UGM-27 Polaris

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Underwater launch of a Polaris A3

The UGM-27 Polaris were strategic medium-range missiles of the US Army that could be fired from missile submarines (SSBN). So they were “ Submarine-launched ballistic missiles ” (SLBM). They are no longer in active fleet service and have been replaced by the UGM-73 Poseidon .

Polaris A1 (UGM-27A)

history

Polaris A1 on the launch pad in Cape Canaveral

Development of the Polaris A1 began in 1956 at the suggestion of Admiral Arleigh Burke , after Edward Teller declared it was possible to build a nuclear warhead small enough to fit in a submarine-supported missile.

On July 20, 1960, the USS George Washington (SSBN-598) was the first submerged submarine to fire a Polaris A1 missile and three hours later a second missile of the same type. The same ship left on November 15, 1960 loaded with 16 Polaris A1s for the first patrol trip with the new missile. On May 6, 1962, a Polaris A1 from the USS Ethan Allen (SSBN-608) with a sharp nuclear warhead was successfully fired at a target as part of the " Frigate Bird " exercise. This was the only complete test of a US strategic weapons system from fire to nuclear detonation.

On October 14, 1965, the USS Abraham Lincoln (SSBN-602) called the USA for overhaul. As part of this overhaul, the last Polaris A1 in service were replaced by Polaris A3 and decommissioned.

Technical specifications

  • Weight: 13,000 kg
  • Length: 28.5 feet (8.7 m)
  • Diameter: 54 inches (137 cm)
  • Range: approx. 1000 nautical miles (1850 km)
  • First stage: 8,350 kg of polyurethane fuel plus aluminum admixtures with ammonium perchlorate as an oxidizer
  • Second stage: 3,300 kg, same fuel as first stage
  • Control system: MK1
  • Re-entry body: 1 ( W47 -Y1 / Mk1 with 600 kT)

Polaris A2 (UGM-27B)

history

Polaris A2 on the launch pad in Cape Canaveral

Development for the Polaris A2 began on instructions from the System Program Office on November 28, 1958. The aim was to complete enough missiles for the six SSBNs by October 1961. The missile should have a range of at least 1,500 nautical miles. The Polaris A1 was further developed to achieve this goal. In order to increase the range, the second stage of the A1 was made lighter by using GRP instead of steel for the engine housing and a more energetic fuel was used.

The first A2X was launched on Cape Canaveral on November 11, 1960 , and on October 23, 1961, the Polaris A2 was first fired from the submerged USS Ethan Allen (SSBN-608) . The Ethan Allen was also the first ship to be equipped with the Polaris A2. On June 26, 1962, she started the Polaris A2's first patrol run.

The USS John Marshall (SSBN-611) was the last U.S. Navy ship to be converted to the Polaris A3 as part of the overhaul that began November 1, 1974. The Polaris A2 was then decommissioned.

In 1961 and 1962, the Polaris A2 was equipped with penetration aids against alleged Soviet missile defense systems. These PX-1 electronic counter-countermeasures, however, reduced the range of the Polaris A2 and were - after it became clear that the Soviets had no significant anti-missile defense against ICBMs - removed from the upgraded missiles.

Technical specifications

  • Weight: 14,750 kg
  • Length: 31 feet (9.45 m)
  • Diameter: 54 inches (137 cm)
  • Range: approx. 1,500 nautical miles (500 more than the A1) (2775 km)
  • First stage: 8,700 kg of fuel such as Polaris A1
  • Second stage: 3,350 kg pounds of plasticized nitrocellulose as fuel and oxidizer like stage 1. ABL's DDT-70 engine
  • Control system: MK1
  • Re-entry body: 1 W47 -Y2 / Mk1 with 1.2 MT

Polaris A3 (UGM-27C)

history

Polaris A3 on the launch pad in Cape Canaveral

In contrast to the Polaris A2, which was just a further development of the A1, the Polaris A3 is almost a completely new design.

