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A concept of developing a regenerative water management system (RWMS) for first lunar base missions is reviewed. The principal feature of the concept proposed is the maximum possible unification of RWMS for long-duration orbiting station and a lunar base with due regard to possible modification of the hardware for lunar gravity conditions. The paper is based on the expertise in research, development, testing and flight operation of RWMS in Russia. An upgraded RWMS of the International Space Station may be used for first lunar missions.

The paper deals with the problems of development of physico-chemical systems for water recovery and atmosphere revitalization for long-duration space stations. Schematics of regenerative life support systems featuring a high degree of closure and biotechnological components are presented. A year-long experiment has proved the possibility for Man to stay in a closed artificial environment for a long time by consuming substances regenerated by physico-chemical means from the end products of life. A complex of the life support systems (LSS) on Mir space station allowing for oxygen and 90% water recovery as well as its future updating is considered.

This paper reviews the design and properties of the Water Supply System (WSS). It also discusses the water balance and its delivery amounts, as well as it presents diagrams and properties of water recovery system from humidity condensate WRS-CM and regeneration from urine WRS-UM which are the part of WSS. Some results of activities conducted for provision of water intake in a system of WRS-CM from different modules of station are shown and the problems of WSS interaction of Russian segment (RS) and American segment (USOS) of the International Space Station (ISS) are discussed.

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.

This paper reviews designs of urine distillation systems for spacecraft water recovery. Consideration is given to both air evaporation and vacuum distillation cycles, to the means for improving cycle performance (such as heat pumps, multistaging, and rotary evaporators), and to system concepts offering promise for future development. Vacuum distillation offers lower power consumption, at some increase in system complexity; air evaporation distillation is capable of providing higher water recovery efficiency, which could offset the lower power consumption advantage of vacuum distillation for long-duration missions.

Archived water samples collected on the International Space Station (ISS) and returned to Earth for analysis have, in a few instances, contained trace levels of heavy metals. Building on our previous advances using Colorimetric Solid Phase Extraction (C-SPE) as a biocide monitoring technique [1, 2], we are devising methods for the low level monitoring of nickel(II), lead(II) and other heavy metals. C-SPE is a sorption-spectrophotometric platform based on the extraction of analytes onto a membrane impregnated with a colorimetric reagent that are then quantified on the surface of the membrane using a diffuse reflectance spectrophotometer. Along these lines, we have analyzed nickel(II) via complexation with dimethylglyoxime (DMG) and begun to examine the analysis of lead(II) by its reaction with 2,5-dimercapto-1, 3, 4-thiadiazole (DMTD) and 4-(2-pyridylazo)-resorcinol (PAR).

One of the long-standing concerns in space exploration is the presence of trace organic contaminants in recycled spacecraft water supplies. At present, water samples on the International Space Station (ISS) are collected at regular intervals, stored in Teflon™-lined containers, and returned to Earth for characterization. This approach, while effective in defining water quality, has several notable problems. First, this method of archiving removes a significant volume of the ISS water supply. Second, the archived water consumes valuable cargo space in returning Shuttle and Soyuz vehicles. Third, the organic contaminants present in the collected samples may degrade upon extended storage. The latter problem clearly compromises sample integrity. Upon return to Earth, sample degradation is minimized by refrigeration. Due to present resource constraints, however, refrigeration is not a viable option in space.

The Johnson Space Center Water and Food Analytical Laboratory (WAFAL) performed detailed ground-based analyses of archival water samples for verification of the chemical quality of the International Space Station (ISS) potable water supplies for Expeditions 14 and 15. During the 12-month duration of both expeditions, the Space Shuttle docked with the ISS on four occasions to continue construction and deliver additional crew and supplies; however, no Shuttle potable water was transferred to the station during Expedition 14. Russian ground-supplied potable water and potable water from regeneration of humidity condensate were both available onboard the ISS for consumption by the Expeditions 14 and 15 crews. A total of 16 chemical archival water samples were collected with U.S. hardware during Expeditions 14 and 15 and returned on Shuttle flights STS-116 (12A.1), STS-117 (13A), STS-118 (13A.1), and STS-120 (10A) in December 2006, and June, August, and November of 2007, respectively.

Humidity condensate collected and processed in-flight is an important component of a space station drinking water supply. Water recovery systems in general are designed to handle finite concentrations of specific chemical components. Previous analyses of condensate derived from spacecraft and ground sources showed considerable variation in composition. Consequently, an investigation was conducted to collect condensate on the Shuttle while the vehicle was docked to Mir, and return the condensate to Earth for testing. This scenario emulates an early ISS configuration during a Shuttle docking, because the atmospheres intermix during docking and the condensate composition should reflect that. During the STS-89 and STS-91 flights, a total volume of 50 liters of condensate was collected and returned. Inorganic and organic chemical analyses were performed on aliquots of the fluid.

With the Shuttle fleet grounded, limited capability exists to resupply in-flight water quality monitoring hardware onboard the International Space Station (ISS). As such, verification of the chemical quality of the potable water supplies on ISS has depended entirely upon the collection, return, and ground-analysis of archival water samples. Despite the loss of Shuttle-transferred water as a water source, the two-man crews during Expedition 8 and Expedition 9 maintained station operations for nearly a year relying solely on the two remaining sources of potable water; reclaimed humidity condensate and Russian-launched ground water. Archival potable water samples were only collected every 3 to 4 months from the systems that regenerate water from condensate (SRV-K) and distribute stored potable water (SVO-ZV).

