Browsing by Author "Chullen, Cinda"
Now showing 1 - 20 of 45
- Results Per Page
- Sort Options
Item Advanced Supported Liquid Membranes for Carbon Dioxide Control in Cabin Applications(46th International Conference on Environmental Systems, 2016-07-10) Wickham, David; Chullen, Cinda; Gleason, Kevin; Engel, JeffreyThe development of new, robust, life support systems is critical to NASA’s continued progress in space exploration. One vital function is maintaining the carbon dioxide (CO2) concentration in the cabin at levels that do not impair the health or performance of the crew. The CO2 removal assembly (CDRA) is the current CO2 control technology on-board the International Space Station (ISS). Although the CDRA has met the ISS needs to date, the repeated cycling of the molecular sieve sorbent causes it to break down into small particles that clog filters or generate dust in the cabin. This reduces reliability and increases maintenance requirements. Another approach that has potential advantages over the current system is a membrane that separates CO2 from air. In this approach, cabin air contacts one side of the membrane while other side of the membrane is maintained at low pressure to create a driving force for CO2 transport across the membrane. In this application, the primary power requirement is for the pump that creates the low pressure and then pumps the CO2 to the oxygen recovery system. For a membrane to be practical, it must have high CO2 permeation rate and excellent selectivity for CO2 over air. Unfortunately, conventional gas separation membranes do not have adequate CO2 permeability and selectivity to meet the needs of this application. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over air. In a recently completed Phase II SBIR project, Reaction Systems, Inc. fabricated an SLM that is close to meeting permeability and selectivity objectives for use in the advanced space suit portable life support system. This paper describes work carried out to evaluate its potential for use in spacecraft cabin application.Item Advanced Supported Liquid Membranes for Carbon Dioxide Control in Extravehicular Activity Applications(44th International Conference on Environmental Systems, 2014-07-13) Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Cowley, Scott W.; Chullen, CindaDeveloping a new, robust, portable life support system (PLSS) is currently a high priority for NASA in order to support longer and safer extravehicular activity (EVA) missions. One of the critical PLSS functions is maintaining the carbon dioxide (CO2) concentration in the suit at acceptable levels. Although the Metal Oxide (MetOx) canister has worked well, it has a finite CO2 adsorption capacity. Consequently, the unit would have to be larger and heavier to extend EVA times. Therefore, new CO2 control technologies must be developed to meet mission objectives without increasing the size of the PLSS. Although recent work has centered on sorbents that can be regenerated during the EVA, this strategy increases the system complexity and power consumption. A simpler approach is to use a membrane that selectively vents CO2 to space. A membrane has many advantages over current technology: it is a continuous system with no theoretical capacity limit, it requires no consumables, and it requires no hardware for switching beds between absorption and regeneration. Unfortunately, conventional gas separation membranes do not have adequate selectivity for use in the PLSS. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over oxygen (O2). In a current Phase II Small Business Innovative Research project, Reaction Systems has developed a new reactive liquid that has effectively zero vapor pressure, making it an ideal candidate for use in an SLM. The SLM function has been demonstrated with representative pressures of CO2, O2, and water. The SLM vents moisture to space in addition to being effective for CO2 control. Therefore, this project has demonstrated the feasibility of using an SLM to control CO2 in an EVA application.Item Advanced Technology Infusion into a Spacesuit Portable Life Support System(51st International Conference on Environmental Systems, 7/10/2022) Chullen, CindaAdvancement in technology drives our future. Moreover, the successful implementation of a technology drives its possibilities. The National Aeronautics and Space Administration (NASA) has invested in numerous technologies over the decades. A quote from NASA�s Space Technology Mission Directorates indicates the importance of technology: �Historically, technology has driven humanity�s progress and will continue to define our future. Our nation chooses to invest in new technology not only to maintain our edge in the global economy but also because technology helps us: Redefine the possible; Create a technologically advanced future; and Drive economic growth.