Browsing by Author "Gazda, Daniel"
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Item Assessment of Biocide Impacts on Life Support and Extravehicular Activity Architectures(50th International Conference on Environmental Systems, 7/12/2021) Abney, Morgan; McCarley, Kevin; Campbell, Colin; Callahan, Michael; Williams, Spencer; Gazda, Daniel; Montgomery, Eliza; Delzeit, Lance; Feather, MartinIodine has historically been used to minimize microbial growth in wetted portions of life support and Exploration Extravehicular Mobility Unit (xEMU) systems. Because of challenges with dormancy, the life support water processing team has baselined silver as a biocide for future Exploration missions, but continues to consider iodine, bromine, and chlorine as options. An assessment was conducted to identify and evaluate the trade space for implementation of various biocides in Lunar surface, Mars transit, and Martian surface vehicles. The team identified sixteen possible biocide sources for use in Exploration systems. An evaluation of the effects of each biocide on crew health, life support hardware, and xEMU hardware was conducted and resulted in eleven potential biocide architectures. Here we report the results of the architecture trade study and recommendations for future investigations.Item Assessment of Ethanol Trend on ISS(46th International Conference on Environmental Systems, 2016-07-10) Gazda, Daniel; McCoy, Torin; Limero, Thomas; Perry, Jay; Carter, Donald; Kayatin, MatthewThe International Space Station (ISS) Environmental Control and Life Support System (ECLSS) provides a working environment for 6 crew through atmosphere revitalization and water recovery systems. In the last year, elevated ethanol levels have presented a unique challenge for the ISS ECLSS. Ethanol is monitored on the ISS by the Air Quality Monitor (AQM). The source of this increase is not currently known though it does appear to correlate with vehicle docking. This paper documents the credible sources for the increased ethanol concentration, the monitoring provided by the AQM, and the impact on the atmosphere revitalization and water recovery systems.Item Changes in Chemical Composition of ISS Archive Water Samples from Collection to Analysis(49th International Conference on Environmental Systems, 2019-07-07) Wallace, William; Hudson, Edgar; Dunbar, Brandon; Hamilton, Tanner; Wallace, Sarah; Gazda, DanielAnalysis of archive water samples from the International Space Station provides important insight into the performance of the U.S. Water Processor Assembly (WPA). Ensuring the results from these samples accurately represent the chemical composition of the samples as collected on orbit is essential, as this data is used to make decisions regarding the use of on-orbit replacements for WPA components. Recently, samples of effluent from the Multifiltration (MF) beds were collected to determine if the expected breakthrough products (acetate/bicarbonate) were responsible for increased conductivity measured by in-line sensors. Initial results showed the presence of acetate, but the bicarbonate concentration was lower than expected based on the sensor readings, suggesting the possibility of CO2 diffusing through the sample bags. To assess this possibility, a second set of samples were collected in both the standard archive bags and smaller Teflon bags that were subsequently sealed in Mylar to minimize gas permeation. The MF bed 1 effluent sample collected in the standard bags showed breakthrough of a number of expected species, though many were present at lower than anticipated levels. Analysis of samples sealed in Mylar confirmed that gas diffusion had occurred in the standard bag, as the bicarbonate and conductivity readings were both higher than the standard bags. Interestingly, the acetate concentration was also significantly higher. A repeat analysis of the same sample aliquot performed to verify these findings showed no carboxylate species. A fresh aliquot obtained from the sample bag refrigerated in the Mylar pouch showed acetate results close to the original concentrations, but repeat analysis of this aliquot four days later showed no detectable carboxylates. Here, we will discuss efforts to understand the mechanisms that could lead to the compositional changes seen in the archive samples of MF bed effluent, which appear to be dependent on gas diffusion and temperature.Item Chemical Challenge Tests on ISS Fire Cartridges(2023 International Conference on Environmental Systems, 2023-07-16) Muko, Cristina; Beck, Steven; Wallace, William; Hudson, Edgar; Barrett, Lawrence; Korona, Adam; Williams, Spencer; Gazda, Daniel; Rabel, EmilyFollowing a confirmed