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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1997

Test Report: Low-Cost Access to TDRS Using TOPEX to Emulate Small Satellite Performance

This report lists the objectives and conclusions of a series of experimental contacts between the TOPEX and the TDRS satellites. These experiments are designed to verify the theoretical prediction that a spin-stabilized satellite with a broad-beam, zenith-pointing antenna can have regular, significant contacts with the TDRS and use those contacts for data services. This series of experiments is a joint project between the experimenters at New Mexico State University (NMSU), the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), and the Jet Propulsion Laboratory (JPL). In these experiments, we show that: (1) The satellite contacts during the experiment begin and end as predicted prior to the experiment; (2) The data contact is held for the desired contact duration; (3) The data quality through the contact is high and similar to that required by actual project needs; and (4) The receiving hardware at the White Sands Complex (WSC) is able to track the signals better than expected by analysis of the antenna pattern effects alone predict. We believe that these experiments successfully demonstrate the basic concept and its validity with actual spacecraft systems.

Horan, Stephen↗
NASA NTRS1995

The Development of a Nonequilibrium Radiative Heat Transfer Computational Model for High Altitude Entry Vehicle Flowfield Methods

This final report will attempt to concisely summarize the activities and accomplishments associated with NASA Grant and to include pertinent documents in an appendix. The project initially had one primary and several secondary objectives. The original primary objective was to couple into the NASA Johnson Space Center (JSC) nonequilibrium chemistry Euler equation entry vehicle flowfield code, INEQ3D, the Texas A&M University (TAMU) local thermodynamic nonequilibrium (LTNE) radiation model. This model had previously been developed and verified under NASA Langley and NASA Johnson sponsorship as part of a viscous shock layer entry vehicle flowfield code. The secondary objectives were: (1) to investigate the necessity of including the radiative flux term in the vibrational-electron-electronic (VEE) energy equation as well as in the global energy equation, (2) to determine the importance of including the small net change in electronic energy between products and reactants which occurs during a chemical reaction, and (3) to study the effect of atom-atom impact ionization reactions on entry vehicle nonequilibrium flowfield chemistry and radiation. For each, of these objectives, it was assumed that the code would be applicable to lunar return entry conditions, i.e. altitude above 75 km, velocity greater, than 11 km/sec, where nonequilibrium chemistry and radiative heating phenomena would be significant. In addition, it was tacitly assumed that as part of the project the code would be applied to a variety of flight conditions and geometries.

Carlson, Leland A.↗
NASA NTRS2021

Present and future aerosol impacts on Arctic climate change in the GISS-E2.1 Earth system model

The Arctic is warming 2 to 3 times faster than the global average, partly due to changes in short-lived climate forcers (SLCFs) including aerosols. In order to study the effects of atmospheric aerosols in this warming, recent past (1990–2014) and future (2015–2050) simulations have been carried out using the GISS-E2.1 Earth system model to study the aerosol burdens and their radiative and climate impacts over the Arctic (>60°N), using anthropogenic emissions from the Eclipse V6b and the Coupled Model Intercomparison Project Phase 6 (CMIP6) databases, while global annual mean greenhouse gas concentrations were prescribed and kept fixed in all simulations. Results showed that the simulations have underestimated observed surface aerosol levels, in particular black carbon (BC) and sulfate (SO2−4), by more than 50 %, with the smallest biases calculated for the atmosphere-only simulations, where winds are nudged to reanalysis data. CMIP6 simulations performed slightly better in reproducing the observed surface aerosol concentrations and climate parameters, compared to the Eclipse simulations. In addition, simulations where atmosphere and ocean are fully coupled had slightly smaller biases in aerosol levels compared to atmosphere-only simulations without nudging. Arctic BC, organic aerosol (OA), and SO2−4 burdens decrease significantly in all simulations by 10 %–60 % following the reductions of 7 %–78 % in emission projections, with the Eclipse ensemble showing larger reductions in Arctic aerosol burdens compared to the CMIP6 ensemble. For the 2030–2050 period, the Eclipse ensemble simulated a radiative forcing due to aerosol–radiation interactions (RFARI) of −0.39 ± 0.01 W/sq. m, which is −0.08 W/sq. m larger than the 1990–2010 mean forcing (−0.32 W/sq. m), of which −0.24 ± 0.01 W/sq. m was attributed to the anthropogenic aerosols. The CMIP6 ensemble simulated a RFARI of −0.35 to −0.40 W/sq. m for the same period, which is −0.01 to −0.06 W/sq. m larger than the 1990–2010 mean forcing of −0.35 W/sq. m. The scenarios with little to no mitigation (worst-case scenarios) led to very small changes in the RFARI, while scenarios with medium to large emission mitigations led to increases in the negative RFARI, mainly due to the decrease in the positive BC forcing and the decrease in the negative SO2−4 forcing. The anthropogenic aerosols accounted for −0.24 to −0.26 W/sq. m of the net RFARI in 2030–2050 period, in Eclipse and CMIP6 ensembles, respectively. Finally, all simulations showed an increase in the Arctic surface air temperatures throughout the simulation period. By 2050, surface air temperatures are projected to increase by 2.4 to 2.6 °C in the Eclipse ensemble and 1.9 to 2.6 °C in the CMIP6 ensemble, compared to the 1990–2010 mean. Overall, results show that even the scenarios with largest emission reductions leads to similar impact on the future Arctic surface air temperatures and sea-ice extent compared to scenarios with smaller emission reductions, implying reductions of greenhouse emissions are still necessary to mitigate climate change.

