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To facilitate the selection of a palatable and functional food, eight green onions grown under either cool-white fluorescent lamps (CWF) or high pressure sodium lamps (HPS) were compared for their pungency, tissue nitrate and sulfate status. The effect of lighting intensity and atmospheric CO2 levels on pungency of a selected cultivar was also investigated. Results demonstrate that there was a difference in pungency not only among cultivars, but also between tissue types and developmental stages. The pungency was inversely correlated with nitrate level in tissue, and light quality had profound impact on tissue nitrate level. Pungency in the pseudobulb and leaf of green onion responded differently to increased light intensity and elevated CO2. The effect could be mostly explained by the relative accumulation rates of the flavor precursors and biomass.

The monitoring and control of an artificial climate is necessitated by the Mars Dome Project (MDP) [ref 1]. MDP is designed to grow plants in an enclosed structure under reduced pressure. This system includes a dome enclosure, an environmental control system, a plant growth system, a data logging system, and an external vacuum vessel [ref 2]. Each of these systems is integrated by the use of a solid-state control device located inside the base of the Atmospheric Tower Management System (ATMS). Details of the controller follow a short summary of the major components of the MDP.

The reliability of biological life support systems, critical for long-duration human space missions, has been questioned. We propose that properly engineered biological components are inherently reliable, and support this view with data from nine years of operation of the CELSS Breadboard Facility (CBF) at Kennedy Space Center. Reliability problems in a bioregenerative life support system will generally be caused by support system failures, they will generally not be catastrophic, and the crew will have ample time to respond. Thus, biological system reliability can be good, and the impact of low component reliability would generally be to increase system cost rather than to risk mission failure.

The most important CELSS engineering parameters are, in order of decreasing importance, manpower, mass, and energy (1). The plant component is a significant contributor to total system equivalent mass. In this report, a generic plant component is described and the relative equivalent mass and productivity are derived for a number of instances taken from the KSC CELSS Breadboard Project data and the literature. Typical specific productivities (edible biomass produced over 10 years divided by system equivalent mass) for closed systems are of the order of 0.2.

Controlled Ecological Life Support System (CELSS) technology is critical to the Space Exploration Initiative. NASA's Kennedy Space Center (KSC) has been performing CELSS research tor several years, developing data related to CELSS design. We have developed OCAM (Object-oriented CELSS Analysis and Modeling), a CELSS modeling tool, and have used this tool to evaluate CELSS concepts, using this data. In using OCAM, a CELSS is broken down into components, and each component is modeled as a combination of containers, converters and gates which store, process and exchange carbon, hydrogen, and oxygen on a daily basis. Multiple crops and plant types can be simulated. Resource recovery options modeled include combustion, leaching, enzyme treatment, aerobic or anaerobic digestion, and mushroom and fish growth. Simulation results include printouts and time-history graphs of total system mass, biomass, carbon dioxide, and oxygen quantities; energy consumption; and manpower requirements.