combustion event onboard the International Space Station (ISS), crew members will don Emergency Masks, each fitted with 2 ISS fire cartridge filters. As the crew member breathes through the filters, combustion products in the cabin air are either filtered or catalyzed by the fire cartridge media to minimize crew exposure to harmful levels of contaminants. Rigorous certification, acceptance, and surveillance programs for the fire cartridges ensure that each lot meets stringent performance requirements throughout the service life of the cartridges. In accordance with the Quality/Acceptance Test Plan, multiple fire cartridges from each lot undergo chemical challenge tests involving one or more chemicals at specified concentrations. These tests are conducted at specific temperatures, humidity levels, and gas flow rates intended to mimic the worst-case conditions for fire cartridge performance. These challenge tests are conducted by the Environmental Chemistry Laboratory at the NASA Lyndon B. Johnson Space Center. Many of the challenge tests focus on carbon monoxide (CO), but other gases include hydrogen cyanide (HCN), hydrogen chloride (HCl), cyclohexane, acrolein, ammonia (NH3), and acetaldehyde. A fire cartridge is exposed to the test gas in a chamber at the specified conditions, and the outlet is monitored for breakthrough during the 2.5-hour test. This paper will briefly introduce fire cartridges and how they work and will then discuss details of the challenge gas delivery and exposure system, breakthrough monitoring methods, and discussion of issues that have arisen during the course of the test program. Although the focus of this paper will be on the challenge tests, a general summary of the performance of the fire cartridges will also be provided.Item Effects of Ambient Alcohol Levels on the Real-time Monitoring of the Atmosphere of the International Space Station(51st International Conference on Environmental Systems, 7/10/2022) Wallace, William; Limero, Thomas; Clark, Kenneth; Gazda, Daniel; Hudson, EdgarMonitoring of the spacecraft environment is required to ensure the health of the crew and the vehicle systems. For the ISS atmosphere, routine volatile organic compound (VOC) monitoring has been performed for almost a decade by Air Quality Monitors (AQMs). The target compounds measured by the AQMs include three types of chemicals: 1) those compounds that would be harmful to crew, 2) those compounds that have been detected regularly in archival samples, and 3) compounds that, while not necessarily harmful to crew health, could present problems for Environmental Control and Life Support Systems (ECLSS). Following the docking of SpaceX-Demo1 (SpX-DM1), the AQMs began to report high levels of isopropanol (IPA). While elevated IPA is routinely observed with visiting vehicles, the level measured by the AQM, and its continued presence following multiple days of scrubbing, caused concerns regarding the U.S. Water Recovery System. Following the departure of SpX-DM1, the IPA levels decreased to nominal levels, allowing the team to investigate the cause of the elevated measurements. Based on the changes in the shape of the gas chromatograph (GC) traces in the IPA region during docked operations, it appeared that an unknown coeluting species was causing problems with quantification. However, with the docking of Northrup-Grumman-11 (NG-11), the elevated IPA returned, as well as the changes in GC traces. In contrast to the SpX-DM1 results, the AQM IPA results did not return to nominal levels following the departure of NG-11, suggesting that the changes could not be tied directly to the visiting vehicle. In this paper, we will discuss a number of potential causes for both the genuine (measured in archival samples) increases in IPA as well as the much higher levels measured by the AQM. Additionally, we will discuss methods being explored to decrease the potential for a reoccurrence in the future.Item Effects of Ambient CO2 on Monitoring of the International Space Station Atmosphere with the Air Quality Monitor(48th International Conference on Environmental Systems, 2018-07-08) Wallace, William; Limero, Thomas; Gillispie, Robert; Gazda, DanielSince 2009, gas chromatography-differential mobility spectrometry (GC/DMS) has been used on-board the International Space Station (ISS) to monitor the atmosphere for volatile organic compounds. The technology was originally tested as part of a Station Detailed Test Objective (SDTO) and then transitioned to operational hardware. The operational version of this hardware, the Air Quality Monitor (AQM), currently monitors 22 compounds, though the target list is flexible and can be adjusted