Boeing and Northrop Grumman will develop and sustain the ground-based mid-course defence (GMD) system for the US Missile Defense Agency (MDA).

Boeing will operate and sustain the deployed weapon system, and develop and test innovative technologies to provide greater reliability.

Northrop will design and deploy the command-and-control systems to form the backbone of the GMD system, known as GMD fire control / communications (GFCC) products.

The GMD includes radars, other sensors, command-and-control facilities, communications terminals and a 20,000-mile fibre-optic communications network.

There are currently 20 operational interceptors at Vandenberg Air Force Base in California and Fort Greely in Alaska to defend the US against long-range ballistic missile threats.