Closing the Water Loop for Exploration: 2020-2021 Status of the Brine Processor Assembly

Abstract

Paragon Space Development Corporation has developed a Brine Processor Assembly (BPA) for demonstration on the International Space Station (ISS). BPA will recover water from urine brine produced by the ISS Urine Processor Assembly (UPA) and ground testing has demonstrated to achieve water recovery rates significantly greater than the 75-90% that is currently recovered by the UPA�s Vapor Compression Distillation (VCD) subsystem. BPA utilizes the forced convection of spacecraft cabin air coupled with a robust membrane distillation process to recover purified water from 22.5 liters of brine within a 26 day cycle. An ionomer-microporous membrane pair contains the brine while transferring purified water vapor to the cabin air. The water vapor is collected by the existing spacecraft condensing heat exchangers, which already recover metabolically produced water vapor as humidity condensate. This paper will discuss progress to-date on meeting critical technical and ISS integration milestones. Flight hardware was successfully delivered to NASA in Fall 2020 and the flight unit was launched to the ISS in February 2021. After installation on the ISS, on-orbit experiments will be conducted for a year to evaluate BPA performance in microgravity. By increasing overall water recovery on ISS to greater than 98%, BPA demonstrates a critical capability needed to close the brine processing technology gap identified in NASA�s Water Recovery Technology Roadmap. This technology achieves an essential capability to enable human exploration of deeper space.