Boeing and Northrop Grumman have received the development and sustainment contract (DSC) from the US Missile Defense Agency to continue work on the Ground-based Midcourse Defense (GMD) element of the US Ballistic Missile Defence (BMD) system.

The $3.5bn contract extension covers the development, testing, engineering and manufacture of missile defence systems to protect the nation against long-range ballistic missile threats.

Under the contract, Boeing will lead GMD development, integration, testing and operations, while Northrop will manage the ground system elements and also provide support for operations, system engineering and system tests.

Boeing has been the GMD programme prime contractor since 2001 and currently operates and maintains the deployed GMD weapon system by developing new technologies to provide increased reliability and meet customer needs and requirements.

Northrop has been part of the Boeing GMD team since 1998 and is responsible for designing and deploying the command-and-control systems that form the backbone of the ground system.

Other industry partners in the Boeing-Northrop team include Davidson Technologies, DESE Research, Dynetics, nLogic, Penta Research, Trident Group and Victory Solutions.

GMD uses radars and sensors, command-and-control facilities, communications terminals and a 2,000-mile fibre-optic communications network to defend the US against long-range ballistic missile threats including intercontinental ballistic missiles (ICBMs).

The contract runs to 2018 and work will be carried out at Huntsville, Fort Greely, Vandenberg Air Force Base, Schriever and Peterson Air Force Base, US, as well as other prime, subcontractor and supplier operating locations.

Boeing has so far received $18bn in funding from the mda during the ten years of the programme.

Other bidders for the GMD contract include the Lockheed Martin-led team that comprises Raytheon, ATK Aerospace Systems and Harris Corporation among others.