Life Sciences in the Space Program 



Human dietary requirements are understood and could be provided by a vegetar- 

 ian diet including higher plants and algae. This diet has to be supplied in a 

 CELSS environment with a limited diversity of biomass material and with serious 

 constraints on space and facilities for food preparation. The potential for limited 

 food supplement storage exists, but this must be more fully understood, perhaps 

 at the level of planning meals several months in advance to compensate for plant 

 growth, harvest cycles, and storage life of previously harvested materials. JSC has 

 considerable experience dealing with human requirements, yet its involvement in 

 CELSS-related research has been limited to date. 



The aesthetic contribution of plants mav be important. Soviet experience has 

 shown that plants are psychologically important for crew morale and positive 

 interactions and that lack of diversity in diet can seriously impair psychological 

 well-being. Critical attention must be given to integration of these considerations 

 into the CELSS research and manned demonstration. 



Systems Management and Control. For CELSS to be a success, systems that 

 provide for atmospheric regeneration, food production and processing, and waste 

 management, as well as their control, must be integrated into a reliable system 

 and operated under conditions of reduced gravity. To accomplish these goals, 

 researchers and technicians need to examine monitoring and feedback control 

 systems, automate all systems to reduce human maintenance, establish methods to 

 handle such tasks as maintenance and cleaning, and minimize risk factors and 

 critical failure points. While most of these problems are being investigated at 

 NASA Centers, some contributions have been made by commercial concerns in 

 life sciences, including Boeing, Martin Marietta, and Lockheed. 



Through its manned flight program, NASA has demonstrated the capability to 

 handle physical, chemical, and engineering systems. For CELSS to be successful, 

 that same degree of technological capability must be applied to biological systems. 

 Successful demonstration of a pilot-scale CELSS is of paramount importance to 

 accomplishing this complex task. 



A Summary of Major Constraints 



Limitations on mass, volume, and power are well established in human space 

 flight. Current estimates of 20 m ot pressuri/ed plant growth volume and 10 

 kilowatts of electrical power per person seem reasonable bounds within which a 

 ( ELSS can operate. Robotics development mav solve many of the challenges 

 related to human labor requirements, but serious problems remain in this area 



For ( rop plants to be used over multiple harvest cycles, a viable seed stock must 

 be maintained. The effects oi long-term exposure to the space environment on 

 plant development, growth, and reproduction are not understood. Until adequate 

 long-term flighl experiments can be conducted, CELSS will have to be developed 

 with these unknowns 





