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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Development of Metallic Thermal Protection Systems for the Reusable Launch Vehicle

A reusable Thermal Protection System (TPS) that is not only lightweight, but durable, operable and cost effective is one of the technologies required by the Reusable Launch Vehicle (RLV) to achieve the goal of drastically reducing the cost of delivering payload to orbit. Metallic TPS is one of the systems being developed to meet this challenge. Current efforts involve improving the superalloy honeycomb TPS concept, which consists of a foil-gage metallic box encapsulating a low density fibrous insulation, and evaluating it for RLV requirements. The superalloy honeycomb TPS concept is mechanically attached to the vehicle structure. Improvements include more efficient internal insulation, a simpler, lighter weight configuration, and a quick-release fastener system for easier installation and removal. Evaluation includes thermal and structural analysis, fabrication and testing of both coupons and TPS panels under conditions simulating RLV environments. Coupons of metallic honeycomb sandwich, representative of the outer TPS surface, were subjected to low speed impact, hypervelocity impact, and rain erosion testing as well as subsequent arcjet exposure. Arrays of TPS panels have been subjected to radiant heating in a thermal/vacuum facility, aerodynamic heating in an arcjet facility and acoustic loading.

Blosser, Max L.↗
NASA NTRS2012

Modeling the Meteoroid Input Function at Mid-Latitude Using Meteor Observations by the MU Radar

The Meteoroid Input Function (MIF) model has been developed with the purpose of understanding the temporal and spatial variability of the meteoroid impact in the atmosphere. This model includes the assessment of potential observational biases, namely through the use of empirical measurements to characterize the minimum detectable radar cross-section (RCS) for the particular High Power Large Aperture (HPLA) radar utilized. This RCS sensitivity threshold allows for the characterization of the radar system s ability to detect particles at a given mass and velocity. The MIF has been shown to accurately predict the meteor detection rate of several HPLA radar systems, including the Arecibo Observatory (AO) and the Poker Flat Incoherent Scatter Radar (PFISR), as well as the seasonal and diurnal variations of the meteor flux at various geographic locations. In this paper, the MIF model is used to predict several properties of the meteors observed by the Middle and Upper atmosphere (MU) radar, including the distributions of meteor areal density, speed, and radiant location. This study offers new insight into the accuracy of the MIF, as it addresses the ability of the model to predict meteor observations at middle geographic latitudes and for a radar operating frequency in the low VHF band. Furthermore, the interferometry capability of the MU radar allows for the assessment of the model s ability to capture information about the fundamental input parameters of meteoroid source and speed. This paper demonstrates that the MIF is applicable to a wide range of HPLA radar instruments and increases the confidence of using the MIF as a global model, and it shows that the model accurately considers the speed and sporadic source distributions for the portion of the meteoroid population observable by MU.

Pifko, Steven↗
NASA NTRS2004

Meteoroid Engineering Model (MEM)A Meteoroid Model for the Inner Solar System

In an attempt to overcome some of the deficiencies of existing meteoroid models, NASA's Space Environments and Effects Program sponsored a three year research effort at the University of Western Ontario. The resulting understanding of the sporadic meteoroid environment - particularly the nature and distribution of the sporadic sources - was then incorporated into a new meteoroid environment model (MEM) by members of the Space Environments Team at NASA's Marshall Space Flight Center. This paper discusses some of the revolutionary aspects of MEM which include: a) identification of the sporadic radiants with real sources of meteoroids, such as comets, b) a physics-based approach which yields accurate fluxes and directionality for interplanetary spacecraft anywhere from .2 AU to 2 AU, and c) velocity distributions obtained from theory and validated against observation. Use of the model, which gives penetrating fluxes and average impact speeds on the surfaces of a cube-like structure are also described, along with its current limitations and plans for future improvements.

McNamara, H.↗
NASA NTRS1981

Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. II - Analysis of first year of Nimbus 6 ERB data

The theory of deconvolution considered by Smith and Green (1981) is applied to Nimbus 6 data in order to interpret the data with the maximum obtainable resolution. Attention is given to the data sample, sun-contaminated measurements, the measurement model, the deconvolution, the degree variance, the spherical harmonic coefficients, the geographical distribution of longwave radiation, time histories of zonal coefficients, and the effect of a grid system. Degree variance plots for 12 months of longwave radiation data show that the limit for a spherical harmonic representation of the Nimbus 6 wide field-of-view longwave data is 12th degree. The degree variance plots also reveal that most of the power is in the lower degree terms. Contour maps of the radiation field show the geographical distribution of earth emitted radiant exitance for each month.

