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Polaris A-3 on launch pad in Cape Canaveral

The Polaris missile was a two-stage solid-fuel nuclear-armed submarine-launched ballistic missile (SLBM) built during the Cold War by Lockheed Corporation of California for the United States Navy. It was designed to be used as part of the Navy's contribution to the United States arsenal of nuclear weapons, replacing the Regulus cruise missile. Known as a Fleet Ballistic Missile (FBM), the Polaris was first launched from the Cape Canaveral, Florida, missile test base on January 7, 1960.

Following the Polaris Sales Agreement in 1963, Polaris missiles were also carried on British Royal Navy submarines between 1968 and the mid-1990s.

The Polaris missile was gradually replaced in the US Navy by the Poseidon missile, beginning in 1972. During the 1980s, these missiles were replaced on the newest ten of the boats by the Trident I missile


History and development

The Polaris missile replaced an earlier plan to create a submarine-based missile force based on a huge surfaced submarine carrying four "Jupiter" missiles, which would be carried and launched horizontally. This Navy "Jupiter" missile is not to be confused with the U.S. Army Jupiter Intermediate-range ballistic missile. At Edward Teller's prompting [1], the Navy's "Jupiter" missile plans were abandoned in favor of the much smaller, solid-fuel-propelled Polaris.

Originally, the Navy favored cruise missile systems in a strategic role as deployed on the earlier USS Grayback, but a major drawback of these early cruise missile launch systems (and the Jupiter proposals) was the need to surface, and remain surfaced for some time, to launch. Submarines were very vulnerable to attack during launch, and a fully or partially fueled missile on deck was a serious hazard. Rough weather was another major drawback for these designs, but rough sea conditions did not unduly affect Polaris launches.

It quickly became apparent solid-fueled ballistic missiles had advantages over cruise missiles in range and accuracy, and unlike both Jupiter and cruise, were able to be launched from a submerged submarine, improving submarine survivability.

The prime contractor for all three versions of Polaris was Lockheed, now Lockheed Martin.

The Polaris program started development in 1956. The USS George Washington, the first US missile submarine, successfully launched the first Polaris missile from a submerged submarine on July 20, 1960. The A-2 version of the Polaris missile was essentially an upgraded A-1, and it entered service in late 1961. It was fitted on a total of 13 submarines and served until June 1974.(1). Ongoing problems with the W-47 warhead, especially with its mechanical arming and safing equipment, led to large numbers of the missiles being recalled for modifications, and the U.S. Navy sought a replacement with either a larger yield or equivalent destructive power. The result was the W-58 warhead used in a "cluster" of three warheads for the Polaris A-3, the final model of the Polaris missile. This missile replaced the earlier A-1 and A-2 models in the US Navy, and also equipped the British Polaris force. The A-3 had a range extended to 2,500 nautical miles (4,630 km) and a new weapon bay housing three Mk 2 re-entry vehicles (ReB or Re-Entry Body in US Navy and British usage); and the new W-58 warhead of 200kT yield. This arrangement was originally described as a "cluster warhead" but was replaced with the term Multiple Re-Entry Vehicle (MRV). The three warheads were spread about a common target and were not independently targeted (such as a MIRV missile is). The three warheads were stated to be equivalent in destructive power to a single one-megaton warhead. Later the Polaris A-3 missiles (but not the ReBs) were also given limited hardening to protect the missile electronics against electromagnetic pulse effects while in the boost phase. This was known as the A-3T ("Topsy") and was the final production model.

Polaris A-1

Polaris A-1 on launch pad in Cape Canaveral

The first version, the Polaris A-1, had a range of 1000 nautical miles (1853 km) 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 1800 meters (6000 ft). The two-stage solid propellant missile had a length of 28.5 ft (8.69 m), a body diameter of 54 in (1.37 m), and a launch weight of 28,800 lbs (13,090 kg).

