| Country: |
United States of America |
| Alternate Name: |
UGM-27 |
| Class: |
SLBM |
| Basing: |
Submarine launched |
| Length: |
8.53 m |
| Diameter: |
1.37 m |
| Launch Weight: |
12700 kg |
| Payload: |
Single Mk 1 RV |
| Warhead: |
Nuclear W47-Y1 600 kT |
| Propulsion: |
2-stage solid |
| Range: |
2200 km |
| Status: |
Obsolete |
| In Service: |
1960-1974 |
Details
The UGM-27A Polaris A-1 missile was a medium-range, submarine-launched, solid propellant ballistic missile. It was originally developed from a plan to create a submarine-based Jupiter missile, 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.
Originally, the Navy favored cruise missile systems in a strategic role as deployed on the earlier USS Greyback, but it quickly became apparent that ballistic missile systems had advantages over cruise missiles in range and accuracy. The prime contractor for all three versions was Lockheed, now Lockheed-Martin.
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 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. It had no capability to destroy hardened targets but would have been effective against population centers.
The Polaris A-1 had a range of 2,200 km (1,367 miles) on its single Mk 1 reentry vehicle. It carried a W-47-Y1 600 kT nuclear warhead, which was guided by an inertial guidance system which provided an accuracy of 1,800 m. The missile had a length of 8.53 m, a body diameter of 1.37 m and a launch weight of 12,700 kg. 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-2 was essentially an upgraded A-1 and entered service in late 1961. The A-2 was fitted on a total of 13 submarines and served until June 1974.(1)
Footnotes
- Duncan Lennox, Jane’s Strategic Weapons Systems 46 (Surrey: Jane’s Information Group, January 2007), 610-612.