Bess, T. D.↗
NASA NTRS2004

Meteoroid Engineering Model (MEM): A Meteoroid Model for the Inner Solar System

In an attempt to overcome some of the deficiencies of existing meteoroid models, NASA's Space Environments and Effects (SEE) Program sponsored a three year research effort at the University of Western Ontario. The resulting understanding of the sporadic meteoroid environment - particularly the nature and distribution of the sporadic sources - were then incorporated into a new Meteoroid Engineering Model (MEM) by members of the Space Environments Team at NASA s Marshall Space Flight Center. This paper discusses some of the revolutionary aspects of MEM which include a) identification of the sporadic radiants with real sources of meteoroids, such as comets, b) a physics-based approach which yields accurate fluxes and directionality for interplanetary spacecraft anywhere from 0.2 astronomical units (AU) to 2 AU, and c) velocity distributions obtained from theory and validated against observation. Use of the model, which gives penetrating fluxes and average impact speeds on the surfaces of a cube-like structure, is also described along with its current limitations and plans for future improvements.

McNamara, Heather A.↗
NASA NTRSDate not supplied

Mars 2020 Thermal Protection Systems Sizing and Development

The Mars 2020 spacecraft delivering the Perseverance Rover to Mars was planned to be a build-to-print repeat of the Mars Science Laboratory (MSL) spacecraft that delivered the Curiosity Rover to Mars in 2012. The 2020 mission would deliver a slightly higher mass at a lower entry velocity, so the mission designers were comfortable with the cost saving approach of using an already proven design. The approach used in sizing the thermal protection systems (TPS) for the various components of the MSL spacecraft included convective heating and shock layer radiation (a small contributor) on the heatshield and only convective heating on all of the aft body parts. At the time, it was assumed that the contribution of radiation from the shock layer and the wake was negligible on the aft body at Mars. In the time since the MSL spacecraft was designed, in light of new data and analysis, NASA realized the significance of radiative heating in the aftbody on vehicles entering Mars, beginning with the InSight entry. New analyses showed that the radiant heat fluxes on aft body components at Mars were of the same order or even larger than predicted convective heat fluxes. The Mars 2020 team was tasked with showing that the TPS thicknesses designed for MSL with only convective heating would survive the Mars 2020 convective plus radiative heat flux environments. Luckily, many of the MSL aft body components were sized using an extra conservative approach, often sizing for the worst environment at the lightest, thinnest structure, even though the environments and structures were not co-located. The Mars 2020 team had to more accurately evaluate the environments and structures to show that the design would close

Mars Entry↗
NASA NTRS1972

An analytical and experimental evaluation of shadow shields and their support members.

Review of the major results of an analytical and experimental program aimed at determining the potential effectiveness of shadow shields in minimizing radiant heat transfer into cryogenic propellant tanks on long-duration interplanetary missions, taking into account the thermal interaction between shields and their support structures. Analytical procedures are developed and applied that include the strut-shield interaction in predicting shadow shield performance. The results of experimental studies of the effects of configuration variables on the performance of a scale model of a shadow shield system are presented. The experimental results are used to verify the validity of analytical predictions. The results obtained show that: (1) shadow shields can be effective in reducing the heat transfer into cryogenic propellant tanks, and (2) the conductive heat transfer through supports can be reduced by selective surface coatings.

Stochl, R. J.↗
NASA NTRS1993

Corvid meteoroids and a Giordano Bruno ray are genetically related

Both Corvid meteoroids and the Giordano Bruno (GB) crater are products of recent events. On June 25, or 26, 1178, Corvid meteoroids and a portion of GB ejecta were at the same place in the Solar System and moved in the same direction (right ascension = 12 degrees and declination = +19 degrees). The ground track of this direction is the same as that of the most prominant GB ray (azimuth = 237 degrees). These 'coincidences' could not have occurred by change and, therefore, support the conclusions that the GB impact occurred on June 26, 1178, and that Corvid meteoroids are high-velocity ejecta fragments from that impact. Finally, those fragments ejected with somewhat lower velocities failed to escape from the Earth-Moon system and produced the prominant ray extending southwest from the GB crater. Between June 25 and July 2, 1937, a Corvid meteor shower was observed. The apparent lack of Corvid showers in other years suggests that Corvids are the product of a recent break-up event. The right ascension and declination, corrected for zenith attraction, of 192 degrees and -19 degrees were reported for the radiant of this shower. This corresponds to a right ascension and declination of the direction of motion of Corvid meteoroids of 12 degrees and +19 degrees. In ecliptic coordinates the celestial longitude and latitude of this direction are 18 degrees and +13 degrees.

