| Country: |
United States of America |
| Associated Country: |
United Kingdom |
| Alternate Name: |
UGM-27 |
| Class: |
SLBM |
| Basing: |
Submarine launched |
| Length: |
9.55 m |
| Diameter: |
1.37 m |
| Launch Weight: |
13600 kg |
| Payload: |
3 Mk 2 RVs |
| Warhead: |
Nuclear W58 200 kT |
| Propulsion: |
2-stage solid |
| Range: |
4630 km |
| Status: |
Obsolete |
| In Service: |
1964-1981 |
Details
The UGM-27C Polaris A-3 missile was a intermediate-range, submarine-launched, solid propellant ballistic missile. It was developed off of a proposal to create a submarine-based based Jupiter missile, a proposal which eventually evolved into the far smaller, solid-propellant Polaris. The Polaris program resulted in a series of three missiles, the A-1, A-2 and A-3. The Polaris A-1 was the first missile launched from a submerged submarine, the USS George Washington, as well as the first US missile to use a cold launch system. The Polaris A-3 was also the first US missile with Multiple Reentry Vehicles (MRV).
Originally, the Navy favored cruise missile systems in a strategic role as deployed on the earlier USS Greyback, but it quickly became apparent that the ballistic missiles systems had advantages over the cruise missiles in range and accuracy. The prime contractor for all three versions was Lockheed, now Lockheed-Martin.
The Polaris A-2 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 Russian targets, the Polaris was developed to increase the level of nuclear deterrence and calm concerned allies. During this time period, there was little threat of counterforce strikes as few systems had the accuracy to destroy missile systems. Due to this, the primary advantage of missile submarines was the ability to move shorter ranged systems to within range. However, as the technology developed, the submarine-launched Polaris gained increased survivability over fixed systems. The A-3 likely was likely able to destroy hardened targets due to the use of MRV warheads, which increased the blast radius and increased the probability that one of the warheads would land near the silo. The MRV warheads also increased the overall blast radius and decreased the effectiveness of missile defenses by saturating a target area, increasing the damage that could be done during a retaliatory strike.
The Polaris A-3 shares very little in common with older Polaris systems. Unlike the previous missiles which used mostly steel, the A-3 increased the range to 4,630 km (2,877 miles) by using glass fiber as the primary construction material. This construction resulted in vastly improved performance which allowing the A-3 to be launched from modified Polaris A-1/2 missile tubes due to its length of 9.55 m, body diameter of 1.37 m and launch weight of 13,600 kg. The A-3 fires three Mk 2 RVs each equipped with a specially designed W-58 200 kT yield warhead. It used an improved inertial guidance system which provided an accuracy of 900 m CEP. It used a two-stage solid propellant design.
The Polaris program started development in 1956, with its first flight test in 1959. In 1962, the USS Ethan Allen successfully fired a Polaris A-1 missile equipped with a W-47 nuclear warhead against a test target. The missile entered service onboard the USS George Washington, the first US missile submarine, in 1960. The Polaris A-3 entered development in 1960, with the first flight test occurring in 1962. It was in service from 1964 until 1981. The Polaris was gradually taken out of service in favor of the Poseidon C-3 missile starting in 1969, with thirty missile submarines converted from Polaris to Poseidon by 1977. The UK purchased and deployed the A-3 on four of their Revolution-class missile submarines from 1969 until 1996.
It was considered by the Navy in the 1980s to reactivate some of the Polaris carrying submarines as a second line defense, due to the greater numbers of Soviet seaborne missiles. However, this proposal was rejected because of the limited utility of the antiquated and noisy boats. The age and design of the submarines would make them easily destroyed and dangerously worn.(1)
Footnotes
- Duncan Lennox, Jane’s Strategic Weapons Systems 46 (Surrey: Jane’s Information Group, January 2007), 610-612.
