The most important feature of this new Patriot system, however, will be a completely new missile, a variant of the Lockheed Martin ERINT (Extended Range Interceptor) commonly called PAC-3 (which is a bit confusing because the earlier PAC-3 configuration systems don't use this missile). The PAC-3 missile is highly optimized for the anti-missile role (employing a hit-to-kill capability enhanced by a fragmentation warhead), so that operational PAC-3 Patriot units will be equipped eventually with both MIM-104 and PAC-3 missiles. The latter is significantly smaller than an MIM-104, so that 16 missiles instead of four can be carried in a single launch station. ERINT was first flight-tested in 1992, and selected as the ultimate PAC-3 missile in 1994. The PAC-3/ERINT integration tests took place from 1995 to 1997, and the missile is currently in LRIP (Low Rate Initial Production) status. The PAC-3 missile was also selected as the missile component of the joint US/European MEADS (Medium Extended Air Defense System).
Japan Ground Self-Defense Force personnel stands near PAC-3, land-to-air missile, set up at a base amid the Democratic People's Republic of Korea's planned rocket launch in Akita, northern Japan, Tuesday, March 31, 2009. Batteries of PAC-3 land-to-air missile interceptors have been sent to two northern prefectures that the Democratic People's Republic of Korea's rocket is expected to fly over.