Browsing by Author "Hanford, Anthony"
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Item Design and Analysis of a Fan Outlet Check Valve for the Exploration Portable Life Support System(49th International Conference on Environmental Systems, 2019-07-07) Waguespack, Glenn; Hanford, Anthony; Barnes, BruceCheck valves are required at the outlets of NASA’s Exploration Portable Life Support System (xPLSS) ventilation loop fans to permit forward flow through the ventilation loop while preventing backflow through the fans when they are not running. These check valves must maintain full specified functionality at all orientations in gravitational environments ranging from weightlessness to full terrestrial gravity. A check valve design has been developed to satisfy the above requirements via an iterative process combining mechanical design, computational fluid dynamics (CFD) analysis, Thermal Desktop® analysis, and static force analysis. The initial design concept was a flapper valve in which a mass-balanced flapper freely rotates from fully closed (0°) to a 45° angle, after which a torsional spring engages the flapper to prevent it from opening beyond the point at which reverse flow cannot close the valve. Analysis results, however, indicated that the magnitude of reverse flow induced during contingency purge operations would not always be sufficient to overcome gravitational and frictional moments to close the flapper in its unassisted, free-rotating range. The design was thus revised to provide spring engagement throughout the entire span of valve positions, removing the flapper’s dependency on reverse flow for valve closure. Since commercially-available torsion springs are too stiff for this application, the revised design uses a linear compression spring that engages the flapper at an offset from the flapper’s pivot point. CFD and static force analyses were used to determine acceptable design parameters, from which valve geometry and spring selection were determined.Item Feasibility of Ultraviolet Technology to Disinfect Spacecraft Water Systems(49th International Conference on Environmental Systems, 2019-07-07) Almengor, Audry; Gilbert, Susan; Todd, Kristina; Adam, Niklas; Callahan, Michael; Ott, C. Mark; Hanford, AnthonyAs the National Aeronautics and Space Administration (NASA) expands its scope and begins to venture into long-duration, manned space flights, the function and maintenance of spacecraft water systems becomes increasingly critical and difficult to achieve. New mission requirements will limit opportunities for resupply and demand extended periods of uncrewed operations. Based on lessons learned from the International Space Station (ISS), one particular challenge of future spacecraft water systems will be maintaining adequate microbial control, especially in water sub-systems and component-level elements where effective long-duration biocontrol strategies do not currently exist. To ensure the reliability and redundancy in these systems, new technologies will be needed in order to ensure mission success. This paper summarizes a feasibility study conducted to look into commercial-off-the-shelf (COTS) Ultraviolet (UV) reactor systems intended to aid in slowing the progress of microbial and biofilm growth via the implementation of a single pass, point of use and/or recirculation UV device. Using this technology may reduce the need for consumable resupply, such as filters or biocides, as well as minimize crew time needed to make the repairs on exhausted and/or compromised systems. The ultimate rationale behind developing a UV disinfection system is to increase the stability of water systems as requirements for sterility and microbial control become more stringent for deep space missions. The resulting data from this study will be used to narrow down possible technology demonstrations for selected ISS locations in order to assess the use of UV technology on future exploration-class spacecraft systems.Item Feasibility of UV LEDs in a Spacecraft Wastewater Application: Exploring Biofilm Control in the WPA Wastewater Tank(50th International Conference on Environmental Systems, 7/12/2021) Adam, Niklas; Gilbert, Susan N.; Kelley, Christopher; Almengor, Audry; Harris, Jacob; Callahan, Michael; Hanford, Anthony; Toon, Katherine; Ott, C. MarkAs the National Aeronautics and Space Administration (NASA) expands its scope and begins to venture into long-duration, manned space flights, the function and maintenance of spacecraft water systems becomes increasingly critical and difficult to achieve. New mission requirements will limit opportunities for resupply and demand extended periods of uncrewed operations. Based on lessons learned from the International Space Station (ISS), one particular challenge of future spacecraft water systems will be maintaining adequate microbial control, especially in water subsystems and component-level elements where effective long-duration biocontrol strategies do not currently exist. To ensure the reliability and redundancy in these systems, new technologies will be needed in order to ensure mission success. After proving feasibility of commercial off-the-shelf (COTS) ultraviolet (UV) light emitting diodes (LEDs) disinfection devices in flow through applications in 2018, our current work has focused on the development of UV LED technology for microbial control in bellows-style spacecraft wastewater tank. Two primary strategies were developed used to determine initial feasibility. The strategies included, (1) flow into, continuous recirculation, and flow out of the tank volume through a standalone UV reactor system, and (2) direct UV irradiation on the wetted tank surfaces using an integrated UV-tank array. This paper summarizes the feasibility of these approaches through benchtop and subscale tank testing and outlines the proposed development pathway of these technologies for biofilm control in a wastewater tank applications.Item Integrated Computational Fluid Dynamics and Thermal Desktop Thermal Modeling for Assessment of the EMU in Support of ISS EVA 80(2023 International Conference on Environmental Systems, 2023-07-16) Lancaster, Blain; Baukus, Abigail; Andish, Kambiz; Hanford, AnthonyFollowing