An interceptor missile fired from a Navy ship knocked a target rocket out of the sky over the Pacific on Thursday in the first successful test of a U.S. missile defense system in more than a year, military officials said.

In June, an interceptor missile missed the target rocket in a similar test.

An Aegis cruiser (search) launched a Standard Missile-3 interceptor (search) -- designed to destroy its target by colliding with it rather than using a large explosion -- from an undisclosed location in the Pacific. The defense has been compared to hitting a bullet with a bullet.

The target missile launched from Kauai was intercepted at 8:14 a.m. Hawaii time at an altitude of about 85 miles, said Chris Taylor, Washington-based spokesman for the federal Missile Defense Agency. The interceptor was traveling more than 8,000 mph, Taylor said.

Last December, President Bush ordered the Pentagon to have ready for use within two years a bare-bones system for defending American territory, troops and allies against attack by ballistic missiles.

Under Bush's plan, 20 Standard Missile-3 interceptors would be placed aboard three Navy ships with improved versions of the Aegis system.

This sea-based system was outlawed under the 1972 Anti-Ballistic Missile Treaty, but the United States withdrew from the treaty last year. The plan also calls for the development of ground-based interceptors.