Ground Demonstration and Evaluation of the Brine Processor Assembly as a Primary Urine Processor

The Brine Processor Assembly (BPA) was developed by Paragon Space Development Corporation as a technology demonstration for the International Space Station (ISS) and has now been in operation for three years. 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. An ionomer microporous membrane-based bladder retains the liquid brine while water vapor pervaporates into the cabin, for collection as humidity condensate. While the BPA continues to operate on ISS, Paragon has investigated the technology's potential as a standalone urine processing solution that could supersede the combined UPA+BPA for the next generation of space stations. The Primary Urine Processor (PUP) uses the same flight-proven distillation technology of the BPA, but with a continuous feed of urine and adjusted operating parameters. The presented work discusses the development, demonstration, and evaluation of a PUP Engineering Development Unit (EDU), based on the BPA flight design with several modifications to allow for continuous-feed urine processing. 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 and nearing 2-crew-equivalent urine processing with a single bladder assembly. These results both demonstrate PUP as a viable alternative to the ISS urine water recovery solution and provide insight into the technology for further optimization and scaling to design a full-scale flight prototype for direct comparison to the ISS systems on the bases of mass, volume, power, consumables, safety, and complexity. Implementation of this technology into new space stations will help pave the way for deep-space human exploration.