Currently, these three sources form the primary inputs to life support water reclamation systems. Disinfectants must be added to the reclaimed waters to prevent the growth of pathogenic microorganisms. Water contained in feces and other solid waste is lost from the system and must be made up by onboard water production facilities or by resupply. Three separate water purification loops are used onboard the Russian Mir space station. Urine is purified as a feed to the electrolysis cells which generate oxygen.
Hygiene water is reprocessed for re-use only as hygiene water.
This is similar to the original water reclamation scheme for the Space Station Freedom program.