On complexity-level based classification of regenerative life support systems for manned spacecraft

The paper addresses definitions and concepts of a complex engineering system. It identifies key operational aspects or regenerative life support systems for manned spacecraft, which characterize them as a complex engineering system. It elaborates complexity criteria and proposes a classification system for regenerative life support systems based on their level of complexity. Complexity of regenerative life support systems is analyzed using the example of atmosphere revitalization equipment as a component part of such systems. It is pointed out that while having the same functions their supporting component parts may belong to different levels of complexity, and, therefore, may significantly differ in development time and costs. The proposed system for classifying component parts of regenerative life support systems will make it possible to uniquely define the complexity level of new assemblies and systems under development at their initial design phase, as well as to make a preliminary estimate of schedules and costs of their development and manufacturing.