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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Source Contaminant Control System Design, Operation, and Testing for the Trash Compaction and Processing System

The Trash Compaction and Processing System (TCPS) aims to reduce volume, biologically safen, physically stabilize, manage effluents, and recover resources from astronaut trash in the International Space Station (ISS). This process involves heating the trash to high temperatures, which in turn releases gaseous contaminants. Effluent management scenarios involve releasing these gases back to the ISS cabin after processing and/or directly venting these gases out to space via the Vacuum Exhaust System (VES). Concerns for recovering the gases back to cabin are crew health, safety, and spacecraft environmental impact. The Heat Melt Compactor (HMC) at NASA Ames Research Center (ARC) serves as a test system that supports TCPS development by conducting risk reduction activities associated with an ISS flight demonstration. Previous gas effluent studies were conducted on the HMC. The results consisted of contaminants from the trash exhaust to exceed Spacecraft Maximum Allowable Concentrations (SMAC), which are selected airborne contaminants that can elicit toxicity symptoms to crewmembers via exposure. The Source Contaminant Control System (SCCS) aims to reduce that risk by converting the contaminants into carbon dioxide (CO2) and water (H2O) vapor. The SCCS is composed of a carbon adsorbent bed, to avoid catalyst poisoning, and a catalytic oxidizer (CatOx), which promotes oxidation of the contaminants to CO2 and H2O. In turn, the gases coming out of the SCCS should be compatible to the ISS cabin and systems such as the Trace Contaminant Control System (TCCS). Preparation for SCCS testing alongside the HMC Gen 3 are currently underway at ARC. The main objectives are to evaluate CatOx efficiency by CO2 conversion and characterize effectiveness of removal by comparing contaminant results before and after CatOx. This paper will report on the SCCS design, operation, and testing with results.

Janine Young↗
NASA NTRS2013

JPL Contamination Control Engineering

JPL has extensive expertise fielding contamination sensitive missions-in house and with our NASA/industry/academic partners.t Development and implementation of performance-driven cleanliness requirements for a wide range missions and payloads - UV-Vis-IR: GALEX, Dawn, Juno, WFPC-II, AIRS, TES, et al - Propulsion, thermal control, robotic sample acquisition systems. Contamination control engineering across the mission life cycle: - System and payload requirements derivation, analysis, and contamination control implementation plans - Hardware Design, Risk trades, Requirements V-V - Assembly, Integration & Test planning and implementation - Launch site operations and launch vehicle/payload integration - Flight ops center dot Personnel on staff have expertise with space materials development and flight experiments. JPL has capabilities and expertise to successfully address contamination issues presented by space and habitable environments. JPL has extensive experience fielding and managing contamination sensitive missions. Excellent working relationship with the aerospace contamination control engineering community/.

Molecular Contamination Spectral Effects (MCSE) Ch↗
DOE OSTI2025

Development of the Contamination Distribution Centered Toxics Mobility Vulnerability Index in the Beaumont–Port Arthur Region of Texas

This study advances the Toxics Mobility Inventory (TMI) and the Toxics Mobility Vulnerability Index (TMVI) to develop a new tool to assess the movement of hazardous substances and their implications for vulnerable communities. It emphasizes the need to include contamination distribution variables in such indices to address disproportionate impacts and more accurately reflect vulnerability. The study uses the TMI framework and TMVI methodology in the Beaumont–Port Arthur region of Texas, also integrating contamination distribution considerations into the analysis to develop a new framework and process. The new Contamination Distribution Centered Toxics Mobility Vulnerability Index (CDC-TMVI) consolidates climate change and topography variables into a broader built environment vulnerability category while introducing a contamination sources category. Using ArcGIS Pro and ToxPi tools, the study evaluates 27 geospatial variables across four categories: built environment vulnerability, social vulnerability, health outcomes, and contamination sources. The results indicate significant contributions from contamination and social vulnerability variables, highlighting areas with higher risks of flooding and air pollution. This article advocates for future research and policy efforts to enhance the integration of contamination sources and their spatial distributions into toxics mobility assessments to better protect vulnerable populations. Furthermore, the unique methodology and findings serve as a basis for developing targeted measures and strategic planning to improve environmental health.

contamination↗
NASA NTRS2024

Contamination Results of MISSE 8 Wake and Nadir Samples After 2 Years of Space Exposure on the International Space Station

Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet, x-ray and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen. In addition, on-orbit spacecraft contamination is a serious spaceflight issue, with silicone contamination being a particular concern. In an effort to understand on-orbit contamination of Materials International Space Station Experiment 8 (MISSE 8) flight samples and other International Space Station (ISS) payloads, contamination studies were conducted post-flight on retrieved Teflon fluorinated ethylene propylene (FEP) samples flown in the wake and nadir orientations on MISSE 8. The wake sample was Teflon FEP (M8-W11) flown as part of the Glenn MISSE 8 Polymers Experiment on the Optical Reflector Materials Experiment-III Ram/Wake (ORMatE-III R/W) tray and exposed to the LEO wake environment for 2.0 years. The nadir samples were silver-Teflon FEP radiator pieces taken from the MISSE 8 Single Events Upset Xilinx-Sandia Experiment II (SEUXSE II) Power Box and exposed to the LEO nadir environment for 2.14 years. The Teflon FEP flight materials were analyzed for changes in surface morphology and chemistry as compared to pristine control samples. The wake samples were also analyzed for changes in optical properties. There was no evidence of a molecular contamination layer present on the surface of the MISSE 8 wake or nadir facing Teflon FEP flight samples, although both the wake and nadir flight samples contained particulate contamination in some regions. The analyzed nadir particles were primarily zinc rich. The majority of analyzed wake particles were comprised of oxidized aluminum with small amounts of zinc and magnesium. The wake particles appear to have arrived early in the mission (or pre-flight) during a single event. This paper provides details of the MISSE 8 sample contamination analyses.

Erosion↗
DOE OSTI2026

Solvent-mediated contaminant removal from plastic waste using thermodynamic modeling

Plastics recycling is hindered by the compositional complexity of plastic waste, which can include numerous polymer components as well as low concentrations of additives and non-intentionally added substances. These latter small-molecule species, which we collectively refer to as contaminants, can harm human health and will build up in recycled plastic causing environmental and downstream processing challenges if not removed. In this work, we present molecular modeling approaches using the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) to guide the selection of solvents that are capable of removing targeted contaminants from plastic waste. By considering the thermodynamic partitioning of contaminant species between a solvent phase and polymer phase, we identify guidelines for solvent selection to promote either the low-temperature extraction of contaminants from plastic waste or the removal of contaminants as part of a dissolution-based plastics recycling process. We present four case studies to illustrate the application of the computational approach to the removal of brominated flame retardants, phthalates, and selected perfluoroalkyl substances, and compare to both literature and newly collected experimental data to illustrate model prediction accuracy. Furthermore, the case studies highlight the capability of the modeling approach to help design recycling processes that explicitly account for contaminant removal, thereby increasing product purity during dissolution-based recycling or facilitating chemical recycling of contaminant-free plastics.

Zhou, Panzheng [University of, Wisconsin, Madison,↗
DOE OSTI2025

Accumulation of trace elements in soil and fauna within a site historically contaminated with coal combustion residues

Legacy contaminants tied to energy production are a worldwide concern. Coal combustion residues (CCRs) contain high concentrations of potentially toxic trace elements such as arsenic (As), mercury (Hg), and selenium (Se), which can persist for decades after initial contamination. Coal combustion residue disposal methods, including aquatic settling basins and landfills, can facilitate environmental exposure through intentional and accidental releases. Wildlife exposed to CCRs can experience numerous deleterious effects, such as on development, reproduction, and survival. In the current study, we quantified and compared concentrations of As, Hg, Se, and strontium (Sr) within soils and target fauna (three vertebrate and three invertebrate taxa) from a CCR-contaminated site and a reference site within the U.S. Department of Energy’s Savannah River Site, South Carolina, United States. Our objectives were to (1) compare current concentrations of tested elements in soil and resident fauna to levels from our reference site, (2) assess natural attenuation of elements in soils by comparing current concentrations to historic levels, and (3) evaluate the biomagnification potential of the elements measured via body burden and trophic position correlations among fauna. Here, element concentrations were higher in contaminated soils than reference soils; however, concentrations in 2022 were unchanged from concentrations measured in 2003, suggesting no natural attenuation of tested elements. Additionally, target fauna had elevated As, Se, and Sr levels in comparison to reference samples. A positive correlation was observed in southern toads between Sr concentrations and trophic position, as assessed by nitrogen stable isotope ratios, suggesting potential for biomagnification of Sr within our study system. Collectively, our results demonstrate that legacy contaminants are still present and bioaccumulate in a diversity of taxa in a CCR-contaminated site that has not received effluents in more than 50 years, suggesting monitoring programs in CCR-contaminated sites should be maintained long term in the absence of remediation.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗
DOE OSTI2024

Performance Losses and Current-Driven Recovery from Cation Contaminants in PEM Water Electrolysis

