NASA Achieves Water Recycling Milestone Aboard the International Space Station
In a pioneering development, astronauts aboard the International Space Station (ISS) have attained a 98% water recovery rate, an important milestone for low-orbit space missions. The recovery was achieved by recycling or regenerating the essentials such as food, air, and water, which are crucial for astronauts’ daily needs without relying on resupply missions.
The Environmental Control and Life Support System (ECLSS), a combination of advanced hardware, played a crucial role in reaching this milestone. The ECLSS includes a Water Recovery System that collects wastewater and dehumidifiers that capture moisture from the crew’s breath and sweat. This collected water is then sent to the Water Processor Assembly (WPA), which produces potable water.
A noteworthy part of the ECLSS is the improved Urine Processor Assembly (UPA), which recovers water from urine using vacuum distillation. The process, however, creates a by-product called brine, which still contains some unused water. To extract this remaining wastewater, a Brine Processor Assembly (BPA) was added to the UPA. The BPA successfully demonstrated its operations in the microgravity of space, enabling the ECLSS to reach the 98% goal. Jill Williamson, ECLSS water subsystems manager, remarked, “We have now demonstrated that we can reach a total water recovery of 98%, thanks to the brine processor”.
The BPA works by passing the brine through a series of special membranes, introducing it to warm dry air that evaporates its water content. This process creates humid air similar to the breath of ISS crew members, which can be collected by ECLSS dehumidifiers. The collected water is treated with a series of specialized filters and a catalytic reactor, which breaks down any remaining trace contaminants. Sensors then check the water’s purity. Water that doesn’t meet standards is sent back for reprocessing. Once deemed acceptable, iodine is added to prevent the growth of microbes, and the water is stored for the crew to use at a later point.
Responding to the question of whether astronauts are consuming recycled urine in space, the answer is clear; absolutely not. The water produced aboard the ISS is in fact superior to what municipal water systems produce here on Earth. The water is reclaimed, filtered, and cleaned to a level that it is cleaner than what we drink on Earth. “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,” Williamson clarified. She further added, “We have a lot of processes in place and a lot of ground testing to provide confidence that we are producing clean, potable water”.
This achievement is a significant step towards future space missions that will see astronauts spend more time in space during long stays on the lunar surface and crewed missions to Mars. The success of the ECLSS systems in achieving the 98% water recovery milestone indicates a promising future for long-term space missions. As resupplying becomes more challenging during space exploration, the ability to reclaim all the resources the crew needs becomes essential. “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,” Williamson concluded.
