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The Polaris Missile

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In the early days of the Cold War the need grew for an intercontinental ballistic missile that could be launched from a submarine. This technology, up until the late 1950’s, was nothing more than a pipe dream. Many believed that a missile could not be launched from a submarine and hit its target half a world a way.

Rockets until then were unreliable to say the least; they could not deliver a warhead beyond a thousand miles reliably and could not be counted on in times of war or to be used as a plausible deterrent. But why were they needed? The answer was simple: a rocket launched from sea would be mobile and could demonstrate America’s presence around the world. The challenges, however, were daunting. In 1956, the U.S. Navy was given authorization to build a solid propellant missile with a range of 1700 miles and a nuclear warhead as its payload. The range was intended to match that of the Jupiter missile, but that is where their similarities end. The Polaris missile would have to be an autonomous missile once it was launched from a submarine. Unlike its predecessors, it could not depend on ground telemetry to reach its target accurately.

The Polaris missile, which is named after the North Star that shines brightly at night, was expected to be a major offensive weapon in the event of thermonuclear war. By 1957, however, with the launch of Sputnik in October, the development of the Polaris missile became an urgent national project. Even if the missile was never used in an act of war it would provide a deterrent to keep it from happening.

In order to keep up with the Soviet Union and avoid a “gap” in technology the Navy scaled down the requirements that they had originally mandated for the Polaris. These revisions would allow for a functioning missile by 1960. Unfortunately, its’ range was compromised down to about 1400 miles.

The first Polaris to come off of the assembly line was called the A1. It was a two-stage rocket with a gross weight of 28,000 lb.’s and a length of 28 feet. After many redesigns it ultimately had a range of 1000 miles—a far cry from the original range estimates. Regardless of the range problem and numerous failed test launches, a key element of the A1 was right on target. The self-contained inertial guidance system was working well. Initially it was this system that appeared to be the real roadblock to development during the design phases of Polaris, but its independent controls revolutionized computers in the 1960’s. Perched on top of the Polaris A1 was a thermonuclear warhead with a yield of 500 kilotons.