Aerosols↗
NASA NTRS2017

Corrosion on Mars: An Investigation of Corrosion Mechanisms Under Relevant Simulated Martian Environments

This one-year project was selected by NASA's Science Innovation Fund in FY17 to address Corrosion on Mars which is a problem that has not been addressed before. Corrosion resistance is one of the most important properties in selecting materials for landed spacecraft and structures that will support surface operations for the human exploration of Mars. Currently, the selection of materials is done by assuming that the corrosion behavior of a material on Mars will be the same as that on Earth. This is understandable given that there is no data regarding the corrosion resistance of materials in the Mars environment. However, given that corrosion is defined as the degradation of a metal that results from its chemical interaction with the environment, it cannot be assumed that corrosion is going to be the same in both environments since they are significantly different. The goal of this research is to develop a systematic approach to understand corrosion of spacecraft materials on Mars by conducting a literature search of available data, relevant to corrosion in the Mars environment, and by performing preliminary laboratory experiments under relevant simulated Martian conditions. This project was motivated by the newly found evidence for the presence of transient liquid brines on Mars that coincided with the suggestion, by a team of researchers, that some of the structural degradation observed on Curiosity's wheels may be caused by corrosive interactions with the brines, while the most significant damage was attributed to rock scratching. An extensive literature search on data relevant to Mars corrosion confirmed the need for further investigation of the interaction between materials used for spacecraft and structures designed to support long-term surface operations on Mars. Simple preliminary experiments, designed to look at the interaction between an aerospace aluminum alloy (AA7075-T73) and the gases present in the Mars atmosphere, at 20degC and a pressure of 700 Pa, showed that there is an interaction between the small amount of oxygen present in the Mars gas and the alloy when there is a scratch that removes the protective aluminum oxide film. Further studies are needed to consider many other important components of the Mars environment that can affect this interaction such as: the effect of oxidants, the effect of radiation on their oxidizing properties and the possible catalytic effects of the clays present in the Martian regolith. The results of this one-year project provide strong justification for further investigation of the corrosion mechanism of materials relevant to long-term surface operations in support of future human exploration missions on Mars.

Perchlorates↗
NASA NTRS1985

A transient heating event in the history of a highlands troctolite from Apollo 12 soil 12033

A 2-mm particle, consisting of a troctolite clast attached to a small amount of glassy soil breccia, was found in a thin section of grains from Apollo 12 sample 12033,66. A description is given of the evolutionary history of the troctolite, taking into account the unique texture. It appears that the particle was broken from its parent rock and projected to Oceanus Procellarum from a source area in the highlands. Before, during, or after the flight, the troctolite was welded to a soil breccia by a minor amount of melting along the contact. It is argued that two separate heating events may be involved. The hypothesis is considered that the partial remelting and quenching of the troctolite took place very rapidly. Attention is given to melting experiments which test and confirm this hypothesis.

Marvin, U. B.↗
NASA NTRS1990

A cloudiness transition in a marine boundary layer

Boundary layer cloudiness plays several important roles in the energy budget of the earth. Low level stratocumulus are highly reflective clouds which reduce the net incoming shortwave radiation at the earth's surface. Climatically, the transition to a small area fraction of scattered cumulus clouds occurs as the air flows over warmer water. Although these clouds reflect less sunlight, they still play an important role in the boundary layer equilibrium by transporting water vapor upwards, and enhancing the surface evaporation. The First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) included a marine stratocumulus experiment off the southern California coast from June 29 to July 19, 1987. The objectives of this experiment were to study the controls on fractional cloudiness, and to assess the role of cloud-top entrainment instability (CTEI) and mesoscale structure in determining cloud type. The focus is one research day, July 7, 1987, when coordinated aircraft missions were flown by four research aircraft, centered on a LANDSAT scene at 1830 UTC. The remarkable feature of this LANDSAT scene is the transition from a clear sky in the west through broken cumulus to solid stratocumulus in the east. The dynamic and thermodynamic structure of this transition in cloudiness is analyzed using data from the NCAR Electra. By averaging the aircraft data, the internal structure of the different cloud regimes is documented, and it is shown that the transition between broken cumulus and stratocumulus is associated with a change in structure with respect to the CTEI condition. However, this results not from sea surface temperature changes, but mostly from a transition in the air above the inversion, and the breakup appears to be at a structure on the unstable side of the wet virtual adiabat.

