Japan has bought nine American SM3 anti-missile missiles, along with the needed upgrades to the Aegis radar systems on some of its warships (that use the SM-3 missile.) This is costing about half a billion dollars. Japan plans to equip half a dozen, or more, of its Aegis warships with the SM-3, to provide protection from North Korean, or Chinese, ballistic missiles. The SM-3 missile has been one of the bright spots in the American anti-missile effort. Japan has also agreed to contribute a billion dollars to the three billion dollar development work being done on the SM-3. The U.S. has already stationed Aegis SM-3 equipped ships off the coast of Korea, to provide protection against North Korean missiles.
The Standard 3 (or SM3) is designed to reach out 500 kilometers to hit incoming missiles. The Standard 3 is based on the failed anti-missile version of the Standard 2 and costs over three million dollars each. The Standard 3 has four stages. The first two stages boost the interceptor out of the atmosphere. The third stage fires twice to boost the interceptor farther beyond the earth's atmosphere. Prior to each motor firing it takes a GPS reading to correct course for approaching the target. The fourth stage is the 20 pound LEAP kill vehicle, which uses infrared sensors to close on the target and ram it.