Short answers, pulled from the story.
The UGM-27 Polaris served in the United States Navy from 1961 to 1980. It was the Navy's first submarine-launched ballistic missile and was eventually replaced by the Poseidon and Trident missiles.
At Project Nobska in the summer of 1956 at Nobska Point in Woods Hole, Massachusetts, Teller promised to develop a lightweight one-megaton warhead within five years. His Livermore laboratory received the project, and his estimate was later backed by the Atomic Energy Commission in early September of that year.
The first successful submerged launch of a Polaris missile took place on the 20th of July 1960. The only American test of a live strategic nuclear missile, called the Frigate Bird test, occurred on the 6th of May 1962 using a Polaris A-2 with a live W47 warhead in the central Pacific Ocean.
The 1962 Nassau Agreement, reached between Harold Macmillan and John F. Kennedy, committed the United States to supplying Britain with Polaris missiles, launch tubes, re-entry bodies, and fire-control systems. The formal Polaris Sales Agreement was signed on the 6th of April 1963, and Britain built its own warheads. The Labour government later reduced the original five-submarine plan to four boats, each carrying 16 missiles.
Chevaline was a British program that added decoys, chaff, and other countermeasures to the Polaris missile to help it penetrate Soviet anti-ballistic missile defenses around Moscow. Formally approved in January 1975, its cost nearly quadrupled the original estimate. The system became operational in mid-1982 and was withdrawn from service in 1996.
The Program Evaluation and Review Technique, known as PERT, was developed for the Polaris program to replace the simpler Gantt chart methodology. It allowed managers to map task dependencies and identify the critical path for a project's completion.