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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 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Evaluation of coated columbian alloy heat shields for space shuttle thermal protection system application. Volume 1: Phase 1 - Environmental criteria and material characterization, October 1970 - March 1972

The studies presented are directed toward establishing criteria for a niobium alloy thermal protection system for the space shuttle. Evaluation of three niobium alloys and two silicon coatings for heat shield configurations culminated in the selection of two coating/substrate combinations for environmental criteria and material characterization tests. Specimens were exposed to boost and reentry temperatures, pressure, and loads simulating a space shuttle orbiter flight profile.

Black, W. E.↗
NASA NTRS2002

Thermal Cyclic Behavior of Thermal and Environmental Barrier Coatings Investigated Under High-Heat-Flux Conditions

Environmental barrier coatings (EBC's) have been developed to protect silicon-carbide- (SiC) based ceramic components in gas turbine engines from high-temperature environmental attack. With continuously increasing demands for significantly higher engine operating temperature, future EBC systems must be designed for both thermal and environmental protection of the engine components in combustion gases. In particular, the thermal barrier functions of EBC's become a necessity for reducing the engine-component thermal loads and chemical reaction rates, thus maintaining the required mechanical properties and durability of these components. Advances in the development of thermal and environmental barrier coatings (TBC's and EBC's, respectively) will directly impact the successful use of ceramic components in advanced engines. To develop high-performance coating systems, researchers must establish advanced test approaches. In this study, a laser high-heat-flux technique was employed to investigate the thermal cyclic behavior of TBC's and EBC's on SiC-reinforced SiC ceramic matrix composite substrates (SiC/SiC) under high thermal gradient and thermal cycling conditions. Because the laser heat flux test approach can monitor the coating's real-time thermal conductivity variations at high temperature, the coating thermal insulation performance, sintering, and delamination can all be obtained during thermal cycling tests. Plasma-sprayed yttria-stabilized zirconia (ZrO2-8 wt% Y2O3) thermal barrier and barium strontium aluminosilicate-based environmental barrier coatings (BSAS/BSAS+mullite/Si) on SiC/SiC ceramic matrix composites were investigated in this study. These coatings were laser tested in air under thermal gradients (the surface and interface temperatures were approximately 1482 and 1300 C, respectively). Some coating specimens were also subject to alternating furnace cycling (in a 90-percent water vapor environment at 1300 C) and laser thermal gradient cycling tests (in air), to investigate the water vapor effect. All cyclic tests were conducted using a 60-min hot-time temperature.

Zhu, Dongming↗
NASA NTRS2007

Crew Exploration Vehicle Environmental Control and Life Support Fire Protection Approach

As part of preparing for the Crew Exploration Vehicle (CEV), the National Aeronautics and Space Administration (NASA) worked on developing the requirements to manage the fire risk. The new CEV poses unique challenges to current fire protection systems. The size and configuration of the vehicle resembles the Apollo capsule instead of the current Space Shuttle or the International Space Station. The smaller free air volume and fully cold plated avionic bays of the CEV requires a different approach in fire protection than the ones currently utilized. The fire protection approach discussed in this paper incorporates historical lessons learned and fire detection and suppression system design philosophy spanning from Apollo to the International Space Station. Working with NASA fire and materials experts, this approach outlines the best requirements for both the closed out area of the vehicle, such as the avionics bay, and the crew cabin area to address the unique challenges due to the size and configuration of the CEV.

Lewis, John F.↗
NASA NTRS2014

Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

Research efforts are under way to replace current corrosion inhibitors with more environmentally friendly alternatives. However, problems with corrosion inhibition efficiency, coating compatibility and solubility have hindered the use of many of these materials as simple pigment additives.This paper will present technical details on how the Corrosion Technology Lab at NASAs Kennedy Space Center (KSC) has addressed these issues by encapsulating environmentally friendly inhibitors into organic and inorganic microparticles and microcapsules. The synthetic process for polymer particles was characterized and post-synthesis analysis was performed to determine the interactions between the inhibitors and the encapsulation material. The pH-controlled release of inhibitors from various particle formulations in aqueous base was monitored and compared to both electrochemical and salt immersion accelerated corrosion experiment. Furthermore, synergistic corrosion inhibition effects observed during the corrosion testing of several inhibitor combinations will be presented.

