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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

Thermal Systems Modeling of Chemical Integrated Power Source (CHIPS) to Survive Lunar Night Environments

This paper presents the results of the systems level thermal modeling for a conceptual Chemical Heat Integrated Power Source (CHIPS). This proposed system offers a combined thermal and electrical power source to support survival of spacecraft operating in extreme low temperature lunar environments, without the use of radioisotope-based sources. A conceptual design study has been completed for this system, that uses heat generated by an exothermic chemical reaction in place of radioisotope or electrical heat sources. The goal of the study was to evaluate the feasibility of such as system through thermodynamic and chemical analysis and thermal modeling, and to identify technology gaps to inform a technology development and maturation plan. The specific technical objectives focused on delivery of 90-100 Wth thermal power and 30-40 We electrical power for 336 hours to a representative Commercial Lunar Payload Services (CLPS) lander, to support lunar surface survival and limited operations through a lunar night. The total system mass was targeted at ≤50 kg. A highly exothermic chemical reaction system is used to generate on-board electrical power for spacecraft systems, and thermal power to maintain critical spacecraft/lander systems within their allowable flight temperature (AFTs). Based on the very high energy content of the chemical reaction system, a much higher amount of heat per unit mass can be delivered to the spacecraft, relative to a rechargeable lithium-ion battery and electrical heater(s). Since radioisotope heaters or generators are not used, the system will be orders of magnitude lower in cost than a radioisotope heating/power unit, without the attendant regulatory complexities. As part of the CHIPS concept, a fraction of the thermal power generated is converted to electrical power via an appropriate thermal-to-electric converter technology (such as a free piston Stirling converter or a thermoelectric generator module), to provide power to critical loads. This approach is ideally suited to support operation of commercial landers (e.g., via the CLPS program). In most cases, these landers are only designed to operate during a portion of the lunar day, with no provision for survival through the lunar night. By supporting lunar night survival, a mission can be extended through the lunar night and at least into another lunar day, thus turning a nominal eight-day mission into a 36-day mission. Therefore, the current system demonstration will focus on scalability to support at least 336 hours (one lunar night) of continuous thermal and electrical power generation. Although initially targeted to support lunar equatorial landings, the technology is extensible to missions at the lunar poles, other extreme environments in the Solar System or even air-independent applications on Earth (e.g., ocean exploration).

West, William↗
NASA NTRS2021

Thermal Systems Modeling of Chemical Heat Integrated Power Source (CHIPS) to Survive Lunar Night Environments

This paper presents the results of the systems level thermal modeling for a conceptual Chemical Heat Integrated Power Source (CHIPS). This proposed system offers a combined thermal and electrical power source to support survival of spacecraft operating in extreme low temperature lunar environments, without the use of radioisotope-based sources. A conceptual design study has been completed for this system, that uses heat generated by an exothermic chemical reaction in place of radioisotope or electrical heat sources. The goal of the study was to evaluate the feasibility of such a system through thermodynamic and chemical analysis and thermal modeling, and to identify technology gaps to inform a technology development and maturation plan. The specific technical objectives focused on delivery of 90 to 100 Wth thermal power and 30 to 40 We electrical power for 336 hours to a representative Commercial Lunar Payload Services (CLPS) lander, to support lunar surface survival and limited operations through a lunar night. The total system mass was targeted at ≤50 kg. A highly exothermic chemical reaction system is used to generate on-board electrical power for spacecraft systems, and thermal power to maintain critical spacecraft/lander systems within their allowable flight temperature (AFTs). Based on the very high energy content of the chemical reaction system, a much higher amount of heat per unit mass can be delivered to the spacecraft, relative to a rechargeable lithium-ion battery and electrical heater(s). Since radioisotope heaters or generators are not used, the system will be orders of magnitude lower in cost than a radioisotope heating/power unit, without the attendant regulatory complexities. As part of the CHIPS concept, a fraction of the thermal power generated is converted to electrical power via an appropriate thermal-to-electric converter technology (such as a free piston Stirling converter or a thermoelectric generator module), to provide power to critical loads. This approach is ideally suited to support operation of commercial landers (e.g., via the CLPS program). In most cases, these landers are only designed to operate during a portion of the lunar day, with no provision for survival through the lunar night. By supporting lunar night survival, a mission can be extended through the lunar night and at least into another lunar day, thus turning a nominal eight-day mission into a 36-day mission. Therefore, the current system demonstration will focus on scalability to support at least 336 hours (one lunar night) of continuous thermal and electrical power generation. Although initially targeted to support lunar equatorial landings, the technology is extensible to missions at the lunar poles, other extreme environments in the Solar System or even air-independent applications on Earth (e.g., ocean exploration).

