Browsing by Author "Belancik, Grace"
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Item A Capillary Fluidic CO2 Scrubber for Spacecraft: the Liquid Amine Carbon Dioxide Removal Assembly(2024 International Conference on Environmnetal Systems, 2024-07-21) Torres, Logan; Weislogel, Mark; Chen, Yongkang; Krishcko, Oleg; Jenson, Ryan; Belancik, Grace; Alcid, Marian; Levri, Julie; Hand, Lawrence; Cortez, Adrian; Heavner, Selda; Graf, JohnReliable air revitalization systems are in the critical path of the human exploration of space. The current state of the art regenerable solid sorbent CO2 removal systems have provided decades of service in low-earth orbit. However, certain novel technologies are rapidly developing that purport attractive and essential features for deep space missions: i.e., quiet, reliable, and continuous operation with lower-power, lower-volume, and lower-maintenance expectations. The recently successful ISS flight demonstration of the Capisorb Visible System (CVS) has increased awareness and confidence in the potential application of massively parallelized open-channel capillary fluidic devices and surfaces to perform the largely passive wet CO2 scrubbing air revitalization function. Such approaches have been exploited aboard submarines employing �falling films� for decades with high-affinity amine liquid sorbents (MEA, DGA, etc.), a feat that could be replicated in re-formatted fashion in the microgravity environment of orbiting or coast spacecraft. The Liquid Amines Carbon dioxide Removal (LACR) system is a simple closed loop cycle with a flow-through �thin capillary film� contactor that reacts with and absorbs CO2 directly from the cabin air. The sorbent is then drawn into a second capillary fluidic device where vacuum pressures and elevated temperatures reverse the reaction and degas the liquid, venting, re-routing, or storing the CO2 for subsequent processing. A single pump returns the regenerated sorbent to the contactor for continuous cabin air conditioning. The key components of the LACR system include a Porous-sheet Contactor (absorber), Capillary Conduit Degasser and Separator (desorber), and Capillary Condensing Heat eXchanger (CCHX). The design and function of these devices are reported along with quantitative performance characteristics of loop operation collected during ground tests. Scale-up of the system for a crew of four suggests significant (>2x) reductions in system size, mass, power, and consumables over the current state of the art.Item Analysis of Spacecraft Cabin Carbon Dioxide Capture via Deposition(48th International Conference on Environmental Systems, 2018-07-08) Belancik, Grace; Jan, Darrell; Huang, RogerExtended manned missions through deep space present a number of unique challenges yet to be solved before said missions are feasible. One pertinent challenge is the CO2 removal system, as the current state-of-the-art requires repeated, costly maintenance. Multiple alternative CO2 removal systems are currently being evaluated as potential successors, including solid and liquid sorbents. An alternative to sorption techniques entirely is deposition of CO2 from the cabin atmosphere onto a cold surface. Deposition provides numerous benefits, including multiple methods of generating a cold surface. Cryogenic coolers and thermal radiators are two methods that are both highly reliable. Another benefit is the ability to provide humidity and trace contaminant control, as well as CO2 storage and compression, in addition to CO2 capture. Cryogenic coolers, specifically Stirling coolers, are currently being tested for use in Martian atmosphere CO2 capture, but the work described in this paper is one of the first examinations into the application of spacecraft cabin atmosphere. After the Stirling cooler CO2 deposition system was built, a test matrix of varying inlet flow rates, CO2 concentrations, and temperature set points was completed to evaluate the system. In addition, one set of parameters was selected to ensure repeatability and determine a working cycle time. A decaying increase of CO2 removal rate with decreasing temperature was observed at all tested inlet flow rates and concentrations. Also, CO2 removal rate decayed with system run time. The data gleaned from this initial study will be used to inform a more efficient, cycling CO2 deposition system design.Item Capillary Fluidic CO2 Scrubbing Aboard Spacecraft: the CVS Demonstration on ISS: Part I Overview(2024 International Conference on Environmnetal Systems, 2024-07-21) Weislogel,Mark; Torres, Logan; Krishcko, Oleg; Jenson, Ryan; Levri, Julie; Belancik, Grace; Jan, Darrell; Heavner, Selda; Hand, Lawerance; Graf, JohnFalling liquid film amine sorbent reactors have been successfully employed to scrub CO2 aboard submarines for decades. However, applying such proven methods aboard orbiting and coast spacecraft is significantly challenged by the nearly weightless environment, where liquid sprays and films do not fall, and vapor