Water contaminants are a common cause of failure for polymer electrolyte membrane (PEM) electrolyzers in the field as well as a confounding factor in research on cell performance and durability. In this study, we investigated the performance impacts of feed water containing representative tap water cations at concentrations ranging from 0.5–500 μ M, with conductivities spanning from ASTM Type II to tap-water levels. We present multiple diagnostic signatures to help identify the presence of contaminants in PEM electrolysis cells. Through analysis of polarization curves and impedance spectroscopy to understand the origins of performance losses, we found that a switch from the acidic to alkaline hydrogen evolution mechanism is a key factor in contaminated cell behavior. Finally, we demonstrated that this mechanism switching can be harnessed to remove cation contaminants and recover cell performance without the use of an acid wash. We demonstrated near-complete recovery of cells contaminated with sodium and calcium, and partial recovery of a cell contaminated with iron, which was further investigated by post-mortem microscopy. The improved understanding of contaminant impacts from this work can inform development of strategies to mitigate or recover performance losses as well as improve the consistency and rigor of electrolysis research.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2025

A Murine Model of Radionuclide Lung Contamination for the Evaluation of Americium Decorporation Treatments

The hydroxypyridinone ligand 3,4,3-LI(1,2-HOPO) (HOPO), has been previously characterized as a promising chelating agent for in vivo decorporation of actinides, with decorporation being the removal of internally deposited contaminants from the body after exposure. The large majority of relevant literature reports have detailed the efficacy profile of HOPO as a decorporation agent in rodent models, where controlled radionuclide contamination is conducted via intravenous injection. However, this method of contamination does not necessarily reflect an accurate predictive model of the most probable biodistribution of free metal in the body. In the event of a radiological dispersal device or nuclear power plant accident scenario, it is most likely that first responders, military personnel, and victims of the event will be contaminated via air and water transmission. Therefore, research into the efficacy of chelating agents to treat lung-contaminated in vivo models needs to be carried out. Here, we establish a murine model with controlled, reproducible lung contamination using two different radionuclides, 89Zr and 241Am, for orthogonal biodistribution validation by positron emission tomography and ex vivo radioanalysis, respectively. In addition, we report effective chelation treatment of 241Am-contaminated lungs using HOPO, which improves decorporation by up to 40% compared to Ca-DTPA, the current standard of care.

Arino, Trevor↗
NASA NTRS1971

Active cleaning technique for removing contamination from optical surfaces in space

Plasma cleaning experiments were completed on hydrocarbon contaminant films, experiments were initiated to determine a satisfactory technique for depositing contaminant films, and an experiment was conducted to determine whether specimens are being thermally cleaned rather than plasma cleaned. Results of plasma cleaning experiments on hydrocarbon contaminant films showed that the optical properties of mirrors and gratings could be satisfactorily restored. Results on fused silica optical flats were inconclusive because of the insensitivity of measurement techniques to the contaminant films. White thermal control surfaces, degraded by the hydrocarbon contaminant film, could not be restored by oxygen plasma exposure. The reflectance of silvered FEP Teflon thermal control surfaces could be restored by plasma cleaning. Experiments with a silicone contaminant indicated that it could not be easily polymerized onto surfaces with ultraviolet radiation. Results of the thermal cleaning experiment showed that the polymerized hydrocarbon contaminant film could not be removed by heating in vacuum to a temperature in excess of that expected during plasma cleaning.

Gillette, R. B.↗
NASA NTRS1975

Payload/orbiter contamination control requirement study

The results of a contamination impact analysis upon the spacelab carrier and the spacelab carrier upon some of its potential payloads are presented. These results are based upon contamination computer modeling techniques developed to predict the induced environment for spacelab and to provide the basis for evaluation of the predicted environment against the current on orbit contamination control criteria as specified for payloads. Those spacelab carrier contamination sources evaluated against the stated contamination control criteria were outgassing/offgassing of the major nonmetallic thermal control coating of the spacelab carriers, spacelab core and experiment module and tunnel cabin atmosphere leakage, avionics bay vent, spacelab condensate vent, random particulate sloughing, and the return flux of the molecular content of these sources from the gas-gas interactions with the ambient orbital environment. It is indicated that the spacelab carrier can meet the intent of the contamination control criteria through incorporating known contamination control practices.

Bareiss, L. E.↗
NASA NTRS1983

Spacecraft contamination environment; Proceedings of the Meeting, Arlington, VA, May 4-6, 1982

Aspects of IECM debriefing are considered, taking into account preliminary results of the induced environment contamination monitor measurements of STS-2, the humidity monitor and dew point hygrometer, the induced environment contamination monitor cascade impactor, the optical effects module and passive sample array, temperature-controlled quartz crystal microbalance measurements on STS-2, camera/photometer results, the mass spectrometer, and a summary regarding the induced environment contamination monitor/space transport system. Other subjects explored are related to contamination management and control, contamination/optical degradation, and contamination assessments and measurements. Attention is given to approaches for controlling contamination before launch, the coronagraph as the ultimate device to monitor orbiting particulates in the Space Transport System environment, and the contamination sensitivity of typical mirror coatings.

