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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.

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).

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.

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.

Following the Colombia accident, the Extravehicular Mobility Units (EMU) onboard ISS were unused for several months. Upon startup, the units experienced a failure in the coolant system. This failure resulted in the loss of Extravehicular Activity (EVA) capability from the US segment of ISS. With limited on-orbit evidence, a team of chemists, engineers, metallurgists, and microbiologists were able to identify the cause of the failure and develop recovery hardware and procedures. As a result of this work, the ISS crew regained the capability to perform EVAs from the US segment of the ISS Figure 1.

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.

During the twelve month period comprising Expeditions 10 and 11, the chemical quality of the potable water onboard the International Space Station (ISS) was verified through the return and ground analysis of water samples. The two-man Expedition 10 crew relied solely on Russian-provided ground water and reclaimed cabin humidity condensate as their sources of potable water. Collection of archival water samples with U.S. hardware has remained extremely restricted since the Columbia tragedy because of very limited return volume on Russian Soyuz vehicles. As a result only two such samples were collected during Expedition 10 and returned on Soyuz 9. The average return sample volume was only 250 milliliters, which limited the breadth of chemical analysis that could be performed. Despite the Space Shuttle vehicle returning to flight in July 2005, only two potable water samples were collected with U.S. hardware during Expedition 11 and returned on Shuttle flight STS-114 (LF1).

Ever since the first crew arrived at the International Space Station (ISS), archival potable water samples have been collected and returned to the ground for detailed chemical analysis in order to verify that the water supplies onboard are suitable for crew consumption. The Columbia tragedy, unfortunately, has had a dramatic impact on continued ISS operations. A major portion of the ISS water supply had previously consisted of Shuttle-transferred water. The other two remaining sources of potable water, i.e., reclaimed humidity condensate and Russian-launched ground water, are together insufficient to maintain 3-person crews. The Expedition 7 crew launched in April of 2003 was, therefore, reduced from three to two persons. Without the Shuttle, resupply of ISS crews and supplies is dependent entirely on Russian launch vehicles (Soyuz and Progress) with severely limited up and down mass.

Potable water supplies onboard the International Space Station (ISS) include both reclaimed water from treatment of atmospheric humidity condensate and stored water that is either Shuttle-transferred or ground-supplied. Space station medical operations requirements call for real-time monitoring of key water quality parameters, such as total organic carbon, total inorganic carbon, total carbon, pH, and conductivity, to ensure that crew health is protected from unsafe drinking water. A Total Organic Carbon Analyzer (TOCA) designed to meet these requirements was developed as part of the Crew Health Care System and launched to the ISS in April of 2001. The initial design of the ISS TOCA was previously presented at this conference in 1998. The current design of the instrument includes an improved reagent system and upgraded software to enhance accuracy through the capability to measure organic contamination of the reagents and correct analytical results.

The Crew Health Care System (CHeCS) is responsible for providing environmental monitoring to protect crew health, including in-flight chemical water quality analysis. To meet this objective, Total Organic Carbon Analyzer (TOCA) Serial Number (SN) 1002 was launched to the International Space Station (ISS) in April of 2001 as part of the CHeCS hardware. Since that time it has been used to evaluate the quality of the potable water supplies consisting of reprocessed atmospheric condensate water, Shuttle-transferred water, and ground-supplied water. Potable water is available for crew use from the Service Module System for Regeneration of Water from Condensate (SRV-K) galley hot and warm ports and the Stored Potable Water System (SVO-ZV) port. Potable water samples are periodically collected from each of these ports for in-flight analysis with the TOCA.

Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements.

We are developing a drinking water test kit based on colorimetric-solid phase extraction (C-SPE) for use onboard the International Space Station (ISS) and on future Lunar and/or Mars missions. C-SPE involves measuring the change in diffuse reflectance of indicator disks following their exposure to a water sample. We previously demonstrated the effectiveness of C-SPE in measuring iodine in microgravity. This analytical method has now been extended to encompass the measurement of total I (i.e., iodine, iodide, and triiodide). This objective was accomplished by introducing an oxidizing agent to convert iodide and triiodide to iodine, which is then measured using the indicator disks previously developed for iodine. We report here the results of a recent series of C-9 microgravity tests of this method. The results demonstrate that C-SPE technology is poised to meet the total I monitoring requirements of the international space program.

Following the Columbia accident, the EMUs (Extravehicular Mobility Units) onboard the ISS (International Space Station) went unused for an extended period of time. Upon startup, the units experienced a failure in the coolant systems. The failure resulted in a loss of EVA (Extravehicular Activity) capability from the US segment of the ISS. A failure investigation determined that chemical and biological contaminants and byproducts from the ISS Airlock Heat Exchanger, and the EMU itself, fouled the magnetically coupled pump in the EMU Transport Loop Fan/Pump Separator leading to a lack of coolant flow. Remediation hardware (the Airlock Coolant Loop Remediation water processing kit) and a process to periodically clean the EMU coolant loops on orbit were devised and implemented. The intent of this paper is to report on the successful implementation of the resultant hardware and process, and to highlight the go-forward plan.

An EMU water processing kit (Airlock Coolant Loop Recovery – A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of post-flight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives were implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit items, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements.

A sorption-spectrophotometric platform for the concentration and subsequent quantification of biocides in spacecraft drinking water is described. This methodology, termed Colorimetric Solid Phase Extraction (C-SPE), is based on the extraction of analytes onto a membrane impregnated with a colorimetric reagent. Quantification of the extracted analytes is accomplished by interrogating the surface of the membrane with a commercially available diffuse reflectance spectrophotometer. Ground-based experiments have shown that C-SPE is a viable means to determine biocide concentrations in the range commonly found in water samples from the Space Shuttle and the International Space Station (ISS). This paper details efforts to advance C-SPE closer to space flight qualification and ISS implementation, starting with the modification of the ground based biocide detection platform to simplify operation in a microgravity environment.