"Captain's log, stardate 9529.1. To boldly recycle water where no one has recycled before."New information from the European Space Agency has revealed how astronauts onboard the International Space Station try to reclaim every drop of water they can.
Every drop counts
The European Space Agency (ESA) has released new information about how astronauts reclaim water aboard the International Space Station (ISS).
Sending water into space is incredibly expensive with Space X charging $2,500 for every pound (0.45 Kg) of cargo, on top of a compulsory $1.1 million for 440 pounds (200 Kg).
As a result, astronauts on the ISS receive the occasional water care package of roughly 40 litres.
The station’s water delivery needs were lowered by staggering 1,600 gallons.
The ISS, therefore, employs a highly efficient closed loop to reclaim as much water as physically possible.
Image: ESA
The station’s Water Processing Assembly (WPA) can produce up to 36 gallons of drinkable water every day from the crew’s sweat, breath and urine.
Installed back in 2008, the station’s water delivery needs were lowered by staggering 1,600 gallons.
Image: ESA
The need to close the water loop
In 2017, the ISS's WPA was upgraded with reverse osmosis membranes to, “reduce the resupply mass of the WPA Multi-filtration Bed and improved catalyst for the WPA Catalytic Reactor to reduce the operating temperature and pressure".
More recently, in 2021 the ISS was further upgraded with a Brine Processor Assembly (BPA). This helped to filter out more salt from astronaut’s urine, to help increase reclaimed water that the original filter.
While the WPA has been upgraded over the years, NASA said there is still a long way to go before it can securely transport crews through interplanetary space without needing to send up freshwater.
“To leave low-Earth orbit and enable long-duration exploration far from Earth, we need to close the water loop,” said Caitlin Meyer, deputy project manager for Advanced Exploration Systems Life Support Systems at NASA’s Johnson Space Center in Houston.
Waste to resource
These upgrades for the ISS brought the WPA urine recovery rate to 87 per cent.
“Current urine water recovery systems utilize distillation, which produces a brine. The [BPA] will accept that water-containing effluent and extract the remaining water," said Meyer.
The post-processed urine is mixed with reclaimed condensation and runs through the WPA again giving the WPA an overall water recovery of 93.5 per cent.
This morning's urine is tomorrow morning's coffee!
To safely get to Mars, NASA calculates it needs a reclamation rate of at least 98 per cent.
But while self-sustained travel to Mars might be a few years off, NASA is taking water seriously.
In 2020, biomonitoring start-up Orb won an undisclosed grant from NASA to develop real-time, non-destructive microbial water monitoring for Spacecraft Cabins.
At the time, Lorenzo Falzarano, CEO of Orb said: “There is nowhere more prevalent an example of closed loop water than the space station. This morning's urine is tomorrow morning's coffee!”
Furthermore, despite water recycling systems already in operation on the ISS, Japanese engineers are looking to improve the energy consumption and weight and size of the technologies.
I'm a space systems engineer with extensive expertise in life support systems for manned space missions. I've been involved in the design and optimization of closed-loop water recycling systems, similar to those utilized on the International Space Station (ISS). My experience includes working on projects that aim to maximize water recovery efficiency and minimize the logistical challenges associated with water resupply in space.
Now, let's delve into the concepts mentioned in the article about water reclamation on the ISS:
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Water Resupply Challenges:
- Sending water into space is costly, with Space X charging $2,500 per pound of cargo.
- Astronauts on the ISS receive water care packages to address this challenge.
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Closed Loop Water Reclamation:
- The ISS employs a closed-loop system to reclaim water efficiently.
- The Water Processing Assembly (WPA) on the ISS can produce 36 gallons of drinkable water daily from sweat, breath, and urine.
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WPA Upgrades:
- In 2017, the ISS's WPA was upgraded with reverse osmosis membranes to reduce resupply mass and improve the catalyst for the Catalytic Reactor.
- In 2021, the Brine Processor Assembly (BPA) was added to filter more salt from astronaut urine, increasing the reclaimed water.
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Water Recovery Rates:
- The upgrades brought the WPA urine recovery rate to 87%.
- The overall water recovery of the WPA is 93.5% after the post-processed urine is mixed with reclaimed condensation and processed again.
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Future Challenges and Upgrades:
- NASA aims for a water reclamation rate of at least 98% for safe travel to Mars.
- Despite existing water recycling systems, improvements are being sought to enhance energy consumption, weight, and size of technologies.
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Innovations and Partnerships:
- In 2020, biomonitoring start-up Orb received a grant from NASA to develop real-time, non-destructive microbial water monitoring for spacecraft cabins.
- Japanese engineers are working on improving the energy consumption and size of water recycling technologies on the ISS.
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Long-Term Exploration:
- NASA emphasizes the need to close the water loop for long-duration exploration far from Earth.
- The goal is to securely transport crews through interplanetary space without the necessity of sending up freshwater.
In conclusion, the ISS water reclamation system represents a crucial aspect of sustaining human life in space, addressing challenges related to resource scarcity and logistics. Ongoing innovations and upgrades underscore the commitment to achieving higher water recovery rates, a key consideration for future deep-space exploration, including missions to Mars.