West, William↗
NASA NTRS1983

Experimental study of the thermal-acoustic efficiency in a long turbulent diffusion-flame burner

A two-year study of noise production in a long tubular burner is described. The research was motivated by an interest in understanding and eventually reducing core noise in gas turbine engines. The general approach is to employ an acoustic source/propagation model to interpret the sound pressure spectrum in the acoustic far field of the burner in terms of the source spectrum that must have produced it. In the model the sources are assumed to be due uniquely to the unsteady component of combustion heat release; thus only direct combustion-noise is considered. The source spectrum is then the variation with frequency of the thermal-acoustic efficiency, defined as the fraction of combustion heat release which is converted into acoustic energy at a given frequency. The thrust of the research was to study the variation of the source spectrum with the design and operating parameters of the burner.

Mahan, J. R.↗
NASA NTRS1999

Energetic Neutral Atom Imager on the Swedish Microsatellite Astrid

The Swedish microsatellite ASTRID was launched by a Russian Cosmos rocket on January 24, 1995 into a 1000 km circular orbit with 83 deg inclination. Besides the main objective of technological demonstration, imaging of energetic neutral atoms (ENAS) was attempted. The imager detected ENA in the energy range 0.1 - 140 keV utilizing two different techniques. Neutrals of the energy 13 - 140 keV were recorded by 14 solid state detectors with the total field of view 5 deg x 322 deg. For half a spin (approx. 1.5 s) of the ASTRID spacecraft, almost all of space was covered with an angular resolution 2.5 deg x 25 deg. Less energetic neutrals of approx. 0.1 - 70 keV were converted on a graphite target into secondary particles which then were detected by a microchannel plate with 32 anodes. A fraction of primary neutrals was directly reflected towards the sensor. This technique provided the total ENA flux with an angular resolution 4.6 deg x 11.5 deg. The instrument weight is 3.13 kg. Successful operation of the instrument during the first 5 weeks of the mission provided the first ENA images of the ring current at low altitudes.

Barabash, S.↗
NASA NTRS2008

Framework for the Parametric System Modeling of Space Exploration Architectures

This paper presents a methodology for performing architecture definition and assessment prior to, or during, program formulation that utilizes a centralized, integrated architecture modeling framework operated by a small, core team of general space architects. This framework, known as the Exploration Architecture Model for IN-space and Earth-to-orbit (EXAMINE), enables: 1) a significantly larger fraction of an architecture trade space to be assessed in a given study timeframe; and 2) the complex element-to-element and element-to-system relationships to be quantitatively explored earlier in the design process. Discussion of the methodology advantages and disadvantages with respect to the distributed study team approach typically used within NASA to perform architecture studies is presented along with an overview of EXAMINE s functional components and tools. An example Mars transportation system architecture model is used to demonstrate EXAMINE s capabilities in this paper. However, the framework is generally applicable for exploration architecture modeling with destinations to any celestial body in the solar system.

Komar, David R.↗
NASA NTRS2018

The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model

An accurate historical record of evolving Arctic conditions is integral to furthering our understanding of climate processes and to providing a foundation for predicting future climate scenarios in northern high latitudes. Atmospheric reanalyses are seen as an important source of information on the recent past for the data-sparse Arctic region. An assessment of near-surface Arctic air temperatures finds significant discrepancies among the various modern reanalyses. An important point is the treatment of surface boundary conditions: specifically, the sea ice cover and sea surface temperatures (SSTs) over the Arctic Ocean. Reanalyses use different methodologies and data sources for SSTs and sea ice concentration boundary forcing. Notably, the Modern Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) both use boundary forcing derived from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) over an extended, overlapping period of time. This allows for an examination of differences between the two systems while both concurrently employ the same fractional sea ice coverage. To further understand these differences, an ensemble of AMIP-style simulations using the MERRA-2 atmospheric model - but without data assimilation - shows considerable differences in Arctic temperatures as compared to reanalyses, particularly in autumn and winter months. Results from the AMIP simulations suggest that the surface representation over sea ice used in the MERRA-2 model provides an intrinsic warm bias and obfuscates Arctic Amplification, an established feature present in observations and reanalyses. An additional ensemble of AMIP-style simulations using the MERRA-2 atmospheric model was performed using boundary conditions derived from the ERA-Interim reanalysis. An in-depth comparison of surface temperatures over the Arctic from the two reanalyses and two AMIP-style ensembles will be presented, along with an assessment of the effects of the varying Arctic temperature time series on the atmospheric general circulation and energy budget.

