You'd be a lying crazy person if you said it hasn't crossed your mind, and in the 1960s it was one of the most common questions posed to NASA's astronauts: how do you go to the bathroom in space? The answer is less sophisticated than you might expect and there was never a space age solution to the problem. Rather, the galactic crapper was born out of necessity.
NASA's first manned spaceflight program flew the Mercury capsule, which was one of the most complex and intricate machines ever built when the program began manned flights in 1961. Closed negative feedback loops made all the onboard systems self-regulating. As a safety measure, the capsule could be controlled by the astronaut, mission control, or by a flight plan pre-programmed into the capsule's computer. The cabin was pressurized, too, with 100-percent oxygen and featured an environmental control system that removed odors, carbon dioxide, and moisture. Pure oxygen also circulated through the astronauts' pressure suit with the same effects; he stayed cool and dry because the oxygen flow promoted evaporation of his sweat.
Despite the high-tech capsule and clothing, there was one glaring oversight in the original Mercury mission planning: there was no thought to the astronaut having to urinate during the flight. McDonnell Aircraft, the company who built the capsule, makes no mention of bathrooms of any kind in the nearly 500 page familiarization manual it sent to NASA.
It wasn't as if everyone just forgot astronauts are human and need to pee; no one thought it was something worth addressing this early on in the space age. The flights were short, surly the astronauts could hold it for a few hours while they orbited the Earth. Details of human functions in space could wait for later missions. It wasn't a detail anyone thought should slow progress towards getting a man in space.
From the astronaut's perspective, however, a spaceflight is a different story. No mission ever lasted the few minutes or hours planned; the astronaut spent hours waiting for launch locked inside his capsule during countdown. Any holds for technical glitches or weather just made his wait longer. A short mission could easily turn into a full day.
This was the problem facing Alan Shepard, America's first astronaut, as he lay on his couch in his Freedom 7 capsule. Shepard's flight was a fifteen minute suborbital hop — a very doable flight plan without a washroom handy. But Shepard's role in the flight didn't last a mere fifteen minutes. He entered the capsule hours before launch, and by the time he was getting close to blasting off, the astronaut had to, you know, go real bad.
He radioed fellow Mercury astronaut Gordon Cooper who was serving as capcom for the mission for permission to leave the capsule to use the washroom — the gantry was still attached to the capsule, how difficult could it be? His request was denied. Depressurizing the capsule, exiting, and then going through the whole process of ingress and repressurization would set the countdown back. Cooper advised Shepard to hold it.
Desperate, Shepard told Cooper he was going to have to wet his suit, a potentially risky move since he was covered inside and out with biomedical sensors. Sensing defeat, mission control relented. But no, they didn't let him out to race to wherever an astronaut could potentially race at a launchpad, The biomed sensors were turned off and Shepard was free to relieve himself safely in his suit. His supine position meant he was momentarily lying in a sizable puddle of his own urine before the oxygen flow inside the suit dried his long underwear. Within minutes, he was dry and the biomed sensors were back online. Not long after, America's first astronaut launched comfortably into history.
The second manned spaceflight was a copy of the first — Gus Grissom made the same short flight, which meant that his mission also lacked a urine collection device. Hoping to prevent a repeat of Shepard's wet episode, Grissom was given a makeshift, homemade system: a garter belt with a condom connected to a collection bag allowed Grissom to urinate without wetting his suit. It also gave Grissom the distinction of being the only astronaut of the era to fly in lingerie.
The garter belt and condom was replaced with a properly designed urine collection system. An external urine collection device — a tube emptying into a bag with a one-way valve to prevent backflow — allowed the astronauts to relieve themselves during a mission.
Longer missions complicated things as one bag wouldn't be sufficient. For the last Mercury flight, Gordon Cooper's Faith 7, a urine containment system was added to the capsule. Cooper had multiple urine bags to which he could attach the tube. His urine could either be pumped out the side of the capsule or brought back to the lab for scientific analysis.The system was a little difficult to use, but it did the job. The external urine collection device became a staple of space race-era missions.
With the Gemini program, a second "function" posed a new challenge. One of the program's central goals was to achieve long-duration spaceflight since a trip to the moon was expected to take up to two weeks. This means that a urine collection system wouldn't be enough; Gemini mission planners had to develop a poop containment system as well.
This was a harder nut to crack since fecal matter couldn't be dumped out of the spacecraft like urine. It had to be stored as neatly as possible.
As a preemptive measure, Gemini crews were given low residue foods in the hope of making their bowel movements smaller and less frequent. Nevertheless, they still needed a system. The solution was a foot long tube-shaped bag with an adhesive lining the open rim containing a small number of crystals designed to absorb moisture and neutralize odors. The bags were stored in the spacecraft and the samples analyzed by doctors after splashdown to determine how the body absorbs and digests nutrients without gravity.
Using this crude space crapper was a difficult task. Astronauts had to take special care to make sure everything remained contained — feces floating around a spacecraft in zero gravity has got to be a universally unappealing image. In many cases, the astronauts would try to hold off using the "fecal containment system," as it was called, but some missions were just too long, like Gemini 7's record two week mission. Astronauts Jim Lovell and Frank Borman broke down and had to use. The Navy SEALS who recovered the crew after splashdown commented that their spacecraft smelled worse than a latrine.
The larger Apollo spacecraft afforded the crew a very minimal amount of washroom privacy. Common practice had one astronaut strip down completely naked — wedding rings and all — while the other two crew members got has far away from him as possible. Being nude made clean up a comparatively easier affair.
For the crews who landed on the moon, using the washroom was both easier and harder. The one-sixth gravity was enough to keep anything from floating around the cabin. The flip side of a stay on the moon was that astronauts couldn't just pop back into the lunar module to relieve themselves midway through a moonwalk.
So, NASA diapered its astronauts. (Neil Armstrong's is pictured below.) Underneath their long johns and inside the highly sophisticated pressure suit that allowed the astronauts to travel freely around the lunar surface, delivered a steady flow of oxygen, controlled his temperature, and kept fresh drinking water within reach of his mouth, all moon-walking astronauts had a urine collection bag like the Mercury astronauts and a diaper.
The prospect of cleaning up after using a diaper was unappealing — washing on an Apollo mission meant wiping up with a damp towel, and in the LM there was no source of hot water. With this in mind, no moonwalker ever used the diaper. Still, accidents happened. Charlie Duke chose to urinate just before lifting off from the moon on Apollo 16. He only found out that his urine containment system had become unattached from his person when he felt a warm stream running down one leg. He began his trip back to Earth with a squishy left boot.
Longer term missions lasting months on the International Space Station have yielded advances in washroom technology in space, and the shift to mixed-gender crews has made moderate privacy a necessity. Still, there's something so human about American heros dealing with diapers on the moon. And now you know how astronauts go to the bathroom on the moon.