depending on changes in materials or the spacecraft environmental control systems. After separation on the GC column, target compounds are ionized via charge transfer from a Reactant Ion (RI). In the positive mode, H+(H2O)n is the RI while O2-(H2O)n acts as the RI in the negative mode. In the early stages of the SDTO, it was discovered that the position of the RI Peak (RIP) in the negative mode was shifting with time on orbit and the instrument was losing sensitivity to certain compounds. This shift of the RIP appeared to be correlated with increasing concentrations of CO2 in the recirculation system of the instrument. The operational version of the AQM uses larger, replaceable sieve packs to clean the recirculated carrier gas. It was hypothesized that incorporation of the large sieve packs would minimize the effect of CO2 on the position of the RIP. Unfortunately, this phenomenon has also been observed on the first two sets of AQMs that were operated on the ISS. In this paper, we will discuss the mechanisms behind the shifting RIP as well as the effects on the ionization of selected target compounds. Additionally, we will discuss potential approaches to mitigate the impact of the RIP shift and extend the current 6-month life of sieve packs on-orbit.Item Effects of Material Choice on Biocide Loss in Orion Water Storage Tanks(46th International Conference on Environmental Systems, 2016-07-10) Wallace, William; Castro-Wallace, Sarah; Kuo, C.K. Mike; Loh, Leslie; Hudson, Edgar; Gazda, Daniel; Lewis, JohnWhen preparing for long-duration spaceflight missions, maintaining a safe supply of potable water is of the utmost importance. One major aspect of that is ensuring that microbial growth is minimized. Historically, this challenge has been addressed through the use of biocides. When using biocides, the choice of materials for the storage containers is important, because surface reactions can reduce biocide concentrations below their effective range. In the water storage system baselined for the Orion vehicle, the primary wetted materials are stainless steel (316 L) and a titanium alloy (Ti6Al4V). Previous testing with these materials has shown that the biocide selected for use in the system (ionic silver) will plate out rapidly upon initial wetting of the system. One potential approach for maintaining an adequate biocide concentration is to spike the water supply with high levels of biocide in an attempt to passivate the surface. To evaluate this hypothesis, samples of the wetted materials were tested individually and together to determine the relative loss of biocide under representative surface area-to-volume ratios after 24 hours. Additionally, we have analyzed the efficacy of disinfecting a system containing these materials by measuring reductions in bacterial counts in the same test conditions. Preliminary results indicate that the use of titanium, either individually or in combination with stainless steel, can result in over 95% loss of biocide, while less than 5% is lost when using stainless steel. In bacterial testing, viable organisms were recovered from samples exposed to the titanium coupons after 24 hours. By comparison, no organisms were recovered from the test vessels containing only stainless steel. These results indicate that titanium, while possessing some favorable attributes, may pose additional challenges when used in water storage tanks with ionic silver biocide.Item Enhanced AQM: Development of an Exploration Compatible Air Quality Monitor(49th International Conference on Environmental Systems, 2019-07-07) Wallace, William; Limero, Thomas; Clark, Kenneth; Macatangay, Ariel; Mudgett, Paul; Gazda, DanielReal-time monitoring of volatile organic compounds (VOCs) on the International Space Station (ISS) is currently performed using a pair of Air Quality Monitors (AQMs), instruments that combine gas chromatography (GC) separation with differential mobility spectrometry (DMS) detection. Each AQM occupies a volume of approximately 4900 cm3 and has a mass of 3.7 kg. Each AQM also requires a power supply that is roughly the same size and mass. While these parameters do not present a concern on the ISS, they are too large for future exploration missions. The most obvious avenue for decreasing the size and mass of the AQMs lies in the reduction from two instruments and power supplies to a single unit and power supply. As currently configured, the required target VOCs cannot be successfully monitored on a single GC column, as the column cannot be cooled sufficiently to allow separation of early-eluting compounds. Here, we will show how limited method changes and additional cooling of the GC column can minimize