page_title: UGM-27 Polaris
section_title: Polaris A-1
hierarchical_section_title: UGM-27 Polaris / Polaris A-1
context_page_description: The UGM-27 Polaris missile was a two-stage solid-fueled nuclear-armed submarine-launched ballistic missile. As the United States Navy's first SLBM, it served from 1961 to 1996.
  In the mid-1950s the Navy was involved in the Jupiter missile project with the U.S. Army, and had influenced the design by making it squat so it would fit in submarines. However, they had concerns about the use of liquid fuel rockets onboard ships, and some consideration was given to a solid fuel version, Jupiter S. In 1956, during an anti-submarine study known as Project Nobska, Edward Teller suggested that very small hydrogen bomb warheads were possible. A crash program to develop a missile suitable for carrying such warheads began as Polaris, launching its first shot less than four years later, in February 1960.
  As the Polaris missile was fired underwater from a moving platform, it was essentially invulnerable to counterattack. This led the Navy to suggest, starting around 1959, that they be given the entire nuclear deterrent role. This led to new infighting between the Navy and the U.S.
context_section_description: The initial test model of the Polaris was referred to as the AX series and made its maiden flight from Cape Canaveral on September 24, 1958. The missile failed to perform its pitch and roll maneuver and instead just flew straight up, however the flight was considered a partial success (at that time, "partial success" was used for any missile test that returned usable data). The next flight on October 15 failed spectacularly when the second stage ignited on the pad and took off by itself. Range Safety blew up the errant rocket while the first stage sat on the pad and burned. The third and fourth tests (December 30 and January 9) had problems due to overheating in the boattail section. This necessitated adding extra shielding and insulation to wiring and other components. When the final AX flight was conducted a year after the program began, 17 Polaris missiles had been flown of which five met all of their test objectives.
  The first operational version, the Polaris A-1, had a range of 1,400 nautical miles (2,600 kilometres) and a single Mk 1 re-entry vehicle, carrying a single W-47-Y1 600 kt nuclear warhead, with an inertial guidance system which provided a circular error probable (CEP) of 1,800 meters (5,900 feet). The two-stage solid propellant missile had a length of 28.5 ft (8.7 m), a body diameter of 54 inches (1.4 m), and a launch weight of 28,800 pounds (13,100 kg).
  USS George Washington was the first fleet ballistic missile submarine (SSBN in U.S. naval terminology) and she and all other Polaris submarines carried 16 missiles. Forty more SSBNs were launched in 1960 to 1966.
  Work on its W47 nuclear warhead began in 1957 at the facility that is now called the Lawrence Livermore National Laboratory by a team headed by John Foster and Harold Brown. The Navy accepted delivery of the first 16 warheads in July 1960. On May 6, 1962, a Polaris A-2 missile with a live W47 warhead was tested in the "Frigate Bird" test of Operation Dominic by USS Ethan Allen in the central Pacific Ocean, the only American test of a live strategic nuclear missile.
  The two stages were both steered by thrust vectoring. Inertial navigation guided the missile to about a 900 m (3,000-foot) CEP, insufficient for use against hardened targets. They were mostly useful for attacking dispersed military surface targets (airfields or radar sites), clearing a pathway for heavy bombers, although in the general public perception Polaris was a strategic second-strike retaliatory weapon.
caption: Polaris A-1 on launch pad in Cape Canaveral
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