Multiple people have covertly snuck items on to space missions without the knowledge of their superiors. During the Gemini program, Deke Slayton issued a memo to all astronauts urging a halt to the practice: “… the attempt … to bootleg any item on board not approved by me will result in appropriate disciplinary action. In addition to jeopardizing your personal careers, it must be recognized that seemingly insignificant items can and have affected the prerogatives of follow-on crews."[1] Despite this and other warnings, the practice continued. Here is a partial list of those items.
