Response time Time available to detect and intercept missiles is very short
High Altitude Advanced technology required capable of guiding interceptors accurately at extremely high altitudes
Small target Need improved radar capability to detect and track small,
high speed target missiles plus capability to destroy them by a hit-to-kill
Requires High Performance Intercept System

Q2 What is the current status of the BMD system development?

A2.By the end of fiscal year 2010, the Aegis destroyers of the MSDF, “Kongo,” “Chokai,” “Myoko,” and “Kirishima,” completed equipment with BMD capabilities.

Regarding the Patriot PAC-3, the ASDF successfully modified a total of 16 fire units of the 1st Air Defense Missile Group (Iruma), the 2nd Air Defense Missile Group (Kasuga), the 4th Air Defense Missile Group (Gifu), the Air Defense Missile Training Group and the 2nd Technical School (Hamamatsu) into PAC-3 capable units.

Q3 What is the future development plan of BMD system?

A3.Concerning Aegis Destroyers, in addition to the existing four “Kongo” class Aegis Destroyers, two “Atago” class Aegis Destroyers are to be equipped with BMD capabilities.

Regarding the Patriot PAC-3, one more fire unit of the 5th air defense missile group (Okinawa) will be upgraded into a PAC-3 capable unit. In parallel with the realignment of the existing PAC-3 units, every air defense missile group will have BMD capable PAC-3 fire unit.

Moreover, the MOD will continuously promote the Japan–U.S. cooperative development of the advanced ballistic missile interceptor (SM-3 Block IIA) in order to respond to future threats and enhance the capabilities of future interceptor missiles.

Future BMD System Improvements

  Destroyers equipped with Aegis system

Destroyers equipped with Aegis system

Strengthening of structure to deal with ballistic missiles by newly incorporating BMD capability to 2 Atago class Aegis ships in addition to the current 4 Kongo class Aegis ships.

  Patriot surface-to-air guided missile (PAC-3)

Deploy PAC-3 to all the SAM groups by upgrading 1FU of the 5th SAM group in Okinawa to PAC-3 and relocating already deployed PAC-3 units.

Patriot surface-to-air guided missile (PAC-3)

  Expansion of Defended Areas through Future Improvement in Capabilities of BMD Missiles (Image)

  Advanced Ballistic Missile Interceptor
(Japan – U.S. Cooperative Development)

Advanced Ballistic Missile Interceptor (Japan – U.S. Cooperative Development)

Continuously promote the Japan-U.S. cooperative development of advanced ballistic missile interceptor (SM-3 Block IIA) in order to respond to future threats.

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