By Andrea Shalal-Esa
WASHINGTON (Reuters) - The U.S. military on Tuesday conducted its first operational test of Lockheed Martin Corp's THAAD missile defense system paired with the ship-based Aegis system, intercepting two medium-range ballistic missiles fired nearly simultaneously.
The test was conducted early Tuesday near the U.S. Army Kwajalein Atoll test site and surrounding areas in the western Pacific, according to a Pentagon statement.
Missile defense experts and congressional sources said the test was important because it demonstrated the ability of the U.S. military to defend against possible regional ballistic missile threats from countries like Iran or North Korea or even accidental releases.
Launch crews had been waiting for nearly month for the test but were not given any specific details on when the missiles would be fired or from where, the sources said.
Rick Lehner, spokesman for the U.S. Missile Defense Agency, said Lockheed's Terminal High Altitude Area Defense (THAAD) system had been successfully tested 10 times, but this was the first operational test of that system and its ability to work together with the Aegis system on the USS Decatur, a guided-missile destroyer in the region.
The U.S. Defense Department said the flight test was planned more than a year ago and was not connected to events in the Middle East, where the United States is weighing a limited strike on Syria over its use of chemical weapons.
Earlier this year, after North Korea threatened to launch a nuclear attack on the United States, the Pentagon moved two Aegis guided-missile destroyers to the western Pacific and a THAAD system to Guam.
Riki Ellison, chairman and founder of the nonprofit group Missile Defense Advocacy Alliance, called the test a "tremendous achievement" and said it demonstrated the layered capabilities of the U.S. Ballistic Missile Defense System.
"This historic test presents the most realistic operational success of intercepting ballistic missiles with current capabilities," Ellison said. He urged the Pentagon to move a THAAD system to Turkey, Jordan or Israel to protect any potential chemical ballistic missiles fired by Syria.
Lehner declined comment when asked if there were plans to move the THAAD system to the Middle East.
In Tuesday's test, two medium-range ballistic missile targets were launched on operationally realistic trajectories towards a defended area near Kwajalein.
Those missiles were tracked using satellites and ground- and sea-based radars, which relayed that information to the destroyer, which used a Standard Missile-3 (SM-3) built by Raytheon Co to destroy one target, and to the THAAD system, which destroyed the second target missile.
The THAAD system also launched a second interceptor at the target destroyed by the ship-based Aegis system, in case that system missed its target, according to the Pentagon statement.
The Pentagon said U.S. Navy, Air Force and Army forces from multiple combatant commands operated the systems, giving them "a unique opportunity to refine operational doctrine and tactics while increasing confidence in the execution of integrated air and missile defense plans."
One congressional aide said the surprise nature of the test should answer critics who complained that the United States did not conduct realistic testing of its missile defenses.
"These guys were sitting out there for almost a month," said the aide, speaking on background. "They had no idea what they were going to be defending against, or when it would be."
Doug Graham, vice president of advanced programs for Strategic and Missile Defense Systems at Lockheed, said the test involved the first flight of a new enhanced target developed by Lockheed that is launched out of the back of a C-17 cargo plane.
Taylor Lawrence, president of Raytheon Missile Systems, said the test underscored the reliability of Raytheon's SM-3 missiles and AN/TPY-2 radars, which are deployed around the world.
"This operational test proves our nation has capable, reliable systems deployed today defending the U.S. and its allies against the growing ballistic missile threat," he said.
(Reporting by Andrea Shalal-Esa; Editing by Cynthia Osterman)