The aim was to increase the range to 2500 nautical miles in order to open up the Pacific as an area of ​​operations for the SSBN and thus to avoid the Soviet anti-submarine defense in the Atlantic . Improved penetration of the presumed Soviet missile defense measures was also sought. These increased requirements required new drives for the rocket stages, improved flight control and navigation, new penetration aids (PX-2) and more re-entry bodies (three pieces). The individual improved systems were initially installed in A2X test rockets and tested on many test flights. Many problems arose here, particularly with flight control in the propulsion system.

The first test launch of a Polaris A3 took place on August 7, 1962 in Cape Canaveral, the USS Andrew Jackson (SSBN-619) fired the first A3 underwater on October 26, 1963, and on September 28, 1964 the first 16 operational A3 were launched on patrol aboard the USS Daniel Webster (SSBN-626) . The first Pacific patrol was launched on December 25, 1964 by the USS Daniel Boone (SSBN-629) from Apra Harbor , Guam. At that time, the Polaris A3 was a globally deployable weapon for the first time.

Disarmed and modified Polaris A3 missiles are used under the name STARS as target missiles in the US missile defense program .

Technical specifications

  • Weight: 16,200 kg
  • Length: 31 feet (9.85 m)
  • Diameter: 54 inches (137 cm)
  • Range: approx. 2,500 nautical miles (1,000 more than the A2, 1,500 more than the A1) (4625 km)
  • First stage: 9,900 kg nitro-plasticized polyurethane fuel
  • second stage: 4,100 kg nitrocellulose
  • Control system:?
  • Re-entry body: 3

Polaris B3 (studies)

As part of the strategic studies of the years 1962–1964 it was postulated that after 1967 the Soviet Union could have an effective defense against US ICBMs with improved radar surveillance and interceptor missiles.

Therefore, Polaris were equipped with penetration aids as described above. At the same time, however, work was also carried out on the Polaris B3. It was 66 inches in diameter, instead of the 54 inches that is common on the Polaris. There were models with one or three re-entry bodies with different equipment (one warhead, several warheads, each with and without penetration aids). The configurations were named B3A, B3B and so on.

The B3D proposed by Lockheed was even supposed to have a diameter of 74 inches (this is the diameter of the Trident SLBMs in use today ) and required massive modifications to the launch systems of the existing U-ships. Its range should be 2000 nautical miles and included three warheads and penetration aids. The warheads and penetrators were mounted on a platform ( bus ), which controlled the re-entry into the atmosphere with nozzles that ejected liquid nitrogen. The warheads could be used against hard targets as well as defended cities and industrial facilities.

With the introduction of new Mk12 re-entry bodies in March 1964, a new Polaris B3 was developed that could carry six Mk12 and penetration aids. This rocket also had a range of only 2000 nautical miles, since according to the doctrine of the time it was more a payload than the range of the rocket that mattered. The transport platform for combating multiple targets has also been improved and is no longer called "Bus", but "Mailman".

In October 1964, Lockheed proposed B3 variants with four Mk12 or twelve new small re-entry bodies. A modification of the Mailman should allow a more flexible multiple target fight ( Flexi-flier ).

In the same year, plans were also unveiled to deploy large ICBMs on the ocean floor to a depth of up to 2,600 meters below sea level. However, this idea was not pursued because it did not fit the strategic role of the US Navy (fighting cities and industrial areas).

The UGM-73 Poseidon was developed from the Polaris B3 studies .

British Polaris

In 1962, in the Nassau Agreement , the US and Great Britain agreed to supply 80 Polaris to the UK. To compensate, the United States Navy was given the right to operate a submarine base in Holy Loch near Glasgow . These Polaris were fitted with British warheads and stationed on Resolution-class submarines . They replaced the airborne Blue Steel missiles.

Web links

Commons : UGM-27 Polaris  - collection of images, videos and audio files