Hartung, Jack B.↗
NASA NTRS2015

The 2014 KCG Meteor Outburst: Clues to a Parent Body

The Kappa Cygnid (KCG) meteor shower exhibited unusually high activity in 2014, producing ten times the typical number of meteors. The shower was detected in both radar and optical systems and meteoroids associated with the outburst spanned at least five decades in mass. In total, the Canadian Meteor Orbit Radar, European Network, and NASA All Sky and Southern Ontario Meteor Network produced thousands of KCG meteor trajectories. Using these data, we have undertaken a new and improved characterization of the dynamics of this little-studied, variable meteor shower. The Cygnids have a di use radiant and a significant spread in orbital characteristics, with multiple resonances appearing to play a role in the shower dynamics. We conducted a new search for parent bodies and found that several known asteroids are orbitally similar to the KCGs. N-body simulations show that the two best parent body candidates readily transfer meteoroids to the Earth in recent centuries, but neither produces an exact match to the KCG radiant, velocity, and solar longitude. We nevertheless identify asteroid 2001 MG1 as a promising parent body candidate.

Moorhead, Althea V.↗
NASA NTRS2014

Multi-Dimensional Sensors and Sensing Systems

A universal microelectromechanical (MEMS) nano-sensor platform having a substrate and conductive layer deposited in a pattern on the surface to make several devices at the same time, a patterned insulation layer, wherein the insulation layer is configured to expose one or more portions of the conductive layer, and one or more functionalization layers deposited on the exposed portions of the conductive layer to make multiple sensing capability on a single MEMS fabricated device. The functionalization layers are adapted to provide one or more transducer sensor classes selected from the group consisting of: radiant, electrochemical, electronic, mechanical, magnetic, and thermal sensors for chemical and physical variables and producing more than one type of sensor for one or more significant parameters that need to be monitored.

Stetter, Joseph R.↗
NASA NTRS1984

NASA/General Electric broad-specification fuels combustion technology program

The NASA/General Electric Broad Specification Fuels Combustion Technology Program is being conducted to evolve and demonstrate the technology required to use broadened-properties fuels in current and next generation commercial aircraft engines. The first phase of this program, completed in 1982, involved the design and test evaluation of three different combustor concepts. All combustors were designed for the General Electric CF6-80A engine envelope and operating conditions, using Experimental Referee Broad Specification (ERBS) fuel having a fuel hydrogen content of 12.8% by weight. Several different configurations of each combustor concept were evaluated in a series of high pressure sector combustor component tests. A total of 25 sector tests were conducted during phase 1. Combustor metal temperatures, emissions, exit temperature profiles, and radiant heat flux were measured over the full range of steady-state operating conditions using four fuels having nominal hydrogen contents between 11.8 and 14%. During the current phase 2 program, the two most promising concepts from phase 1 are being further refined and evaluated. For phase 2 testing, two additional fuels representing a wider range of fluidity and volatility are also being used in combustion system tests.

Dodds, W. J.↗
NASA NTRS2006

Using Satellite Data in Weather Forecasting: I

The GOES Product Generation System (GPGS) is a set of computer codes and scripts that enable the assimilation of real-time Geostationary Operational Environmental Satellite (GOES) data into regional-weather-forecasting mathematical models. The GPGS can be used to derive such geophysical parameters as land surface temperature, the amount of precipitable water, the degree of cloud cover, the surface albedo, and the amount of insolation from satellite measurements of radiant energy emitted by the Earth and its atmosphere. GPGS incorporates a priori information (initial guesses of thermodynamic parameters of the atmosphere) and radiometric measurements from the geostationary operational environmental satellites along with mathematical models of physical principles that govern the transfer of energy in the atmosphere. GPGS solves the radiative-transfer equation and provides the resulting data products in formats suitable for use by weather-forecasting computer programs. The data-assimilation capability afforded by GPGS offers the potential to improve local weather forecasts ranging from 3 hours to 2 days - especially with respect to temperature, humidity, cloud cover, and the probability of precipitation. The improvements afforded by GPGS could be of interest to news media, utility companies, and other organizations that utilize regional weather forecasts.

