The US Military has shot down a mock enemy missile in what was the most complex and challenging test of the missile defence system to date.

A mock enemy missile fired from Kodiak in Alaska, was successfully exploded over the coast of California by an interceptor missile fired from Vandenberg Air Force Base in California.

The operation marked the first time that a synchronised network of varied sensor types and frequencies had been used to successfully track, report and intercept a single target.

Army Lt. Gen. Patrick J O’Reilly said that the core of the missile defence system is the ability to operate in layers and have multiple systems working together.

“The key is to have all of these different sensors simultaneously tracking, and working together to know that it is not multiple objects but one object up there,” O’Reilly said.

The test combined an early warning radar system, a mobile radar system, two Aegis ballistic missile defence ships off the Pacific coast and a sea-based radar system.

Each of the systems was networked together, despite their varied sizes and frequencies, to form an accurate, single-target track.

US officials had hoped to deploy countermeasures during the flight that would test the system’s reaction to multiple objects such as chaff, decoys or replicas; however the countermeasures failed to deploy.

Lt. Gen O’Reilly commented that “Countermeasures are very difficult to deploy. Even though countermeasures didn’t deploy, the upper stage of the mock enemy missile was still in the area, however, this meant that the interceptor still saw two objects and had to understand the data sent from the sensors to discern which object to hit,” O’Reilly said.

This test cost $120m to $150m. 13 similar tests have been conducted since 1999, seven successfully hitting their targets.

The US military has 24 ground-interceptors in silos in Alaska and California, and 21 sea-based interceptors.

By Daniel Garrun.