Water recovery from urine is one of the most important components of the closed life support system complex during a long manned space flight and it requires some of the most complicate technologies. Various negative factors of space flight and microgravity conditions directly affect the peculiarities of both metabolic processes in the human body and technological processes of regeneration, which requires verification of technical characteristics achieved on the ground in real conditions of space flight. Since April 2018, a space flight experiment has been conducted in the MRM1 ISS module to study the technology of crew urine distillation in a five-stage centrifugal vacuum distiller with additional recovery of condensation heat in a semiconductor heat pump. During experiment from 2018 to 2023, 290 L of urine was processed and 210 L of untreated water was obtained from which 170 L was used by the crew for the preparation of food and beverages with the preliminary sorption-catalytic purification in the system of water regeneration from the condensate of the SRV-K2M of Service Module. The quality of the recovered water fully met the requirements, the power consumption of the system did not exceed 325 W which is less than designed 360 W. But some system's characteristics in the flight experiment negative differed from the ones obtained in the long-term ground tests: - Recovery rate was up to 84%, lower than the 90% from the ground tests; - Significantly lower reliability of individual units of the system in space conditions did not allow to transfer it to permanent operation with water production for crew needs. The paper analyzes the results of the flight experiment and obtained characteristics of the system based on the centrifugal multistage vacuum distiller, revealed positive sides of the applied technologies, causes of shortcomings and ways of their possible elimination.
Petr Andreychuk (Sun,) studied this question.