Jedlovec, Gary J.↗
DOE OSTI2023

Dependence of simulated radiation damage on crystal structure and atomic misfit in metals

This study investigates the evolution of radiation damage in three metals in the low temperature and high radiant flux regime using molecular statics and a Frenkel pair accumulation method to simulate up to 2.0 displacements per atom. The metals considered include Fe, equiatomic CrCoNi, and a fictitious metal with similar bulk properties to the CrCoNi composed of a single atom type referred to as an A-atom. CrCoNi is found to sustain higher concentrations of dislocations than either the Fe or A-atom systems and more stacking faults than the A-atom system. The results suggest that the difference between the concentrations of vacancies and interstitials is substantially smaller for CrCoNi than the A-atom system, perhaps reflecting that the sink capture radius is smaller in CrCoNi due to the roughened potential energy landscape. A model that partitions the major contributions from defects to the stored energy is described, and serves to highlight a general need for higher fidelity approaches to point defect identification.

36 MATERIALS SCIENCE↗
NASA NTRS1979

Radiation energy conversion in space

Topics discussed at the third NASA conference on radiant energy conversion are reviewed. The unconcentrated-photovoltaic-generation version of a solar power satellite is described, noting that it will consist of a 21.3 x 5.3-sq-km silicon-solar-cell array expected to provide 17 Gw of electrical power, with 1 km in diam transmitters oriented to beam 2.45 GHz microwave power to two receiving/rectifying 'rectennas' on earth. The Solares space-energy-system concept, designed for providing a large fraction of the world's energy needs at costs comparable to those of future coal/nuclear alternative, is considered, as are subsystems for improving the economics of the solar power satellite. A concept proposing the use of relativistic-electron-storage rings for electron-beam energy transmission and storage, and a report on the production of a high temperature plasma with concentrated solar radiation are taken into account. Laser-conversion systems, including the direct-solar-pumped space laser, and the telec-powered spacecraft, are discussed.

Billman, K. W.↗
NASA NTRS1958

A Comparative Analysis of the Performance of Long-Range Hypervelocity Vehicles

Long-range hypervelocity vehicles are studied in terms of their motion in powered flight. Powered flight is analyzed for an idealized propulsion system which approximates rocket motors. Unpowered flight is characterized by a return to earth along a ballistic, skip, or glide trajectory. Only those trajectories are treated which yield the maximum range for a given velocity at the end of powered flight. Aerodynamic heating is treated in a manner similar to that employed previously by the senior authors in studying ballistic missiles (NACA rep. 1381), with the exception that radiant as well as convective heat transfer is considered in connection with glide and skip vehicles. As a final performance consideration, it is shown that on the basis of equal ratios of mass at take-off to mass at the end of powered flight, the hypervelocity vehicle compares favorably with the supersonic airplane for ranges in the neighborhood of and greater than one half the circumference of the earth. In the light of this and previous findings, it is concluded that the ballistic and glide vehicles have, in addition to the advantages usually ascribed to great speed, the attractive possibility of providing relatively efficient long-range flight.

Eggers, Alfred J , Jr↗
NASA NTRS1979

Infrared Heaters

The heating units shown in the accompanying photos are Panelbloc infrared heaters, energy savers which burn little fuel in relation to their effective heat output. Produced by Bettcher Manufacturing Corporation, Cleveland, Ohio, Panelblocs are applicable to industrial or other facilities which have ceilings more than 12 feet high, such as those pictured: at left the Bare Hills Tennis Club, Baltimore, Maryland and at right, CVA Lincoln- Mercury, Gaithersburg, Maryland. The heaters are mounted high above the floor and they radiate infrared energy downward. Panelblocs do not waste energy by warming the surrounding air. Instead, they beam invisible heat rays directly to objects which absorb the radiation- people, floors, machinery and other plant equipment. All these objects in turn re-radiate the energy to the air. A key element in the Panelbloc design is a coating applied to the aluminized steel outer surface of the heater. This coating must be corrosion resistant at high temperatures and it must have high "emissivity"-the ability of a surface to emit radiant energy. The Bettcher company formerly used a porcelain coating, but it caused a production problem. Bettcher did not have the capability to apply the material in its own plant, so the heaters had to be shipped out of state for porcelainizing, which entailed extra cost. Bettcher sought a coating which could meet the specifications yet be applied in its own facilities. The company asked The Knowledge Availability Systems Center, Pittsburgh, Pennsylvania, a NASA Industrial Applications Center (IAC), for a search of NASA's files