A test launch from a U.S. Navy submarine on July 20, 1960, was the first underwater guided-missile launch (apart from German experiments during World War 2). The USS George Washington was the first fleet ballistic missile submarine (SSBN in U.S. naval terminology) and she and all of the 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 Edward Teller and Harold Brown[2]. The Navy accepted delivery of the first 16 warheads in July 1960. On May 6, 1962, a Polaris missile with a live W47 warhead was tested in Operation Dominic in the central Pacific Ocean, the only American test of a live strategic nuclear missile. However, the warhead that was employed in this test had been designed to have a much-lower yield than the W47 warheads that were deployed for nuclear warfare

[Tactical surface-to-air and air-to-air missiles with nuclear warheads were also tested in the atmosphere, usually over the Nevada Test Site.]

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.

Strategic role

The Polaris A-1 missile served as a strategic asset. The missile was developed to complement the limited number of medium-range systems deployed throughout Europe. As those systems lacked the range to attack major Soviet targets, Polaris was developed to increase the level of nuclear deterrence. At this time there was little threat of counterforce strikes, as few systems had the accuracy to destroy missile systems. The primary advantages of ballistic missile submarines was their ability to launch submerged, which offered improved survivability for the submarine while also (like their Regulus predecessors) move shorter ranged systems within range.

The USN had forward-basing arrangements for its Atlantic-based Polaris fleet with both the United Kingdom and Spain permitting the use of bases at the Holy Loch in Scotland and at Rota in the Bay of Cadiz that were much closer to patrol areas, avoiding the necessity for lengthy transit times from U.S. East Coast bases. This forward-basing arrangement was continued when Poseidon replaced Polaris. Polaris was not accurate enough to destroy hardened targets but would have been effective against dispersed surface targets, such as airfields, radar and SAM sites, as well as military and industrial centers of strategic importance. The military authorities, however, regarded Polaris as but one of a team of players, each with its own function. The task allotted to Polaris of 'taking out' peripheral defenses was well-suited to its characteristics and limitations.

Later versions

The later versions (the A-2, A-3, and B-3) were larger, weighed more, and had longer ranges than the A-1. The range increase was most important: The A-2 range was 1,500 nautical miles (2,779 km), the A-3 2,500 nautical miles (4,631 km), and the B-3 2,000 nautical miles (3,705 km). The A-3 featured multiple re-entry vehicles (MRVs) which spread the warheads about a common target, and the B-3 was to have penetration aids to counter Soviet Anti-Ballistic Missile defenses. The B-3 missile evolved into the C-3 Poseidon missile, which abandoned the decoy concept in favor of using the C3's greater throw-weight for larger numbers (10-14) of new hardened high-re-entry-speed reentry vehicles that could overwhelm Soviet defences by sheer weight of numbers, and its high speed after re-entry. The abandoned decoy system for the B-3 (Antelope) was known to the UK where it was adopted and evolved into Super Antelope, KH.793 and later re-labeled Chevaline.

British Polaris

British Polaris, Imperial War Museum, London

The British became interested in Polaris after the cancellations of the Blue Streak and Skybolt missiles in the 1960s. Under the Nassau agreement that emerged from the 1962 Nassau Conference between Harold Macmillan and John F. Kennedy, the United States would supply Britain with Polaris missiles, launch tubes, ReBs, and the fire-control systems (fire-control systems have nothing to do with putting out fires, but rather with the aiming and guidance of naval artillery and missiles). Great Britain would make its own warheads and submarines. However, by that time, all British thermonuclear bombs were made using American designs - which had been provided to the United Kingdom in a strategic-weapons partnership dating back to the Manhattan Project.

In return, the British agreed to assign control over their Polaris missile targeting to the SACEUR (Supreme Allied Commander, Europe), always an American, with the provision that in a national emergency when unsupported by the NATO allies, the targeting, permission to fire, and firing of those Polaris missiles would reside with the British national authorities. Nevertheless, the consent of the British Prime Minister is and has been always required for the use of British nuclear weapons, including the Polaris and Trident missiles.

