A Japanese navy ship intercepted a medium-range ballistic missile in a test off Kauai, the U.S. and Japanese militaries said yesterday.

The drill was the third such test for Japan, which began investing in a U.S.-developed ballistic missile defense system after North Korea test-fired a long-range missile over northern Japan in 1998.
The U.S. fired the test’s target from the Pacific Missile Range Facility on Kauai, and the JS Myoko destroyer detected the target, tracked it, then fired an SM-3 interceptor missile from its deck.
The interceptor hit the target in space about 100 miles above the Pacific Ocean, the militaries said in a joint news release.
The target’s warhead separated from its booster rocket, so the interceptor had to distinguish between the two parts and hit the warhead.
Two U.S. Navy vessels based at Pearl Harbor, the USS Paul Hamilton and the USS Lake Erie, tracked the target alongside the Myoko.
The SM-3 interceptors fired from ships are designed to intercept missiles midway through their flights. The U.S. is developing other systems to shoot down missiles in their initial and final stages.
The Myoko is the third of four Japanese ships to be upgraded with ballistic missile defense technology.
The second, the JS Chokai, participated in a test off Hawaii last November but an unidentified problem prevented its interceptor from shooting down the target. An investigation is ongoing.
The first Japanese attempt, from the JS Kongo in 2007, was successful.
U.S. ships have intercepted target missiles multiple times in similar tests. The U.S.-created Aegis ballistic missile defense system is used by both nations but it’s been modified slightly to suit Japanese ship specifications.
Japan and the U.S. are also jointly developing future upgrades to the SM-3 missile.
In addition to the Aegis-sea based systems, Japan has deployed four PAC-3 missile defense units — each including several launchers, a radar vehicle and a control station — around Tokyo.
Japan plans to deploy the units at several more bases by March 2011.
The land-based PAC-3 anti-missile batteries are designed to shoot down missiles in their final stage of flight.