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Current projections for the crop mix in the Bio-Plex and the future Lunar bioregenerative life support system indicate that without supplemental oil production, the crew's diet will be extremely low in fat, with little refined oil available for food processing or preparation. Although soybeans, peanuts and dwarf brassica (similar to canola) have been suggested as oil crops, each one poses significant problems either in horticulture, harvesting, productivity or byproduct utilization. An alternative to plant oils is “single-cell oil” or SCO. Lipid-accumulating “oleaginous” micro-organisms may accumulate up to 60% of their dry weight as triglycerides. Their high growth rates enable them to synthesize lipids with far greater productivity than higher plant systems. The current top candidate species for use in a bioregenerative system is a yeast, Cryptococcus curvatus.

Viability of bioregeneration for life support – providing food, water and air – on long-duration missions depends critically on cost of the plant habitat and on plant productivity in this habitat. Previous estimates, e.g. Drysdale and Wheeler, 2002 of both cost and productivity have been made using existing chamber designs, in particular the BIO-Plex (Bioregenerative Planetary Life Support Systems Test Complex) Plant Growth System intermediate design review (IDR) design. However, this design was developed for a terrestrial testbed, and is not optimized for use in space, much less for a particular space environment. Nor has productivity been determined experimentally for this configuration. We have examined this design and updated it for use on the Moon, with 709-hr days (light / dark cycles), using both natural and artificial light. Each system within the plant habitat was evaluated and modified to some extent for the desired use.

The most important CELSS engineering parameters are, in order of decreasing importance, manpower, mass, and energy (1). The plant component is a significant contributor to total system equivalent mass. In this report, a generic plant component is described and the relative equivalent mass and productivity are derived for a number of instances taken from the KSC CELSS Breadboard Project data and the literature. Typical specific productivities (edible biomass produced over 10 years divided by system equivalent mass) for closed systems are of the order of 0.2.

Most work on food production for long-duration missions has focused either on biomass production or nutritional modeling. Food processing, while not a basic life support technology, has the potential to significantly affect both life support system performance and the crew's quality of life. Food processing includes the following tasks: Separation of edible biomass (food) from inedible biomass Conversion of inedible biomass into foodstuffs (optional) Processing of foodstuffs into convenience ingredients or storable forms Storage management for locally produced foods and foods supplied from Earth Cooking and serving of fresh and stored foods Management of wastes and leftovers Cleaning and maintenance of equipment Questions to be answered in design of a food processing system include: What processing and labor-saving equipment is required, and with what capacity? How must earth-based processing technology be adapted for hypogravity?

This paper presents background information and describes operating experience with Mars Base Zero, a terrestrial analog of a Mars base situated in Fairbanks, Alaska. Mars Base Zero is the current stage in a progression from a vegetable garden to a fully closed system (Nauvik) that the International Space Exploration and Colonization Company (ISECCo) has undertaken. Mars Base Zero is an 80 m2 greenhouse, with 18m2 of living space attached. The primary goal is to determine the necessary size for Nauvik in order to support one to four people using current ISECCo techniques for growing food crops. In the spring of 2004 Mars Base Zero was planted, and in the fall of 2004, one subject, Ray Collins, was closed in the system for 39 days. The data from this closure indicates that, using ISECCo cropping techniques, Nauvik will need 150 m2 of crop area to support one person. While problems were encountered, the minimum goal of 30 days closure was exceeded.