Otto Hahn is one of only four nuclear-powered cargo vessels ever built. Planning of a German-built trade and research vessel to test the feasibility of nuclear power in civil service began in 1960, and Otto Hahn's keel was laid down in 1963 by Howaldtswerke Deutsche Werft AG of Kiel. She was launched in 1964 and named in honor of Otto Hahn, the German chemist and Nobel prizewinner, who had discovered the nuclear fission of uranium in 1938. "THE FATHER OF NUCLEAR CHEMISTRY" (Glenn T. Seaborg, President of the United States Atomic Energy Commission, Washington D.C.) The first captain of Otto Hahn was Heinrich Lehmann-Willenbrock, a famous German U-Boat ace of WW II. In 1968, the ship's 38-megawatt nuclear reactor was taken critical and sea trials began. In October of that year, NS Otto Hahn was certified for commercial freight transport and research.