� It is difficult for a technology to satisfy these goals unless it can be successfully infused into a system. For a technology to continue to evolve, become a reality, and infuse into NASA�s missions, there must exist a compilation of success-oriented factors for the technology to reach fruition. Understanding these factors could help decrease the complexity of technology infusion and bridge the gap between technology developers and system integrators. Ultimately, the knowledge gained could facilitate the design, development, and infusion of a technology to be more effective and efficient. Successful technology infusion is complex and can be even more daunting when advanced technologies infuse into complex systems such as a spacesuit portable life support system (PLSS). Overall, there is a need to understand and measure the success of infusing an advanced technology into a complex system. Industry and academia desire understand the infusion process. This paper focuses on advanced technology infusion into a spacesuit PLSS. A discussion of how the infusion began with a schematic study performed and documented in 2007 which influenced and shaped the design of the Exploration PLSS protype for the last 15 years. This research could help NASA and industry�s project managers and system mangers integrate advanced technologies more effectively and efficiently.Item Carbon-Based Regenerable Sorbents for the Combined Carbon Dioxide and Ammonia Removal for the Primary Life Support System (PLSS)(44th International Conference on Environmental Systems, 2014-07-13) Wójtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Manthina, Venkata; Singh, Prabhakar; Chullen, CindaResults are presented on the development of reversible sorbents for the combined carbon dioxide and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs). Since ammonia is the most important TC to be captured, data on TC sorption presented in this paper are limited to ammonia, with results relevant to other TCs to be reported at a later time. The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. The objective of this study was to demonstrate the feasibility of using carbon sorbents for the reversible, concurrent sorption of carbon dioxide and ammonia. Several carbon sorbents were fabricated and tested, and multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also a carbon surface conditioning technique that enhances the combined carbon dioxide and ammonia sorption without impairing sorbent regeneration.Item Chip-Scale, Nanoengineered CO2 Gas Sensors for Integrated Spacesuit Monitoring(47th International Conference on Environmental Systems, 2017-07-16) Chullen, Cinda; Xie, Ting; Thomson, Brian; Wen, Baomei; Rani, Asha; Debnath, Ratan; Motayed, AbhishekNASA and N5 Sensors, Inc. through a STTR program are jointly developing ultra-small, low-power carbon dioxide (CO2) and oxygen (O2) gas sensors, ideally suited for integrated space suit monitoring. During extravehicular activities, it is vital to monitor the effectiveness of the Portable Life Support System (PLSS) in real-time to ensure the safety of the astronaut. Due to the unique environmental conditions within the space suit such as high humidity, large temperature swings, and operating pressure swings, measurement of key gases such as carbon dioxide relevant to astronaut’s safety and health are quite challenging. Additionally, size, weight, and power constraints on such detection devices make it impractical to use conventional sensors. Unique chip-scale, nanoengineered chemiresistive gas sensor architecture has been developed for this application, which can be operated in the typical space suit environmental conditions. Unique design combining the selective adsorption properties of the nanoclusters of metal-oxides and metals, provides selective detection of CO2 in high relative-humidity conditions. Future works will focus on sensor design refinement as well as implementation of other on-chip components for reliable operation. In addition, a fully-integrated prototype system will be developed that can be tested in a simulated environment to evaluate the figures of merit.Item Compact Multi-gas Monitor for Life Support Systems Control in Space: Evaluation Under Realistic Environmental Conditions(44th International Conference on Environmental Systems, 2014-07-13) Alonso, Jesús Delgado; Phillips, Straun; Chullen, Cinda; Mendoza, EdgarAdvanced space life support systems require lightweight, low-power, durable sensors for monitoring critical gas components. A luminescence-based optical flow-through cell to monitor carbon dioxide, oxygen, and humidity has been developed and was demonstrated using bench-top instrumentation under environmental conditions relevant to portable life support systems, including initially pure oxygen atmosphere, temperature range from 50°F to 150°F, and humidity from dry to 100% RH and under conditions of water condensation. This paper presents the most recent progress in the development of this sensor technology. Trace gas contaminants in a space suit, originating from hardware