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A Total Organic Carbon (TOC) Analyzer has been developed for a Life Sciences Risk Mitigation Flight Experiment to be conducted on Spacehab and the Russian space station, Mir. Initial launch is scheduled for December 1996 (flight STS-81). The analyzer will be tested on the Orbiter in the Spacehab module, including when the Orbiter is docked at the Mir space station. The analyzer is scheduled to be launched again in May 1997 (STS-84) when it will be transferred to Mir. During both flights the analyzer will measure the quality of recycled and ground-supplied potable water on the space station. Samples will be archived for later return to the ground, where they will be analyzed for comparison to in-flight results. Water test samples of known composition, brought up with the analyzer, also will be used to test its performance in microgravity. Ground-based analyses of duplicates of those test samples will be conducted concurrently with the in-flight analyses.

A computer interfaced instrument designed to quantify ammonia and other nitrogenous species that are important regenerative life support water quality parameters is described in this paper. Measurements can be made either discretely by Flow Injection Analysis (FIA) or continuously using a split stream from a process flow. The monitor exhibits a predictable quadratic response for ammonia injections between 10 μg/L to 20 mg/L with a response time less than six minutes. A full description of the ammonia monitor's response to a variety of challenge solutions including real sewage treatment plant effluent is given. In addition, the response time characteristics, the effects of temperature, and interferences are described.

The Microbial Check Valve (MCV) is a reloadable flow-through canister containing iodinated ion exchange resin, which is used aboard the Shuttle Orbiter as a disinfectant to maintain water potability. The MCV exhibits a significant contact kill and imparts a biocidal residual I2 concentration to the effluent. MCVs in current use have nominal 30 day lives. MCVs baselined for Space Station Freedom will have 90 day lives, and will require replacement 120 times over 30 years. Means to extend MCV life are desirable to minimize resupply penalties. New technology has been developed for fully autonomous in situ regeneration of an expended MCV canister. The Regenerative Microbial Check Valve (RMCV) consists of an MCV, a packed bed of crystalline I2, a flow diverter valve, an in-line iodine monitor and a microcontroller. During regeneration, flow is directed first through the packed I2 bed and then into the MCV where the resin is replenished.

Two simulated spacecraft water systems are being used to evaluate the effectiveness of iodine for controlling microbial contamination within such systems. An iodine concentration of about 2.0 mg/L is maintained in one system by passing ultrapure water through an iodinated ion exchange resin. Stainless steel coupons with electropolished and mechanically-polished sides are being used to monitor biofilm formation. Results after three years of operation show a single episode of significant bacterial growth in the iodinated system when the iodine level dropped to 1.9 mg/L. This growth was apparently controlled by replacing the iodinated ion exchange resin, thereby increasing the iodine level. The second batch of resin has remained effective in controlling microbial growth down to an iodine level of 1.0 mg/L. Scanning electron microscopy indicates that the iodine has impeded but may have not completely eliminated the formation of biofilm.

The ability of iodine to maintain microbial water quality in a simulated spacecraft water system is being studied. An iodine level of about 2.0 mg/L is maintained by passing ultrapure influent water through an iodinated ion exchange resin. Six liters are withdrawn daily and the chemical and microbial quality of the water is monitored regularly. Stainless steel coupons used to monitor biofilm formation are being analyzed by culture methods, epifluorescence microscopy, and scanning electron microscopy. Results from the first two years of operation show a single episode of high bacterial colony counts in the iodinated system. This growth was apparently controlled by replacing the iodinated ion exchange resin. Scanning electron microscopy indicates that the iodine has limited but not completely eliminated the formation of biofilm during the first two years of operation.

The Federal Government is increasingly interested in potential commercial applications for technology developed under Government funding. This emphasis has been especially evident in the Small Business Innovative Research (SBIR) Program. Experiences in commercialization efforts are presented. Benefits as well as hindrances of Government policies and regulations are discussed. Suggestions are presented based on a Small Business perspective as well as that of a Government Technical Monitor. Experience has proven that advancement to Phase III commercialization is a slow tedious process and is dependent upon a number of variables. Some technologies, such as communications, microprocessing, and medical systems are directly marketable both inside and outside of the Government.

