Otto Hahn was one of only four nuclear-powered cargo vessels built to date. Planning of a German-built trade and research vessel to test the feasibility of nuclear power in civil service began in 1960 under the supervision of German physicist Erich Bagge. Launched in 1964, his nuclear reactor was deactivated 15 years later in 1979 and replaced by a conventional diesel engine room. The ship was scrapped in 2009.