and material off-gassing and crew member metabolism, are from many chemical families. The result is a gas mix much more complex than the pure oxygen fed into the space suit, and this complexity may interfere with gas sensor readings. This paper presents an evaluation of optical sensor performance when exposed to the most significant trace gases reported to be found in space suits. A study of the calibration stability of the sensors is also presented. For that purpose, a profile of temperature, pressure, humidity, and gas composition for the duration of an EVA has been defined, and the performance of sensors operated repeatedly under those conditions has been studied. Finally, this paper presents the first compact readout unit for these optical sensors, designed for the volume, power, and weight restrictions of a PLSS.Item Continued Advancement of Supported Liquid Membranes for Carbon Dioxide Control in Extravehicular Activity Applications(45th International Conference on Environmental Systems, 2015-07-12) Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Cowley, Scott W.; Chullen, CindaThe development of a new, robust, portable life support system (PLSS) is currently a high NASA priority to support longer and safer extravehicular activity (EVA) missions that will be necessary as space travel extends to near-Earth asteroids and eventually Mars. One of the critical PLSS functions is maintaining the carbon dioxide (CO2) concentration in the suit at acceptable levels. The Metal Oxide canister has a finite CO2 adsorption capacity. To extend mission times, the unit would have to be larger and heavier, which is undesirable; therefore, new CO2 control technologies must be developed. While recent work has centered on the use of alternating sorbent beds that can be regenerated during the EVA, this strategy increases the system complexity and power consumption. A simpler approach is to use a membrane that vents CO2 to space but retains oxygen (O2). A membrane has many advantages over current technology: it is a continuous system with no theoretical capacity limit, it requires no consumables, and it requires no hardware for switching beds between absorption and regeneration. Conventional gas separation membranes do not have adequate selectivity for use in the PLSS, but the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous film filled with a liquid that selectively reacts with CO2 over O2. In a recently completed Phase II Small Business Innovative Research project, Reaction Systems developed a new reactive liquid that has effectively zero vapor pressure, making it an ideal candidate for use in an SLM. Results obtained with the SLM in a flat sheet configuration with representative pressures of CO2, O2, and water have shown that the CO2 permeation rate and CO2/O2 selectivity requirements have been met. In addition, the SLM vents moisture to space very effectively. The SLM has also been prepared and tested in a hollow fiber form, which will be necessary to meet size requirements in the PLSS. In initial tests, the required CO2 permeance values have been obtained, while the current CO2/O2 selectivity values are somewhat lower than needed. However, the performance of the SLM is a strong function of the method used to impregnate the sorbent in the hollow fiber walls, and rapid progress is being made in that area.Item Continued Development of Compact Multi-gas Monitor for Life Support Systems Control in Space(46th International Conference on Environmental Systems, 2016-07-10) Alonso, Jesus Delgado; Chullen, Cinda; Quinn, Gregory; Berry, David; Dicarmine, PaulMiniature optical gas sensors based on luminescent materials have shown great potential as alternatives to NIR-based gas sensor systems for the Portable Life Support System (PLSS). The unique capability of luminescent sensors for carbon dioxide and oxygen monitoring under wet conditions has been reported, as has the fast recovery of humidity sensors after long periods of being wet. Lower volume and power requirements are also potential advantages over both traditional and advanced non-dispersive infrared (NDIR) gas sensors, which have so far shown longer life than luminescent sensors. In this paper we present the most recent results in the development and analytical validation of a compact multi-gas sensor unit based on luminescent sensors for the PLSS. Results of extensive testing are presented, including studies conducted in Intelligent Optical Systems laboratories, and a United Technologies Corporation Aerospace Systems (UTC) laboratory. The potential of this sensor technology for gas monitoring in PLSSs and other life support systems, and the advantages and limitations found through detailed sensor validation are discussed.Item Continued Development of Non-intrusive, Distributed Gas Sensing Technology for Advanced Spacesuits(47th International Conference on Environmental Systems, 2017-07-16) Chullen, Cinda; Alonso, Jesus Delgado; Dicarmine, PaulSpacesuit