Life Sciences in the Space Program 



Program Development: The Research Program 



The CELSS Program began in 1979 at ARC as a series of workshops that led to a 

 work plan and a series of research grants in 1980. The initial research phase, 1981 

 to 1985, focused on four major areas. First, research was directed toward increasing 

 food production and processing efficiency and improving growth methods for a 

 range of plants required for a complete human diet. This effort focused partly on 

 the use of algal biomass and a yeast culture to supplement crop plants in the 

 balanced diet and on a continued search for food producing systems more 

 efficient than photosynthesis. Secondly, research on waste processing was directed 

 toward methods to recycle mineral nutrients. Thirdly, work on human require- 

 ments was oriented toward optimizing the food production and processing system. 

 Finally, systems research concentrated on developing basic designs and defining 

 the requirements for a pilot study. 



Results from the initial studies in increasing food production were very encour- 

 aging. By 1984, energy conversion efficiencies of 7-9 percent were obtained with 

 higher plants and 14-18 percent with algae in laboratory studies. The initial studies 

 indicated that a photosynthetically based CELSS could potentially function with as 

 little as 20 m : of growing area (20 m 1 of pressurized plant growth volume) and 6 

 kilowatts of electrical power per person. Subsequent studies continue to support 

 the estimate of 20 m ; , but actual power measurements in CELSS research 

 laboratories indicate that lighting systems and support equipment require from 10 

 to 15 kilowatts per person. Compared to resupply from Earth, the estimated cost 

 of a bioregenerarive system for a 12-person lunar base will reach a break-even 

 point within 5 years at 50-percent food closure and 9 years at 97-percent food clo- 

 sure. Closure of the water and air systems alone results in an immediate 

 advantage when compared to resupply from Earth (5). These high conversion 

 efficiencies coupled with the low area and power requirements, plus the break- 

 even time between resupply and self sufficiency, were considered the basis for 

 starting a pilot study. 



CELSS research at ARC is currently focused on maximizing the growth of higher 

 plants under controlled conditions. The plants under study include wheat, barley, 

 soybeans, potatoes, and leaf lettuce. Other research at ARC includes development 

 of a sealed plant-growth facility using both green (Chlorella, Scenedesmus) and blue- 

 green (Spirulina) algae as a human food source, controlling algal growth, and 

 evaluating waste processing, especially wet oxidation techniques. Current plans are 

 to continue ongoing research and to request funds tor the following: expansion 

 into flight experiments to evaluate crop plant and algal growth in space, and 

 expansion of the evaluation of supercritical wet oxidation processes, cellulose 



Stion, growth of legumes for CELSS, reclamation, recycling of nitrogen and 

 salts required tor plant growth, development of ground-based and flight growth 

 i I i.unbers, and development o( ecological models of bioregenerarive systems. A 

 program plan has not yet been approved for the ARC effort. 



Program Development: Tfie Breadboard Project 



e KSC Breadboard Project, started in 1985, has three primary goals: 



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