Browsing by Author "Meyer, Caitlin"
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Item Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams(45th International Conference on Environmental Systems, 2015-07-12) Coutts, Janelle L.; Lunn, Griffin M.; Vega, Leticia M.; Meyer, CaitlinIn membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center’s sub-scale MABRs, as well as Johnson Space Center’s full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need for secondary mitigation.Item Biologically Pre-Treated Habitation Waste Water as a Sustainable Green Urine Pre-Treat Solution(47th International Conference on Environmental Systems, 2017-07-16) Jackson, William; Thompson, Bret; Sevanthi, Ritesh; Morse, Audra; Meyer, Caitlin; Callahan, MichaelThe ability to recover water from urine and flush water is a critical process to allow long term sustainable human habitation in space or bases on the moon or mars. Organic N present as urea or similar compounds can hydrolyze producing free ammonia. This reaction results in an increase in the pH converting ammonium to ammonia which is volatile and not removed by distillation. The increase in pH will also cause precipitation reactions to occur. In order to prevent this urine on ISS is combined with a pretreat solution. While this process has been successful there are a number of draw backs including: storage and use of highly hazardous solutions, limitations on water recovery (<85%), and production of brine with pore dewatering characteristics. We evaluated the use of biologically treated habitation wastewaters (ISS and early planetary base) to replace the current pretreat solution. We evaluated both amended and un-amended bioreactor effluent. For the amended effluent we evaluated “green” pretreat chemicals including citric acid and citric acid amended with benzoic acid. We used a mock urine/air separator modeled after the urine collection assembly on ISS. The urine/air separator was challenged continually for ~6 months. Depending on the test point, the separator was challenged daily with donated urine and flushed with amended or un-amended reactor effluent. We monitored the pH of the urine, flush solution and residual pH in the urine/air separator after each urine event. We also evaluated solids production and biological growth. Our results support the use of both un-amended and amended bioreactor effluent to maintain the operability of the urine /air separator. The ability to use bioreactor effluent could decrease consumable cost, reduce hazards associated with current pre-treat chemicals, allow other membrane based desalination processes to be utilized, and improve brine characteristics.Item Closing the Water Loop for Exploration: 2020-2021 Status of the Brine Processor Assembly(50th International Conference on Environmental Systems, 7/12/2021) Kelsey, Laura; Boyce, Stephanie; Speight, Garland; Pasadilla, Patrick; Tewes, Philipp; Rabel, Emily; Meyer, CaitlinParagon Space Development Corporation has developed a Brine Processor Assembly (BPA) for demonstration on the International Space Station (ISS). BPA will recover water from urine brine produced by the ISS Urine Processor Assembly (UPA) and ground testing has demonstrated to achieve water recovery rates significantly greater than the 75-90% that is currently recovered by the UPA's Vapor Compression Distillation (VCD) subsystem. BPA utilizes the forced convection of spacecraft cabin air coupled with a robust membrane distillation process to recover purified water from 22.5 liters of brine within a 26 day cycle. An ionomer-microporous membrane pair contains the brine while transferring purified water vapor to the cabin air. The water vapor is collected by the existing spacecraft condensing heat exchangers, which already recover metabolically produced water vapor as humidity condensate. This paper will discuss progress to-date on meeting critical technical and ISS integration milestones. Flight hardware was successfully delivered to NASA in Fall 2020 and the flight unit was launched to the ISS in February 2021. After installation on the ISS, on-orbit experiments will be conducted for a year to evaluate BPA performance in microgravity. By increasing overall water recovery on ISS to greater than 98%, BPA demonstrates a critical capability needed to close the brine processing technology gap identified in NASA's Water Recovery Technology Roadmap. This technology achieves an essential capability to enable human exploration of deeper space.Item Closing the Water Loop for Exploration: 2022 Status of the Brine Processor Assembly(51st International Conference on Environmental Systems, 7/10/2022) Boyce, Stephanie; Molina, Sunday; Harrington, Walter; Joyce, Connor; Pasadilla, Patrick; Tewes, Philipp; Williamson, Jill; Perry, Jay; Toon, Katherine; Meyer, Caitlin; Harper, Susana TapiaParagon Space Development Corporation developed a Brine Processor Assembly (BPA) for demonstration on the International Space Station (ISS). BPA recovers water from urine brine produced by the ISS Urine Processor Assembly (UPA) via a patented process and ground testing has demonstrated water recovery rates greater than 90% from the previously concentrated urine brine. BPA utilizes the forced convection of spacecraft cabin air coupled with a membrane distillation process to recover purified water from 22.5 liters of brine within a 26 day cycle. By increasing overall water recovery on ISS to greater than 98%, BPA demonstrates a critical capability needed to close the brine processing technology gap identified in NASA's Water Recovery Technology Roadmap. This paper discusses operational progress since launch to the ISS in February 2021. After installation, checkout, and activation on the ISS, BPA operations were successfully initiated