Project Zeus (French: Operation Zeus; German: Das Zeussprojekt) was the code name for the 1950's French nuclear weapons program. Project Zeus is believed to have been begun as early as the late 1940's and began in earnest after the 1952 International Science Exhibition in Berlin. The majority of the work on Zeus was done at the French nuclear labs outside of Oran in the remote Sahara Desert, and in 1955 the scientists performed what they believed to be a fission reaction. The plans for a weaponized model were complete within three years and the French conducted five nuclear tests - world's first - in the Algerian Desert at Al-Arabiya in the fall of 1958 and the spring of 1959.