The first milk chocolate M&M's were made in 1941 solely for U.S. administration individuals conveyed abroad during the Second World War. Chocolate bars were at that point part of military rations already, however the M&M's sweets shell was something that they didn't know they needed. It made their ration more convenient for them. The thought was that the treats shell would make it workable for the soldiers to have chocolate without the all the melted mess it made.

The very characteristics that made them strong and reliable ration in the war made them ideal for space travel too. So on demand from the team on board NASA's space transport, Columbia, M&M's turned into the primary candy to rocket into space in 1981.