bubbles and gases do not rise. The Capillary sorbent Visible System (CVS) is a technology demonstration experiment performed aboard the ISS April 18 � 21, 2023. The system establishes stable steady thin liquid film flows in Contactor (absorber) and Degasser (desorber/stripper) replacing the passive role of gravity with the combined passive roles of surface tension, wetting, and system geometry. A viscous TOX-0 fructose ersatz liquid sorbent is employed such that the �transparent� experiments can be performed and filmed by the crew in the open cabin of the ISS. Completed objectives include demonstrations of stable passive �massively� parallel planar thin film capillary flows across atmospheric pressure Contactor and sealed heated Degasser. The impacts of varying flow rate, flow direction, heat input, viscosity, condensate collection and return, fluid distribution, interfacial stability, and others are reported. Over 49 diagnostics are recorded for digitization and subsequent thermal-fluids model validation by a single HD video downlink during the nearly 22 hours of operations. This paper (Part I) provides an overview of the flight hardware including description of the components, diagnostics, crew procedures, flight operations, and summary of accomplishments. A second paper (Part II) provides further details of the diagnostics, tests performed, data reduction, data archive, analysis, and technology impacts.Item Capillary Fluidic CO2 Scrubbing Aboard Spacecraft: the CVS Demonstration on ISS: Part II Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Weislogel,Mark; Torres, Logan; Krishcko, Oleg; Bizeau, Ben; Jenson, Ryan; Levri, Julie; Belancik, Grace; Jan, Darrell; Heavner, Selda; Hand, Lawerance; Graf, JohnThe CVS flight experiments conducted aboard ISS during April 18 � 21, 2023 focus on microgravity thermal-fluid technology demonstrations related to liquid amine CO2 scrubbing aboard spacecraft. The central objectives of the work include the establishment and limits of stable passive capillary-driven �massively� parallel planar thin film flows across �Contactor� and �Degasser� as functions of flow rate, flow direction, flow resistance, heat input, viscosity gradients, condensate collection and return, fluid distribution, and interfacial stability, among others. An overview of the flight hardware including description of the components, crew procedures, flight operations, and summary of accomplishments is reported in a companion paper (Part I). This paper (Part II) highlights certain details of the tests performed, data reduction, data archive, analysis, and technology impacts. Over 49 diagnostics are recorded using a single HD video downlink during the nearly 22 hours of operations.Item Characterizing Cryogenic Carbon Dioxide Capture for Life Support Systems(47th International Conference on Environmental Systems, 2017-07-16) Belancik, Grace; Jan, Darrell; Huang, Roger; Paredes-Garcia, Jordi; Chambliss, JoeWithout a vastly improved cabin air CO2 removal system technology, deep space missions will not be plausible. The carbon dioxide removal assembly (CDRA) on ISS has repeated replacement and maintenance costs due to adsorbent material degradation. A current effort to evaluate CO2 removal systems to succeed CDRA is underway. Alternative adsorption and thermal amine technologies are included. Cryogenic capture of CO2 in a cabin atmosphere is a newly-explored solution. Cryogenics are highly reliable, self-sufficient systems with great potential in this area of study. The added benefit of a cryogenic system is that it can provide humidity and trace contaminant control in addition to CO2 capture. Whereas cryogenic cooling technologies are established and Mars atmosphere CO2 capture has been tested, little research has been done on the application of cryogenic cooling to life support CO2 capture. This paper describes the design, build and initial functional testing of a lab-scale cryogenic system to remove CO2 from simulated cabin air. The system is ready to test both CO2/N2 mixed and dry CO2-loaded air, and production rate, cycle time, and power requirements will be characterized so that future flight-like system requirements may be better modeled.Item CO2 Capacity Sorbent Analysis Using Volumetric Measurement Approach(47th International Conference on Environmental Systems, 2017-07-16) Huang, Roger; Belancik, Grace; Jan, Darrell; Knox, James; Richardson, Tra-My JustineIn support of air revitalization system sorbent selection for future space missions, Ames Research Center (ARC) has performed CO2 capacity tests on various solid sorbents to complement structural strength tests conducted at Marshall Space Flight Center (MSFC). The materials of interest are: Grace Davison Grade 544 13X, Honeywell UOP APG III, LiLSX VSA-10, BASF 13X, and Grace Davison Grade 522 5A. CO2 capacity was for all sorbent materials using a Micromeritics ASAP 2020 Physisorption Volumetric Analysis machine to produce 0°C, 10°C, 25°C, 50°C, and 75°C isotherms. These