The Polaris Missile was a submarine-
launched ballistic missile 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 Lawrence
Livermore National. 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, 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 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.