Source record↗
NASA NTRS2011

Real-Time Thermographic-Phosphor-Based Temperature Measurements of Thermal Barrier Coating Surfaces Subjected to a High-Velocity Combustor Burner Environment

Surface temperature measurements were conducted on metallic specimens coated with an yttria-stabilized zirconia (YSZ) thermal barrier coating (TBC) with a YAG:Dy phosphor layer that were subjected to an aggressive high-velocity combustor burner environment. Luminescence-based surface temperature measurements of the same TBC system have previously been demonstrated for specimens subjected to static furnace or laser heating. Surface temperatures were determined from the decay time of the luminescence signal of the YAG:Dy phosphor layer that was excited by a pulsed laser source. However, the furnace and laser heating provides a much more benign environment than that which exists in a turbine engine, where there are additional challenges of a highly radiant background and high velocity gases. As the next step in validating the suitability of luminescence-based temperature measurements for turbine engine environments, new testing was performed where heating was provided by a high-velocity combustor burner rig at Williams International. Real-time surface temperature measurements during burner rig heating were obtained from the decay of the luminescence from the YAG:Dy surface layer. The robustness of several temperature probe designs in the sonic velocity, high radiance flame environment was evaluated. In addition, analysis was performed to show whether the luminescence decay could be satisfactorily extracted from the high radiance background.

Eldridge, Jeffrey I.↗
NASA NTRS2014

Spinoff 2013

Topics covered include: Innovative Software Tools Measure Behavioral Alertness; Miniaturized, Portable Sensors Monitor Metabolic Health; Patient Simulators Train Emergency Caregivers; Solar Refrigerators Store Life-Saving Vaccines; Monitors Enable Medication Management in Patients' Homes; Handheld Diagnostic Device Delivers Quick Medical Readings; Experiments Result in Safer, Spin-Resistant Aircraft; Interfaces Visualize Data for Airline Safety, Efficiency; Data Mining Tools Make Flights Safer, More Efficient; NASA Standards Inform Comfortable Car Seats; Heat Shield Paves the Way for Commercial Space; Air Systems Provide Life Support to Miners; Coatings Preserve Metal, Stone, Tile, and Concrete; Robots Spur Software That Lends a Hand; Cloud-Based Data Sharing Connects Emergency Managers; Catalytic Converters Maintain Air Quality in Mines; NASA-Enhanced Water Bottles Filter Water on the Go; Brainwave Monitoring Software Improves Distracted Minds; Thermal Materials Protect Priceless, Personal Keepsakes; Home Air Purifiers Eradicate Harmful Pathogens; Thermal Materials Drive Professional Apparel Line; Radiant Barriers Save Energy in Buildings; Open Source Initiative Powers Real-Time Data Streams; Shuttle Engine Designs Revolutionize Solar Power; Procedure-Authoring Tool Improves Safety on Oil Rigs; Satellite Data Aid Monitoring of Nation's Forests; Mars Technologies Spawn Durable Wind Turbines; Programs Visualize Earth and Space for Interactive Education; Processor Units Reduce Satellite Construction Costs; Software Accelerates Computing Time for Complex Math; Simulation Tools Prevent Signal Interference on Spacecraft; Software Simplifies the Sharing of Numerical Models; Virtual Machine Language Controls Remote Devices; Micro-Accelerometers Monitor Equipment Health; Reactors Save Energy, Costs for Hydrogen Production; Cameras Monitor Spacecraft Integrity to Prevent Failures; Testing Devices Garner Data on Insulation Performance; Smart Sensors Gather Information for Machine Diagnostics; Oxygen Sensors Monitor Bioreactors and Ensure Health and Safety; Vision Algorithms Catch Defects in Screen Displays; and Deformable Mirrors Capture Exoplanet Data, Reflect Lasers.

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