Collow, Allison B. Marquardt↗
NASA NTRS1996

Twin Knudsen Cell Configuration for Activity Measurements by Mass Spectrometry

A twin Knudsen cell apparatus for alloy activity measurements by mass spectrometry is described. Two Knudsen cells - one containing an alloy and one containing a pure component - are mounted on a single flange and translated into the sampling region via a motorized x-y table. Mixing of the molecular beams from the cells is minimized by a novel system of shutters. Activity measurements were taken on two well-characterized alloys to verify the operation of the system. Silver activity measurements are reported for Ag-Cu alloys and aluminum activity measurements are reported for Fe-Al alloys. The temperature dependence of activity for a 0.474 mol fraction Al-Fe alloy gives a partial molar heat of aluminum. Measurements taken with the twin cell show good agreement with literature values for these alloys.

Jacobson, N. S.↗
NASA NTRS2002

Life Beneath Glacial Ice - Earth(!) Mars(?) Europa(?)

We are investigating a set of cold springs that deposit sulfur and carbonate minerals on the surface of a Canadian arctic glacier. The spring waters and mineral deposits contain microorganisms, as well as clear evidence that biological processes mediate subglacial chemistry, mineralogy, and isotope fractionation . The formation of native sulphur and associated deposits are related to bacterially mediated reduction and oxidation of sulphur below the glacier. A non-volcanic, topography driven geothermal system, harboring a microbiological community, operates in an extremely cold environment and discharges through solid ice. Microbial life can thus exist in isolated geothermal refuges despite long-term subfreezing surface conditions. Earth history includes several periods of essentially total glaciation. lee in the near subsurface of Mars may have discharged liquid water in the recent past Cracks in the ice crust of Europa have apparently allowed the release of water to the surface. Chemolithotrophic bacteria, such as those in the Canadian springs, could have survived beneath the ice of "Snowball Earth", and life forms with similar characteristics might exist beneath the ice of Mars or Europa. Discharges of water from such refuges may have brought to the surface living microbes, as well as longlasting chemical, mineralogical, and isotopic indications of subsurface life.

Allen, Carlton C.↗
NASA NTRS2012

Telescopes in Near Space: Balloon Exoplanet Nulling Interferometer (BigBENI)

A significant and often overlooked path to advancing both science and technology for direct imaging and spectroscopic characterization of exosolar planets is to fly "near space" missions, i.e. balloon borne exosolar missions. A near space balloon mission with two or more telescopes, coherently combined, is capable of achieving a subset of the mission science goals of a single large space telescope at a small fraction of the cost. Additionally such an approach advances technologies toward flight readiness for space flight. Herein we discuss the feasibility of flying two 1.2 meter telescopes, with a baseline separation of 3.6 meters, operating in visible light, on a composite boom structure coupled to a modified visible nulling coronagraph operating to achieve an inner working angle of 60 milli-arcseconds. We discuss the potential science return, atmospheric residuals at 135,000 feet, pointing control and visible nulling and evaluate the state-or-art of these technologies with regards to balloon missions.

Lyon, Richard G.↗
NASA NTRS2014

Fabrication of Turbine Disk Materials by Additive Manufacturing

Precipitation-strengthened, nickel-based superalloys are widely used in the aerospace and energy industries due to their excellent environmental resistance and outstanding mechanical properties under extreme conditions. Powder-bed additive manufacturing (AM) technologies offer the potential to revolutionize the processing of superalloy turbine components by eliminating the need for extensive inventory or expensive legacy tooling. Like selective laser melting (SLM), electron beam melting (EBM) constructs three-dimensional dense components layer-by-layer by melting and solidification of atomized, pre-alloyed powder feedstock within 50-200 micron layers. While SLM has been more widely used for AM of nickel alloys like 718, EBM offers several distinct advantages, such as less retained residual stress, lower risk of contamination, and faster build rates with multiple-electron-beam configurations. These advantages are particularly attractive for turbine disks, for which excessive residual stress and contamination can shorten disk life during high-temperature operation. In this presentation, we will discuss the feasibility of fabricating disk superalloy components using EBM AM. Originally developed using powder metallurgy forging processing, disk superalloys contain a higher refractory content and precipitate volume fraction than alloy 718, thus making them more prone to thermal cracking during AM. This and other challenges to produce homogeneous builds with desired properties will be presented. In particular, the quality of lab-scale samples fabricated via a design of experiments, in which the beam current, build temperature, and beam velocity were varied, will be summarized. The relationship between processing parameters, microstructure, grain orientation, and mechanical response will be discussed.

