A US test to knock out a dummy warhead in space has proved a success.
The Pentagon says its interceptor rocket hit the warhead 144 miles over the South Pacific on Monday night.
It is the third successful test of the controversial missile defence system.
The Minuteman ll missile was launched, after some delay for bad weather, from Vandenberg Air Force Base in California. The interceptor was launched 22 minutes later from Kwajalein Atoll in the Marshall Islands.
The dummy warhead carried a large balloon to be jettisoned in an attempt to fool the interceptor - a tactic the interceptor was programmed to ignore. The missile and rocket collided at 15,000mph.
Critics say the $100m test was unrealistic because the Pentagon already had exact information as to where the missile was.
But Lieutenant General Ronald Kadish said it was designed to test only certain parts of the system and was not meant to be realistic.
George W Bush says a defence system is needed to counter the threat of hostile nations aiming long-rage missiles at the US. Opponents, including Russia, say the system will violate the anti-ballistic missile treaty.