Browsing by Author "Lange, Kevin"
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Item Analysis of Candidate Technologies for a Partial Gravity Water Recovery System(2020 International Conference on Environmental Systems, 2020-07-31) Baryakova, Tsvetelina; Lange, KevinThe development of a Partial Gravity Water Recovery System (PGWRS) for a future long-duration mission to a lunar/planetary surface is an unmet need. The Water Recovery System currently used aboard the ISS recovers potable water from urine, flush water, and humidity condensate and necessarily employs microgravity-compatible technologies. A PGWRS, in comparison, is amenable to the inclusion of more reliable gravity-based separation techniques and may additionally be required to process hygiene and laundry wastewaters. Here, we discuss the anticipated compositions and flow rates of the types of wastewaters expected to be produced on an early planetary base, the general structure of a water recovery architecture capable of taking such waste streams to potable quality, and several different candidate technologies that can fulfill one or more processing functions. Additionally, we present a mathematical model of a Membrane Aerated Bioreactor (MABR) - Reverse Osmosis (RO) system that was used in trading four different simple water recovery architectures, each accommodating either a mixed waste stream or two segregated waste streams and featuring an RO system in either an internal recycle or MABR recycle configuration. Our analysis results suggest that the architecture masses are sensitive to certain parameters, such as the RO recovery fraction, with each of the four configurations being potentially lucrative under the appropriate set of operating conditions. Finally, we identify knowledge gaps for promising technologies that arose during our analysis and that we recommend closing via future modeling and/or testing efforts.Item Comparison of Exploration Oxygen Recovery Technology Options Using ESM and LSMAC(2020 International Conference on Environmental Systems, 2020-07-31) Abney, Morgan; Gatens, Robyn; Lange, Kevin; Brown, Brittany; Wetzel, John; Morrow, Robert; Schneider, Walter; Stanley, ChristineIn preparation for long duration manned space flight, numerous technology development efforts are ongoing in the area of environmental control and life support (ECLS). In cooperation with international, industry, and academic partners, NASA seeks to leverage the International Space Station as a testbed for technologies targeted for Exploration-class missions. In recent years, Equivalent Systems Mass (ESM) analyses have been conducted to evaluate the relative breakeven points and to compare technologies as part of ECLS architectural trades. While these studies have provided important data pertaining to key engineering metrics, additional considerations are important to more fully understand the potential impacts and costs associated with selecting a specific architecture. A tool, called the Life Support Multi-Dimensional Assessment Criteria (LSMAC), was recently proposed by Sierra Nevada Corporation in an attempt to incorporate influences of these additional considerations including Maintainability, Risk Analysis, Technology Readiness Level, Radiation Impacts, Manufacturing Costs, Reliability, Human Factors, and Un-Crewed Operations. As a first step toward evaluating and implementing this tool, LSMAC was used to revisit the ISS oxygen recovery trade from the 1990’s wherein Sabatier was selected over Bosch technology. Second, the tool was used to compare oxygen recovery developmental technologies currently in work. The results of these studies as well as a comparison with standalone ESM analyses are reported. Further, a discussion of the potential application of the tool across the ECLS portfolio and its potential use in future technology selection for ISS flight demonstrations is provided.Item Dynamic Modeling of Ammonia Removal with Phosphoric-Acid-Treated Activated Carbon(48th International Conference on Environmental Systems, 2018-07-08) Roohi, Stephanie; Monje, Oscar; Perry, Jay; Lange, KevinThis paper describes the initial development of a dynamic model of ammonia removal by chemisorption using Ammonasorb II (Calgon Carbon), a phosphoric-acid-treated activated carbon. The model is being developed using a commercial adsorption modeling software product (Aspen Adsorption™). An adsorption isotherm equation was derived based on aqueous solution chemistry and compared to measured ammonia capacities for Ammonasorb II under wet conditions. Predicted capacities using the measured phosphoric acid content of one carbon and parameters derived from solution chemistry show good agreement with measurements over a range of ammonia concentration. Both solution-phase and solid-phase equilibrium simulations were performed in support of the isotherm development. Using the dynamic model, a preliminary overall linear mass transfer coefficient was estimated by fitting available ammonia breakthrough data. Additional data are needed to more fully describe and validate the dynamic performance behavior. The model development is directed at sizing trace contaminant control beds for low volume applications such as spacesuits and suit loops where dynamic performance is critical.Item Dynamic Modeling of Gaseous Multicomponent Trace Contaminant Adsorption(49th International Conference on Environmental Systems, 2019-06-07) Roohi, Stephanie; Lange, Kevin; Perry, Jay; Kayatin, MatthewActivated carbon is a porous material in the Trace Contaminant Control (TCC) system that physically adsorbs volatile organic compounds generated within spacecraft and spacesuit environments. Several isotherm models exist to predict adsorption equilibria for processes involving multicomponent systems. This paper investigates the use of Ideal Adsorbed Solution Theory (IAST) for predicting multicomponent trace contaminant adsorption behavior using single-component isotherms based on potential theory. Developing simulations of high velocity, low aspect ratio (HVLA) adsorption processes and classic low velocity, high aspect ratio (LVHA) adsorption processes will gauge the validity of the theorem on the sizing