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Results for “NASA Program CELSS”

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220 records · Page 13Linked to original sources

PubMed1996

Consideration in selecting crops for the human-rated life support system: a Linear Programming model.

A Linear Programming model has been constructed which aids in selecting appropriate crops for CELSS (Controlled Environment Life Support System) food production. A team of Controlled Environment Agriculture (CEA) faculty, staff, graduate students and invited experts representing more than a dozen disciplines, provided a wide range of expertise in developing the model and the crop production program. The model incorporates nutritional content and controlled-environment based production yields of carefully chosen crops into a framework where a crop mix can be constructed to suit the astronauts' needs. The crew's nutritional requirements can be adequately satisfied with only a few crops (assuming vitamin mineral supplements are provided) but this will not be satisfactory from a culinary standpoint. This model is flexible enough that taste and variety driven food choices can be built into the model.

Crops, Agricultural↗

PubMed1996

Enzyme conversion of lignocellulosic plant materials for resource recovery in a Controlled Ecological Life Support System.

A large amount of inedible plant material composed primarily of the carbohydrate materials cellulose, hemicellulose, and lignin is generated as a result of plant growth in a Controlled Ecological Life-Support System (CELSS). Cellulose is a linear homopolymer of glucose, which when properly processed will yield glucose, a valuable sugar because it can be added directly to human diets. Hemicellulose is a heteropolymer of hexoses and pentoses that can be treated to give a sugar mixture that is potentially a valuable fermentable carbon source. Such fermentations yield desirable supplements to the edible products from hydroponically-grown plants such as rapeseed, soybean, cowpea, or rice. Lignin is a three-dimensionally branched aromatic polymer, composed of phenyl propane units, which is susceptible to bioconversion through the growth of the white rot fungus, Pluerotus ostreatus. Processing conditions, that include both a hot water pretreatment and fungal growth and that lead to the facile conversion of plant polysaccharides to glucose, are presented.

Biodegradation, Environmental↗

PubMed1996

A bioreactor system for the nitrogen loop in a Controlled Ecological Life Support System.

As space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. This problem can be addressed by the development of Controlled Ecological Life Support Systems (CELSS) (i.e., Engineered Closed/Controlled Eco-Systems (ECCES)), consisting of human and plant modules. One of the waste streams leaving the human module is urine. In addition to the reclamation of water from urine, recovery of the nitrogen is important because it is an essential nutrient for the plant module. A 3-step biological process for the recycling of nitrogenous waste (urea) is proposed. A packed-bed bioreactor system for this purpose was modeled, and the issues of reaction step segregation, reactor type and volume, support particle size, and pressure drop were addressed. Based on minimization of volume, a bioreactor system consisting of a plug flow immobilized urease reactor, a completely mixed flow immobilized cell reactor to convert ammonia to nitrite, and a plug flow immobilized cell reactor to produce nitrate from nitrite is recommended. It is apparent that this 3-step bioprocess meets the requirements for space applications.

Ammonia↗

PubMed1996

Nitrogen dynamics in the CELSS Breadboard facility at Kennedy Space Center.

For the past 9 years, the Breadboard Project at Kennedy Space Center has studied the feasibility of using crop plants in bioregenerative life support systems for long-duration space missions. Nitrogen (N) has been emphasized in nutrient balance studies because it is a major plant nutrient, undergoes biogenic and abiogenic transformations, and is often limiting to plant growth under field conditions. Nitrogen budgets have been calculated from experimental results to quantify utilization and losses associated with specific crop production systems. The Breadboard Project has recently completed a 418-day potato crop study using recycled nutrient solution to evaluate the impact of continuous production on life support functions. A continuous production system is desirable in maintaining N balance within a solution because crop uptake rates vary dramatically depending upon the stage of crop development. Strategies for recycling N using biological techniques (e.g., biomass degradation with microbial bioreactors) have required that the production system be modified to distribute inputs more evenly over time. Recovery of N is dependent on the form of N entering the bioreactor and the desired output. Aerobic and anaerobic bioreactors for the recovery of N from waste streams and its transformation into a form usable by higher plants are being designed and tested.

Aerobiosis↗