How Capable Are Japanese Patriot Missiles Against Threats?

Last Line Of Defense

Ever since North Korea’s nuclear program and the development of ballistic missiles were exposed, Japan has been eager to create a Missile Defense system to intercept such threats.

This thirty-year effort has paid off, with the establishment of a two-layer defense:

(1) First attempt by Aegis destroyers at sea
(2) Final interception by land-based Patriot Missiles (PAC-3)

As such, the PAC-3 missiles are regarded as literally the last line of defense for Japan, leading to its procurement of more than 48 units.

• General Overview (PAC-3 MSE)

Developed by the US for air defense, the Patriot proved its usefulness in intercepting ballistic missiles during the 1991 Gulf War, and were later viewed by the Japanese government as a critical asset for countering the North Korean missile threat.

Though the Patriots were originally designed for anti-aircraft purposes, the PAC-3s introduced by Japan in 2006 were modified versions capable of destroying ballistic projectiles.

The PAC-3 was placed under the Air-Force (JASDF) rather than the Army, mostly because of JASDF’s historic role in handling airborne threats.

Each unit includes a launcher, multi-function radar, fire-control system, information processing device and a power supply equipment, all of which can be loaded on trucks for rapid deployment.

After deployment, the system can be remotely operated by a minimum of three people, and is able to perform independently in case communications with air defense command are severed.

The multi-function radar

In the event of actual combat, the unit will fire two PAC-3 missiles towards each target to ensure its certain kill.

Considering the fact that PAC-3s only have a range of 30km/18.6miles, the reaction time against warheads plunging at a speed of several miles per second is limited to less than a minute. So, this double insurance is actually rational to guarantee its effectiveness as the last line of defense.

Upon firing, the missiles are guided by the multi-function radar, later switching to its own active radar to seek and track targets.

Following final adjustments by small motor injections, the PAC-3 is to destroy its airborne target, but while the conventional version “the CRI (Cost Reduction Initiative)” directly collides with the enemy warhead, the newer “MSE (Missile Segment Enhancement)” uses a fragmentation method.