Optimization of Feedstock Composition and PreProcessing for Composting in Advanced Life Support Systems

Advanced Life Support (ALS) systems designed for long-duration manned space missions, particularly permanent bases on the Moon or Mars, are likely to employ extensive use of regenerative closed loop systems, including the production of higher plants for food. Such systems will produce substantial amounts of inedible plant material in addition to other standard mission wastes. Composting is one of the several methods currently under investigation for waste processing and resource recovery in ALS systems. While composting is a robust microbiological process that can be utilized to treat a variety of organic materials under a wide range of environmental conditions, both feedstock preparation and process control require optimization. For instance, initial waste feedstock composition, carbon to nitrogen ratio (C:N), particle size, and moisture content are critical factors for ensuring optimal processing conditions and maximal rates of degradation. In order to efficiently and flexibly coordinate various factors in an ALS composting system, a management information system (MIS) will be beneficial, particularly in regard to feedstock preparation. To this end, an MIS was developed to examine and provide an interface between waste production and compost feedstock preparation. In addition, operational and processing conditions, and other variable conditions arising from other subsystems (Crew, Biomass Production and Food Processing) in ALS systems are examined.