Bioregenerative life support as self-sustaining ecosystem in space.

Recent results of research on the development of biological systems and the related technologies for life support ecosystem in space have been reviewed. The integration of higher plants and algal subsystems and the technologies for food and atmospheric regeneration, water reclamation as waste recycling are the aspects which have been dealt with and need critical evaluation before they can be tested in space. The adaptation of living organisms and their ability to multiply and regenerate in space environment during long duration missions is one of the important criteria for their final selection. It is not yet clear to what extent bioregenerative subsystems can be accommodated in the space station Freedom, which will depend on their mass and functional stability, maintainability and operational cost. But it can be expected that bioregenerative life support systems will continue to evolve during the life time of space station Freedom leading towards an integrated ecosystem with further simplification and an increased degree of closure. Several biological and physico-chemical life support systems currently developed are under investigation on the MIR space station.