What was the name of the first atomic powered submarine?

What was the name of the first atomic powered submarine? The answer is Nautilus, specifically USS Nautilus (SSN-571). Commissioned by the United States Navy in 1954, it was the world's first operational nuclear-powered submarine and demonstrated how atomic energy could transform undersea warfare.

Nautilus was designed under the direction of Admiral Hyman G. Rickover, widely known as the father of the U.S. nuclear navy. Its pressurized-water reactor powered steam turbines without requiring atmospheric oxygen, allowing the submarine to remain submerged far longer than diesel-electric boats. Its famous first underway signal, sent in January 1955, read “Underway on nuclear power.”

The submarine later became famous for Operation Sunshine, its 1958 voyage beneath the North Pole. That journey showed the strategic reach made possible by nuclear propulsion. Nautilus was decommissioned in 1980 and preserved as a museum ship at the Submarine Force Library and Museum in Groton, Connecticut. It is sometimes confused with earlier submarines named Nautilus, including fictional and conventionally powered vessels; SSN-571 is the nuclear-powered pioneer meant here.