The US Missile Defence Agency (MDA), Boeing, and Raytheon have pulled off an historic first as a dummy ICBM warhead was intercepted in space over the Pacific Ocean by not one, but two interceptor missiles. The test, called a "two-shot salvo," involved a target launched from Kwajalein Atoll in the Marshall Islands, which was destroyed by two Ground-based Midcourse Defense (GMD) system kill vehicles fired from Vandenberg Air Force Base in California.

Knocking out an ICBM warhead in flight has been compared to hitting a bullet with a bullet, but today's test was more like hitting a bullet with another bullet while a third bullet was flying in for a second tap – all the while assessing the situation and selecting its target.

For the test, two Raytheon Exoatmospheric Kill Vehicles (EKVs) zeroed in on a threat-representative dummy warhead high above the Earth's atmosphere on a suborbital trajectory. While in flight, the first EKV lined up to destroy the target, while the second monitored the impact and relayed the data to mission control before homing in to destroy additional debris that survived the first impact.

According to Raytheon, tracking and targeting data was provided by the company's Sea-Based X-band radar and AN/TPY-2 radar, but the EKVs themselves identified the threat before evading countermeasures and destroying the target. Because both the dummy warhead and the interceptors were flying at hypersonic speeds, no explosives were needed.

Today's test was the 11th GMD program intercept and the second of an ICBM. The GMD interceptors are based at Vandenberg Air Force Base and Alaska's Fort Greely, where their main mission is to protect North America from accidental and rogue-state nuclear attacks by intercepting and destroying missiles far from populated areas.

"The data collected from this test will enhance missile defense for years to come and solidify confidence in the system," says Paul Smith, Boeing vice president and program director, Ground-based Midcourse Defense. "We continue to increase the system's reliability as the US government plans to expand the number of interceptors protecting the country."

Sources: Boeing, Raytheon