development and ground-based testing require sensing and analytical instrumentation for characterizing and validating prototypes. While miniature thermosensors measure reliably at low cost, and can be incorporated all around spacesuit prototypes, incorporating gas sensors at locations of interest inside a spacesuit has been a significant challenge – in particular for human subject tests – because of the size and cost of available instrumentation. The first system has been developed for non-intrusive gas sensing in space suit prototypes based on flexible sensitive patches positioned inside the prototypes and interrogated by optical fibers routed outside the suit, taking advantage of the transparent materials of the suit prototypes. In this paper, the most recent results are presented of the development and analytical validation of sensor patches for carbon dioxide, humidity, oxygen, and ammonia. Studies conducted to evaluate the sensor analytical characteristics and the calibration requirements are presented. Operation of the sensors using Mark III-like helmet parts is presented. Data collected to show the system flexibility for choosing multiple sensing points, fitting the sensor elements into the spacesuit, and cost effectively relocating the sensor elements as desired, is discussed.Item Continued Development of the Rapid Cycle Amine System for Advanced Extravehicular Activity Systems(44th International Conference on Environmental Systems, 2014-07-13) Papale, William; Chullen, Cinda; Campbell, Colin; Conger, Bruce; McMillin, SummerDevelopment activities related to the Rapid Cycle Amine (RCA) Carbon Dioxide and Humidity control system have progressed to the point of integrating the RCA into an advanced Portable Life Support System (PLSS) 2.0 to evaluate the interaction of the RCA among other PLSS components in a ground test environment. The RCA 2.0 assembly (integrated into PLSS 2.0) consists of a valve assembly with commercial actuator motor, a sorbent canister, and a field-programmable gate array-based process node controller. Continued design and development activities for RCA 3.0 have been aimed at optimizing the canister size and incorporating greater fidelity in the valve actuator motor and valve position feedback design. Further, the RCA process node controller is envisioned to incorporate a higher degree of functionality to support a distributed PLSS control architecture. This paper will describe the progression of technology readiness levels of RCA 1.0, 2.0 and 3.0, along with a review of the design and manufacturing successes and challenges for 2.0 and 3.0 units. The anticipated interfaces and interactions with the PLSS 2.0/2.5/3.0 assemblies will also be discussed.Item Design and Development Comparison of Rapid Cycle Amine 1.0, 2.0, and 3.0(46th International Conference on Environmental Systems, 2016-07-10) Chullen, Cinda; Campbell, Colin; Papale, William; Conger, Bruce; Mcmillin, SummerThe development of the Rapid Cycle Amine (RCA) swing-bed technology for carbon dioxide (CO2) removal has been in progress since favorable results were published in 1996. Shortly thereafter, a prototype was designed, developed, and tested successfully and delivered to Johnson Space Center in 1999. An improved prototype (RCA 1.0) was delivered to NASA in 2006 and sized for the extravehicular activity (EVA). The RCA swing-bed technology is a regenerative system which employs two alternating solid-amine sorbent beds to remove CO2 and water. The two-bed design employs a chemisorption process whereby the beds alternate between adsorbtion and desorbsion. This process provides for an efficient RCA operation so that while one bed is in adsorb (uptake) mode, the other is in the desorb (regeneration) mode. The RCA has progressed through several iterations of technology readiness levels. Test articles have now been designed, developed, and tested for the advanced space suit portable life support system (PLSS) including RCA 1.0, RCA 2.0, and RCA 3.0. The RCA 3.0 was the most recent RCA fabrication and was delivered to NASA-JSC in June 2015. The RCA 1.0 test article was designed with a pneumatically actuated linear motion spool valve. The RCA 2.0 and 3.0 test articles were designed with a valve assembly which allows for switching between uptake and regeneration modes while minimizing gas volume losses to the vacuum source. RCA 2.0 and 3.0 also include an embedded controller design to control RCA operation and provide the capability of interfacing with various sensors and other ventilation loop components. The RCA technology is low power, small, and has fulfilled all test requirements levied upon the technology during development testing thus far. This paper will provide an overview of the design and development of RCA 1.0, 2.0 and 3.0 including detail differences between the design specifications of each.Item Design Process Intended to Protect xEMU Components from Lunar Dust(2023 International Conference on