United States
On January 21, 1954, the USS Nautilus was launched, becoming the world’s first operational nuclear-powered submarine. It was powered by a pressurized-water reactor, giving it unprecedented underwater endurance and stealth. The Nautilus ushered in a new era of submarine warfare and naval strategy. Its ability to stay submerged for long periods reshaped Cold War naval deterrence. The vessel later completed the first under-ice transit of the North Pole in 1958, proving its capabilities.
