The first American to travel into space, Alan Shepard, had been lying on his back in the Mercury capsule he had named Friendship 7 for over 4 hours.

Technical problems had delayed the launch, and Shepard was beginning to experience uncomfortable pressure in his bladder. National Aeronautics and Space Administration (NASA) engineers had not anticipated that Shepard would spend such a long time in the space suit, and so the suit had no provision for dealing with bodily waste. In desperation, Shepard requested permission from the engineers to urinate in the space suit. The engineers and doctors conferred briefly and decided it was safe to do so. Friendship 7 lifted off on May 5, 1961.

Since that first historic flight the bathroom facilities on spacecraft have improved...