On the March 23 flight, NASA had some food experiments to test on the two-man crew of the Gemini III space capsule, Commander Gus Grissom and Pilot John Young. The prime focus was to see how astronauts could work and eat efficiently while keeping mess and odor to a minimum.
The Gemini III menu contained hot dogs, brownies, chicken legs and apple sauce, all contained in squeezy tubes or small packets. Each item was delicately packaged to save on space, improve on safety and convenience. The main point here was that it was to be a controlled scientific experiment.
Alas, John Young had other ideas.
A little under two hours into the mission, just as the two astronauts were discussing the food that had been packed for them, Young produced a corned beef on rye sandwich from his flight suit pocket and presented it to a surprised Commander Grissom.