Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Otto Hahn was one of only four nuclear-powered cargo vessels so far 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 honour of Otto Hahn, the German chemist and Nobel prizewinner, who was credited with the discovery of nuclear fission of uranium in 1938. The first captain of the Otto Hahn was Heinrich Lehmann-Willenbrock, a famous German U-Boat ace of World War 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.