USS Nautilus was the first operational nuclear-powered submarine and shared its name with Jules Verne’s classic novel, ‘Twenty Thousand Leagues Under the Sea,’ from 1870. The submarine was built for the US Armed Forces and had the distinction of not being designed as a warship but instead as a symbol of the peaceful use of nuclear energy.Its nuclear propulsion allowed it to submerge for longer periods than conventional submarines, and Nautilus broke several records during its first years of operation. However, its most significant achievement came in the summer of 1958, when over 100 sailors embarked on a scientific expedition without precedents: to cross from the Pacific to the Atlantic underneath the North Pole’s ice casket.