in April 2021. Despite successful nominal operation, crew members expressed discomfort due to malodor from effluent BPA air. After the initial dewatering cycle was completed, it was determined that BPA would need to mitigate odor before on-orbit operations resumed. To address these concerns, an outlet filter system was developed, and an extensive characterization study was conducted to test the efficacy of the filter in reducing odor. This study included analysis of gas, odor, and condensate samples of filtered and unfiltered effluent air during a brine dewatering cycle with an identical BPA ground unit. The filter assembly demonstrated > 85% first pass reduction in odor without detrimental effects to BPA operations. As a result, a similar assembly was launched to the ISS, installed, and BPA operations were resumed in October 2021. This technology achieves an essential capability to enable human exploration of deeper space, and this experiment was an opportunity to identify the importance of human factors in life support spaceflight hardware.Item Closing the Water Loop for Exploration: Status of the Brine Processor Assembly(47th International Conference on Environmental Systems, 2017-07-16) Kelsey, Laura; Meyer, Caitlin; Shull, Sarah; Pasadilla, Patrick; Brockbank, Jason; Locke, Barrett; Lopez, Javier; Cognata, Thomas; Orlando, Thomas; Hahn, NormanThe NASA Advanced Exploration Systems (AES) Life Support Systems (LSS) project together with Paragon Space Development Corporation are working to develop a brine processor assembly for demonstration on the International Space Station (ISS). The Brine Processor will demonstrate the recovery of water from urine brine produced by the ISS Urine Processor Assembly (UPA). If successful, the Brine Processor will demonstrate water recovery rates greater than the current 75-90% possible using vapor compression distillation. The Brine Processor aims to recover up to 98% of water on ISS by utilizing forced convection of spacecraft cabin air coupled with a robust membrane distillation process to purify water from 22.5 liters of brine within a 26 day cycle. An ionomer-microporous membrane pair will be used to contain the brine while transferring water vapor to the cabin air. The water vapor is collected by the existing spacecraft condensing heat exchanger(s), which recover metabolically produced water vapor as humidity condensate. This paper will discuss progress to-date in the project including many critical technical and ISS integration milestones that the project has to meet in order to successfully deliver the proto-flight unit in August 2018.Item Compatibility between Exploration EVA System and Exploration Spacecrafts(2023 International Conference on Environmental Systems, 2023-07-16) Kovich, Christine; Meyer, CaitlinOver the life of the Extravehicular Mobility Unit (EMU), numerous products detailing “how to build Extravehicular Activity (EVA) System hardware”, “how to interface with EVA System hardware” and “how to design hardware EVA will access and utilize” were generated to provide interoperability between a suited crewmember and the specified vehicle’s EVA task. Since the inception of these products, some have continued to receive updates due to the necessity of an on-going program while others remained unchanged for years and have led to discrepancies between the current accepted values and those considered outdated. For EVA-suited crewmember tasks beyond Low Earth Orbit (LEO), new vehicles need a single consolidated location for the best practices and lessons learned from the EVA Community. This paper outlines what common EVA compatibility design requirements are expected of an Exploration spacecraft that has interactions between the vehicle and an EVA suited crewmember for and an approach for standardizing EVA compatibility across various vehicles at various destinations. The approach of standardization allows for flexibility by tailoring the applicability to meet the EVA tasks required for that vehicle’s operation beyond Low Earth Orbit. This paper will also describe the broad difference between microgravity and partial gravity EVA compatibility and how those requirements were identified and will be informed.Item Further Investigations into the Performance of Membrane- Aerated Biological Reactors Treating a Space Based Waste Stream(45th International Conference on Environmental Systems, 2015-07-12) Christenson, Dylan; Sevanthi, Ritesh; Baldwin, Daniel; Morse, Audra; Jackson, W. Andrew; Meyer, Caitlin; Vega, Leticia; Pickering, Karen; Barta, DanielMembrane aerated biological reactors (MABR) have proven in terrestrial testing to be a sustainable and robust technology for treating space based waste streams that prove challenging for conventional systems due to high concentrations of carbon and nitrogen. Biological pretreatment stabilizes the waste stream without the use of harsh chemicals and also provides several distinct advantages including: 1) the conversion of NH3 to N2(gas), a required atmospheric component, or NOx species that are easily rejected by evaporative or membrane systems; 2) the transformation of organic matter to increase the efficiency of desalinization processes and produce a more stable waste product (brine); 3) the production of metabolic water; 4) the reduction in pH that facilitates membrane and distillation processes and reduces the required consumables and increases the life span of the processes; and 5) the potential elimination of the current hazardous pre-treat chemicals thereby producing a brine from which water can be recovered more easily. Work at both Texas Tech University (TTU) and Johnson Space Center (JSC) using the Counter-diffusion Membrane Aerated Nitrifying Denitrifying Reactor (CoMANDR) design has shown the ability