Environmental Systems, 2023-07-16) Stapleton, Thomas; Chullen, Cinda; Bloom, Kelsey; Walton, Otis; Yan, Beichuan; Thakur, Saikat ChakrabortyThe xEMU is being developed to supply astronauts with a safe environment during terrestrial exploration. Lunar dust has been identified as one of the greatest challenges to the xEMU during lunar exploration. Fine, glass like dust particles proved detrimental to Apollo hardware operation and has the potential to cause significant performance degradation to manned flight hardware. Lunar Dust Mitigation Devices (LDMD) were designed, fabricated and tested in fulfillment a NASA SBIR Phase I to protect xEMU venting components, during lunar exploration (EVA/IVA), from the threat lunar dust particles presented against six xEMU venting component operations. A structured approach was developed, during a SBIR Ph II, to better understand how electrostatically charged lunar dust could impact dust protection designs. Following preliminary fluid and magnetic force analysis a complex simulation tool will be developed to predict the cohesive strength of lunar dust to LDMD surface and the ability of xEMU component purge gas to clean these surfaces. The cohesive analysis will be based on lunar dust triboelectric/adhesion properties, predicting cohesive forces between the dust and LDMD surfaces. Developed code will then be coupled within an existing ParaEllip3d-CFD, coupled Computational Fluid-Dynamics and Discrete Element Method (CFD/DEM) simulation model. This integrated tool intends to predict if the purge gases offer adequate shearing forces to clean LDMD surface of lunar dust. LDMD designs will be modified to enhance the self-cleaning approach and prototypes will then be fabricated. Testing at Auburn University intends to challenge LDMD prototypes by replicating Dusty Plasma, which contains electrostatically charged, simulated lunar dust as floats in clouds above the lunar surface. Ideally, results from this testing will validate the prediction models offer a guide to allow the design of LDMD, and other protection devices, to be effective.Item Development History of the High-Performance Infrared Laser Sensor into NASA Architectures via the Small Business Innovation Research (SBIR) Program(50th International Conference on Environmental Systems, 7/12/2021) Chullen, Cinda; Meginnis, Carly; Graf, John; Mudgett, Paul; Skow, Mary Coan; Vogel, MatthewGas sensing in space is difficult. Current commercial off the shelf (COTS) devices are not qualified to measure multiple gas constituents in space platforms. Vista Photonics, Inc. (VPI) has taken lessons learned from several Small Business Innovative Research (SBIR) awards and progressed their innovative technology to a point of infusing into a NASA flight program. Their development progression through the SBIR Program included Phase I, II, and III awards along with program matching-fund awards (Phase II-E and Commercialization Readiness Program). Development goals included increase sensing capability; ensure calibration and system stability were maintained; ensure valid sensor measurements; eliminate complexity, reduce power, volume, and cost; improve response time; and increase the Technology Readiness Level (TRL). The SBIR awards have resulted in several laser based gas sensing prototypes that were designed, built, tested, and delivered for NASA�s evaluation including an Advanced Space Suit Portable Life Support System (PLSS) gas sensor, an In-Flight Contingency Monitor and a Post-Landing Contingency Monitor. VPI leveraged lessons learned from the initial SBIR development of the Multi-Gas Monitor (MGM). The MGM was a technology demonstration onboard the International Space Station. This successful demonstration led NASA to consider the sensor technology as a potential candidate for the Exploration Extravehicular Mobility Unit PLSS. The Orion Program has selected a derivative of VPI�s technology for its Anomaly Gas Analyzer to detect vehicle combustion products. This paper articulates the technology development progression of VPI�s gas sensor through the SBIR Program to increase the TRL and technically infuse into the Orion architecture for gas sensing.Item The Development of Carbon-Based Sorbent Monoliths – a Review(2023 International Conference on Environmental Systems, 2023-07-16) Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Carlson, Andrew E.; Chullen, CindaItem Exploration Portable Life Support System Hatch Component Design Challenges and Progress(2020 International Conference on Environmental Systems, 2020-07-31) Todd, Kristina; Hostetler, John; Espinosa, Nicolas; Chullen, CindaAs the design for the Exploration Extra-vehicular Mobility Unit (xEMU) is developed, there are obvious gaps in technologies which need to be fulfilled to meet the new exploration requirements. Various Exploration Portable Life Support System (xPLSS) Hatch components have been at a stall in technology development for many years and require innovative