How long can the station's air and water recyclers run without resupply?

"The International Space Station’s Urine Processor (UPA) has been operational since November 2008 and has processed over 99,000 lbs of pretreated urine."

"This paper addresses this gap by using the International Space Station (ISS) as a case study, given its advanced regenerative ECLSS architecture."

"Throughout these operational years, the UPA has only needed approximately 6.7% of that production mass of total up-mass in replacement hardware."

"In July 2023, UPA received an even further upgraded purge pump that focuses on exploration missions; the Purge Pump and Separator Assembly (PPSA). This new pump showed excellent performance metrics until a failure of the isolation valve causing the inability to purge the Distillation Assembly (DA)."

"Recovery also included a successful high risk engineering effort of building a viable pump, on orbit, from two failed purge pumps, requiring access to areas unplanned to be accessible by crew."

"Temporary operational constraints were also levied onto UPA to limit runtime in hopes to extend the installation time while still managing urine storage risks."

"Many microbiological studies were performed during the development of the Space Station Water Recovery and Management System from1990-2009."

"As a result, it was found that water electrolysis could be performed under microgravity conditions with almost the same performance as on the ground, and the flow rate thresholds that indicate microgravity effects were also obtained."

"In the demonstration experiment, a sub-scale water treatment system was used to purify the artificially synthesis urine as raw water to be treated."

"Water Recovery Test, Stages 1A/2A/3A, which took place at the Marshall Space Flight Center, Huntsville, Alabama."

"The Brine Processor Assembly (BPA), developed by Paragon Space Development Corporation as a one-year Technology Demonstration"

"BPA recovers available water from urine-brine produced by the ISS Urine Processor Assembly (UPA) via forced convection of cabin air coupled with a patented membrane distillation process."

"It was successful, and remains on board the ISS permanently."

"has now been in operation onboard the International Space Station (ISS) for almost four years."

"The PUP EDU processed 314 L of 95th percentile pretreated and augmented urine over a span of 4 months, recovering 99.5% of the available water in the pretreated urine"

"has led to a revised operational level of recovering 70% of the water content."

"With the majority of science objectives met and ISS integration milestones achieved, the BPA has slowly transitioned from a technology demonstration to a regularly operating piece of the ISS Water Recovery and Management (WRM) architecture."

"nearing 2-crew-equivalent urine processing with a single bladder assembly."

"Over the years, reactor performance gradually declined."

"As of February 2025, 60 full operational runs have been completed spanning 864 days of active operations, recovering an estimated 1087 kg (L) (over a metric ton!) of water from urine-brine."

"This water-saving capability reduced the needed water in cargo resupply by 400 liters per year."

"This represents a cost savings of roughly $81 million from the mass of water and supporting equipment that has not needed to be launched to or discarded from the ISS, minus the cost of consumables (bladders and odor filters)."

"The Water Recovery System was installed initially in Destiny on a temporary basis in November 2008"