Scientists solving problem of thirsty astronauts with recycled pee

By Dean Murray via SWNS

Scientists are solving the problem of thirsty astronauts by using recycled urine.

NASA has developed a way to convert almost all urine produced on the International Space Station (ISS) into consumable water.

A so-called Urine Processor Assembly (UPA) recovers water from the liquid waste using vacuum distillation.

A process purifies the liquid to ensure it has become clean enough for drinking, with a claim it is purer than standard Earth-based tap water.

NASA explains: "For space missions that venture beyond low Earth orbit, new challenges include how to provide basic needs for crew members without resupplying missions from the ground.

"Each crew member needs about a gallon of water per day for consumption, food preparation, and hygiene such as brushing teeth."

To tackle the issue, NASA is developing life support systems that can regenerate or recycle consumables such as food, air, and water and is testing them on the International Space Station.

The space agency explains: "Ideally, life support systems need to recover close to 98% of the water that crews bring along at the start of a long journey.

"The space station’s Environmental Control and Life Support System (ECLSS) recently demonstrated that it can achieve that significant goal."

ECLSS is a combination of hardware that includes a Water Recovery System. This system collects wastewater and sends it to the Water Processor Assembly (WPA), which produces drinkable water.

One specialized component uses advanced dehumidifiers to capture moisture released into the cabin air from crew breath and sweat.

The UPA is another subsystem to ensure water is recycled effectively.

NASA says the team acknowledges that the idea of drinking recycled urine "might make some people squeamish," but they stress that the end result is far superior to what municipal water systems produce on the ground.

“This is a very important step forward in the evolution of life support systems,” says Christopher Brown, part of the team at Johnson Space Center that manages the space station’s life support system.

“Let’s say you collect 100 pounds of water on 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.”

“Before the BPA, our total water recovery was between 93 and 94% overall,” says Jill Williamson, ECLSS water subsystems manager.

“We have now demonstrated that we can reach total water recovery of 98%, thanks to the brine processor.”

The BPA takes the brine produced by the UPA and runs it through a special membrane technology, then blows warm, dry air over the brine to evaporate the water. That process creates humid air, which, just like crew breath and perspiration, is collected by the station’s water collection systems.

All the collected water is treated by the WPA. It first uses a series of specialized filters, then a catalytic reactor that breaks down any trace contaminants that remain. Sensors check the water purity and unacceptable water is reprocessed.

The system also adds iodine to the acceptable water to prevent microbial growth and stores it, ready for the crew to use.

“The processing is fundamentally similar to some terrestrial water distribution systems, just done in microgravity,” Williamson says.

“The crew is not drinking urine; they are drinking water that has been reclaimed, filtered, and cleaned such that it is cleaner than what we drink here on Earth. We have a lot of processes in place and a lot of ground testing to provide confidence that we are producing clean, potable water.”

NASA says the systems in ECLSS have been carefully tested, not only to ensure that they perform as intended but also to demonstrate that each is reliable and can operate long-term without a lot of maintenance or spare parts.

“The regenerative ECLSS systems become ever more important as we go beyond low Earth orbit,” Williamson says.

“The inability of resupply during exploration means we need to be able to reclaim all the resources the crew needs on these missions. The less water and oxygen we have to ship up, the more science that can be added to the launch vehicle. Reliable, robust regenerative systems mean the crew doesn’t have to worry about it and can focus on the true intent of their mission.”