data are to be used for modeling data and to provide a basis for continued sorbent research. The volumetric analysis method proved to be effective in generating consistent and repeatable data for the 13X sorbents, but the method needs to be refined to tailor to different sorbents.Item Continued Development of a Liquid Amine Carbon Dioxide Removal System for Microgravity Applications(49th International Conference on Environmental Systems, 2019-07-07) Alvarez, Giraldo; DeGraff, Geoff; Swickrath, Michael; Belancik, Grace; Sweterlitsch, JeffreyCarbon dioxide (CO2) can rapidly accumulate in spacecraft, creating a dangerous breathing environment if not properly controlled. Traditionally, solid adsorbents have been used to capture and release the CO2 generated by crew metabolic activity. Liquid absorbents have generally been avoided, due to the added complexity of handling fluids in a microgravity environment. However, with the advent of advanced manufacturing techniques using three-dimensional printing, a capillary-based gas/liquid contactor and degasser system has been developed and tested. Test data and an accompanying mathematical model have been developed for the contactor portion of the system. Flux rate data were then used to size a concept for application in a spacecraft. Finally, an integrated test stand was configured with the degasser and thermal control equipment. The integrated test stand was operated in a bench-scale format, confirming that the sizing analyses are realistic. A process model for the overall system developed in previous efforts was updated with all of the data collected during the most recent fiscal year. In aggregate, the results of parallel experimentation and modeling efforts continue to be encouraging for alternative liquid amine-based CO2 capture system.Item Design and Development of Vortex Phase Separator-Based Spacecraft Cabin Air Humidity Control Subsystem Prototype for CO2 Removal using Regenerable Ionic Liquid Desiccant(2024 International Conference on Environmnetal Systems, 2024-07-21) Byanjankar, Chirag; Bostanci, Huseyin; Kurwitz, Cable; Belancik, GraceNASA�s challenging deep space exploration missions demand innovative, reliable, and cost-effective technologies for life support systems. Air revitalization, particularly CO2 removal, in this manner, is a key life support system. However, the legacy solid sorbent (zeolite)-based CO2 removal technology used in the ISS experiences reliability issues and capability gaps. One of the alternative technologies under consideration is CO2 deposition. Recent NASA studies demonstrated that utilizing cryogenic coolers offers cold surfaces for CO2 capture (deposition) and can be an effective approach to revitalize cabin air. Nevertheless, to maintain purity to feed to a downstream Sabatier reactor, and to ensure high efficiency of CO2 capture, humidity from cabin air must be removed prior to CO2 deposition on cold surfaces. The current ISS dehumidification system employs solid desiccants (silica gels) and has maintenance and high energy consumption challenges. A liquid desiccant can instead be utilized to build a humidity control subsystem as part of a CO2 deposition system and enhance its performance. This work aims to utilize a unique Vortex Phase Separator (VPS)-based air-desiccant contactor design that can achieve a direct-contact, high-efficiency heat and mass exchange between air and desiccant and offer reliable, high-throughput operation for dehumidification/re-humidification. Such a subsystem employs a cold and hot VPS to serve as the absorber and desorber portions of the process system, produces temperature gradient by a heater and a chiller, as well as a regenerative heat exchanger, and uses two pumps for liquid desiccant recirculation. Therefore, the subsystem can continuously operate to dehumidify /re-humidify cabin air and regenerate desiccant. This paper describes design and development efforts of the VPS-based spacecraft cabin air dehumidification/re-humidification prototype that utilizes a selected regenerable liquid desiccant (ionic liquid [EMIM][ESO4]), and indicates the potential of this humidity control subsystem for implementation as part of an alternative spacecraft CO2 removal system.Item Design for an Integrated Closed-Loop System for Carbon Dioxide Removal Using Diglycolamine(2024 International Conference on Environmnetal Systems, 2024-07-21) Cortez, Adrian; Costa, Tiago; Alcid, Marian; Belancik, GraceCrewed Space missions require maintaining a safe environment that can both sustain a breathable atmosphere and remove airborne pollutants. Carbon dioxide (CO2), while not toxic in low concentrations, accumulates as crew members respire and can eventually affect the crew's health. Therefore, a system to constantly remove CO2 buildup is necessary for long-term missions. Currently, the prevailing method used to capture, transfer, and remove CO2 from air in submarines and industrial flue gas utilizes the liquid sorbent