Betts, Alan K.↗
NASA NTRS1990

On the length of the drift region in the Ramsey cavity

The interaction of atoms in a beam with the microwave field in a separated field geometry such as a Ramsey cavity is generally described in terms of the three regions traversed successively by the atoms, namely two interaction regions of length (l) separated by a drift, or free precession, region of length L. For a monokinetic beam of velocity v, the linewidth of the central fringe in the Ramsey resonance pattern is usually expressed as delta omega equals pi v/L. A more detailed calculation shows, however, that the linewidth is equal to pi v/L asterisk, where the equivalent drift L asterisk is larger than L by an amount of the order of l/L. The correction depends on the field distribution in the interaction regions. Its origin lies in the fact that atomic precession is not limited to the field-free regions but also occurs in the interaction regions, where atomic coherence builds up or decreases continuously. Although the correction to the equivalent length of the drift region is small, it may be relevant to the evaluation of the second-order Doppler effect bias in primary cesium-beam standards to the extent that the atomic velocity is deduced from the lineshape and from the geometrical parameters of the cavity. It is shown that in current and projected standards with atoms of average thermal velocity, use of corrected dimensions may lead to a change of the calculated bias of the order of 10(exp -14), which is significant at the levels of accuracy considered nowadays.

Thomann, Pierre↗
NASA NTRS1991

Research and development of optical measurement techniques for aerospace propulsion research: A NASA Lewis Research Center perspective

The applied research effort required to develop new nonintrusive measurement techniques capable of obtaining the data required by aerospace propulsion researchers and of operating in the harsh environments encountered in research and test facilities is discussed and illustrated through several ongoing projects at NASA's Lewis Research Center. Factors including length of development time, funding levels, and collaborative support from fluid-thermal researchers are cited. Progress in developing new instrumentation via a multi-path approach, including NASA research, grant, and government-sponsored research through mechanisms like the Small Business Innovative Research program, is also described.

Lesco, Daniel J.↗
NASA NTRS1990

Terrestrial ionospheric signatures of field-aligned currents

The occurrence of traveling field-aligned current filaments and twin-vortex patterns is suggested to be related to sudden changes in solar wind dynamic pressure and/or the IMF. Greenland magnetometer observations of the cleft region magnetic perturbations associated with small-scale twin-vortex patterns show that these events occur on both sides of the magnetic local noon, contradicting Glassmeier at al.'s (1989) statistical analysis of 82 twin-vortex subauroral-latitude events obtained by the Scandinavian Magnetometer Array; the stations are closer to the ionospheric projection of the cleft earlier in magnetic local time, relative to the across-the-cleft-located Greenland stations.

Friis-Christensen, E.↗
NASA NTRS1998

Protocol Development for the NASA-JSC Lunar-Mars Life Support Test Project (LMLSTP) Phase 3 Project: A Report on Baseline Studies at KSC for Continuous Salad Production

The Phase 3 Lunar-Mars Life Support Test Project (LMLSTP) was conducted in a 20-foot chamber at Johnson Space Center. The overall objective of the Phase 3 project was to conduct a 90-day regenerative life support system test involving 4 human subjects to demonstrate an integrated biological and physicochemical life support system. A secondary objective of the Phase 3 LMLSTP was to demonstrate the ability to produce salad-type vegetable by integration of a small benchtop growth chamber located within the crew habitat area. This small chamber, commercially manufactured as the Controlled Environment Research Ecosystem (CERES 2010(TM)), functioned as a means to continuously provide fresh lettuce crops for crew members. The CERES 2010(TM) growth chamber utilized hardware components developed for effective plant biomass production in spaceflight applications. These components included: (1) LED lighting; (2) Astroculture(TM) Root Trays; and (3) Zeoponic media. In planning for the LMLSTP Phase 3, a request was put forward for KSC scientists to generate a protocol for successful continuous planting, culturing, and harvesting of the salad-crop, lettuce. By conducting baseline tests with components of the CERES 2010(TM), a protocol was developed.