Environmentally Friendly↗
NASA NTRS2016

Weathering the Storm: Unmanned Aircraft Systems in the Maritime, Atmospheric and Polar Environments

Unmanned systems have the potential to efficiently, effectively, economically, and safely bridge critical observation requirements in an environmentally friendly manner. As the United States Atmospheric, Marine and Arctic areas of interest expand and include hard-to-reach regions of the Earth (such as the Arctic and remote oceanic areas) optimizing unmanned capabilities will be needed to advance the United States science, technology and security efforts. Through increased multi-mission and multi-agency operations using improved inter-operable and autonomous unmanned systems, the research and operations communities will better collect environmental intelligence and better protect our country against hazardous weather, environmental, marine and polar hazards. This presentation will examine UAS (Unmanned Aircraft Systems) operations which includes developing a coordinated effort to maximize the efficiency and capabilities of unmanned systems across the federal government and research partners. Numerous intra- and inter-agency operational demonstrations and assessments have been made to verify and validated these UAS observations. The NASA-specific elements will consist of an overview of NASA UAVs (Unmanned Aerial Vehicles) available to science and recent missions.

Atmospheric↗
NASA NTRS2015

Superhydrophobic Post Treatment and Coating Extenders for Improved Asset Sustainability

Launch structures, hardware, and ground support equipment, at NASA's John F. Kennedy Space Center in Florida, are exposed to a highly corrosive natural coastal marine environment. In addition, during launches, rocket exhaust deposition is also highly corrosive. Superhydrophobic coatings are being considered for additional corrosion protection on existing structures to enhance corrosion resistance and add an additional layer of protection against harsh environmental elements. These coatings have come into their own recently, and are now being investigated as corrosion protective coatings due to their water repelling capability. These coatings can be used on existing coatings, newly coated materials, or used on bare substrates. The coatings are not suitable for permanent corrosion protection, but can be used where additional corrosion control is desired or only when temporary corrosion control is needed, such as in hardware sitting on a launch pad for 30-45 days prior to a launch. In this study, superhydrophobic coatings were applied on various coated and uncoated substrates and exposed to the spaceport environment for various times up to 60 days. This paper highlights the current results of the superhydrophobic coatings performance evaluated by X-ray photoelectron spectroscopy, and contact angle measurements.

Coating↗
DOE OSTI2025

A mechanistic study on environment gas in laser powder bed fusion

A variety of protective or reactive environmental gases have recently gained growing attention in laser-based metal additive manufacturing (AM) technologies due to their unique thermophysical properties and the potential improvements they can bring to the build processes. However, much remains unclear regarding the effects of different gas environments on critical phenomena in laser AM, such as rapid cooling, energy coupling, and defect generation. Through simultaneous high-speed synchrotron x-ray imaging and thermal imaging, we identify distinct effects of two environmental gases in laser AM and gained a deeper understanding of the underlying mechanisms. Compared to the commonly used protective gas, argon, it is found that helium has a negligible effect on cooling the part. However, helium can suppress unstable keyholes by decreasing effective energy absorption, thus mitigating keyhole porosity generation and reducing pore size under certain processing conditions. In conclusion, these observations provide guidelines for the strategic use of environmental gases in laser AM to produce parts with improved quality.

36 MATERIALS SCIENCE↗
NASA NTRS2014

NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

Corrosion is the degradation of a material that results from its interaction with the environment. The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the United States. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the 70 tons of highly corrosive hydrochloric acid that were generated by the solid rocket boosters. Numerous failures at the launch pads are caused by corrosion.The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. As a result of fifty years of experience with launch and ground operations in a natural marine environment that is highly corrosive, NASAs Corrosion Technology Laboratory at KSC is a major source of corrosion control expertise in the launch and other environments. Throughout its history, the Laboratory has evolved from what started as an atmospheric exposure facility near NASAs launch pads into a world-wide recognized capability that provides technical innovations and engineering services in all areas of corrosion for NASA and external customers.This presentation will provide a historical overview of the role of NASAs Corrosion Technology in anticipating, managing, and preventing corrosion. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

Corrosion↗
DOE OSTI2022

Comparison of 200-IA-1 Operable Unit Soil Concentrations to Preliminary Remediation Goals Protective of Groundwater

This environmental calculation file (ECF) documents the methodology used to determine if current site conditions for the representative waste sites assigned to the 200-IA-1 Operable Unit (OU) based on available sample results are greater than the 200 East or 200 West unit-length preliminary remediation goals (PRGs) for the protection of groundwater.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2014

A Five-year Performance Study of Low VOC Coatings over Zinc Thermal Spray for the Protection of Carbon Steel at the Kennedy Space Center