When construction of Space Station Freedom reaches the Permanent Manned Capability stage, plans call for the Water Recovery and Management Subsystem to treat distilled urine, spent hygiene water, and humidity condensate in order to reclaim water of potable quality. The reclamation technologies currently baselined to process these wastewaters include adsorption, ion exchange, catalytic oxidation, and disinfection. To ensure that baselined technologies will be able to effectively remove those compounds that present health risks to the crew, the National Research Council has recommended that additional information be gathered on specific contaminants in wastewaters representative of those to be encountered on Space Station. This paper reports the efforts by the Water and Food Analytical Laboratory at the Johnson Space Center to enlarge the database of potential contaminants in humidity condensate.

The primary source of potable water planned for the International Space Station will be generated from the reclamation of humidity condensate, urine, and hygiene waters. It is vital to crew health and performance that this reclaimed water be safe for human consumption, and that health risks associated with recycled water consumption be identified and quantified. Only recently has data been available on the chemical constituents in reclaimed waters generated in microgravity. Results for samples collected during Mir-21 reveal that both the reclaimed water and stored water are of potable quality, although the samples did not meet U.S. standards for total organic carbon (TOC), total phenols, and turbidity.

Twenty-nine recycled water, eight stored (ground-supplied) water, and twenty-eight humidity condensate samples were collected on board the Mir Space Station during the Phase One Program (1995-1998). These samples were analyzed to determine potability of the recycled and ground-supplied water, to support the development of water quality monitoring procedures and standards, and to assist in the development of water reclamation hardware. This paper describes and summarizes the results of these analyses and lists the lessons learned from this project. Results show that the recycled water and stored water on board Mir, in general, met NASA, Russian Space Agency (RSA), and U.S. Environmental Protection Agency (EPA) standards.

A significant decline in molecular iodine concentration is associated with the iodination of heavily contaminant-laden process water streams such as humidity condensate and urine distillate. Iodine loss is attributable to the reaction of this biocide with organic constituents. This phenomenon has been investigated using time resolved molecular absorption spectrophotometry of iodinated ersatz humidity condensates and iodinated ersatz urine distillates across the ultraviolet and visible spectral regions. Rates of iodine loss have also been studied using single contaminant systems at equivalent concentrations. The predominant reactive species have been identified as thiourea and formic acid. Pseudo-first order rate constants have been determined for ersatz contaminant model mixtures and for individual reactive constituents. Second order rate constants have been determined for the bimolecular reaction of iodine and formic acid.

Potable- and hygiene-quality water will be supplied to crews on the International Space Station through the recovery and purification of spacecraft wastewaters, including humidity condensate, urine, and wash water. Contaminants released into the cabin air from human metabolism, hardware offgassing, flight experiments, and routine operations will be present in spacecraft humidity condensate; normal constituents of urine and bathing water will be present in urine and untreated wash water. This report describes results from detailed analyses of Mir reclaimed potable water, ground-supplied water, and humidity condensate. These results are being used to develop and test water recycling and monitoring systems for the International Space Station (ISS); to evaluate the efficiency of the Mir water processors; and to determine the potability of the recycled water on board.

Iodine depletion in a simulated water storage tank and distribution system was examined to support a larger research program aimed at developing disinfection methods for spacecraft potable water systems. The main objective of this study was to determine the rate of iodine depletion with respect to the surface area of the stainless steel components contacting iodinated water. Two model configurations were tested. The first, representing a storage and distribution system, consisted of a stainless steel bellows tank, a coil of stainless steel tubing and valves to isolate the components. The second represented segments of a water distribution system and consisted of eight individual lengths of 21-6-9 stainless tubing similar to that used in the Shuttle Orbiter. The tubing has a relatively high and constant surface area to volume ratio (S/V) and the bellows tank a lower and variable S/V.

In 1985, the Man-Systems Division at the Johnson Space Center initiated a program for the development of a whole body shower suitable for operation in a microgravity environment. Supporting this development effort has been a systematic research program focused on four critical aspects of the design (i.e., human factors engineering, biomedical, mechanical, and electrical) and on the interfaces between the whole body shower system and the other systems to be aboard the Space Station (e.g., the water reclamation and air revitalization systems). A series of tests has been conducted to help define the design requirements for the whole body shower. Crew interface research has identified major design parameters related to enclosure configurations, consumable quantities, operation timelines, displays and controls, and shower and cleanup protocols.

