The Polaris Missile was a submarine-launched ballistic missile (SLBM) carrying a nuclear warhead developed during the Cold War for the United States Navy.

Lockheed developed it as a solid fuel Fleet Ballistic Missile (FBM) for the US Navy. The first successful test flight was from Cape Canaveral on January 7, 1960.

The nuclear warhead was developed at the (now) Lawrence Livermore National Laboratory by a team headed by Harold Brown from 1957. In July 1960, the Navy accepted delivery of the first 16 warheads and on November 15 the first Polaris missile was test launched from a submarine.

The missile was 12.3 m (40.5 ft) long and with a finspan of 2.6 m (8.5 ft) and capable of delivering a 1 Mt warhead 4000 km.

The Polaris's first version, the A-1, weighed 28,800 lb (13 t), stood 28.5 ft (8.7 m) tall, had a diameter of 54 in (1.4 m), and had a range of 1000 nautical miles (1,852 km). A test launch from the submarine on July 20, 1960, was the first ever rocket launch from a submerged launch platform. The USS George Washington was the first fleet ballistic missile submarine (SSBN in US naval terminology), carrying sixteen missiles. From 1960 to 1966 a further forty SSBNs were launched.

On May 6, 1962, a Polaris missile with a live W47 warhead was tested in Operation Frigate Bird, and was the only ever test of a live nuclear missile undertaken by the United States.

Later versions (the A-2, A-3, and B-3) were larger, weighed more, and had longer ranges. The range increase was most important: The A-2 could fly 1500 nautical miles (2,300 km), the A-3 2500 nautical miles (4,600 km), and the B-3 2000 nautical miles (3,700 km). The A-3 featured multiple-reentry vehicles (MRVs) and the B-3 was to have featured penetration aids to counter Soviet Anti-Ballistic Missile defenses. The B-3 evolved into the C-3 Poseidon missile.

Polaris missiles had two stages, both of which are steered by thrust vectoring. Guidance was via an inertial navigation system with accuracy down to about 900 meters (3000 feet) CEP. This made them unsuitable for use against hardened targets, which means they were mostly a retaliation-type weapon.

The missile began to be replaced by Poseidon beginning in 1972, in the 1980s both were replaced by the Trident I.

British Polaris

The British use of Polaris stems from the failure of the Blue Streak missile and the cancellation of the Skybolt project in the 1950s. Harold Macmillan and John F. Kennedy agreed at the 1962 Nassau Conference (referred to as the Nassau Agreement) that the United States would supply Britain with Polaris missiles. America would supply the missiles, the launch tubes and the fire control system, while the warheads and submarines would be British made. In return America was given certain assurances by Britain regarding the use of the missile. The Polaris Sales Agreement was signed on April 6, 1963.

The British Polaris submarines were the Resolution-class ballistic missile submarines. The Polaris system underwent a significant, British designed, life extension programme called Chevaline, which while reducing the total number of warheads available added various defensive measures.

The British eventually upgraded to the Trident missile after much political wrangling over the cost and necessity, but waited for the Trident II (D5) variant.

See also: Program Evaluation and Review Technique, List of missiles

Fiction

• The Spy Who Loved Me (1977), 10th Bond movie
• For Your Eyes Only (1981), 12th Bond movie

External link

• Federation of American Scientists history of A-1 Polaris; see also "a-2.htm," "a-3.htm," and "b-3.htm". (http://www.fas.org/nuke/guide/usa/slbm/a-1.htm)