Browsing by Author "Homer, Margie"
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Item Calibration and Performance of the Spacecraft Atmosphere Monitor, an Air Constituent Monitor for Human Spaceflight(2023 International Conference on Environmental Systems, 2023-07-16) Darrach, Murray; Bae, Byunghoon; Fu, Dejian; Garkanian, Vachik; Homer, Margie; Kidd, Richard; Jung-Kubiak, Cecile; Kraus, Hannes; Maiwald, Frank; Madzunkov, Stojan; Malone, Charles; Nikolic, Dragan; Rais-Zadeh, Mina; Simcic, Jurij; Tillmans, Tina; Zhong, FangThe Spacecraft Atmosphere Monitor (S.A.M.) is a miniaturized gas chromatograph mass spectrometer (GC/MS) instrument for monitoring the cabin atmosphere for human spaceflight missions. The first Technology Demonstration Unit (TDU1) operated successfully aboard the International Space Station (ISS) from August 2019 to July 2021. The second unit, TDU2, will be delivered to ISS in 2023. While on-station, TDU2 will continuously monitor the major atmospheric constituents and, on command, perform analysis of the cabin atmosphere for trace organic volatiles. The S.A.M. TDU2 uses the same quadrupole ion trap mass spectrometer (QITMS) sensor as in TDU1, but includes a MEMS preconcentrator, gas chromatograph, and microvalve system. Its miniature, ruggedized form factor allows the S.A.M. to be aisle-deployed to monitor the cabin in different locations and during activities such as exercise and sleep.Item Photocatalytic Oxidation Using TiO2 and UV for Total Organic Carbon Analysis of Water(2020 International Conference on Environmental Systems, 2020-07-31) Gonzalez, Marianne; Lopez, Valeria; Kidd, Richard; Homer, Margie; Noell, Aaron; Morrison, Chad; Jewell, April; Firdosy, Samad; Darrach, Murray; Callahan, Mike; Christensen, Lance; Winiberg, FredWater quality monitoring is vital for long-duration human missions. In particular, monitoring potable water Total Organic Carbon (TOC) is an important metric to understand water quality. The International Space Station (ISS) currently has this capability with its Total Organic Carbon Analyzer (TOCA) that performs off-line analysis. Currently an effort is underway to develop a Miniature Total Organic Carbon Analyzer (mini-TOCA), which aims to decrease the mass, volume, and power specifications to enable long-duration human exploration without sacrificing analytical capability. The main steps of TOC analysis are oxidation of the water sample and the detection of carbon dioxide. One novel oxidation method for use in a TOCA instrument is photocatalytic oxidation using a titanium dioxide (TiO¬2) coating combined with UV LEDs emitting at the TiO2 bandgap (365 nm). Several reactor prototype configurations using this method were procured and tested. The considered design parameters included various surface geometries of the fluidic channels, catalyst application methods, and UV duration and intensity. The application of catalytic TiO2 was attempted using a commercial coating, and atomic layer deposition (ALD) on machined steel and 3D printed titanium. Direct formation of the catalytic later was also tried with titanium substrate via heat treating. The extent of oxidation for different reactor configurations and coatings was determined by changes in direct conductivity measurements of water samples containing trace organic compounds. The ALD catalyst coating was most effective for oxidizing sample. The amount of UV output was also varied to understand the time required for full oxidation. Further work is planned to introduce more types of samples, perform lifetime testing, and integrate the reactor with a tunable laser spectrometer.Item Progress on the Organic and Inorganic Modules of the Spacecraft Water Impurity Monitor, a Next Generation Complete Water Analysis System for Crewed Vehicles(2023 International Conference on Environmental Systems, 2023-07-16) Pensinger, Stuart; Callahan, Michael; Neidholdt, Evan; Noell, Aaron; Oborny, Nathan; Bae, Byunghoon; Lopez, Valeria; Hancock, Bruce; Gonzalez, Marianne; Homer, Margie; Madzunkov, Stojan; Darrach, Murray; Kidd, RichardThe Dragonfly Mass