Maag, C. R.↗
NASA NTRS1983

Contamination control plan for prelaunch operations

A unified, systematic plan is presented for contamination control for space flight systems. Allowable contaminant quantities, or contamination budgets, are determined based on system performance margins and system-level allowable degradations. These contamination budgets are compared to contamination rates in ground environments to establish the controls required in each ground environment. The use of feedback from contamination monitoring and some contamination control procedures are discussed.

Austin, J. D.↗
NASA NTRS1987

Contamination assessment for OSSA space station IOC payloads

The results are presented from a study for the Space Station Planners Group of the Office of Space Sciences and Applications. The objectives of the study are: (1) the development of contamination protection requirements for protection of Space Station attached payloads, serviced payloads and platforms; and (2) the determination of unknowns or major impacts requiring further assessment. The nature, sources, and quantitative properties of the external contaminants to be encountered on the Station are summarized. The OSSA payload contamination protection requirements provided by the payload program managers are reviewed and the level of contamination awareness among them is discussed. Preparation of revisions to the contamination protection requirements are detailed. The comparative impact of flying the Station at constant atmospheric density rather than constant altitude is assessed. The impact of the transverse boom configuration of the Station on contamination is also assessed. The contamination protection guidelines which OSSA should enforce during their development of payloads are summarized.

Chinn, S.↗
NASA NTRS1988

WF/PC internal molecular contamination during system thermal-vacuum test

During the recent system thermal vacuum test of the Wide-Field/Planetary Camera (WF/PC), instrumentation was added to the WF/PC to characterize the internal molecular contamination and verify the instrument throughput down to 1470 angstroms. Analysis of data elements revealed two contaminants affecting the far-ultraviolet (FUV) performance of the WF/PC. The one contaminant (heavy volatile) is correlated with the electronic and housing temperature, and the contamination is significantly reduced when the electronics are operated below plus 8 degrees to plus 10 degrees C. The other contaminant (light volatile) is controlled by the heat pipe temperature, and the contamination is significantly reduced when the Thermal Electric Cooler (TEC) hot-junction temperature is below minus 40 degrees to minus 50 degrees C. The utility of contamination sensors located behind instruments during system tests was demonstrated.

Taylor, Daniel M.↗
NASA NTRS1991

Contamination effects on Space Station Freedom electric power system performance

One design issue for Space Station Freedom (SSF) is the potential performance decrease of the electric power system (EPS) solar arrays and radiators as a result of contamination on sensitive surfaces. The authors discuss SSF potential contamination sources and contamination effects on the solar array and radiator performance due to these sources. With these contamination consideration, the SSF EPS is designed for the induced contamination environment at an optimal cost. The efforts on contamination protection and control are undergoing continual update because of the changes in the SSF configuration and in the contamination requirements, and observations from recent flight and laboratory test data are continuously being incorporated into the design.

Lu, Cheng-Yi↗
NASA NTRS1993

Spacecraft contamination issues from LDEF: Issues for design

Many contamination sources have been identified on the Long Duration Exposure Facility (LDEF). Effects of contamination from these sources are being quantified and have been reported on in several papers. For a designer, the essential question is how much contamination from all sources can be tolerated without causing a given spacecraft system to degrade below a critical performance level, or fail altogether. Even a rudimentary knowledge of the mechanisms by which molecular and particulate contamination can occur will allow simple design options to be chosen to circumvent potential contamination problems and reduce contamination levels. Because of the varied nature and condition of hardware used on LDEF experiments, examples of many types of contamination were seen and these provide a useful guide to expected performance of many types of materials in space environments.

Pippin, Gary↗
NASA NTRS1994

Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces

For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.

Dever, Joyce A.↗
NASA NTRS1994

Study on contaminants on flight and other critical surfaces

The control of surface contamination in the manufacture of space hardware can become a critical step in the production process. Bonded surfaces have been shown to be affected markedly by contamination. It is important to insure surface cleanliness by preventing contamination prior to bonding. In this vein techniques are needed in which the contamination which may affect bonding are easily found and removed. Likewise, if materials which are detrimental to bonding are not easily removed, then they should not be used in the manufacturing process. This study will address the development of techniques to locate and quantify contamination levels of particular contaminants. With other data becoming available from MSFC and its contractors, this study will also quantify how certain contaminants affect bondlines and how easily they are removed in manufacturing.

Workman, Gary L.↗