Critical Analysis of ISRU Plants Integration in Complex Architectures for Planetary Human Colonies Development

A sustainable expansion of human presence in space should be based on the development of self-sustaining outposts and permanent bases, and therefore on the capability of producing part, or possibly the entire amount, of necessary resources in situ. Most useful resources can be extracted from local materials (e.g. from the lunar regolith or the martian atmosphere), by means of dedicated In-Situ Resources Utilization (ISRU) plants which must be included within the overall surface architecture. These plants might require different mobile elements (e.g. miners and haulers) to extract and transport raw materials from the excavation site to the plant, to transport by-products to secondary plants or to containment facilities, and, possibly, to transport the produced resources to storage facilities. EVA activities might be required for servicing and maintenance activities or, in case of man-tended plants, to manage and control the ISRU process phases. Thus, the integration of an ISRU plant into a manned base involves several surface elements together with the planning, scheduling and management of activities and operations. This paper presents an analysis of the requirements, constraints, and risks which characterize and drive that integration and describes the synergies and the interfaces which must be considered in developing the build-up and maintenance process of manned surface architectures including ISRU systems. A trade off analysis between completely autonomous plants and man-tended ones is proposed, including safety and reliability considerations. The critical analysis here presented is supported by parametrical models of ISRU production requirements and performances to support a manned base, exploiting a library of dynamic models of ISRU plants, Environmental Control and Life Support Systems (ECLSSs) and power provision systems developed at Politecnico di Milano - DIA.