the effects of compound coelution and allow all analytes to be monitored on a single AQM. We will also discuss other potential improvements that could increase the sensitivity and further reduce the size of an exploration-ready AQM.Item An Evaluation of Technology to Remove Problematic Organic Compounds from the International Space Station Potable Water(44th International Conference on Environmental Systems, 2014-07-13) Rector, Tony; Metselaar, Carol; Peyton, Barbara; Steele, John; Michalek, William; Bowman, Elizabeth; Wilson, Mark; Gazda, Daniel; Carter, LayneSince activation of the Water Processor Assembly (WPA) on the International Space Station (ISS) in November of 2008, there have been three events in which the TOC (Total Organic Carbon) in the product water has increased to approximately 3 mg/L and has subsequently recovered. Analysis of the product water in 2010 identified the primary component of the TOC as dimethylsilanediol (DMSD). An investigation into the fate of DMSD in the WPA ultimately determined that replacement of both Multifiltration (MF) Beds is the solution to recovering product water quality. The MF Beds were designed to ensure that ionic breakthrough occurs before organic breakthrough. However, DMSD saturated both MF Beds in the series, requiring removal and replacement of both MF Beds with significant life remaining. Analysis of the MF Beds determined that the adsorbent was not effectively removing DMSD, trimethylsilanol, various polydimethylsiloxanes, or dimethylsulfone. Coupled with the fact that the current adsorbent is now obsolete, the authors evaluated various media to identify a replacement adsorbent as well as media with greater capacity for these problematic organic contaminants. This paper provides the results and recommendations of this collaborative study.Item A Fast, Accurate and Sensitive GC-FID Method for the Analyses of Glycols in Water and Urine(47th International Conference on Environmental Systems, 2017-07-16) Kuo, Chung-Kung; Alverson, James; Gazda, DanielGlycols, specifically ethylene glycol and 1,2-propanediol, are some of the major organic compounds found in the humidity condensate samples collected on the International Space Station. The current analytical method for glycols is a GC/MS method with direct sample injection. This method is simple and fast, but it is not very sensitive. Reporting limits for ethylene glycol and 1,2-propanediol are only 1 ppm. A much more sensitive GC/FID method was developed, in which glycols were derivatized with benzoyl chloride for 10 minutes before being extracted with hexane. Using 1,3-propanediol as an internal standard, the detection limits for the GC/FID method for both glycols were determined to be 50 ppb and the analysis only takes 7 minutes. Data from the GC/MS and the GC/FID methods shows excellent agreement with each other. Factors affecting the sensitivity, including sample volume, NaOH concentration and volume, volume of benzoyl chloride, reaction time and temperature, were investigated. Interferences during derivatization and possible methods to reduce interferences were also investigated.Item NASA Environmental Control and Life Support Technology Development for Exploration: 2022-2023 Status(2023 International Conference on Environmental Systems, 2023-07-16) Schneider, Walter; Brown, Arthur; Allen, Chris; Barta, Daniel; Gazda, Daniel; McKinley, Melissa; Ridley, Alesha; Stambaugh, ImeldaNASA is pursing Environmental Control and Life Support technology developments and hardware upgrades to support Gateway, lunar surface, Mars transit, and Mars surface missions. This paper will highlight 2022-2023 progress of the technologies and how they are maturing on the path to ground testing and demonstration in microgravity. Technologies NASA is trading, new developments, and particular challenging issues will be highlighted. Technologies addressed in this paper are in the areas of atmosphere revitalization, water recovery and management, waste management, and environmental monitoring.Item Quantitation of Trace Water in ISS Atmosphere Samples Recovered from CO2-Removal Systems(51st International Conference on Environmental Systems, 7/10/2022) Beck, Steven; King, William; Muko, Cristina; Gazda, DanielAs crewed spaceflight continues to push the limits of exploration, instruments and hardware used to maintain and monitor crew and vehicle health must become more integrated, reliable, and efficient. By combining a carbon dioxide (CO2) removal system with a resource recovery system like a Sabatier or Bosch reactor, the waste gas from the removal system can be converted into valuable resources that help reduce reliance on ground resupply. Due