ideas. The xPLSS Hatch consists of the Feedwater Supply Assembly, Trace Contaminant Control System, and the Thermal loop filters. The lag in development of these hatch components is due to the previous misconception that these were simple components, which would require little effort. As the design has progressed, there have been various changes in requirements along with challenges, which will be covered throughout this paper. NASA has plans to go to the moon and as the mission extends further out of Lower Earth Orbit, durability and extensibility will become some of the most important requirements. The development of each of these components is relevant not only to the xEMU, but also to the International Space Station (ISS), Gateway, and commercial space businesses. As the xPLSS is being designed, built, integrated and tested at the Johnson Space Center (JSC) technology solutions will have a direct incorporation path as the xPLSS is matured to meet design and performance goals. The status and future work for the hatch components will also be presented in this paper.Item Exploration Portable Life Support System Hatch Component Implementation and Testing(50th International Conference on Environmental Systems, 7/12/2021) Todd, Kristina; Hostetler, John; Espinosa, Nick; Chullen, Cinda; Stein, JamesNASA has plans to go back to the Moon. In order to do this, a new spacesuit is being designed for microgravity, cislunar, and lunar surface exploration. The design for the Exploration Extravehicular Mobility Unit (xEMU) is in continuous development and many previous gaps in technologies have begun initial development. Various Exploration Portable Life Support System (xPLSS) components within the Hatch had been at a stall in technology development for many years, specifically the Feedwater Supply Assembly, Trace Contaminant Control System, and the thermal loop filters. A previous paper outlined the challenging requirements and initial design of these components. The advancement of each of these components is relevant not only to the xEMU, but also to the International Space Station, Gateway, and commercial space businesses. As the xPLSS is being designed, built, integrated, and tested at the NASA Johnson Space Center, technology solutions will have a direct incorporation path as the xPLSS is matured to meet design and performance goals. This is a follow on paper to discuss the initial implementation of the hatch component designs, changes due to existing challenges, and performance results of these components as the xEMU project completes the first phase towards flight, known as Design Verification Test (DVT).Item Low-Power, Chip-Scale, Carbon Dioxide Gas Sensors for Spacesuit Monitoring(48th International Conference on Environmental Systems, 2018-07-08) Motayed, Abhishek; Chullen, Cinda; Rani, Asha; Shi, Chen; Thomson, Brian; Debnath, Ratan; Wen, BoameiN5 Sensors, Inc. through a Small Business Technology Transfer (STTR) contract award has been developing ultra-small, low-power carbon dioxide (CO2) gas sensors, suited for monitoring CO2 levels inside NASA spacesuits. Due to the unique environmental conditions within the spacesuits, such as high humidity, large temperature swings, and operating pressure swings, measurement of key gases relevant to astronaut’s safety and health such as(CO2), is quite challenging. Conventional non-dispersive infrared absorption based CO2 sensors present challenges inside the spacesuits due to size, weight, and power constraints, along with the ability to sense CO2 in a high humidity environment. Unique chip-scale, nanoengineered chemiresistive gas-sensing architecture has been developed for this application, which can be operated in typical spacesuit environmental conditions. Unique design combining the selective adsorption properties of the nanophotocatalytic clusters of metal-oxides and metals, provides selective detection of CO2 in high relative humidity conditions. All electronic design provides a compact and low-power solution, which can be implemented for multipoint detection of CO2 inside the spacesuits. This paper will describe the sensor architecture, development of new photocatalytic material for better sensor response, and advanced structure for better sensitivity and shorter response times.Item Monolithic Trace-Contaminant Sorbents Fabricated from 3D-printed Polymer Precursors(49th International Conference on Environmental Systems, 2019-07-07) Wójtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Carlson, Andy; Chullen, CindaThe current trace-contaminant (TC) removal technology for use in Extravehicular Activities (EVAs) involves the use of a packed bed of acid-impregnated granular charcoal, which is difficult to regenerate. In this paper, results will be presented on the development of vacuum-regenerable TC sorbents for use in the Portable Life Support System (PLSS). The sorbents will be derived from 3D-printed polymer monoliths (e.g., honeycomb structures), which