Browsing by Author "Neidholdt, Evan L."
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Item Developmental Hardware Testing Results and Forward Plans for the Spacecraft Water Impurity Monitor (SWIM) Organic Water Module (OWM)(2024 International Conference on Environmnetal Systems, 2024-07-21) Neidholdt, Evan L.; Pensinger, Stuart; Callahan, Michael; Madzunkov, Stojan; Nikolic, Dragan; Malone, Charles; Darrach,MurrayWe present testing results for developmental hardware of the Spacecraft Water Impurity Monitor (SWIM) Organic Water Module (OWM). SWIM-OWM will monitor spacecraft potable water and system water for trace organic contaminants. The system will detect and identify the specific organic chemical that makes up a given total organic carbon reading. We have built a first development unit (1DU) for SWIM-OWM, which directly injects aqueous water samples and detects chemicals with both a thermal conductivity detector and mass spectrometer sensor. The gas chromatography mass spectrometer (GCMS) system that comprises SWIM-OWM draws on the success of ISS-proven mass spectrometer hardware, and the demonstration of GCMS detection of trace organic contaminants in ISS cabin air. SWIM-OWM benefits from the excellent sensitivity and specificity afforded by GCMS. We have demonstrated detection of a set of chemicals relevant to both crew health and performance as well as system monitoring; these target chemicals range from light, volatile organics such as acetone and ethanol, to heavier, very non-volatile compounds such as dimethyl sulfone and o-phthalaldehyde. Direct aqueous injection was chosen for the general applicability of the technique to clean water sampling and to preclude sample pre-processing, which facilitates an on-line implementation of the SWIM-OWM when deployed in a spacecraft or habitation module. A specific advantage of direct aqueous injection when coupled with appropriate methods is that both the light, volatile organics and heavier non-volatiles can be detected from a single injection, in a single chromatogram. Results from 1DU testing will be discussed, and forward plans will be outlined for continued maturation of SWIM-OWM with the goal of implementing a technology demonstration for the purposes of maturing the engineering design and operations in an environment relevant to NASA�s future goals of exploring and setting up habitation on the Moon and Mars.Item Progress Report on the Spacecraft Atmosphere Monitor(46th International Conference on Environmental Systems, 2016-07-10) Madzunkov, Stojan; Bae, Byunghoon; Simcic, Jurij; Rellergert, Wade; Gill, John; Schaefer, Rembrandt; Neidholdt, Evan L.; Nikolic, Dragan; Kidd, Richard; Darrach, MurrayThe Spacecraft Atmosphere Monitor (SAM) is a miniature gas chromatograph mass spectrometer (GCMS) 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 SAM is a technology demonstration planned to launch in Feb 2018 and we report here on recent developments taking place in preparation for building an engineering model of the instrument. We have demonstrated successful micro-electro-mechanical system (MEMS) GC injection and its coupling to a quadrupole ion trap mass spectrometer (QITMS). The SAM 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 SAM instrument will provide on-demand reporting on trace volatile organic compounds (VOC) at ppm to ppb levels of 40+ species relevant for astronaut health.