Boeing has been awarded a contract to provide sustaining engineering support for the guidance system of the US Air Force’s (USAF) LGM-30G Minuteman III intercontinental ballistic missile (ICBM).

The $51m contract is expected to ensure the safety, security, and effectiveness of the US’ land-based nuclear deterrent.

Boeing Directed Energy & Strategic Systems vice-president Peggy Morse said: "Since 1958, Boeing has stood alongside the US Air Force to design, develop, and test ICBM systems.

"Boeing’s uninterrupted support will ensure the Minuteman III force remains safe, secure, and effective.

"Boeing’s uninterrupted support will ensure the Minuteman III force remains safe, secure, and effective."

"Our team has extensive design and test data knowledge, and a record of zero discrepancies in nuclear weapons-related material inspections."

The NS50 guidance system is dubbed the navigational heart of the Minuteman III weapon. It features advanced electronics that not only improve the in-flight reliability, but also the maintainability.

Boeing is the original equipment manufacturer of the guidance system, and has been maintaining the systems at its facility in Heath, Ohio, US, since 1998. The firm ensures availability of flight tests and nuclear hardness testing.

The Boeing-built Minuteman III is a ground-based, long-range, solid-fuel, three-stage intercontinental ballistic missile designed to carry single or multiple nuclear warheads.

The missile forms one component of a nuclear triad that is complemented by the Trident submarine-launched ballistic missile, and by nuclear weapons carried by a long-range strategic bomber aircraft.

The missiles entered service with the USAF in 1968. They are located in silos at the 90th Missile Wing at Warren Air Force Base (AFB) in Wyoming, as well as the 341st Missile Wing at Malmstrom AFB in Montana, and the 91st Missile Wing at Minot AFB in North Dakota, US.