The launch facilities at the Kennedy Space Center (KSC) are located approximately 1000 feet from the Atlantic Ocean where they are exposed to salt deposits, high humidity, high UV degradation, and acidic exhaust from solid rocket boosters. These assets are constructed from carbon steel, which requires a suitable coating to provide long-term protection to reduce corrosion and its associated costs. While currently used coating systems provide excellent corrosion control performance, they are subject to occupational, safety, and environmental regulations at the Federal and State levels that limit their use. Many contain high volatile organic compounds (VOCs), hazardous air pollutants, and other hazardous materials. Hazardous waste from coating operations include vacuum filters, zinc dust, hazardous paint related material, and solid paint. There are also worker safety issues such as exposure to solvents and isocyanates. To address these issues, top-coated thermal spray zinc coating systems were investigated as a promising environmentally friendly corrosion protection for carbon steel in an acidic launch environment. Additional benefits of the combined coating system include a long service life, cathodic protection to the substrate, no volatile contaminants, and high service temperatures. This paper reports the results of a performance based study to evaluate low VOC topcoats (for thermal spray zinc coatings) on carbon steel for use in a space launch environment.

Zinc Thermal Spray↗
NASA NTRS2014

Dissertation Defense: Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems

Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional validation by test only mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions.Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations. This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions. The method accounts for all uncertainty terms from both numerical and input variables. Objective three is to compile a table of uncertainty parameters that could be used to estimate the error in a Computational Fluid Dynamics model of the Environmental Control System spacecraft system.Previous studies have looked at the uncertainty in a Computational Fluid Dynamics model for a single output variable at a single point, for example the re-attachment length of a backward facing step. For the flow regime being analyzed (turbulent, three-dimensional, incompressible), the error at a single point can propagate into the solution both via flow physics and numerical methods. Calculating the uncertainty in using Computational Fluid Dynamics to accurately predict airflow speeds around encapsulated spacecraft in is imperative to the success of future missions.

Fluid Dynamics↗
NASA NTRS2014

Dissertation Defense Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems

Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional "validation by test only" mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions. The method accounts for all uncertainty terms from both numerical and input variables. Objective three is to compile a table of uncertainty parameters that could be used to estimate the error in a Computational Fluid Dynamics model of the Environmental Control System /spacecraft system. Previous studies have looked at the uncertainty in a Computational Fluid Dynamics model for a single output variable at a single point, for example the re-attachment length of a backward facing step. For the flow regime being analyzed (turbulent, three-dimensional, incompressible), the error at a single point can propagate into the solution both via flow physics and numerical methods. Calculating the uncertainty in using Computational Fluid Dynamics to accurately predict airflow speeds around encapsulated spacecraft in is imperative to the success of future missions.

CFD↗
NASA NTRS2013

Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems

Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This proposal describes an approach to validate the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft. The research described here is absolutely cutting edge. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional"validation by test only'' mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computationaf Fluid Dynamics can be used to veritY these requirements; however, the model must be validated by test data. The proposed research project includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT and OPEN FOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid . . . Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions. The method accounts for all uncertainty terms from both numerical and input variables. Objective three is to compile a table of uncertainty parameters that could be used to estimate the error in a Computational Fluid Dynamics model of the Environmental Control System /spacecraft system. Previous studies have looked at the uncertainty in a Computational Fluid Dynamics model for a single output variable at a single point, for example the re-attachment length of a backward facing step. To date, the author is the only person to look at the uncertainty in the entire computational domain. For the flow regime being analyzed (turbulent, threedimensional, incompressible), the error at a single point can propagate into the solution both via flow physics and numerical methods. Calculating the uncertainty in using Computational Fluid Dynamics to accurately predict airflow speeds around encapsulated spacecraft in is imperative to the success of future missions.

Groves, Curtis E.↗
NASA NTRS1978

Helicopter external noise requirements: FAA perspective

Enactment of helicopter noise certification standards for the control of noise impact contributing to community annoyance is considered in terms of the development of helicopters as an environmentally compatible air transportation mode. Increased use of helicopters for commercial applications and public awareness of aircraft noise are cited as factors making development of helicopter noise standards necessary both for the protection of the environmental interest of the community and to ensure the orderly growth of the helicopter industry itself. Noise sources, technology trends in helicopter design, and design concepts to control helicopter noise are discussed along with the regulatory background and specific helicopter regulatory concepts.

