Man’s quest to sustain life in the extreme environments of the ocean depths and space was realized in the 20th century during the Cold War. NASA and the navy faced many of the same challenges and hazards, including the effect of extreme temperatures on materials, pressurization, and an unimaginably slim margin of error. For these reasons, NASA and navy scientists collaborated on research and watched each other’s progress very closely. In many ways, the Cold War was a race of technology and scientific discovery.

On a frigid New Year’s Day morning in 1945, the nearly completed hull of the U.S. Navy’s newest submarine, USS Requin (SS 481), entered the water for the first time. As it readied for battle, the world was drastically changing. While at his Georgia retreat, President Roosevelt died, and Vice President Truman was sworn in. Allied troops were rushing to Berlin as the war in Europe was ending. But as history had it, Requin never actually entered battle. Its scheduled departure date was Aug. 21, 1945. Fortunately, World War II officially ended on the 15th.

Commissioned on April 28, 1945, as a standard fleet submarine, Requin made its first journey to Hawaii to join the Pacific Fleet at Balboa. Arriving at Pearl Harbor in early August of the same year, the submarine prepared for its first war patrol. In port at Pearl Harbor naval base when World War II ended, Requin departed and headed west for Guam. The submarine was recalled to Pearl Harbor on Oct. 26, 1945, with ultimate orders to sail to Staten Island, N.Y.

In January 1946, Requin was assigned to Submarine Squadron 4 for antisubmarine training. In August of the same year, the submarine returned to Portsmouth Naval Shipyard, where it underwent its first of three conversions to become the first U.S. Navy radar picket submarine.

In November 1946, Requin departed the shipyard and headed for the Caribbean to test the conversion. In November 1947, the submarine moved for exercises north of the Arctic Circle under operational control of Submarine Division 82 and sailed with the USS Spinax.

On Jan. 20, 1948, Requin reported back to Portsmouth Naval Shipyard, where it underwent its second conversion, a Migraine II conversion, and was reclassified to SSR 481. In December, the submarine departed the shipyard and was assigned to Submarine Squadron 8 in New London, Conn.

In 1949, Requin sailed its first deployment with the Sixth Fleet. In 1951, it departed Norfolk, Va., for a four-month deployment to the Mediterranean Sea. Over the next five years, the submarine would be deployed to the Mediterranean Sea four times until 1956, when it resumed duty with the Sixth Fleet in the Atlantic Ocean and Mediterranean Sea.

In June 1959, Requin reported to Charleston Naval Shipyard, Charleston, S.C., for its final conversion to a Fleet Snorkel boat. Its radar equipment was removed, and it was reclassified to SS 481. In 1960, the submarine was deployed to the Mediterranean Sea once again.

Requin continued its operations with the Sixth Fleet until May 1964, when it resumed its duties with the Second Fleet.

On Sept. 20, 1963, Requin completed its 5,000th dive.

In the fall of 1966, the submarine extended deployment for operation UNITAS VII, cruising around South America on exercises with various navies.

On April 4, 1967, Requin began its final deployment with the Sixth Fleet, searching for a lost nuclear submarine.

On June 29, 1968, the submarine was reclassified as AGSS 481, noncombat duties. In October 1968, it became inactive at Norfolk, Va. Finally, on Dec. 3, 1968, Requin was decommissioned.

In 1969, the submarine remained in service as a Naval Reserve trainer in St. Petersburg, Fla. It remained a trainer until 1971, when it was reclassified as IXSS 481, an unclassified submarine. Requin was finally struck from the U.S. Navy list on Dec. 20, 1971.

Today, Requin serves a very different purpose, educating hundreds of thousands of visitors about life and science aboard a submarine in the mid-20th century. Preserved within USS Requin’s 312-foot-long hull is the technology of a bygone era, a far cry from the sleek nuclear-powered behemoths that now patrol our seas.