oxidation↗
NASA NTRSDate not supplied

GeoXO Atmospheric Composition Instrument (AC) Measurements Conditions Assessment

NOAA’s next generation Geostationary Extended Observations (GeoXO) satellite system will advance Earth observations from geostationary orbit. GeoXO will supply vital information supporting the U.S. weather, ocean, and climate operations. The recommended three-satellite constellation includes spacecraft at GOES-Central position, that will carry an Atmospheric Composition Instrument (ACX) among its payloads; the requirement on the ACX is to scan its region of interest in one hour. An assessment of ACX observational conditions is presented, based on view geometry and solar angle range over the year. The availability for observations of each pixel is estimated per day of the year, as function of the geometric air mass factor (AMF), which can be related to signal to noise ratio using a model of the ACX instrument performance, and ultimately to expected column error for specific atmospheric species. In addition, cloud climatology – based on statistics derived from GOES-16 ABI cloud product data – is considered to determine typical fractions of cloud-free ACX observations and typical cloud optical depths, for each pixel as function of time of day and season. The results of such assessments can be used to prepare for GeoXO ACX data and further the understanding and development of the future instrument operations.

Boryana Efremova↗
NASA NTRS2012

Experimental Investigation of Transient Sublimator Performance

Sublimators have been used as heat rejection devices for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered for operations in a cyclical topping mode, which represents a new mode of operation for sublimators. Sublimators can be used as a supplemental heat rejection device during mission phases where the environmental temperature or heat rejection requirement changes rapidly. This scenario may occur during low lunar orbit, low earth orbit, or other planetary orbits. In these mission phases, the need for supplemental heat rejection will vary between zero and some fraction of the overall heat load. In particular, supplemental heat rejection is required for the portion of the orbit where the radiative sink temperature exceeds the system setpoint temperature. This paper will describe the effects of these transient starts and stops on the feedwater utilization during various feedwater timing scenarios. Experimental data from various scenarios is analyzed to investigate feedwater consumption efficiency under the cyclical conditions. Start up utilization tests were conducted to better understand the transient performance. This paper also provides recommendations for future sublimator design and transient operation.

Sheth, Rubik B.↗
NASA NTRS1986

Isotopic characterisation of prebiotic synthesis of organic material

Many primitive meteorites contain an insoluble organic material, much like terrestrial kerogen, whose mode of origin is currently unknown. When sujbected to stepwise decomposition, this material, unlike its terrestrial counterpart, reveals characteristic release patterns for the stable isotopes of carbon, hydrogen and nitrogen as a function of fractional release of each element. The purpose of this study is to try to match those release patterns using organic matter synthesised in the laboratory under controlled conditions. If successful, such a study would shed light on the origin of kerogen-like organic matter in the early solar system and, by extension, on prebiotic organic synthesis in general. The range of possible syntheses, starting materials and reaction conditions to be investigated is considerable. Samples analysed to date include: a heavy oil produced by Fischer-Tropsch-type catalysis of CO + H2; a solid residue generated by a plasma discharge in CO + H2 + N2; a solid deposited on the electrodes of a Miller-Urey synthesis operating on CH4 + H2O + N2; and a solid residue formed by polymerization of light hydrocarbons procured by a Miller-Urey discharge acting on CH4. Significant structure is observed in the release patterns for the carbon and hydrogen isotopes from the synthetic samples, though there is little evidence for isotopic fractionation during the analysis itself.

Kerridge, J. F.↗
NASA NTRS1987

Kinetics of mineral condensation in the solar nebula

A natural extension of the type of gas-mineral-melt condensation experiments is to study the gas-mineral-melt reaction process by controlling the reaction times of appropriate gas compositions with silicate materials. In a condensing and vaporizing gas-solid system, important processes that could influence the composition of and speciation in the gas phase are the kinetics of vaporization of components from silicate crystals and melts. The high vacuum attainable in the space station would provide an environment for studying these processes at gas pressures much lower than those obtainable in experimental devices operated at terrestrial conditions in which the gas phase and mineral or melt would be allowed to come to exchange equilibrium. Further experiments would be performed at variable gas flow rates to simulate disequilibrium vapor fractionation. In this type of experiment it is desirable to analyze directly the species in the gas phase in equilibrium with the condensed silicate material. This analytical method would provide a direct determination of the species present in the gas phase. Currently, the notion of gas speciation is based on calculations from thermodynamic data. The proposed experiments require similar furnace designs and use similar experimental starting compositions, pressures, and temperatures as those described by Mysen.