Goins, G. D.↗
NASA NTRS2011

Portable Multigas Monitors for International Space Station

The Environmental Health System (EHS) on International Space Station (ISS) includes portable instruments to measure various cabin gases that acutely impact crew health. These hand-held devices measure oxygen, carbon dioxide, carbon monoxide, hydrogen chloride and hydrogen cyanide. The oxygen and carbon dioxide units also serve to back up key functions of the Major Constituent Analyzers. Wherever possible, commercial off-the-shelf (COTS) devices are employed by EHS to save development and sustaining costs. COTS hardware designed for general terrestrial applications however has limitations such as no pressure compensation, limited life of the active sensor, calibration drift, battery issues, unpredictable vendor support and obsolescence. The EHS fleet (inflight and ground inventory) of instruments is both aging and dwindling in number. With the retirement of the US Space Shuttle, maintenance of on-orbit equipment becomes all the more difficult. A project is underway to search for gas monitoring technology that is highly reliable and stable for years. Tunable Diode Laser Spectroscopy (TDLS) seems to be the front-runner technology, but generally is not yet commercially available in portable form. NASA has fostered the development of TDLS through the Small Business Innovative Research (SBIR) program. A number of gases of interest to the aerospace and submarine communities can be addressed by TDLS including the list mentioned above plus hydrogen fluoride, ammonia and water (humidity). There are several different forms of TDLS including photoacoustic and direct absorption spectroscopy using various multipass cell geometries. This paper describes the history of portable gas monitoring on NASA spacecraft and provides a status of the development of TDLS based instruments. Planned TDLS flight experiments on ISS could lead both to operational use on ISS and important roles in future Exploration spacecraft and habitats.

Mudgett, Paul D.↗
NASA NTRS2014

X-Ray Polarization Capabilities of a Small Explorer Mission

X-ray polarization measurements hold great promise for studying the geometry and emission mechanisms in the strong gravitational and magnetic fields that surround black holes and neutron stars. In spite of this, the observational situation remains very limited; the last instrument dedicated to X-ray polarimetry flew decades ago on OSO-8, and the few recent measurements have been made by instruments optimized for other purposes. However, the technical capabilities to greatly advance the observational situation are in hand. Recent developments in micro-pattern gas detectors allow use of the polarization sensitivity of the photo-electric effect, which is the dominant interaction in the band above 2 keV. We present the scientific and technical requirements for an X-ray polarization observatory consistent with the scope of a NASA Small Explorer (SMEX) mission, along with a representative catalog of what the observational capabilities and expected sensitivities for the first year of operation could be. The mission is based on the technically robust design of the Gravity and Extreme Magnetism SMEX (GEMS) which completed a Phase B study and Preliminary Design Review in 2012. The GEMS mission is enabled by time projection detectors sensitive to the photo-electric effect. Prototype detectors have been designed, and provide engineering and performance data which support the mission design. The detectors are further characterized by low background, modest spectral resolution, and sub-millisecond timing resolution. The mission also incorporates high efficiency grazing incidence X-ray mirrors, design features that reduce systematic errors (identical telescopes at different azimuthal angles with respect to the look axis, and mounted on a rotating spacecraft platform), and a moderate capability to perform Target of Opportunity observations. The mission operates autonomously in a low earth, low inclination orbit with one to ten downlinks per day and one or more uplinks per week. Data and calibration products will be made available through the High Energy Astrophysics Science and Archival Research Center (HEASARC).

GEMS↗
NASA NTRS1996

International Research Project on the Effects of Chemical Ageing of Polymers on Performance Properties: Chemical and Thermal Analysis

Work during the past six months has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted small changes in the molecular weight distribution. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Ultra- Violet Scanning Analysis, GC/Mass Spectrometry, Differential Scanning Calorimetry and Thermomechanical Analysis. In the ultra-violet analysis we noted the presence of an absorption band indicative of triene formation. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. We also cast films at SWT and subjected these films to a refluxing methanol 1% ethylene diamine solution. An updated literature search was conducted using Dialog and DROLLS to identify any new papers that may have been published in the open literature since the start of this project. The updated literature search and abstracts are contained in the Appendix section of this report.

Bulluck, J. W.↗
NASA NTRS1979

Small signal amplifiers and converters for millimeter wave Satcom systems

This paper describes the current state of the art and the various design tradeoffs encompassing the variety of small signal active circuit 'building blocks' deployed in millimeter wave Satcom receivers and transmitters. Included in this catagory are such low noise receiver components as parametric and FET amplifiers and low loss mixer downconverters as well as low level transmitter driver components such as resistive and varactor upconverters. Current and projected state of the art performance data will be presented along with specific examples of operating hardware.

