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The Plant Generic BioProcessing Apparatus (PGBA), a plant growth facility developed for commercial space biotechnology research, has flown successfully on 3 spaceflight missions for 4, 10 and 16 days. The environmental control systems of this plant growth chamber (28 liter/0.075 m2) provide atmospheric, thermal, and humidity control, as well as lighting and nutrient supply. Typical performance profiles of water transpiration and dehumidification, carbon dioxide absorption (photosynthesis) and respiration rates in the PGBA unit (on orbit and ground) are presented. Data were collected on single and mixed crops. Design options and considerations for the different sub-systems are compared with those of similar hardware.

Plant growth chambers, whether designed for Earth or space applications, should provide the basic means for supporting healthy plant growth of almost any species. These chambers typically satisfy species- and age-specific light, atmosphere composition, water and nutrient requirements. Engineering solutions to satisfy these basic requirements in different plant chambers may vary widely, and each species or each experimental protocol may need individual testing and adaptation of the supporting hardware and science protocols. This paper will summarize the design trades, tests and evaluation experiments conducted to ensure proper hardware functionality and proper hardware / lifeware compatibility for the desired experimental protocols in space.

The increased demand in the area of space life sciences necessitates the need for more experimentation hardware with increased capabilities. Due to the high cost of hardware development for space based research, new hardware should be modular in design and suited to handle a variety of different experiments. The fluid handling systems found in experimentation hardware will often share many of the same requirements for different experiments. A design process that can be used for biological fluid handling systems that cover a wide range of experimentation requirements is proposed. Important parameters to be considered when making a trade study for selection of system components will be discussed. This paper will address topics of current research in space life sciences and describe state of the art hardware that is available or under development for use.

Water reuse is essential for long duration space missions. However, water recycle systems also provide a habitat for microorganisms and allow accumulation of chemical compounds which may be acutely or chronically toxic to mission crew members. Contaminant fate and accumulation in closed-loop water recycle systems is being investigated at the University of Colorado and Martin Marietta as part of the activities of the Center for Space Environmental Health (CSEH), a NASA Specialized Center of Research and Training (NSCORT). The water contaminant distribution research uses a scaled-down physical model of a water (shower, laundry, urine and/or condensate) recycle system to analyze for and model four “indicator” contaminants: viruses and bacteria, nitrogen species, and selected organic and inorganic compounds. The water recycle test bed is comprised of five or more individual water treatment processes linked in a closed loop, and spiked with chemical and biological contaminants.

Until now, NASA's space water reuse research program has not considered the transport of water borne infectious enteric viruses; however, viral diseases probably are a significant concern in long duration space missions. To simplify monitoring and prediction of pathogen distribution, model indicator strains historically have been used. In this research, the male specific RNA coliphage MS-2 is used as a model of enteric viruses due to their similar size and biochemical composition. Inactivation of some water borne enteric viruses by iodine has previously been characterized. In this paper, iodine inactivation of the model coliphage MS-2 in buffered water is compared with earlier bench-scale disinfection survival data and with survival in iodinated simulated shower water used in a test water recycling system.

An event in which electronic insulation consisting of polytetrafluoroethylene undergoes thermodegradation on the Space Station Freedom is considered experimentally and theoretically from the initial chemistry and convective transport through pulmonary deposition in humans. The low-gravity environment impacts various stages of event simulation. Vapor-phase and particulate thermodegradation products were considered as potential spacecraft contaminants. A potential pathway for the production of ultrafine particles was identified. Different approaches to the simulation and prediction of contaminant transport were studied and used to predict the distribution of generic vapor-phase products in a Space Station model.

It is well known that selection of the pressure/oxygen ratio for a human space habitat is a critical decision for the well-being and mission performance of astronauts. It has also been noted how this ratio affects the requirement for pre- and post-breathing and the type and flexibility of EVA/EHA astronaut suits. However, little attention has been paid to how these issues interact with various mission design strategies. Using the first manned mission to Mars as a baseline mission, we have separated the mission into its component parts as it relates to habitat type (i.e., the Earth-Mars interplanetary vehicle, the ascent/descent vehicle, the base, human rover vehicles, etc.) and have determined the oxygen resupply requirements for each part as they reflect a mission design strategy. These component parts form a matrix where duration of stay, loss of oxygen due to leakage and usage, and oxygen resupply needs are calculated.

Accurate root zone moisture control in microgravity plant growth systems is problematic. With gravity, excess water drains along a vertical gradient, and water recovery is easily accomplished. In microgravity, the distribution of water is less predictable and can easily lead to flooding, as well as anoxia. Microgravity water delivery systems range from solidified agar, water-saturated foams, soils and hydroponics soil surrogates including matrix-free porous tube delivery systems. Surface tension and wetting along the root substrate provides the means for adequate and uniform water distribution. Reliable active soil moisture sensors for an automated microgravity water delivery system currently do not exist. Surrogate parameters such as water delivery pressure have been less successful.