The Evolution of Space Sanitation: From Spacesuits to Space Toilets

“Relieve yourself in the suit.” This was the startling directive given to Alan Shepherd, the first American in space, on May 5, 1961, when he informed the launch pad team of his need to urinate. He complied, leading to the short-circuiting of his spacesuit’s electronic biosensors.

Space Toilets

Shepherd’s spacesuit lacked a urine collection system because his mission was not anticipated to necessitate urination. However, NASA learned from this and equipped John Glenn’s spacesuit with the first operational urine collection system for his mission during the inaugural Mercury orbital flight on February 20, 1962.

This system, which included a wearable containment belt, latex roll-on cuff, plastic tube, valve, clamp, and plastic collection bag, set the standard for male astronauts throughout the space shuttle program. Glenn’s urine collection system is so significant that it has been exhibited at the National Air and Space Museum since 1976.

As space missions extended, with astronauts at the International Space Station (ISS) staying for up to six months, the need for more advanced sanitation solutions became apparent. This led to the development of space toilets, designed to cater to the most basic human needs in space while considering practicality and comfort.

The Functioning of Space Toilets

On Earth, toilets vary widely based on culture and geographical location. However, all terrestrial toilets rely on one principle: gravity. In space, the microgravity environment complicates waste disposal, making it potentially hazardous.

Without gravity, waste could float from space toilets, posing health risks to astronauts and potentially damaging sensitive equipment. To counteract this, space toilets on the ISS and spacecraft use suction and airflow. Astronauts must strap themselves to the toilet due to the weak gravity of space.

Handholds and footholds prevent astronauts from drifting off the toilet. While urinating, astronauts use a suction funnel to prevent leaks. When passing solids, suctioning begins immediately to reduce odors.

Waste Disposal in Space

Solid waste is sucked into garbage bags, then placed in airtight containers. Toilet paper, wipes, and gloves are also placed in these containers. These containers are loaded into cargo ships that bring resources from Earth to the ISS crew. The ships are then dropped back into Earth’s atmosphere, where they burn up, permanently disposing of the astronauts’ solid waste. Some feces are freeze-dried and returned to Earth for testing.

Water is a valuable resource in space, so urine can’t be allowed to be destroyed in the atmosphere. Each ISS crewmember needs about 1 gallon (3.8 liters) of water each day for drinking, food preparation, and hygiene uses like brushing teeth. Urine is collected by ISS toilets and passed to the Water Recovery System, which also collects sweat and moisture in expelled breath. This is then forwarded to the Water Processor Assembly (WPA), which turns it into drinkable water.

Advancements in Space Toilets

The first space toilet was designed for use in NASA’s Skylab orbiting platform, the first space station, in 1973. The toilet was a simple hole in the wall attached to a bag and fan where astronauts defecated, with feces being heat-dried.

In 2018, NASA developed its first new space toilet in decades, the Universal Waste Management System (UWMS), a titanium unit costing $23 million to develop. The toilet, sent to the ISS in 2020, is 28 inches (71 centimeters) tall, making it around half the size of the Russian-constructed toilets at the space station.

The UWMS toilet has been designed to be better suited to women, with the toilet seat tilted and raised to make it easier to use while seated. The newer toilet has also been designed with elongated and scooped-out funnels that allow astronauts to urinate and defecate at the same time.

Apollo 11 Astronauts and Sanitation

The Apollo 11 astronauts didn’t have toilets. Instead, they urinated into a urine collection device worn under their clothing, which they attached to themselves using roll-on cuffs. The urine was transferred through a rubber transfer tube to a tank, from where the majority of the liquid waste was vented into space with a small amount was freeze-dried and stored for testing upon return to Earth.

Laundry in Space

Astronauts on the space station wear their clothes until they are too dirty to continue to wear. After this, they place the clothes into waste receptacles, and they are eventually burned up in the atmosphere. Washing clothes in space is unfeasible because any detergent used would make the recycling process and water purification difficult.

Water Supply in Space

Water is recycled constantly on the ISS, with NASA aiming to achieve the recycling of 98% of used water expelled by the crew in sweat, breath, and urine. This is handled by the ISS’s Environmental Control and Life Support System (ECLSS), including its Urine Processor Assembly (UPA), Water Recovery System, and Water Processor Assembly (WPA).