NASA successfully recycles 98 percent of urine and sweat into drinking water on the ISS

NASA demonstrated a 98 percent water recyclability rate on the ISS for all wastewater, including sweat and pee.
Tejasri Gururaj
NASA astronaut Kayla Barron replacing a filter in the BPA on the ISS.
NASA astronaut Kayla Barron replacing a filter in the BPA on the ISS.


In an exciting announcement, NASA has announced that astronauts aboard the International Space Station (ISS) have achieved a water recovery rate of 98 percent. The ISS used its Environmental Control and Life Support Systems (ECLSS) to achieve this remarkable goal, according to a press release.

The ECLSS is a combination of multiple water recovery systems, including advanced dehumidifiers, a Water Processor Assembly (WPA), a Urine Processor Assembly (UPA), and a Brine Processor Assembly (BPA).

You read it right. Water was recycled from sweat and urine. 

Space missions beyond low Earth orbit, such as those to the Moon or Mars, present unique challenges when it comes to effectively managing crew supplies. Therefore, they require a comprehensive approach to resource management, emphasizing recycling, regeneration, and sustainable practices. 

The aim is to minimize reliance on resupply missions and enable crews to sustain themselves for extended durations in the challenging environments of deep space. NASA has been developing and testing life support missions on the ISS that can help provide basic needs for the crew without resupply missions.

NASA successfully recycles 98 percent of urine and sweat into drinking water on the ISS
NASA astronaut Chris Hadfield drinking water on the ISS.

The ECLSS water recovery system

The ECLSS is designed to provide a habitable environment and essential life support for astronauts. In addition to recycling water, the ECLSS is responsible for managing air supply and atmosphere control, thermal control, and radiation protection.

The water recovery system of the ECLSS collects wastewater from various sources, including urine, humidity condensation, and other sources of moisture within the spacecraft. The advanced dehumidifiers collect wastewater from the astronauts' breath and sweat.

The UPA is responsible for recovering water from urine. It successfully distills urine but produces brine as a by-product, which makes the water undrinkable. This is where the BPA comes in handy.

The BPA is responsible for extracting the brine and providing drinkable water. The BPA takes the brine produced by the UPA and passes it via a series of specialized membranes before introducing it to dry air, which evaporates its water content.

This produces humid air, similar to that produced by the ISS crew members' breath, which is collected by ECLSS dehumidifiers. 

The WPA then treats all wastewater through a series of filters and a catalytic reactor, which breaks down any leftover contaminants in the water.

Before the water is stored, sensors test the water quality to ensure it is suitable for drinking. If the standards are not met, the water is returned for processing. Additionally, iodine is added to inhibit the growth of microbes, after which the water is stored for later use by the crew.

Achieving 98 percent recovered water

According to NASA's recent assessments, the BPA was the main component that helped them to achieve a 98 percent water recovery goal in microgravity. 

Christopher Brown, a member of the Johnson Space Center, said, "This is a very important step forward in the evolution of life support systems. Let's say you collect 100 pounds of water at the station. You lose two pounds of that, and the other 98% just keeps going around and around. Keeping that running is a pretty awesome achievement."

The Johnson Space Center manages the life support system of the ISS. Jill Williamson, the CLSS water subsystems manager, further added, "Before the BPA, our total water recovery was between 93 and 94% overall. "We have now demonstrated that we can reach total water recovery of 98%, thanks to the brine processor."

The ECLSS systems are rigorously tested to guarantee that they work as intended and that each component can run for extended periods without requiring extensive maintenance or replacement spare parts. 

The 98 percent achievement bodes well for future space missions, where humans are expected to undertake prolonged stays on the lunar surface and embark on crewed voyages to Mars.

This article was written and edited by a human, with the assistance of Generative AI tools. Find out more about our policy on AI-powered writing here

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