Okean, H. C.↗
NASA NTRS1991

A nonradial pulsation model for the rapidly rotating Delta Scuti star Kappa(2) Bootis

A sectorial nonradial pulsation model is used to construct theoretical line profiles which mimic the variations for Kappa(2) Boo. Synthetic spectra generated with the appropriate Teff and log g are used as input. It is found that the data can be reproduced by the combination of a high-degree l is approximately equal to 12 mode with P(osc) aproximately equal to 0.071 d, and a low-degree mode, l is approximately equal to 0-2 with P(osc) approximately equal to 0.071-0.079 d. The projected rotational velocity (v sin i - 115 +/-5 km/s) was determined by fitting synthetic line profiles to the observed spectra. The velocity amplitude of the high-degree oscillations is estimated to be about 3.5 km/s. It is found that the ratio of the horizontal and radial pulsation amplitudes is small (about 0.02) and consistent with p-mode oscillations. Comparisons are made with models invoking starspots, and it is impossible to fit the observations of Kappa(2) Boo by a starspot model without assuming unrealistic values of radius or equatorial velocity.

Kennelly, E. J.↗
NASA NTRS1993

A COMPACT model reduction methodology for articulated, multi-flexible bodies structures

To simulate the dynamical motion of articulated, multiflexible body structures, one can use multibody simulation packages such as DISCOS. To this end, one need appropriate reduced-order models for all the flexible components involved. The component modes projection and assembly model reduction methodology is one way to construct these reduced-order component models. However, the generated reduced-order system models typically contain high frequency extraneous modes. The presence of high frequency extraneous modes in a reduced-order system model forces us to use a small stepsize in the numerical integration of that model, resulting in an increase in the elapsed time of the integration process. To eliminate these high-frequency modes, we first identify and discard the component modes that 'contributed' to the generations of these modes. A sensitivity analysis is then used to determine how the remaining component modes should be perturbed in order to still closely capture the selected system modes. The effectiveness of the proposed methodology has been successfully verified using a finite-element model of the Galileo spacecraft.

Lee, Allan Y.↗
NASA NTRS1995

The axis ratio distribution of faint galaxies: Evidence for a populatin of dwarfgalaxies at I approximately 20.5

The axis ratio distribution of faint galaxies observed by the Hubble Space Telescope (HST) as part of the Medium Deep Survey (MDS) key project suggests that a very large fraction of the total population at magnitudes I greater than or equal to 20 mag consists of a class of galaxies with luminosity profile, axis ratio distribution, angular size, and color that resemble local dwarfs. We find that galaxies with exponential light profiles and small angular sizes (half-light radius less than 0.6 sec) have an axis ratio distribution that is incompatible with their being intrinsically flattened objects and is instead consistent with local elliptical galaxies. We call these objects 'Small Exponential Ellipticals.' They are most likely dwarf galaxies, and they are numerous enough that, together with irregular galaxies, they can account for most if not all of the excess in the number counts at I approximately 20-21 mag with respect to the standard no-evolution models. This may suggest that the excess number counts are best explained by dwarf-rich models with strong luminosity evolution of the dwarf galaxies. Our data also supports a very mild luminosity evolution of the giant galaxy populations, which contributes little to the excess number counts.

Im, Myungshin↗
NASA NTRS1999

Premixed Turbulent Flame Propagation in Microgravity

A combined numerical-experimental study has been carried out to investigate the structure and propagation characteristics of turbulent premixed flames with and without the influence of buoyancy. Experimentally, the premixed flame characteristics are studied in the wrinkled regime using a Couette flow facility and an isotropic flow facility in order to resolve the scale of flame wrinkling. Both facilities were chosen for their ability to achieve sustained turbulence at low Reynolds number. This implies that conventional diagnostics can be employed to resolve the smallest scales of wrinkling. The Couette facility was also built keeping in mind the constraints imposed by the drop tower requirements. Results showed that the flow in this Couette flow facility achieves full-developed turbulence at low Re and all turbulence statistics are in good agreement with past measurements on large-scale facilities. Premixed flame propagation studies were then carried out both using the isotropic box and the Couette facility. Flame imaging showed that fine scales of wrinkling occurs during flame propagation. Both cases in Ig showed significant buoyancy effect. To demonstrate that micro-g can remove this buoyancy effect, a small drop tower was built and drop experiments were conducted using the isotropic box. Results using the Couette facility confirmed the ability to carry out these unique reacting flow experiments at least in 1g. Drop experiments at NASA GRC were planned but were not completed due to termination of this project.

Menon, Suresh↗