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A simple, mass balance model of carbon flow in a controlled ecological life support systemInternal cycling of chemical elements is a fundamental aspect of a Controlled Ecological Life Support System (CELSS). Mathematical models are useful tools for evaluating fluxes and reservoirs of elements associated with potential CELSS configurations. A simple mass balance model of carbon flow in CELSS was developed based on data from the CELSS Breadboard project at Kennedy Space Center. All carbon reservoirs and fluxes were calculated based on steady state conditions and modelled using linear, donor-controlled transfer coefficients. The linear expression of photosynthetic flux was replaced with Michaelis-Menten kinetics based on dynamical analysis of the model which found that the latter produced more adequate model output. Sensitivity analysis of the model indicated that accurate determination of the maximum rate of gross primary production is critical to the development of an accurate model of carbon flow. Atmospheric carbon dioxide was particularly sensitive to changes in photosynthetic rate. The small reservoir of CO2 relative to large CO2 fluxes increases the potential for volatility in CO2 concentration. Feedback control mechanisms regulating CO2 concentration will probably be necessary in a CELSS to reduce this system instability.
Document ID
19900001255
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Garland, Jay L.
(Virginia Univ. Charlottesville, VA, United States)
Date Acquired
September 6, 2013
Publication Date
March 1, 1989
Subject Category
Man/System Technology And Life Support
Report/Patent Number
NASA-TM-102151
NAS 1.15:102151
Accession Number
90N10571
Funding Number(s)
CONTRACT_GRANT: NAS10-10285
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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