Spectrometer (DraMS) is an instrument on the Dragonfly mission operating on the surface of the Titan, the Saturn’s largest moon. Titan's atmosphere is nitrogen rich and has surface atmospheric pressure of 147 kPa and temperature of 94 K. Since electronics cannot survive at these extreme temperatures, significant thermal isolation is needed between the electronics and the Titan atmosphere to maintain the components above their survival temperatures. However, the main electronic box (MEB) for the DraMS instrument dissipates significant amount of heat over small volume and a conventional conductive cooling approach cannot be used without significant mass additions. Instead, a fan cooled approach was chosen. Conditioned room-temperature air, supplied by the Dragonfly lander, will flow directly over the MEB’s boards during DraMS operational scenarios. A cooling air manifold is designed with the help of computational fluid dynamics (CFD) simulations to effectively distribute the flow over the actively cooled boards. Since the fan will operate at denser-than-Earth pressures on Titan but Earth-like pressures during ground testing, a thermal test was performed to verify the fan’s thermal performance (at varying levels of pressure) and compared against CFD predictions. This test was performed with a 3-D printed mockup of the MEB with heated metallic plates to simulate the circuit boards. This paper will discuss the analytical CFD work and the thermal tests performed to aid the development of the DraMS thermal/mechanical MEB design.Item Progress Report on the Spacecraft Atmosphere Monitor Development Model(47th International Conference on Environmental Systems, 2017-07-16) Madzunkov, Stojan; Darrach, Murray; Kidd, Richard; Schaefer, Rembrandt; Simcic, Jurij; Nikolic, Dragan; Diaz, Ernesto; Homer, Margie; Schowalter, Steven; Bae, Byunghoon; Gill, JohnThe Spacecraft Atmosphere Monitor (S.A.M.) is a miniature gas chromatograph (GC) mass spectrometer (MS) intended for assessing trace volatile organic compounds and the major constituents in the atmosphere of present and future crewed spacecraft. As such, SAM will continuously sample concentrations of major air constituents (CH4, H2O, N2, O2, and CO2) and report results in two-second intervals. The S.A.M. is a technology demonstration planned to launch in 2018 and we report here on recent developments taking place in building a testbed and development model of the instrument. The S.A.M. is mechanically designed to operate under hi-G loads present during launch events and can operate at sub-atmospheric pressures relevant to extra-vehicular activities. Total instrument mass is projected at 9.5 kg with power consumption estimated at 35 W. The S.A.M. instrument will provide on-demand reporting on trace volatile organic compounds (VOC) at ppm to ppb levels of 40+ species relevant for astronaut health.Item Status and Results of the Spacecraft Atmosphere Monitor Technology Demonstration Instrument(51st International Conference on Environmental Systems, 7/10/2022) Darrach, Murray; Madzunkov, Stojan; Bae, Byunghoon; Kidd, Richard; Maiwald, Frank; Malone, Charles; Nikolic, Dragan; Belousov, Anton; Zhong, Fang; Simcic, Jurij; Homer, Margie; Gonzales, Marianne; Garkanian, Vachik; Lopez, Valeria; Jung-Kubiak, Cecile; Rais-Zadeh, Mina; Krause, Hannes; Tillmans, TinaThe Spacecraft Atmosphere Monitor (S.A.M.) is a miniaturized gas chromatograph mass spectrometer (GC/MS) instrument that is being developed for monitoring the cabin atmosphere for human spaceflight missions. The first Technology Demonstration Unit (TDU1) operated successfully aboard the International Space Station (ISS) from August 2019 to July 2021, exceeding its 1 year planned operational lifetime. The TDU1 continuously monitored the ISS cabin atmosphere for the major constituents. In June 2020 the TDU1 was also reconfigured at the request of the ISS vehicle office and successfully determined that there was no benzene leaking into the ISS atmosphere. The technology demonstration unit #2 (TDU2) is scheduled to be deployed on the ISS in 2022. While