As NASA begins sending humans into space for extended periods, the space agency is looking for new ways to meet the basic needs of crew members without any resupply missions from Earth. Some of the research conducted aboard the International Space Station (ISS) involves processing consumables such as food, air, water and urine collected from astronauts.

NASA will soon be sending humans into space longer than ever before, thanks to the Artemis missions. Artemis will initially focus on the Moon, but the space agency is already planning trips to Mars as well. For these long journeys to be possible, astronauts need to make sure they have the basics of life. That’s exactly what current astronauts are testing with the Space Station’s Environmental Control and Life Support System (ECLSS).

“This is a very important step in the evolution of life support systems,” said Christopher Brown, a member of the Johnson Space Center team that manages the space station’s life support system. Let’s say you collect 100 kilos of water at the station. You lose two pounds and the remaining 98% continues to spin. Maintaining this and keeping it running is quite an astonishing feat.

NASA says ECLSS is a combination of hardware that includes a water recovery system. The system not only collects wastewater and converts it into potable water, it also uses a special component that can capture moisture released into the cabin air from crew sweat and breathing.

The recycling process also includes a subsystem called the Urine Processor Assembly (UPA), which recovers water from the astronaut’s urine by vacuum distillation. Improvements to the UPA Distillery have added the ability to produce water and urine brine that still contains some recycled water. A brine treatment unit (BPA) was also developed to remove residual wastewater from the space station.

“Prior to the introduction of BPA, our overall wastewater recovery was 93 to 94% overall,” said Jill Williamson, ECLSS Water Subsystems Manager. “We have shown that we can achieve a total water recovery of 98% with the brine treater.”

To achieve its purpose, BPA takes the brine produced by UPA and then passes it through a special membrane technology that “blows the brine with hot, dry air to evaporate the water.” This process creates moist air that is collected by the ISS water collection system. This is similar to how crew breath and sweat are used.

Security measures such as sensors to check the purity of the water are included in the system and if found unacceptable, the water is re-purified. It also adds iodine to acceptable water to prevent any microbial growth and then stores it. This process goes a long way in providing the essential water every astronaut needs every day for consumption, cooking and personal hygiene.

The team acknowledges that the thought of drinking recycled urine makes some people nauseous. However, they emphasize that the result is “much better” than what we all drink on Earth.

“The process is basically similar to some land-based water delivery systems, only done in microgravity,” explains Williamson. He adds that the crew didn’t actually drink urine, but instead drank water that was remanufactured, filtered, and purified to a level “purer than what we drink here on Earth.”

Williamson says the importance of ECLSS becomes extremely important as humans move beyond low Earth orbit. The inability to frequently send resources to astronauts during exploration means that NASA and other space agencies must be able to return these critical resources for the needs of the crew. The ability to recycle these resources allows the astronauts on board to focus on the task at hand and not worry about how to survive. Source