monoethanolamine. Diglycolamine (DGA) is an alternate primary amine that has similar performance with less volatility. DGA is currently being studied at Ames Research Center as the primary candidate for the operation of the sub-scale liquid amine CO2 removal test stand. The test stand is used to investigate liquid flow and liquid/gas interfaces for a system designed for both microgravity and surface applications. The test stand includes a wedge tray design that utilizes capillary action to contain DGA while allowing gas-liquid surface interaction for CO2 transfer. Trays using this wedge design are placed in a contactor unit to remove CO2 from the air stream as well as a degasser unit to regenerate the DGA. A capillary condensing heat exchanger to recapture water evaporated in the degasser unit is also incorporated. Nominal operating conditions for the contactor are an air flow rate of 26 SCFM enriched with pure CO2 to a concentration of 2600 ppm and a liquid mixture of 65/35vol% DGA/H2O flowing at a rate of 0.65 mL/min, while the degasser is operated at 100?C under slight vacuum. Integrated closed-loop operation yielded a final CO2 flux of 0.946 kg/m2/day and a total CO2 capture of 0.192 kg/day. All sub-assemblies in the system can be improved to increase the overall CO2 capture performance.Item Design, Modeling, and Initial Characterization of a Subscale Variable Conductance Radiator for CO2 Deposition System in Deep Space Transit(2023 International Conference on Environmental Systems, 2023-07-16) Sarvadi, Alexander; Bostanci, Huseyin; Kurwitz, Cable; Belancik, GraceDeep space, long-duration human exploration missions require critical technical advancements in areas such as air revitalization, since resupply is not accessible and resources including mass, power, and volume must be minimized for all subsystems. NASA is currently conducting research on a CO2 capture technique that involves using cryogenic coolers to create cold surfaces. By cooling cabin air to extremely low temperatures, CO2 is deposited onto these surfaces. This process is performed in a continuous, cyclic manner to demonstrate concept of operation. However, since the implementation of cryogenic coolers results in high power consumption, alternative methods are needed to achieve energy efficient air revitalization systems. As Mars transit missions provide a capability to view deep space at low temperatures, utilizing radiators for heat rejection is emerging as an opportunity to complement or replace cryogenic coolers for CO2 deposition. This study focuses on the Variable Conductance Radiator (VCR)-based CO2 deposition system that mainly features two internal CO2 capture/recovery panels and one external heat rejection panel (radiator). The closed-loop system circulates a working fluid between two panels: the CO2 capture panel and the heat rejection panel. The CO2 capture panel is maintained at approximately 130K, allowing CO2 from the cabin air to be deposited on it. The heat rejection panel, exposed to the deep space environment at around 4K, dissipates the heat absorbed from the air stream. The two internal panels operate alternately; while one panel involves circulating working fluid to maintain a cold surface for CO2 deposition, the other one involves stagnant, non-condensable gas and is heated for CO2 sublimation. A subscale, VCR-based CO2 deposition system is investigated to demonstrate its feasibility for deep space applications. Initial efforts include developing the design geometry and performing analytical and numerical analysis to evaluate various design parameters for the external heat rejection panel (radiator).Item Development of the Liquid Amines Ground-Based Test System(50th International Conference on Environmental Systems, 7/12/2021) Chu, Lisa; Belancik, Grace; Samson, Jason; Jagtap, Pranav; Jan, Darrell; Yau, AllenRemoving carbon dioxide from breathable air is of vital safety and importance to future crewed missions. NASA Ames Research Center (ARC) is specifically investigating how to do this more efficiently using a liquid sorbent. One approach utilizes liquid amines as a liquid sorbent manipulated and contained via capillary flow. A test stand originally designed at NASA Johnson Space Center (JSC) is currently being used for testing which allows for air plug flow across a liquid sorbent contactor assembly. The current contactor configuration is set up with vertically oriented capillary flow wedges, but carbon dioxide (CO2) capture rates were found to be significantly lower than expected. Due to gravity, the liquid flow through the vertical wedges results in very low Diglycolamine Agent (DGA) retention time in the contactor assembly giving the DGA mixture insufficient time to absorb CO2. Furthermore, the current wedge orientation unfortunately does not allow for testing of different flow regimes because gravity-assist is currently the main limiting flow driver. Alternatively, it can be hypothesized that using a horizontal wedge configuration will