US missile defence system rocket successfully intercepts warhead

A US missile intercepted a mock strategic warhead launched into space over the Pacific Ocean on Friday 28 September in a successful test of a component of the futuristic US missile defence system. A representative of the Pentagon's Missile Defence Agency (MDA) said it was a direct hit.

The interceptor missile was launched from Vandenberg Air Force Base in California, 17 minutes after the target missile was launched from Kodiak Island in Alaska. The 'kill vehicle' deployed by the interceptor missile collided with the mock warhead boosted into space by the target missile. This is the seventh successful intercept since the Pentagon started anti-ballistic-missile (ABM) tests in 1999.

There have been 12 tests since the start of the programme, of which four failed. In May it had a "non test" when the target missile failed to launch. Each test costs about 100 million dollars. Friday's was the first intercept test in over a year.

The interceptor missile is guided into the path of the incoming long-range missile warhead. It then releases a 'kill vehicle' that is designed to seek out and steer itself into a collision with the warhead. MDA officials said an early warning radar at Beale Air Force Base in California tracked the target missile from the time of its launch.

A key objective of the test was to show that the recently upgraded radar was able to acquire, track and relay data on the target. Military crews manning the missile defence command centres were not told what time the target launch would occur, so they had to rely on data from the radar and other sensors to detect, track and target the missile.

The target warhead also was tracked by a huge floating X-Band radar in the Pacific and by a US Aegis warship with an onboard targeting radar.