Browsing by Author "Almengor, Audry"
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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 To Biocide or not to Biocide? Exploring the "No Biocide" Option in Spacecraft Potable Water Systems(2023 International Conference on Environmental Systems, 2023-07-16) Nadeau, Mary Lou; Almengor, Audry; Muirhead, Dean; Ott, Mark; Callahan, MichaelResidual biocide has been used to protect against microbial growth in spacecraft potable water systems since the Gemini program. Iodine, the biocide currently used on the International Space Station (ISS) has a long history of use but presents a few challenges for exploration: it must be removed using a consumable absorbent before crew consumption and is known to lose its biocidal concentration due to interactions with wetted components, especially during periods of dormancy. Biocidal silver is being considered for exploration missions as it is safe for crew consumption, but it too has challenges with proper material design to maintain sufficient disinfection residuals. An idea proposed by some in the Environmental Control and Life Support System (ECLSS) community has been that the biocide does not provide a true barrier against microbial growth, and therefore, perhaps the challenges of maintaining a residual biocide in the system could be best overcome by removing the biocide altogether. In this argument, they point to the regenerative water treatment system on the ISS which produces high purity water that theoretically meets the microbiological requirements before the iodine is added. Exploration water processing systems are expected to have similar water processing capabilities. This paper will discuss the role that residual biocide may play in controlling microbial growth and presents perspectives on the potential risks associated with removing it from exploration water systems.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.