Foster, C. R.↗
NASA NTRS2010

Planetary Protection Considerations for Life Support and Habitation Systems

Life support systems for future human missions beyond low Earth orbit may include a combination of existing hardware components and advanced technologies. Discipline areas for technology development include atmosphere revitalization, water recovery, solid waste management, crew accommodations, food production, thermal systems, environmental monitoring, fire protection and radiation protection. Life support systems will be influenced by in situ resource utilization (ISRU), crew mobility and the degree of extravehicular activity. Planetary protection represents an additional set of requirements that technology developers have generally not considered. Planetary protection guidelines will affect the kind of operations, processes, and functions that can take place during future exploration missions, including venting and discharge of liquids and solids, ejection of wastes, use of ISRU, requirements for cabin atmospheric trace contaminant concentrations, cabin leakage and restrictions on what materials, organisms, and technologies that may be brought on missions. Compliance with planetary protection requirements may drive development of new capabilities or processes (e.g. in situ sterilization, waste containment, contaminant measurement) and limit or prohibit certain kinds of operations or processes (e.g. unfiltered venting). Ultimately, there will be an effect on mission costs, including the mission trade space. Planetary protection requirements need to be considered early in technology development programs. It is expected that planetary protection will have a major impact on technology selection for future missions.

Barta, Daniel J.↗
NASA NTRS2009

The Crop Evaluation Research for Environmental Strategies (CERES) Remote Sensing 2008 Project Activities

In recent years, the use of Plant Incorporated Protectant (PIP) corn by American producers has been increasing dramatically. PIP corn contains genetically inserted traits that produce toxins in the plant that provide narrowly targeted protection against specific insect pests. The plant producing t oxms can offer significant reductions in the application of broad -spectrum pesticides that have ecological and human health consequences. PIP corn as a percentage of total corn acreage planted in the US is expected to continue to increase as these protective traits are "stacked" with other desirable traits by seed companies, and producers are seeing considerable increases in corn yield as a result. The introduction of corn as a bio-fuel source for ethanol has increased production by over 6 million hectares in 2007. The United States Environmental Protection Agency (USEPA), which is responsible for the registration of PIP crops under the Federal Insecticide, Fungicide and Rodenticide Act, views the use of PIP corn as positive. Broad spectrum pesticide use has declined since the PIP traits have been introduced. As the agricultural landscape sees a higher percentage of corn acres using the PIP technology, the risk of the targeted insect pest populations developing resistance to the toxins, thereby rendering the in will increase as well. This result would negate the effectiveness of the PIP corn traits and could reduce production of a US field corn crop valued at $33 billion dollars in 2006 and place US food and now energy security at risk. Concerns over insect pest resistance development to PIP traits have led the USEPA to team with NASA and the Institute for Technology Development (ITD) to develop geo-spatial technologies designed to proactively monitor the corn production landscape for insect pest infestation and possible resistance development. USEPA resistance management simulation models are combined with NASA remote sensi ng products to monitor the corn landscape for resistance development. The two agencies have entered into an agreement which could potentially lead to the development of next generation NASA sensors that will more specifically address the requirements of the USEPA's resistance development strategy and offer opportunities to study the ever changing ecosystem complexities. The USEPA/NASA/ITD team has developed a broad research project entitled CERES (Crop Evaluation Research for Environmental Strategies). CERES is a research effort leading to decision support system tools that are designed to integrate multi-resolution NASA remote sensing data products and USEPA geo -spatial models to monitor the potential for insect pest resistance development from the regional to the landscape and then to the field level.

Casas, Joseph C.↗
NASA NTRS1990

Single launch lunar habitat derived from an NSTS external tank

A concept for using the spent external tank from a National Space Transportation System (NSTS) to derive a lunar habitat is described. The external tank is carried into low Earth orbit where the oxygen tank-intertank subassembly is separated from the hydrogen tank, berthed to Space Station Freedom and the subassembly outfitted as a 12-person lunar habitat using extravehicular activity (EVA) and intravehicular activity (IVA). A single launch of the NSTS orbiter can place the external tank in LEO, provide orbiter astronauts for disassembly of the external tank, and transport the required subsystem hardware for outfitting the lunar habitat. An estimate of the astronauts' EVA and IVA is provided. The liquid oxygen intertank modifications utilize existing structures and openings for man access without compromising the structural integrity of the tank. The modifications include installation of living quarters, instrumentation, and an airlock. Feasibility studies of the following additional systems include micrometeoroid and radiation protection, thermal control, environmental control and life support, and propulsion. The converted lunar habitat is designed for unmanned transport and autonomous soft landing on the lunar surface without need for site preparation. Lunar regolith is used to fill the micrometeoroid shield volume for radiation protection using a conveyer. The lunar habitat concept is considered to be feasible by the year 2000 with the concurrent development of a space transfer vehicle and a lunar lander for crew changeover and resupply.

King, Charles B.↗