allow for increased liquid retention time and testing of different flow regimes in the liquid sorbent contactor. Preliminary 3D modeling and air flow simulations are being created for a horizontally oriented wedge contactor. Since the original NASA JSC test stand allows for removal and replacement of the vertical contactor assembly, the new horizontal wedge configuration contactor is being designed to connect to the existing structure. With the new contactor design, it would then be possible to experimentally investigate the CO2 absorption relationship on liquid flow rate and other various liquid sorbent properties.Item Efficacy of FTIR Analysis in Determining CO2 Loading on Diglycolamine(48th International Conference on Environmental Systems, 2018-07-08) Huang, Roger; Silveria, Mark; Kong, Jessica; Belancik, Grace; Jan, DarrellIn support of advanced air revitalization technologies to enable human spaceflight beyond low earth orbit, performance studies have been conducted using a liquid amine, Diglycolamine (DGA) between teams at NASA’s Johnson Spaceflight Center (JSC) and Ames Research Center (ARC). Liquid amines have been used in regenerable earth-based systems to remove CO2 from industrial systems as well as for closed-environment air revitalization because they can be regenerated at lower temperatures than solid sorbent systems. As an additional advantage to solid sorbent-based systems, liquid sorbents can be cycled between an adsorbing contactor and degassing chamber, thereby reducing system complexity by operation in a continuous loop. In an effort to inform a regeneration system design for micro-gravity applications, ARC has performed a number of tests to characterize the degas mechanics of DGA. In order to accurately measure the amount of CO2 captured or released by the amine, methods such as gravimetric weighing and chemical desorption are reasonable, however the first iteration test setup for a scaled down degas system required analysis on small sample sizes. Fourier-transform infrared spectroscopy (FTIR) analysis was experimentally evaluated to analyze CO2 concentration because it can produce measurements with sample sizes on the order of 100’s of μL. Calibration against chemical desorption showed relatively good correlation and test data showed reasonable adherence to expected trends, however more extensive testing should be conducted to fully validate the usage of FTIR to determine CO2 loading on DGA.Item Evaluating Capabilities of the Carbon Dioxide Deposition System(2020 International Conference on Environmental Systems, 2020-07-31) Belancik, Grace; Schuh, Michael; Jan, Darrell; Jagtap, PranavHuman space exploration demands a highly reliable spacecraft cabin atmosphere revitalization system. One proposed concept deposits CO2 directly onto a cold surface, capitalizing on the condensation and deposition temperatures of air constituents. The cold surface can be generated using cryogenic coolers or thermal radiators. Since the CO2 Deposition System (CDep) system does not use an adsorbent material, CDep overcomes the limitations caused by performance degradation of the Carbon Dioxide Removal Assembly on ISS. This degradation has repeatedly increased maintenance costs over the years. CDep improves reliability and is an ideal candidate for long duration missions to deep space, moon, and beyond. The goal of this research is to characterize the trace contaminants and humidity capture on the subscale system previously designed for a single crew member. The single crew system consists of three Stirling coolers: one is used to precool the air and the other two operate in a cyclic manner for continuous CO2 removal. To simulate the environment of ISS, this system was evaluated by flowing representative trace contaminants and measuring their concentrations in the outlet gas flows. Additionally, controlled humidity was introduced into the system to determine the performance in maximum humidity conditions. CDep has successfully demonstrated its ability to both capture trace contaminants and withstand humidity loads simultaneously with nominal CO2 capture operation. Furthermore, this paper will also discuss design optimization of the cold surface to maximize the CO2 deposition for a full-scale (4-crew) system. The computational CO2 deposition study was conducted using a multi-physics code that directly modeled the CO2 deposition and conjugate heat transfer.Item Evaluation of Alternative Liquid Sorbents and Additives for Spacecraft CO2 Capture(2023 International Conference on Environmental Systems, 2023-07-16) Belancik, Grace; Chu, Lisa; Costa, Tiago; Soundararajan, MathangiLong-duration missions to the Moon and Mars require robust life support systems capable of dormancy and high-reliability operation. Liquid sorbents, specifically primary amines, have been used with success on submarines for CO2 removal and are therefore being evaluated in a microgravity-tolerant design. In addition to microgravity, other criteria are pivotal