Confusingly, the operational control of the Polaris submarines was assigned to another NATO Supreme Commander, the SACLANT (Supreme Allied Commander, Atlantic), who is based near Norfolk, Virginia, although the SACLANT routinely delegated control or the missiles to his deputy commander in the Eastern Atlantic area, COMEASTLANT, who was always a British admiral. The Polaris Sales Agreement was signed on April 6, 1963.

British Polaris submarines were the Resolution-class ballistic missile submarines. Although one boat of the four was always in a shipyard refitting, recent declassifications of archived files disclose that the Royal Navy deployed four boatloads of reentry vehicles and warheads, plus spare warheads for the Polaris A3T, retaining a limited ability to rather quickly re-arm and put to sea the Polaris boat that was in refit. When replaced by the Chevaline warhead, the sum total of deployed RVs & warheads reduced to three boatloads.

For the origins of the British Polaris program, see Peter Nailor, The Nassau Connection (1988).



The original U.S. Navy Polaris had not been designed to penetrate Anti-ballistic missile (ABM) defenses, but the Royal Navy had to ensure that its small Polaris force operating alone, and often with only one submarine on deterrant patrol, could penetrate the ABM screen around Moscow. The result was a programme called Chevaline that added multiple decoys, chaff, and other defensive countermeasures. Its existence was only revealed in 1980, partly because of the cost overruns of the project, which had almost quadrupled the original estimate given when the project was finally approved in January 1975. The system became operational in mid-1982 on the HMS Renown, and the last British SSBN submarine was equipped with it in mid-1987.[3]


The British Ministry of Defence upgraded its nuclear missiles to the longer-ranged Trident missile after much political wrangling within the Callaghan Labour Party government over its cost and whether it was necessary. The outgoing Prime Minister James Callaghan made his government's papers on Trident available to Margaret Thatcher's new incoming Conservative Party government, which took the decision to acquire the Trident C4 missile.

A subsequent decision to upgrade the missile purchase to the even larger, longer-ranged Trident D5 missile was possibly taken to ensure that there was missile commonality between the U.S. Navy and the Royal Navy, which was considerably important when the Royal Navy Trident submarines were also to use the missile-submarine repair and maintenance naval base at Kings Bay, Georgia.

[Even though the U.S. Navy initially deployed the Trident C4 missile in the original set of its Ohio-class submarines, it was always planned to upgrade all of these submarines to the larger and longer-ranged Trident D5 missile -- and that eventually, all of the C4 missiles would be eliminated from the U.S. Navy. This change-over has been completely carried out, and no Trident C4 missiles remain in service.]

The Polaris missile remained in Royal Navy service long after it had been completely retired and scrapped by the U.S. Navy. Consequently many spare parts and repair facilities for the Polaris that were located in the U.S. ceased to be available. (Such as at the Lockheed Corporation, which had moved on first to the Poseidon missile and then to the two versions of the Trident missile.) The United Kingdom had to have some production lines re-opened at its considerable expense, for example, to extend the life of its solid-fuel propellant motors.


During its reconstruction in 1957-1961, the Italian cruiser Giuseppe Garibaldi had installed in it four launchers for Polaris missiles. However, despite successful tests held in 1961-1962, most of the missiles were never shipped to Italy, mostly for political reasons. Also, the Giuseppe Garibaldi and all other cruisers of the Italian navy have been retired from service since about 2003.The Polaris A3 are today in the La Spezia Arsenal of the Marina Militare ready to use.


 United Kingdom
 United States

See also


  1. ^ 1946:1
  2. ^ "Fifty Years of Innovation through Nuclear Weapon Design". Science & Technology Review: 5—6. January/February 2002. Retrieved 2008-11-17. "Livermore designers, led by physicists Harold Brown and John Foster ...the assignment in 1957 of developing the warhead for the Navy's Polaris missile...".  
  3. ^ History of the British Nuclear Arsenal, Nuclear Weapons Archive website

External links


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