Ramon Lopez/WASHINGTON DC

A second "hit-to-kill" National Missile Defence (NMD) flight test, set for 18 January by the US Ballistic Missile Defense Organization (BMDO), will be technically more challenging than the first last October.

The first successful intercept test, IFT-3, was primarily to demonstrate the hit-to-kill capability of the Raytheon-built exoatmospheric kill vehicle (EKV).The latest test, IFT-4, will include the use of the Defense Support Program satellite system to provide space-based warning of target missile launches, ground-based X-band radar for precision target-tracking and ground-based early warning radars.

Also involved in the test will be battle management, command, control and communications (BM/C3) assets to fuse together sensor information and the interceptors and provide supervision of what is largely an automated process. Eventually the BM/C3 will send targeting updates via the In-Flight Interceptor Communications System (IFICS).

In the October test, the EKV was delivered into a "basket" by pre-programming the target and the interceptor, testing the EKV's ability to intercept and kinetically destroy the target, rather than the NMD radars' tracking and guidance capabilities.

During IFT-4, a modified Minuteman intercontinental ballistic missile with a mock re-entry vehicle and large balloon decoy will be launched from Vandenberg AFB, California, while a surrogate NMD interceptor will be fired from Kwajalein Island Atoll in the central Pacific. A first test of the NMD interceptor is set for April, while IFT-7 - planned for next year - will be the first full NMD test using the interceptor. IFT-5 is due in late April or early May, and will include IFICS.

Weighing about 55kg (120lb), the EKV has two infrared sensors, a visible-light sensor and a small propulsion system.

Boeing is NMD prime contractor. Five flight tests are due before US President Bill Clinton decides this year whether a national anti-ballistic missile system is to be fielded by 2005, for about $11 billion.

Source: Flight International