in optimizing the liquid sorbent. The current baseline sorbent, an aqueous diglycolamine solution, was selected for its low vapor pressure, high CO2 uptake rate and capacity, relatively long shelf life, and moderately low toxicity compared to the most common CO2 liquid sorbent monoethanolamine. An ongoing effort to replace monoethanolamine with more efficient and less toxic alternatives in flue gas systems is currently underway. From additives to improve kinetics or stability, such as carbonic anhydrase or piperazine, to newly created sorbents such as amino acid ionic liquids, a range of comparison studies have been published. This paper describes the application of the promising results of those studies to the specific spacecraft CO2 capture environment. An initial capacity experiment was performed on a variety of sorbent solutions to determine the most promising candidates. The performance of each sorbent or mixture of sorbent and additives was compared to the diglycolamine baseline performance. The results of this study show that the selection of optimal liquid sorbent will be a trade between CO2 capture kinetics to reduce system size, stability to reduce spares mass, and toxicity to minimize mass of containment.Item Exploiting Capillary Sorbent Films for Air Revitalization aboard Spacecraft: Analysis of a Semi-Passive CO2 Scrubber(2020 International Conference on Environmental Systems, 2020-07-31) Weislogel, Mark; Torres, Logan; Jenson, Ryan; Graf, John; Hand, Lawerance; Belancik, Grace; Jan, Darrell; Levri, JulieLiquid sorbents have provided a primary means for robust carbon dioxide (CO2) control aboard submarines for decades. Unfortunately, such systems have not been adopted for use aboard spacecraft due to the fact that fine droplet sprays, thin falling films, and buoyancy-driven bubbly flows are not easily managed in the essentially gravity-free environments of orbiting spacecraft. Such applied engineering challenges have remained outstanding for the microgravity fluid physics community. As a work-around, in this research, a stable, silent capillary-driven ‘thin film’ is produced over a massively parallel network of open channels for both CO2 uptake and degas functions in a microgravity environment. Following several quantified assumptions, simple analytical models of species, heat, mass, and momentum transport are invoked providing clear design guides for a future engineering demonstration of the approach aboard the International Space Station. For critical sorbent properties such as CO2 capacity, effective diffusion rate, and concentration- and temperature-dependent viscosity, we provide the essential requirements of flow rate, size, shape, stability, power draw, and other aspects of the system. The results imply that a considerable reduction in system mass and volume is possible for the liquid sorbent approach for CO2 scrubbing when compared to the current state of the art.Item Highly Thermally Conductive Hybrid Carbon Fiber Polymer Composite for Radiator Application(2023 International Conference on Environmental Systems, 2023-07-16) Kang, Jin Ho; Gordon, Keith; Ward, Darwyn; Belancik, Grace; Jagtap, Pranav; Sauti, GodfreyCarbon fiber (CF) reinforced polymer composites have been used for aerospace structures because they have low mass, high specific strength, high specific stiffness, and low life-cycle maintenance compared to aluminum alloys. However, due to their relatively low thermal conductivity, pristine CF polymer composites fail to provide effective heat flow for certain applications such as heat exchange systems and radiators. The technology described in this paper provides novel CF polymer composites that possess high thermal conductivity by incorporating pyrolytic graphite sheets (PGS). The thermal conductivities of novel hybrid PGS/CF polymer composites were measured to be about 13 to 36 times higher than that of pristine CF polymer composite, and about two times higher than that of aluminum alloy 6061. This new material with sufficient thermal conductivity is applicable to composite radiators of heat exchange systems.Item The Integrated Carbon Dioxide Removal, Compression, and Storage (CRCS) System(47th International Conference on Environmental Systems, 2017-07-16) Richardson, Tra-My Justine; Jan, Darrell; Hogan, John; Palmer, Gary; Huang, Roger; Belancik, Grace; Samson, Jason; Koss, BrianThe Carbon Dioxide Removal, Compression, and Storage (CRCS) system was designed to remove carbon dioxide (CO2(g)) from the spacecraft cabin atmosphere and compress and store the CO2(g) for further processing. Previous conference papers describe the hardware design and functional testing of the single and dual beds. This paper discusses the integrated system test results when dry CO2(g) latent air (2600ppm CO2(g)) enters the system at 30SCFM.Item Integrated Testing of the Air-Cooled Temperature Swing Adsorption Compression System (AC-TSAC) and 4-Bed Molecular Sieve (4BMS)(2023 International Conference on Environmental