 In March 1945 , Oppenheimer created Project Alberta under Parsons to carry out the Manhattan Project 's ultimate mission : the preparation and delivery of nuclear weapons in combat . Bradbury was transferred to Project Alberta to head the Fat Man assembly group . In July 1945 , Bradbury supervised the preparation of " the Gadget " , as the bomb was known , at the Trinity nuclear test . " For me to say " , Bradbury later recalled , " I had any deep emotional thoughts about Trinity ... I didn 't . I was just damned pleased that it went off . " 