will then be carbonized and oxidized in order to develop porosity, and also to enhance the TC-sorption capacity. Results will be presented on the following aspects of carbon-sorbent development: (1) precursor selection; (2) monolith fabrication; (3) shape retention and strength; (4) carbon surface and porosity characterization; (5) TC-sorption capacity and vacuum-regeneration; (6) pressure drop; and (7) sub-scale sorbent prototype. The use of predominantly microporous monolithic carbon is associated with the following benefits: (a) high TC-sorption capacity; (b) low pressure drop; (c) rapid vacuum (pressure-swing) desorption due to thin monolith walls and low pressure drop; (d) good thermal management (high thermal conductivity and low adsorption/desorption thermal effects associated with physisorption); and (e) good resistance to dusty environments.Item Nanoporous Silica as a Regenerable Sorbent for Potential Integration into NASA's Trace Contamination Control System(2023 International Conference on Environmental Systems, 2023-07-16) Materer, Nicholas; Kadossov, Evgueni; Apblett, Allen; Shaikh, Shoaib; Komarneni, Mallikharjuna; Teicheira, Michael; Chullen, Cinda; Boom, Kelsey; Hostetler, JohnDevelopment is underway for the next generation of spacesuits called the Extra-Vehicular Mobility Unit (xEMU). The Exploration Portable Life Support Subsystem (xPLSS) is a vitally important component of the xEMU that is also being developed. The xPLSS is tasked with the maintenance of a breathable atmosphere that is free of noxious volatile molecular species. The purification system that removes contaminants present in the ventilation system is the Trace Contamination Control System (TCC) which is a component in the ventilation loop of the xPLSS. Acid-impregnated activated carbon is the current state of the art for trace contamination control. As this sorbent is non-regenerable consumable, there is a significant impact of logistics on future missions. The primary trace contaminants that must be removed by the sorbent include ammonia, carbon monoxide, formaldehyde, and methyl mercaptan. XploSafe has developed and demonstrated the technical feasibility of a vacuum-regenerable sorbent that could be integrated into the TCC. XploSafe's sorbent media was exposed to 7-day Spacecraft Maximum Allowable Concentrations of the 18 trace contaminants that are present within the xPLSS breathing loop. The trace contaminants were exposed to the sorbent columns individually and in mixtures at relative humidities of 40% and 85% and temperature of 22 C). Adsorption breakthrough volumes and capacities were measured along with regeneration capacity for the sorbent tested with these trace contaminant analytes. Prototype TCC holder design considerations including the required sorbent mass and sorbent holder volume are also discussed.Item Next Generation Life Support Project Status(44th International Conference on Environmental Systems, 2014-07-13) Barta, Daniel J.; Chullen, Cinda; Vega, Leticia; Cox, Marlon R.; Aitchison, Lindsay T.; Lange, Kevin E.; Pensinger, Stuart J.; Meyer, Caitlin E.; Flynn, Michael; Richardson, Tra-My Justine; Jackson, W. Andrew; Abney, Morgan B.; Birmele, Michele N.; Lunn, Griffin M.; Wheeler, Raymond M.Next Generation Life Support (NGLS) is one of more than 20 technology development projects sponsored by NASA’s Game Changing Development Program. The NGLS Project develops selected life support technologies needed for humans to live and work productively in space, with focus on technologies for future use in spacecraft cabin and space suit applications. Over the last 3 years, NGLS had five main project elements: Variable Oxygen Regulator (VOR), Rapid Cycle Amine (RCA) swing bed, High Performance Extravehicular Activity (EVA) Glove (HPEG), Alternative Water Processor (AWP) and Series-Bosch Carbon Dioxide Reduction. The RCA swing bed, VOR and HPEG tasks are directed at key technology needs for the Portable Life Support System (PLSS) and pressure garment for an Advanced Extravehicular Mobility Unit (EMU). Focus is on prototyping and integrated testing in cooperation with the Advanced Exploration Systems (AES) Advanced EVA Project. The HPEG Element, new this fiscal year, includes the generation of requirements and standards to guide development and evaluation of new glove designs. The AWP and Bosch efforts focus on regenerative technologies to further close spacecraft cabin atmosphere revitalization and water recovery loops and to meet technology maturation milestones defined in NASA’s Space Technology Roadmaps. These activities are aimed at increasing affordability, reliability, and vehicle self-sufficiency while decreasing mass and mission cost, supporting a capability-driven architecture for extending human presence beyond low-Earth orbit, along a human path toward Mars. This paper provides a status of current technology development activities with a brief overview of future plans.
- «
- 1 (current)
- 2
- 3
- »