of these systems to provide consistent and efficient carbon removal (>90%) and nitrification (>60%) when treating a space based waste stream consisting of urine, flush water, hygiene and laundry water, and humidity condensate. However, several areas were in need of further investigation. These include the ability of the system to handle on production urine feeding and the impact of membrane density on performance. The study of on production urine feeding allows us to determine the versatility of MABR bioreactors to a range of mission scenarios. Our past work has also identified operational issues for high density membrane modules in which the spacing between membranes is reduced. These high density modules can increase gas transfer but suffer from flow short circuiting due to biofilm bridging. We evaluated this relationship by operating MABRs with a range of specific surface areas and treating an Early Planetary Base waste stream.Item Investigations into the Performance of Membrane-Aerated Biological Reactors Treating a Space Based Waste Stream(46th International Conference on Environmental Systems, 2016-07-10) Sevanthi, Ritesh; Christenson, Dylan; Jackson, William; Morse, Audra; Meyer, Caitlin; Vega, Leticia; Shull, SarahTwo demonstration size membrane aerated biological reactors (MABR) CoMANDR 1.0 and CoMANDR 2.0 have previously demonstrated their ability to stabilize an early planetary base (EPB) waste stream over operating periods of ~1 year. Biological stabilization includes oxidation (>90%) of dissolved organic matter to CO2, partial conversion of organic N to NOx-, and reduced pH. Biological stabilization has a number of advantages including: 1) elimination of hazardous pre-treat chemicals; 2) production of N2(gas); 3) production of metabolic water; 3) a low pH effluent that facilitates membrane and distillation processes; and 4) a effluent that produces a better quality and less hazardous brine for water recovery. Preliminary analysis suggests that water recovery systems that integrated biological treatment may trade favorably compared to all physical/chemical systems. However, previous systems have incorporated reactor geometries and membrane specific surface areas which are not flight compatible. The R-CoMANDR (rectangular Counter-diffusion Membrane Aerated Nitrifying Denitrifying Reactor) system was developed to evaluate the ability of the smaller footprint reactor treat the range of possible waste streams (e.g. ISS to EPB) as well as the potential to operate without a feed tank. Individual waste streams (e.g. urine, hygiene, laundry, humidity condensate) are directly fed to the reactor on production. We will present performance data and evaluate the new flight like system design compared to previous systems.Item NASA Environmental Control and Life Support Technology Development and Maturation for Exploration: 2019 to 2020 Overview(2020 International Conference on Environmental Systems, 2020-07-31) Schneider, Walter; Perry, Jay; Broyan, James; Macatangay, Ariel; McKinley, Melissa; Meyer, Caitlin; Owens, Andrew; Toomarian, Nikzad; Gatens, RobynDuring 2019 and 2020, NASA’s Environmental Control and Life Support (ECLS) technology development projects have taken vital steps toward establishing readiness for the next generation of human space exploration missions. Technology demonstration systems from last year have been operated on the International Space Station (ISS) and others have been launched. Development of future technology demonstrations is on-going. Facility and hardware development for ground testing to be conducted that strategically complements the on-orbit demonstrations and some ground testing has been initiated. Reliability studies have started to define requirements for on-orbit and ground testing and other investments to support exploration missions. These efforts support NASA missions beyond LEO and include Gateway, lunar surface, Mars transportation, and Mars surface. This paper provides an overview of the current ECLS strategic planning and roadmap as well as a synopsis of key technology and maturation project tasks that occurred in 2019 and early 2020 to support the strategic needs. Plans for the remainder of 2020 and subsequent years are also described.Item Results of the Alternative Water Processor Test, A Novel Technology for Exploration Wastewater Remediation(46th International Conference on Environmental Systems, 2016-07-10) Vega, Leticia; Meyer, Caitlin; Shull, Sarah; Pensinger, Stuart; Jackson, William; Christenson, Dylan; Adam, Niklas; Lange, KevinBiologically-based water recovery systems are a regenerative, low energy alternative to physiochemical processes to reclaim water from wastewater. This report summarizes the results of the Alternative Water Processor (AWP) Integrated Test, conducted from June 2013 until April 2014. The system was comprised of four (4) membrane aerated bioreactors (MABRs) to remove carbon and nitrogen from an exploration mission wastewater and a coupled forward and reverse osmosis system to remove large organic and inorganic salts from the biological system effluent. The system exceeded the overall objectives of the test by recovering 90% of the influent wastewater processed into a near potable state and a 64% reduction of consumables from the current state of the art water recovery system on the International Space Station (ISS). However, the biological system fell short of its test goals, failing to remove 75% and 90% of the influent ammonium and organic carbon, respectively. Despite not meeting its test goals, the BWP demonstrated the feasibility of an attached-growth biological system for simultaneous nitrification and denitrification, an innovative, volume- and consumable-saving design that does not require toxic pretreatment.