Browsing by Author "Carpenter, Joyce"
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Item Investigation of the Makeup, Source, and Removal Strategies for Total Organic Carbon in the Oxygen Generation System Recirculation Loop(45th International Conference on Environmental Systems, 2015-07-12) Bowman, Elizabeth M.; Carpenter, Joyce; Roy, Robert J.; Keuren, Steve Van; Wilson, Mark E.Since 2007, the Oxygen Generation System (OGS) on board the International Space Station (ISS) has been producing oxygen for crew respiration via water electrolysis. As water is consumed in the OGS recirculating water loop, make-up water is furnished by the ISS potable water bus. A rise in Total Organic Carbon (TOC) was observed beginning in February 2011, which continues through the present date. Increasing TOC is of concern because the organic constituents responsible for the TOC were unknown and had not been identified; hence their impacts on the operation of the electrolytic cell stack components and on microorganism growth rates and types are unknown. Identification of the compounds responsible for the TOC increase, their sources, and estimates of their loadings in the OGA as well as possible mitigation strategies are presented.Item Poisoning Evaluation of On-Orbit Sabatier Assembly(2020 International Conference on Environmental Systems, 2020-07-31) Carpenter, Joyce; Yu, Ping; Woods, Julius; Goberman, Daniel; Galvin, Lynda; Garr, John; Ulrich, BettyLynnThe Sabatier Assembly (SA) P/N SV1015510-1 was designed by Collins Aerospace to partially close the life support loop on ISS by reacting two waste gases (carbon dioxide and hydrogen) to form water (and waste methane). Waste CO2 is recovered from cabin air by the Carbon Dioxide Recovery Assembly (CDRA) and waste H2 comes from the Oxygen Generation System (OGS). By recycling these waste gases, this reduces the need to launch excess water, which is costly. The SA was successfully launched in 2010, and was in operation from June 2011 through October 2017. During that period of time, Sabatier produced 1081 liters of water. In 2018, the Sabatier on-orbit unit began to show significant signs of degradation in the reactor. To keep the system operating, this required increasingly involved procedures to restart the reaction after a shutdown. Eventually, the decision was made to shut down the Sabatier Assembly and to return it to Collins Aerospace for TT&E (Test, Teardown and Evaluation) with the goal of providing an upgraded system to support Exploration demonstration hardware on ISS. This paper reports the poisoning evaluation results of the catalyst reactor.