on-station, TDU2 will continuously monitor the major atmospheric constituents as well as trace organic volatiles. The S.A.M. TDU2 uses the same quadrupole ion trap mass spectrometer (QITMS) sensor as in TDU1, but includes a MEMS preconcentrator, gas chromatograph, and microvalve system. Its miniature, ruggedized form factor allows the S.A.M. to be aisle-deployed to monitor the cabin in different locations and during activities such as exercise and sleep. The operational performance of TDU1 and the current status of TDU2 will be discussed.Item The Spacecraft Water Impurity Monitor, a Framework for the Next Generation Complete Water Analysis System for Crewed Vehicles Beyond the ISS(51st International Conference on Environmental Systems, 7/10/2022) Kidd, Richard; Homer, Margie; Noell, Aaron; Simcic, Jurij; Bae, Byunghoon; Gonzalez, Marianne; Lopez, Valeria; Darrach, Murray; Pensinger, Stuart; Callahan, Mike; Neidholdt, Evan; Gilbert, NikkiOn-orbit analysis of the total organic carbon (TOC) content of recycled water, as provided by the ISS TOCA, has been an indispensable tool for monitoring the performance of the WRS and for ensuring that water is fit for crew consumption. While TOC has been, and will continue to be an important metric for spacecraft water quality, it provides only limited insight into the total picture. As a measurement, TOC only provides a single �lump sum� quantity of all organic chemicals present in a water sample. Nor does the TOC measurement begin to address inorganic constituents, such as metals resulting from corrosion nor an intentionally-dosed biocide. For exploration missions beyond LEO, the return of water samples to Earth for analysis will be logistically challenging or impossible. The Spacecraft Water Impurity Monitor (SWIM) is a joint collaboration to develop an instrument platform that will perform in-flight measurements and deliver a more complete picture of water quality to decision makers. Eventually, missions to the moon, Mars, and beyond will be equipped with analytical capabilities equaling those found in terrestrial labs. Based on what we know about current and future spacecraft environments, SWIM will seek to provide enhanced analytical capability that enables NASA to confidently send astronauts on distant missions without the possibility of returned water samples. This paper discusses the challenges presented by exploration requirements and the research and development progress toward the goal of a total water analysis system. For organic analysis, one of the analysis technologies that the SWIM team have been developing is a liquid-injection gas chromatograph mass spectrometer system; these systems are the workhorses of analytical chemistry laboratories world-wide. For inorganic analysis, the team is exploring a number of technologies ranging from traditional liquid chromatography technologies (e.g. ion chromatography, capillary electrophoresis) to flight-heritage technology such as ion-specific electrodes.Item Update on the Spacecraft Atmosphere Monitor Technology Demonstration Project(2020 International Conference on Environmental Systems, 2020-07-31) Darrach, Murray; Madzunkov, Stojan; Kidd, Richard; Bae, Byunghoon; Zhong, Fang; Simcic, Jurij; Malone, Charles; Belousov, Anton; Belousov, Anton; Maiwald, Frank; Gonzales, Marianne; Homer, Margie; Diaz, Ernesto; Moore, Bradley; Nikolic, Dragan; Purcell, Richard; Oyake, Amalaye; Tillmans, Tina; Reichenbach, KelseyWe report on the scientific and engineering progress for the second technology demonstration unit (TDU2) of the Spacecraft Atmosphere Monitor (S.A.M.). The S.A.M. TDU2 is a compact gas chromatograph mass spectrometer (GCMS) for monitoring both the trace volatile organics and the major constituents in the astronaut cabin atmosphere. Progress on the micro electro-mechanical systems (MEMS) gas chromatograph is detailed, showing sensitivity and selectivity of the TDU2 analytical measurements. The TDU2 capabilities for monitoring the cabin air major constituents is also detailed, highlighting improvements from the first S.A.M. TDU instrument.