Development of control princi-ples for the desalination unit for closed life support systems of space purposes

Exploring the Solar system by humans implies the development of long-term habitable bases on several planets: the Moon, Mars, and others. Maintaining an environment favorable for a crew on such bases is possible due to life support systems (LSS), where a closed mass transfer of products and waste is imple-mented among the crew, the higher plants and other links. Closure increases the reliability and autonomy of the system, and reduces the cost of its supply.Controlling such mass transfer appears to be a difficult technical task requiring many man-hours, which is a valuable resource in the implementation of manned space missions. In the general case, this problem is solved by means of automation, however, it is neces-sary to take into account the features of the processes that support mass transfer, since this will allow find-ing ways to simplify the hardware and logical components, increase their versatility and reliability. This article presents an analysis of the technological processes of the experimental unit for extracting NaCl from solutions of mineralized human metabolites and proposes a simple control algorithm to be used for all processes of the unit without fundamental changes. Without developing a NaCl transformation cycle, it becomes almost impossible to develop a long-term functioning biological and technical life support sys-tem – the optimal LSS option for alien bases. In such systems, mass transfer occurs between the crew and the higher plants and there is a danger of NaCl accumulation in irrigation solutions and subsequent poi-soning of the plant link. Therefore, the problem of controlling the NaCl transformation cycle in mass trans-fer processes of a high degree of closure is relevant, and the universal principles of automated control can be used not only in space, but also in terrestrial applications: in closed agrotechnical cycles and scientific, and educational stands.