At present, spacecraft water quality is assessed when samples collected on the International Space Station (ISS) are returned to Earth. Several months, however, may pass between sample collection and analysis, potentially compromising sample integrity by risking degradation. For example, iodine and silver, which are the respective biocides used in the U.S. and Russian spacecraft potable water systems, must be held at levels that prevent bacterial growth, while avoiding adverse effects on crew health. A comparable need exists for the detection of many heavy metals, toxic organic compounds, and microorganisms. Lead, cadmium, and nickel have been found, for instance, in the ISS potable water system at amounts that surpass existent requirements. There have been similar occurrences with hazardous organic compounds like formaldehyde and ethylene glycol. Microorganism counts above acceptable limits have also been reported in a few instances.

Colorimetric-solid phase extraction (C-SPE) is being developed as a method for in-flight monitoring of spacecraft water quality. C-SPE is based on measuring the change in the diffuse reflectance spectrum of indicator disks following exposure to a water sample. Previous microgravity testing has shown that air bubbles suspended in water samples can cause uncertainty in the volume of liquid passed through the disks, leading to errors in the determination of water quality parameter concentrations. We report here the results of a recent series of C-9 microgravity experiments designed to evaluate manual manipulation as a means to collect bubble-free water samples of specified volumes from water sample bags containing up to 47% air. The effectiveness of manual manipulation was verified by comparing the results from C-SPE analyses of silver(I) and iodine performed in-flight using samples collected and debubbled in microgravity to those performed on-ground using bubble-free samples.

Contamination of spacecraft water by heavy metals, such as cadmium and lead, is of growing concern. As a consequence, there is need for a rapid, on-board, easy-to-use method for the determination of cadmium(II) at low ppb levels in spacecraft drinking water supplies. This paper describes the preliminary development of a method for the selective, low level determination of cadmium(II) based on colorimetric-solid phase extraction (C-SPE) [1, 2]. In C-SPE, an analyte is extracted from a water sample onto a membrane that has been previously impregnated with a colorimetric reagent, and then quantified as its colorimetric complex directly on the membrane surface using diffuse reflectance spectroscopy. Results from preliminary tests that screened the performance of 1-(4-nitrophenyl)-3-(4-phenyl-azophenyl)triazene (cadion), and organic dyes, rhodamine B, brilliant green, and methyl violet as colorimetric reagents for potential use in a C-SPE analysis of cadmium(II) are described.

This paper reviews the development and testing of the distillation subsystem of water regeneration system from urine (WRS-UM) based on a method of vacuum distillation with a rotary multistage vacuum distiller and a thermal pump. Test results show that with relatively small power consumption the subsystem using rotary three-stage vacuum distiller provides high rates of heat and mass transfer processes, useful productivity and distillate quality. The conducted tests have confirmed that it will be efficient to use the presented system as a part of WRS-UM system in Russian segment of the International Space Station.

Space exploration by humans requires maintenance of an adequate potable water supply. Biocide levels must therefore be kept within allowable limits to prevent bacterial growth without causing adverse effects on crew health. Likewise, contaminants such as heavy metals and toxic organic compounds must be held at or below acceptable limits. Currently, spacecraft water quality analyses are performed on samples collected on the International Space Station and returned to Earth. Several months, however, can pass between sample collection and analysis, which may compromise sample integrity due to degradation. These delays also inhibit implementation of real time correction scenarios. There is, therefore, a critical need for rapid, on-board methods for monitoring trace quantities of several analytes in spacecraft drinking water supplies.

The need to preserve crew health during space missions, combined with the level of demand on both crew time and cargo space, dictates the development of fast, facile methods capable of monitoring trace quantities of several analytes in spacecraft water. This presentation describes our efforts to address this need by using Multiplexed Colorimetric Solid Phase Extraction (MC-SPE). MC-SPE is a sorption-spectrophotometric platform based upon the extraction of analytes onto membranes impregnated with selective colorimetric agents. Quantification is accomplished using Kubelka-Munk values calculated from the diffuse reflectance spectrum of the complex on the surface of the membrane and calibration curves. In traditional C-SPE, concentration factors of up to 1000 can be realized for a single analysis, yielding low detection limits (ppb – ppm range) with a total analysis time of 75–90 s. Herein, we describe the performance and continued refinement of the MC-SPE platform.

This paper describes the development of a prototype fluid pumping system for incorporation into a miniaturized flow injection analyzer. The strategy couples the well-established capabilities of reagent-based flow injection analyses (FIA) with our novel concepts for the design of a miniaturized, low-power pumping system, i.e., an electrochemically-driven micropump. The basis of pump actuation relies on the electrochemically-induced surface tension changes at the electrolyte/mercury interface, resulting in a “piston-like” pumping process devoid of mechanically moving parts. We present herein the results from the preliminary performance tests of a miniaturized fluid flow system with the micropump. As described, the flow rates and pumping displacement volumes have been studied as a function of the amplitude and the frequency of the applied voltage waveform.

The paper analyzes and summarizes experience in developing and flight operation of the system for potable water recovery from humidity condensate. The system schematic and its hardware are reviewed. The system performance data on Salut and Mir space stations are presented. Succession to the development of a similar system for the International Space Station (ISS) service module is shown.

On the International Space Station (ISS), humidity condensate will be collected from the atmosphere and treated by multifiltration to produce potable water for use by the crews. Ground-based development tests have demonstrated that multifiltration beds filled with a series of ion-exchange resins and activated carbons can remove many inorganic and organic contaminants effectively from wastewaters. As a precursor to the use of this technology on the ISS, a demonstration of multifiltration treatment under microgravity conditions was undertaken. On the Space Shuttle, humidity condensate from cabin air is recovered in the atmosphere revitalization system, then stored and periodically vented to space vacuum. A Shuttle Condensate Adsorption Device (SCAD) containing sorbent materials similar to those planned for use on the ISS was developed and flown on STS-68 as a continuation of DSO 317, which was flown initially on STS-45 and STS-47.

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.