The U.S.S. Nautilus was the world's first nuclear-powered submarine. It was launched into the Thames River in Connecticut by none other than the first lady, Mamie Eisenhower.
Photograph by Bates Littlehales, National Geographic

Download this file

  • On January 21, 1954, the U.S.S. Nautilus, the world’s first submarine powered by nuclear energy, was launched on the Thames River in Groton, Connecticut. The technology of the Nautilus would change naval exploration and warfare forever.
    The Nautilus was powered by a nuclear reactor. The reactor produced heat that was used to boil water. Steam from the boiling water drove steam turbines that created electricity. Electricity was used to propel the submarine, maintain living conditions such as temperature and air quality, and even support desalination processes. 
    Unlike engines that run on fossil fuels, nuclear reactors do not require frequent refueling or air. This means the Nautilus and other nuclear-powered submarines could remain underwater for much, much longer time periods than traditional submarines. In fact, the Nautilus’ first voyage became what was then the world’s longest submarine trip—from New London, Connecticut, to San Juan, Puerto Rico. 
    Nuclear reactors also create an enormous amount of power. This allowed the Nautilus and other nuclear-powered submarines to quickly respond to threats. Nuclear-powered submarines can maneuver and change depth much more easily than traditional submarines.
    Today, few nations maintain fleets of nuclear-powered submarines. The complex technology and high cost of maintaining such a fleet has limited these fleets to the United States, Russia, the United Kingdom, France, China, and India.
  • Term Part of Speech Definition Encyclopedic Entry
    air quality Noun

    measurement of pollutants and other harmful materials in the air.

    complex Adjective


    desalination Noun

    process of converting seawater to fresh water by removing salt and minerals.

    electricity Noun

    set of physical phenomena associated with the presence and flow of electric charge.

    engine Noun

    machine that converts energy into power or motion.

    enormous Adjective

    very large.

    exploration Noun

    study and investigation of unknown places, concepts, or issues.

    fleet Noun

    group of ships, usually organized for military purposes.

    fossil fuel Noun

    coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

    frequent Adjective


    maneuver Noun

    a skillful movement.

    nation Noun

    political unit made of people who share a common territory.

    Encyclopedic Entry: nation
    naval Adjective

    having to do with a government's navy, or military ships and crew.

    nuclear energy Noun

    energy released by reactions among the nuclei of atoms.

    Encyclopedic Entry: nuclear energy
    propel Verb

    to push forward.

    require Verb

    to need.

    steam Noun

    water vapor.

    steam turbine Noun

    machine driven by the movement of steam passing over blades or rotors.

    submarine Noun

    vehicle that can travel underwater.

    technology Noun

    the science of using tools and complex machines to make human life easier or more profitable.

    temperature Noun

    degree of hotness or coldness measured by a thermometer with a numerical scale.

    Encyclopedic Entry: temperature
    threat Noun


    voyage Noun

    long journey or trip.

    warfare Noun

    armed conflict between two or more groups of people, usually representing different nations or other political organizations.