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The establishment of a human-tended lunar base requires an autonomous bioregenerative life support system. Bioregeneration within a Lunar Engineered Closed/Controlled EcoSystem (LECCES) can be realized by integrating humans, plants, animals, and waste treatment subsystems. This integration incorporates physical/chemical and biological waste treatment processes that minimize resupply requirements from Earth. A LECCES top-level system integration model is developed based on human metabolic massflow requirements. The proposed model is presented and its components are discussed.

The challenge of food provision in a human-tended Lunar/Martian base necessitates the development of stable, nutritious and palatable foods from limited plant sources. The ability to safely prepare and store a wide variety of foods having physiological and psychological acceptability, with a limited number of starting materials, plays a prime role in the success of long-term missions. Since wheat has been proposed as one of the major crops to be grown on space outposts, this project focuses on identifying novel ways to process food products from wheat under vacuum conditions. Vacuum has not been sufficiently exploited for food processing, and space vacuum can be capitalized for selected food processes. Two techniques currently under investigation are vacuum baking and extrusion. Vacuum oven baking minimizes the need for extensive proofing and/or chemical leavening and decreases preparation time.

Between 1963 and 1969, 301 young rhesus monkeys were exposed to low and intermediate doses of X-rays, protons or electrons to simulate space radiation hazards; 57 control animals were incorporated in the experimental design, and both sexes were represented. The subjects have been followed for nearly 30 years, and major findings of the study include: 1) highly significant incidence of glioblastoma multiforme (high-grade astrocytoma) in male animals exposed to 55-MeV protons; 2) highly significant incidence of severe endometriosis in female subjects exposed to different radiation energies and doses; 3) development of significant late lenticular opacifications (cataracts) in monkeys 20+ years following exposures to low and intermediate doses of protons. As the animals age, abundant data are expected to provide additional insights into the late stochastic (probabilistic) and deterministic effects induced in primates by exposures to low and intermediate doses of particulate radiations.

Photosynthetic use of CO2 by wheat and rice crops were modeled over entire crop cycles. To compare CO2 use under different environments, the flux of CO2 and the rate of plant development were normalized. This normalization procedure yielded models which suggest that development of a generalized model may be possible.

As space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. This problem can be addressed through the integration of human and plant modules in an ecological life support system. 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 can be used as a nutrient for the plant module. A 3-step biological process for the conversion of nitrogenous waste (urea) to resource (nitrate) is proposed. Mathematical modeling was used to investigate the bioreactor system, with the goal of maximizing the ratio of performance to volume and energy requirements. Calculations show that separation of the two microbial conversions into two steps requires a smaller total reactor volume than combining them in a single bioreactor.

Closed ecological life support systems incorporating plants represent the only potential for achieving self-sufficiency in an extraterrestrial biosphere. A model of input/output metabolic mass flow rates for a plant module in an Engineered Closed/Controlled EcoSystem is presented. Wheat crop was chosen as a case study for modeling metabolic mass flow rates. Coefficients for the mass flow rates, for each metabolic element, are determined per unit area of wheat production. The coefficients are utilized to compute the area of edible biomass production necessary to accommodate human food requirements. This model for computing metabolic mass flow rates can be applied for any crop under specified growing conditions.

Structures for use on the Moon and/or Mars face similar requirements and design criteria despite the differences in the corresponding environmental conditions. In both cases, the internal pressure is the dominant load and, therefore, the structure is a pressure vessel. A generic inflatable module is proposed as an efficient and functional structure for a lunar/Martian base. Each module consists of thin membranes supported by an inflated framing system. Module characteristics, including component dimensions, membrane thicknesses and overall mass, are presented.

A BRIC (Biological Research In a Canister) experiment to investigate the effects of reduced gravity at the molecular level using Arabidopsis has been initiated. To ensure an efficient BRIC experiment, a series of ground-based studies have been conducted. These studies were designed to determine: 1) the ideal seed density to obtain enough plant tissue from a single canister; 2) optimum germination surface for tissue recovery after freezing in liquid nitrogen; 3) yield and quality of mRNA from small amounts of tissue; 4) time point to freeze the seedlings; and 5) changes in gene expression that may be caused by stresses during launch.