the reports of water accumulation in the Extravehicular Mobility Unit (EMU) helmet during the ISS US EVA-80, various efforts for mitigation and further understanding of this phenomenon have been undertaken with the goal of prevention and to ensure crew safety in future EVAs. In support of this goal, a combination of Thermal Desktop thermal modeling and Computational Fluid Dynamics (CFD) has been performed in order to characterize the performance of the EMU components, specifically those within the ventilation/cooling water loops. This modeling effort evaluates the dry/wet gas pressure drop and flow distribution through gas and liquid flow paths using CFD, as well as a two-phase flow assessment of condensation production and water separation/removal performance using an integrated Thermal Desktop model of important EMU ventilation loop components. The models assess this overall thermal-fluid performance in comparison with previous existing models and design points, with the potential to evaluate worst case scenarios and historical EVAs.Item Investigation of Silver Biocide as a Disinfection Tehcnology for Spacecraft – An Early Literature Review(48th International Conference on Environmental Systems, 2018-07-08) Li, Wenyan; Calle, Luz; Hanford, Anthony; Stambaugh, Imelda; Callahan, MichaelAn ideal spacecraft water disinfection system should prevent or control microbial growth, inhibit or prevent biofilm formation, and prevent microbial-induced corrosion. In addition, the selected biocide system should be chemically compatible with materials used in the water storage and distribution system, have minimal maintenance requirement, especially for long-duration missions, and should be safe for crew consumption at levels appropriate for biocidal control. Silver ion is a proven broad spectrum biocide. Terrestrially, there has been an increased interest in the biocidal function of silver, both due to its potential to control bacterial resistant species and due to advances in silver and nano-silver biocide technologies. NASA is considering silver as the future biocide for exploration over the current iodine state-of-the-art (SOA) biocide system. In order to select and design a successful silver biocide delivery system to meet NASA’s requirements, it is essential to understand the advantages and disadvantages of moving to a silver disinfection system. To enhance the knowledge base for the application of silver biocides in spacecraft water systems, this paper provides a first compilation of review data related to: (1) Silver as a biocide technology, (2) Options and concepts for silver biocide delivery, and (3) Silver biocide compatibility studies for spacecraft systems.Item Potential Evolution of Crop Production in Space Using Veggie(48th International Conference on Environmental Systems, 2018-07-08) Hanford, Anthony; Anderson, Molly; Ewert, Michael; Stambaugh, ImeldaHistorically, the National Aeronautics and Space Administration (NASA) proposed large chambers to support crop production for food production in closed or partially closed regenerative life support systems. Such concepts relegate crop production, aside from small facilities deemed “salad machines,” to the indefinite future because they require large commitments of infrastructure to enable and support. Significantly, recent NASA mission architectures propose gradually placing capabilities in desirable locations by combining assets from earlier visits. An approach for producing crops might also build up greater capabilities over time. The analyses here consider combining multiple Vegetable Production Systems (Veggies) like the one on the International Space Station (ISS) to provide an ever greater crop production capability. Initial installations might yield a salad per crewmember every other day, while much more capable facilities might provide complete closure for atmospheric revitalization as well as about sixty percent of the crew’s food on a dry mass basis. New technologies for plant growth systems and volume optimization were considered. Sensitivity analysis was also performed to determine what improvements to the physical and biological component performance would provide the most benefit to the system.Item Update on Feasibility of UV LEDs in a Spacecraft Wastewater Tank Application(2020 International Conference on Environmental Systems, 2020-07-31) Adam, Niklas; Callahan, Michael; Almengor, Audry; Gilbert, Nikki; Harris, Jacob; Jimenez, Javier; Hanford, Anthony; Toon, KatherineAs the National Aeronautics and Space Administration (NASA) expands its scope and begins to venture into long-duration manned space flights, the function and maintenance of spacecraft water systems becomes increasingly critical and difficult to achieve. New mission requirements will limit opportunities for resupply and demand extended periods of dormancy during uncrewed operations. Based on lessons learned from the International Space Station (ISS), one particular challenge of future spacecraft water systems will be maintaining adequate microbial control, especially in water system and component-level elements where effective biocontrol strategies do not currently exist. To ensure the reliability and redundancy in these systems, new technologies will be needed in order to ensure mission success. One application specific microbial control technology under consideration is the use of ultra-violet (UV) light emitting diodes (LEDs). UV-LED technology may reduce the need for consumable resupply, such as filters or biocides, and may minimize crew time associated with the repair and refurbishment of exhausted and/or compromised components and/or systems. Having recently proved preliminary feasibility of commercial off the shelf (COTS) UV-LED devices in a number of spacecraft water system applications, this paper reports on the development of this technology for microbial control in the water processing assembly (WPA) wastewater tank application. The resulting data from this study will be are part of on going efforts to explore the use of UV-LED technology to increase the stability of water systems as deep space missions drive requirements toward more stringent needs for sterility and microbial control.