Disinfection and maintenance of an acceptable level of asepsis in spacecraft potable water delivery systems is a formidable task. The major area of research for this project has been to monitor the formation and growth of biofilm, and biofilm attached microorganisms, on stainless steel surfaces (specifically coupons), and the use of ozone for the elimination of these species in a closed loop system. A number of different techniques have been utilized during the course of a typical run. Scraping and sonication of coupon surfaces with subsequent plating as well as epifluorescence microscopy have been utilized to enumerate biofilm protected Pseudomonas aeruginosa. In addition, scanning electron microscopy is the method of choice to examine the integrity of the biofilm. For ozone determinations, the indigo decolorization spectrophotometric method seems most reliable. Both high- and low-nutrient cultured P. aeruginosa organisms were the target species for the ozone disinfection experiments.

The ability to aseptically remove samples and products, and the capability for addition of materials to sterile or otherwise microbially susceptible systems have always been compromised by the lack of a reliable means of sterilizing the mating fixtures. Cultures of mammalian cells are particularly vulnerable to microbial contamination due to the complexity of nutrient media and the lengthy periods required for cell growth. The Microwave Sterilizable Access Port has been developed to overcome this limitation. The system consists of three primary components: a microwave power source, a combined sterilization chamber/in-line valve port assembly, and a specimen transfer interface. Microwave energy is transmitted via coaxial cable to a small pressurized chamber that serves as a sterile transition between the surrounding environment and the system during transfer of materials.

Disinfection of water and wastewater was proven to be feasible using a Breadboard Electrochemical Ozone Generator (EOG). A static gas/liquid separator, containing a microporous, hydrophobic membrane, was tested with the Breadboard EOG, and was found to increase the concentration of the ozone (O3) dissolved in the water. Distilled water and selected wastewaters were disinfected, achieving dissolved O3 concentrations up to 3 mg/L. The hardware is capable of operating in 0-g and 1-g environments. An end-item Electrochemical Ozonator (EO), sized to disinfect 116 kg of potable water per day, was projected to weigh 1.2 kg and consume only 18.5 W.

Controlling microbial growth and biofilm formation in spacecraft water-distribution systems is necessary to protect the health of the crew. Methods to decontaminate the water system in flight may be needed to support long-term missions. We evaluated the ability of iodine and ozone to kill attached bacteria and remove biofilms formed on stainless steel coupons. The biofilms were developed by placing the coupons in a manifold attached to the effluent line of a simulated spacecraft water-distribution system. After biofilms were established, the coupons were removed and placed in a treatment manifold in a separate water treatment system where they were exposed to the chemical treatments for various periods. Disinfection efficiency over time was measured by counting the bacteria that could be recovered from the coupons using a sonication and plate count technique. Scanning electron microscopy was also used to determine whether the treatments actually removed the biofilm.

The objective of this study was to investigate combining GC/MS and CE methods to allow sub-mg/L levels of organic acids to be determined in various water samples. This study also served as a basis for evaluating these instruments for in-flight spacecraft water-quality monitoring and to help determine the modifications needed to convert terrestrial hardware for use in microgravity environments. This paper reports on current GC/MS and CE method development and data generated from some recent spacecraft-related water samples. Plans for further method development are also discussed.

Archival sampling of potable water and condensate for ground laboratory analysis has been an important part of the Shuttle-Mir program because of coolant leaks and other events on Mir that have affected water quality. We report here the development of and preliminary results from a novel device for single phase humidity condensate collection at system pressures. The sampler consists of a commercial-off-the-shelf Teflon® bladder and a custom reinforced Nomex® restraint that is sized properly to absorb the stress of applied pressures. A plastic Luer-Lock disconnect, with poppet actuated by a mating Luer-Lock fitting, prevents the contents from being spilled during transport. In principle, a sampler of any volume can be designed. The empty mass of the reusable one-liter sampler is only 63 grams. Several designs were pressure tested and found to withstand more than 3 atmospheres well in excess of typical spacecraft water or wastewater system pressures.

One of the proposed methods for monitoring the microbial quality of the water supply aboard the International Space Station is membrane filtration. We adapted this method for space flight by using an off-the-shelf filter unit developed by Millipore. This sealed unit allows liquid to be filtered through a 0.45 μm cellulose acetate filter that sits atop an absorbent pad to which growth medium is added. We combined a tetrazolium dye with R2A medium to allow microbial colonies to be seen easily, and modified the medium to remain stable over 70 weeks at 25°C. This hardware was assembled and tested in the laboratory and during parabolic flight; a modified version was then flown on STS-66. After the STS-66 mission, a back-up plastic syringe and an all-metal syringe pump were added to the kit, and the hardware was used successfully to evaluate water quality aboard the Russian Mir space station.