Sputnik Escalates the Cold War
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Missiles, Polaris

Title: Polaris missile
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U.S. Navy submarine-launched ballistic missile (SLBM) carried in nuclear-powered submarines. The SLBM system constituted the initial seaborne leg of what became America's nuclear triad and was part of its nuclear deterrence strategy. This strategy called for the United States to have a survivable nuclear retaliation capability in order to deter a potential Soviet first strike. Bombers and land-based intercontinental ballistic missiles (ICBMs) in hardened silos provided the other legs of the triad, each with its particular advantages and disadvantages. The submarine-based element offered stealth, denying the Soviets knowledge of the number and locations of the embarked missile systems. It was a sound enough strategy, but the Polaris leg was almost scrapped.

The U.S. Navy of the 1950s favored cruise missiles over ballistic missiles. Cruise missiles were cheaper and easier to install on ships and submarines, and the technology was already well understood. However, ballistic missiles offered more range, greater accuracy, and faster response times, and perhaps more importantly, there was no known defense against ballistic missiles at the time. By 1956, the U.S. Navy began to examine the challenges of installing a missile system aboard ships and submarines. The initial proposal to install Jupiter missiles was rejected because of the dangers of storing the missiles' liquid-oxygen oxidizer component in an enclosed hull for any significant period of time. Solid rocket fuel was the chosen option, and the primary contractor, Lockheed, concentrated on developing new and more powerful solid rocket fuels for the project. The first test flight took place in 1959, and the Polaris missile entered service aboard the U.S. Navy submarine George Washington in 1960. The first improved model, the A-2 Polaris, became operational in 1961. It had a range of 1,700 nautical miles and could deliver a single 800-kiloton nuclear warhead within 3,800 feet of the target.

To save money, the navy chose to modify an attack submarine design to carry the missiles. It recognized early that diesel-electric submarines lacked the range and operational capabilities to be effective ballistic-missile platforms. Research and development experience with early nuclear-powered submarines had demonstrated that they had the power to support the missile system and the underwater endurance to prevent the Soviets from detecting the launch platform. Hull testing with the Albacore had also indicated the best hull form. Navy engineers took the design for the new class of attack submarines with an Albacore hull and simply inserted a missile compartment to hold sixteen Polaris missiles. Thus was born the George Washington–class of nuclear-powered ballistic-missile submarines. Close coordination between the missile and submarine design teams precluded any major problems with construction. The lead submarine unit was completed in time to join the missile test program in late 1959.

The Polaris missile system was the cornerstone of the U.S. Navy's ballistic missile system throughout the 1960s, not leaving service until 1974. It was the first missile to be fired from a submerged submarine and the first to use a cold-launch system. That is, a missile's rocket engine did not ignite until after it left the launch tube. A compressed-air slug lifted the missile out of the tube and above the ocean's surface. The rocket engine ignited after the missile broke the ocean's surface. That system saved the navy the challenge, expense, and dangers of containing a rocket ignition within the submarine's hull. It proved reliable in service and has been the standard method for all submarine-launched missiles developed during and after the Cold War.

Carl O. Schuster

Further Reading
Spinardi, Graham. From Polaris to Trident: The Development of U.S. Fleet Ballistic Missiles. Cambridge: Cambridge University Press, 1994.

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