William Schneider - Space Rocket History Podcast

By this time the Astronauts were thinking about a nickname for their spacecraft, but NASA Headquarters now officially refused to allow nicknames for Gemini spacecraft. However, Gordo Cooper was not so easily put off. Pete Conrad’s father-in-law had whittled a model covered wagon, which inspired Cooper with the idea for a crew patch, that would depict a covered wagon, emblazoned with the legend “Eight Days or Bust.” A personal appeal to NASA Administrator Webb led, after much discussion, to approval of the “Cooper patch.” But Webb greatly disliked the motto because he believed if the mission did not go the full eight days, people would say it had “busted.”