A Standard Missile (SM-3) is launched from the Aegis combat system equipped Arleigh Burke class destroyer USS Decatur (DDG 73) during a Missile Defense Agency ballistic missile flight test. Minutes later the SM-3 intercepted a separating ballistic missile threat target, launched from the Pacific Missile Range Facility, Barking Sands, Kauai, Hawaii. It was the first time such a test was conducted from a ballistic missile defense equipped-U.S. Navy destroyer. The previous flight tests were conducted from U.S. Navy cruisers. The maritime capability is designed to intercept short to intermediate-range ballistic missile threats in the midcourse phase of flight. USS Decatur is one of 18 U.S. Navy ships (three cruisers and 15 destroyers) that will be identically equipped, by early 2009, with the ballistic missile defense capabilities of conducting long-range surveillance/tracking and launching the SM-3 missile. U.S. Navy Photo (Released)
The Missile Defense Advocacy Alliance calls it a Hat Trick:
It was the first intercept from a United States Destroyer, the USS Decatur (DDG 73); the first active participation by the country of Spain and their Spanish frigate, MENDEZ NUNEZ; and the first integration of sharing information with a ground based missile defense system — the Terminal High Altitude Area Defense, THAAD.
UPDATE: A commenter asked about the Mendez Nunez’s involvement. Details are sketchy, but it appears that the Mendex Nunez’s Aegis system fed course-correction data to the Decatur. USS Port Royal (CG 73) also contributed tracking data and helped with the differentiation between the separated warhead and the missile itself.
More here: Lockheed Martin Aegis Ballistic Missile Defense System Successfully Destroys Medium-Range Separating Ballistic Missile During Test