Systems, 2023-07-16) Wells, Jonathan; Gan, Kelby; Waddle, Arisa; Belancik, GraceThe Air-Cooled Temperature Swing Adsorption Compression system (AC-TSAC) is a solid state, sorbent based compressor and storage device, intended to replace the CO2 Management System (CMS) on board the International Space Station (ISS). The CMS consists of a mechanical compressor and a set of accumulator tanks. The AC-TSAC is an important technical option in the air revitalization process, and takes low pressure carbon dioxide (CO2) from a CO2 removal system (like the 4 Bed Carbon Dioxide Scrubber, 4BCO2) and stores and pressurizes it for use in the Sabatier reactor. AC-TSAC is appealing for this role due to its lower weight, power usage, and improved reliability (no rotary parts) compared to the CMS. To prepare for this operating environment, AC-TSAC and 4BMS (the ground development unit for 4BCO2) were connected at MSFC for integrated testing of the two systems. Results from integrated testing with one of the current state of the art flight demonstrations for CO2 removal showcases AC-TSAC ability to deliver pressurized CO2 in a more flight-like scenario. Eight different integrated test scenarios were run for 24 hours each representing different scenarios that may be encountered on ISS, a lunar base, or in Mars transit. Integrated test data will allow for system redesign into a more flight-like configuration.Item Microbial Mayhem: Microbial Growth Potential in CO2 Removal Systems Designed for Long-Duration Spaceflight(2023 International Conference on Environmental Systems, 2023-07-16) Whitlock, Nico; Belancik, GraceCrewed missions that venture into deep space require extremely robust life support systems. Amongst these systems is the CO2 removal system, which helps ensure the recirculation of breathable air to crew. To travel to Mars, a new CO2 removal system is needed. Two candidate systems are in development at the NASA Ames Research Center (ARC): Liquid Amine CO2 Removal (LACR) and CO2 Cold Surface Deposition (CDep). Engineering constraints are important in the design process, but biological problems must also be considered; Microbial growth has been detected on a multitude of surfaces on the International Space Station (ISS) and has been shown to cause problems on several occasions due to biofilm formation inhibiting system performance. Should the new CO2 removal system be susceptible to microbial growth, its performance could be hindered and crew health threatened on future long-duration missions. To investigate this possibility, existing relevant literature was thoroughly reviewed for these two ARC candidate systems. The results show that both systems have components that are potentially susceptable for problematic microbial growth. Therefore, wet lab testing to measure performance degradation was designed using dry and wet biofilm-forming species that have been found on the ISS. Further testing was devised to determine the quantity and species of microbes most likely to enter a CO2 removal system by determining the efficiency of charcoal-HEPA filters that filter incoming air. This work will inform the design and preventative measures that NASA will take to avoid problematic microbial growth in future CO2 removal systems.Item Modeling Performance of the Full Scale CO2 Deposition System(50th International Conference on Environmental Systems, 7/12/2021) Belancik, Grace; Schuh, Michael; Jan, Darrell; Jagtap, PranavTo enable long-duration manned travel to the Moon and/or Mars, a highly reliable spacecraft cabin atmosphere revitalization system is required. One new carbon dioxide capture system currently in development is the CO2 Deposition System (CDep), which generates a cold surface to selectively deposit CO2 from cabin air. The cold surface may be generated via multiple methods and does not require use of sorbents. Therefore, CDep is a tunable assembly to minimize launch mass and power for any future spacecraft requirements. A full-scale (4-crew) ground test system is currently in development at Ames Research Center. The system utilizes multiple Stirling coolers and air-to-air heat exchangers to generate the cold surface and minimize power requirements. The system modeling is concurrently being developed in both STAR-CCM+ and Modelica to predict performance of the system. Utilizing the first principles STAR-CCM+ multi-physics code, the temperature, humidity, and CO2 concentration gradients across each of the heat exchangers and deposition surfaces were predicted, as well as the sublimation rates for downstream processing. Process modeling using Modelica was utilized to analyze the overall operation of the system to confirm the multi-physics results and examine the initial cool down and transitional phases alternating between deposition and sublimation. The results of the modeling work not only gave new insight into the CDep full-scale system, they informed design adjustments to improve the system prior to initial prototype completion.