UGM-27 Polaris

UGM-27 Polaris submarine-launched ballistic missiles were the first SLBMs in operational use. Previously, submarine-launched missiles, for the U.S. and Soviet Union, were an early equivalent of cruise missiles, and the submarine had to surface, being quite vulnerable, to launch them.

Deployment

The first version, Polaris A1, was test-fired on July 20, 1960. Aboard the 'USS George Washington, the lead boat of the first U.S. ballistic missile submarine, began its first operational patrol on November 15, 1960. George Washington class boats were adaptations of production attack submarines, which were cut in half and the missile section welded between the two halves.

First test-launched from a submerged submarine on 23 October 1961, the A2 version, which was slightly longer than the A1 but had numerous improvements giving it 1500 mile range, became operational on June 26, 1962. The A2 was aboard the USS Ethan Allan, which was the first ballistic submarine constructed completely for that mission.

Polaris A3 was a significant enhancement, with 2500 mile range and multiple warheads. It was test fired on August 7, 1962. Its operational deployment started on September 28, 1964, aboard the USS Daniel Webster'.