– The U.S. Missile Defense Agency (MDA) said it conducted its second successful test June 5 of a sea-based interceptor intended to knock down incoming missiles in their terminal phase of flight.


U.S. Navy Rear Adm. Brad Hicks, Aegis Ballistic Missile Defense program manager at MDA, said in a June 5 conference call with reporters that the agency is planning to deploy the Standard Missile-2 Block 4 in the near future as an interim measure until it can develop a more capable missile.


There are two versions of the Aegis sea-based missile defense, one intended to engage missiles in their midcourse phase of flight and one for the terminal phase, when the warheads are nearing their target. The midcourse system, which utilizes the Standard Missile-3 interceptor, has been successfully tested several times to date and was used earlier this year to destroy a wayward U.S. spy satellite.


The terminal defense version of the Aegis system is of interest to commanders to augment the ground-based Patriot interceptor system, or to fill gaps where Patriots are not deployed, Hicks said.


Lockheed Martin Maritime Systems and Sensors of Moorestown, N.J., is the prime contractor for the Aegis missile defense effort. The Standard Missile-2 Block 4, initially developed as a self-protection measure for ships against cruise missiles and aircraft, is built by Raytheon Missile Systems of Tucson, Ariz.


During the June 5 test, which took place at the Pacific Missile Test Range off the coast of Hawaii, an Aegis ship fired two Standard Missile-2 Block 4 rockets, both of which exploded near the incoming target as planned, Hicks said.


Unlike the Standard Missile-3, which engages its targets outside the atmosphere and destroys them by force of direct impact, the Standard Missile-2 Block 4 is designed to explode near its target within the atmosphere. The target is destroyed by fragments from the blast. Hicks said
the target in this test featured a warhead that did not separate from its booster, similar to a Scud
missile, but declined to provide further
details except to say it was built outside of the United States.


The Standard Missile-3 already is deployed on a small number of Aegis ships. The MDA plans to equip ships with both types of interceptors in order to allow them to shoot at incoming targets during different phases of flight, Hicks said. This will require a software modification to enable the ships to fire the Standard Missile-2 Block 4, he said.


The MDA is planning a test for late 2008 that would involve a Standard Missile-3 interceptor fired from a Japanese ship, Hicks said. The agency may conduct another test in which
a Standard Missile-3 will be fired from a U.S. ship if it can secure the funding to do so, he said.


Land-based deployment of the Standard Missile-3 also is possible in the future, though the MDA has no firm plans for that at the moment, Hicks said. The agency has fired the missiles from land in the past during testing at White Sands Missile Range, he said.