Grove, T. L.↗
NASA NTRS1989

Energy management and recovery

Energy management is treated by first exploring the energy requirements for a cryogenic tunnel. The requirement is defined as a function of Mach number, Reynolds number, temperature, and tunnel size. A simple program and correlation is described which allow calculation of the energy required. Usage of energy is also addressed in terms of tunnel control and research operation. The potential of a new wet expander is outlined in terms of cost saved by reliquefying a portion of the exhaust. The expander is described as a potentially more efficient way of recovering a fraction of the cold nitrogen gas normally exhausted to the atmosphere from a cryogenic tunnel. The role of tunnel insulation systems is explored in terms of requirements, safety, cost, maintenance, and efficiency. A detailed description of two external insulation systems is given. One is a rigid foam with a fiber glass and epoxy shell. The other is composed of glass fiber mats with a flexible outer vapor barrier; this system is nitrogen purged. The two systems are compared with the purged system being judged superior.

Lawing, Pierce L.↗
NASA NTRS1941

Propeller Analysis from Experimental Data

The operation of the propeller is analyzed by the use of the distribution of forces along the radius, combined with theoretical equations. The data were obtained in the NACA 20-foot wind tunnel on a 4-foot-diameter, two-blade propeller, operating in front of four body shapes, ranging from a small shaft to support the propeller to conventional NACA cowling. A method of estimating the axial and the rotational energy in the wake as a fractional part of the propeller power is given. A knowledge of the total thrust and torque is necessary for the estimation.

Stickle, George W↗
NASA NTRS1995

Simplified Numerical Description of SPT Operations

A simplified numerical model of the plasma discharge within the SPT-100 stationary plasma thruster was developed to aid in understanding thruster operation. A one dimensional description was used. Non-axial velocities were neglected except for the azimuthal electron velocity. A nominal operating condition of 4.5 mg/s of xenon anode flow was considered with 4.5 Amperes of discharge current, and a peak radial magnetic field strength of 130 Gauss. For these conditions, the calculated results indicated ionization fractions of 0.99 near the thruster exit with a potential drop across the discharge of approximately 250 Volts. Peak calculated electron temperatures were found to be sensitive to the choice of total ionization cross section for ionization of atomic xenon by electron bombardment and ranged from 51 eV to 60 eV. The calculated ionization fraction, potential drop, and electron number density agree favorably with previous experiments. Calculated electron temperatures are higher than previously measured.

Manzella, David H.↗
NASA NTRS2001

Pre-Hardware Optimization of Spacecraft Image Processing Software Algorithms and Hardware Implementation

Spacecraft telemetry rates have steadily increased over the last decade presenting a problem for real-time processing by ground facilities. This paper proposes a solution to a related problem for the Geostationary Operational Environmental Spacecraft (GOES-8) image processing application. Although large super-computer facilities are the obvious heritage solution, they are very costly, making it imperative to seek a feasible alternative engineering solution at a fraction of the cost. The solution is based on a Personal Computer (PC) platform and synergy of optimized software algorithms and re-configurable computing hardware technologies, such as Field Programmable Gate Arrays (FPGA) and Digital Signal Processing (DSP). It has been shown in [1] and [2] that this configuration can provide superior inexpensive performance for a chosen application on the ground station or on-board a spacecraft. However, since this technology is still maturing, intensive pre-hardware steps are necessary to achieve the benefits of hardware implementation. This paper describes these steps for the GOES-8 application, a software project developed using Interactive Data Language (IDL) (Trademark of Research Systems, Inc.) on a Workstation/UNIX platform. The solution involves converting the application to a PC/Windows/RC platform, selected mainly by the availability of low cost, adaptable high-speed RC hardware. In order for the hybrid system to run, the IDL software was modified to account for platform differences. It was interesting to examine the gains and losses in performance on the new platform, as well as unexpected observations before implementing hardware. After substantial pre-hardware optimization steps, the necessity of hardware implementation for bottleneck code in the PC environment became evident and solvable beginning with the methodology described in [1], [2], and implementing a novel methodology for this specific application [6]. The PC-RC interface bandwidth problem for the class of applications with moderate input-output data rates but large intermediate multi-thread data streams has been addressed and mitigated. This opens a new class of satellite image processing applications for bottleneck problems solution using RC technologies. The issue of a science algorithm level of abstraction necessary for RC hardware implementation is also described. Selected Matlab functions already implemented in hardware were investigated for their direct applicability to the GOES-8 application with the intent to create a library of Matlab and IDL RC functions for ongoing work. A complete class of spacecraft image processing applications using embedded re-configurable computing technology to meet real-time requirements, including performance results and comparison with the existing system, is described in this paper.

Kizhner, Semion↗