Boeing and Northrop have submitted a joint proposal for the competitive development and sustainment contract for future work on the ground-based midcourse defence (GMD) element of the US ballistic missile defence system.

Boeing vice-president and programme director of GMD Norm Tew said the proposal aimed to offer innovative solutions for future programme evolution at the lowest costs to the customer.

GMD uses radars and other sensors, command-and-control facilities, communications terminals and a 20,000-mile fibre-optic communications network to defend against long-range ballistic missile threats.

Boeing has been supporting The Missile Defense Agency as the prime contractor for the GMD programme since 2001.

Over 20 operational interceptors are based at Vandenberg Air Force Base, California, and at Fort Greely, Alaska, to defend US against long-range ballistic missile threats.