to the high-pressure nature of the Sabatier and Bosch reactions, the vent gas from most CO2 removal systems will need to be compressed before it can be processed. In order to prevent condensation in the compressor of the recovery system, it is critical to ensure that the vent stream from the CO2 removal system does not contain an excess of water. There are currently three different CO2 removal systems that are being developed as candidates for exploration missions. Each of these systems will be evaluated as a technology demonstration on ISS, and vent gas samples will be collected in Summa sampling canisters fitted with Entech valves. Due to the need to measure low levels of water in these samples, it was not possible to use the current ISS miniature grab sample containers (GSCs) to collect these samples. The Summa containers, which were used to collect archive samples during Shuttle missions, have a different surface treatment that makes it possible to measure the low levels of water in samples collected in these containers. This paper will provide some background on the CO2 removal systems being evaluated for exploration missions as well as results from ground-based testing of the current miniature GSCs and Summa canisters. Details on the development of the analytical method and the plan for preparing the canisters that will be used for in-flight sampling are also discussed.Item Status of ISS Water Management and Recovery(47th International Conference on Environmental Systems, 2017-07-16) Carter, Donald; Brown, Chris; Bazley, Jesse; Gazda, Daniel; Takada, Kevin; Schaezler, RyanWater management on ISS is responsible for the provision of water to the crew for drinking water, food preparation, and hygiene, to the Oxygen Generation System (OGS) for oxygen production via electrolysis, to the Waste & Hygiene Compartment (WHC) for flush water, and for experiments on ISS. This paper summarizes water management activities on the ISS US Segment and provides a status of the performance and issues related to the operation of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of June 2017 and describes the technical challenges encountered and lessons learned over the past year.Item Status of ISS Water Management and Recovery(48th International Conference on Environmental Systems, 2018-07-08) Carter, Donald; Schaezler, Ryan; Williamson, Jill; Thomas, Alfred; Gazda, Daniel; Brown, Chris; Bazley, JesseWater management on ISS is responsible for the provision of water to the crew for drinking water, food preparation, and hygiene, to the Oxygen Generation System (OGS) for oxygen production via electrolysis, to the Waste & Hygiene Compartment (WHC) for flush water, and for experiments on ISS. This paper summarizes water management activities on the ISS US Segment and provides a status of the performance and issues related to the operation of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of June 2018 and describes the technical challenges encountered and lessons learned over the past year.Item Status of ISS Water Management and Recovery(49th International Conference on Environmental Systems, 2019-07-07) Carter, Layne; Williamson, Jill; Gazda, Daniel; Brown, Chris; Schaezler, Ryan; Thomas, Frank; Bazley, Jesse; Molina, SundayWater management on ISS is responsible for the provision of water to the crew for drinking water, food preparation, and hygiene, to the Oxygen Generation System (OGS) for oxygen production via electrolysis, to the Waste & Hygiene Compartment (WHC) for flush water, and for experiments on ISS. This paper summarizes water management activities on the ISS US Segment and provides a status of the performance and issues related to the operation of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of June 2019, describes the technical challenges encountered and lessons learned over the past year.Item Status of ISS Water Management and Recovery(46th International Conference on Environmental Systems, 2016-07-10) Carter, Donald; Schaezler, Ryan; Bankers, Lyndsey; Gazda, Daniel; Brown, Chris; Bazley, Jesse; Pruitt, JenniferWater management on ISS is responsible for the provision of water to the crew for drinking water, food preparation, and hygiene, to the Oxygen Generation System (OGS) for oxygen production via electrolysis, to the Waste & Hygiene Compartment (WHC) for flush water, and for experiments on ISS. This paper summarizes water management activities on the ISS US Segment and provides a status of the performance and issues related to the operation of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of June 2016 and describes the technical challenges encountered and lessons learned over the past year.