WASHINGTON — The U.S. Missile Defense Agency (MDA) recently engaged and destroyed two missile targets over the Pacific Ocean in a complex exercise to test how the United States would react to multitiered attack, the agency said Sept. 10. As part of a contingency plan, the Army also fired a third interceptor missile in case the first two interceptors missed. The MDA did not say when the test occurred.

The targets included two air-launched medium-range ballistic missiles, the MDA said. The interceptors were the Standard Missile (SM)-3 Block 1A, an operational interceptor that is currently deployed aboard U.S. and Japanese navy ships, and a Theater High Altitude Area Defense (THAAD) interceptor, which is designed to destroy ballistic missiles both in and above Earth’s atmosphere. 

Raytheon Missile Systems of Tucson, Ariz. builds the SM-3. Lockheed Martin Space Systems of Denver is the prime contractor on the THAAD system, which includes a truck-mounted launcher, interceptor missiles, an AN/TPY-2 tracking radar and an integrated fire control system. 

The USS Decatur, using the Aegis Weapon System, detected and tracked the first target with an AN/SPY-1 radar and launched an SM-3 Block 1A missile, successfully intercepting the target, according to the release.

A radar with the THAAD weapon system then tracked the second target, leading to the launch of a THAAD interceptor that again destroyed the target. 

Finally, as a contingency plan, a second THAAD interceptor was launched at the first target in case the SM-3 missed, the MDA said.

The test, which included members of three armed services, took place over an area that included the Reagan Test Site on the Kwajalein Atoll in the western Pacific.

The event “demonstrated integrated, layered, regional missile defense capabilities to defeat a raid of two threat-representative medium-range ballistic missiles in a combined live-fire operational test,” an MDA press release said. “Soldiers, sailors, and airmen from multiple combatant commands operated the systems, and were provided a unique opportunity to refine operational doctrine and tactics while increasing confidence in the execution of integrated air and missile defense plans.”

An AN/TPY-2 radar and “overhead space assets” provided the launch alerts, the MDA said.

The cost of the test was approximately $180 million, said Richard Lehner, an MDA spokesman.

Defense Department officials stressed the test was not related to events in Syria and had been planned for more than a year. Budget documents show the event was originally planned for spring 2013.

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...