and design of TCCS architecture. Model results are compared with available test data and predictions of the FORTRAN TCCS computer program (TCCS-CP) used historically.Item Modeling Evolvable Water Recovery Systems for Short and Long-Duration Missions in Partial Gravity(2024 International Conference on Environmnetal Systems, 2024-07-21) Carlson, Avery; Lange, Kevin; Callahan, MichaelWater recovery technologies on the International Space Station (ISS) are designed and optimized for microgravity environments, thus creating a need for innovative systems optimized for mission operations in the presence of gravity. Alternative water recovery technologies under research by the Life Support Systems division were compiled into a series of Partial Gravity Water Recovery System (PGWRS) architectures. Individual unit processes were modeled via fundamental physical-chemical process equations to simulate their method of treatment, including chemical or biological oxidation, flash evaporation, filtration, or adsorption and ion exchange. Dimension and sizing data were then utilized to scale each architecture. Modeling was completed on an assortment of architectures assuming three scenarios in which treatment methods could take advantage of partial gravity: a short-duration mission with a temporary surface habitat, a longer duration mission with a more permanent habitat, and a long duration mission without resupply. Total system mass was estimated to quantitatively compare architectures within scenarios, but qualitative observations were also made regarding system robustness, flexibility, and capacity to meet more stringent demands. Technologies that traded most favorably between the scenarios were those that included a pre-oxidation stage to minimize mass loading to downstream absorption and ion exchange beds, exploited gravity in liquid-vapor separation processes, and reconstituted wastewater components into recyclable material streams.Item Modeling of a Solid Oxide Fuel Cell as Part of a Predictive Functional Model for Aerospace Fuel-Cell Systems(2024 International Conference on Environmnetal Systems, 2024-07-21) Nadeau, Mary Lou; Lange, Kevin; Cognata, ThomasThis paper will discuss initial efforts at developing a parametric fuel cell component model for architecture studies of aerospace systems. Fuel cells historically have been used in spacecraft from the Gemini to the Shuttle era for providing spacecraft power with the added benefit of producing water for crew use. However, there are many potential applications for fuel cells and electrolyzers in spaceflight, including oxygen generation, in-situ resource utilization (ISRU) and propellant production. This proof-of-concept model has been developed using a commercial multiphysics modeling software package. Two-dimensional and one-dimensional isothermal models were created based on a certain SOFC design and results were compared to test data from the real system. Local Butler-Volmer kinetic relations were adjusted, and an effective porous medium approach was taken in order to capture how the many interconnects between cells in the gas channels affected fluid flow. The model was able to reproduce polarization curves derived from test data within around 0.02 Volts for a given current density. This model could be adapted to model a solid oxide electrolyzer, proton exchange membrane fuel cell, or other type of fuel cell technology in order to understand how these types of technologies could fit into broader spacecraft designs and advance the capabilities of spaceflight systems.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.Item Trading Advanced Oxygen Recovery Architectures and Technologies(48th International Conference on Environmental Systems, 2018-07-08) Lange, Kevin; French, Melanie; Abney, Morgan; Barta, DanielA trade study was performed to evaluate several technologies designed to increase oxygen recovery from carbon dioxide compared to the International Space Station (ISS) state-of-the-art. The study employed an equivalent system mass (ESM) approach that combined alternative Spacecraft Oxygen Recovery (SCOR) technologies with either unscaled or scaled ISS technologies to complete the functionality of the oxygen generation system architecture (where necessary) and to assess the overall life support system impact. ESM calculations based on a target system reliability (achieved by adding redundancy or spares) were included similar to a 2012 study, but assuming a lower level of reparability. Simpler two-failure tolerant ESM calculations were also performed. A component-level database for several ISS technologies was built to support the calculations. The combination of scalability and lower-level reparability significantly reduces the breakeven time for regenerative technologies compared to previous studies. Although there is currently considerable uncertainty in many of the assumptions and technology characteristics, the results suggest some clear patterns and benefits. The approach has the potential to help guide and prioritize life support technology development as part of an ongoing assessment combined with other considerations such as safety, development risk, and cost.Item Water Recovery Trades for Long-Duration Space Missions(49th International Conference on Environmental Systems, 2019-07-07) French, Melanie; Lange, KevinWater recovery in life support systems is critical for long-duration space missions. Potential sources of recoverable water include humidity condensate, urine, feces, and wet trash. Water can also be recovered from metabolic carbon dioxide when hydrogen is available either as a byproduct of oxygen generation or from storage. An assessment of fecal water recovery is initially presented, including a comparison with baseline storage options that do not recover water. The paper then trades combinations of water recovery approaches for deep space missions considering all of the above sources. The trade study uses equivalent system mass as the primary comparison basis and includes reliability/failure tolerance impacts through the addition of spares. Alternative system sizing approaches are considered in addition to possibilities for dissimilar redundancy.