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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 397 records · Page 22
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NASA NTRS2007

Proceedings of the Seventh International Conference on Mars

The oral and poster sessions of the SEVENTH INTERNATIONAL CONFERENCE ON MARS included; The Distribution and Context of Water-related Minerals on Mars; Poster Session: Mars Geology; Geology of the Martian Surface: Lithologic Variation, Composition, and Structure; Water Through Mars' Geologic History; Poster Session: Mars Water and the Martian Interior; Volatiles and Interior Evolution; The Martian Climate and Atmosphere: Variations in Time and Space; Poster Session: The Martian Climate and Current Processes; Modern Mars: Weather, Atmospheric Chemistry, Geologic Processes, and Water Cycle; Public Lecture: Mars Reconnaissance Orbiter's New View of the Red Planet; The North and South Polar Layered Deposits, Circumpolar Regions, and Changes with Time; Poster Session: Mars Polar Science, Astrobiology, Future Missions/Instruments, and Other Mars Science; Mars Astrobiology and Upcoming Missions; and Martian Stratigraphy and Sedimentology: Reading the Sedimentary Record.

Source record↗
NASA NTRS2022

An Overview of Atmospheric Features Over the Western North Atlantic Ocean and North American East Coast – Part 1: Analysis of Aerosols, Gases, and Wet Deposition Chemistry

The Western North Atlantic Ocean (WNAO) and adjoining East Coast of North America are of great importance for atmospheric research and have been extensively studied for several decades. This broad region exhibits complex meteorological features and a wide range of conditions associated with gas and particulate species from many sources regionally and other continents. As Part 1 of a 2‐part paper series, this work characterizes quantities associated with atmospheric chemistry, including gases, aerosols, and wet deposition, by analyzing available satellite observations, ground‐based data, model simulations, and reanalysis products. Part 2 provides insight into the atmospheric circulation, boundary layer variability, three‐dimensional cloud structure, properties, and precipitation over the WNAO domain. Key results include spatial and seasonal differences in composition along the North American East Coast and over the WNAO associated with varying sources of smoke and dust and meteorological drivers such as temperature, moisture, and precipitation. Spatial and seasonal variations of tropospheric carbon monoxide and ozone highlight different pathways towards the accumulation of these species in the troposphere. Spatial distributions of speciated aerosol optical depth and vertical profiles of aerosol mass mixing ratios show a clear seasonal cycle highlighting the influence of different sources in addition to the impact of intercontinental transport. Analysis of long‐term climate model simulations of aerosol species and satellite observations of carbon monoxide confirm that there has been a significant decline in recent decades among anthropogenic constituents owing to regulatory activities.

ACTIVATE↗
NASA NTRS1989

Thermal evolution of Titan's atmosphere

The present model of Titan's atmosphere/surface evolution assumes the presence of a kilometer-deep ethane-methane ocean at the surface that serves as a tropospheric thermal balance-determining atmospheric-gas reservoir. The evolution of the atmospheric thermal structure is driven by gas-abundance changes occurring as stratospheric photolysis irreversibly converts methane into higher hydrocarbons, whereby the ocean becomes ethane-enriched and methane-depleted. A family of evolution models is presented whose various members correspond to different present-day ocean compositions, various atmospheric hydrogen abundances, and different schemes for frequency-averaging the gas opacity. A slow evolution over several billion years is envisioned.

Lunine, Jonathan I.↗
NASA NTRS1972

Space Shuttle Atmospheric ascent flight dynamics

The atmospheric ascent flight phase of the mated composite booster and orbiter is discussed. The composite recoverable space shuttle booster and orbiter exhibits unique flight control characteristics. This uniqueness results from large lifting surfaces and aerodynamic and structural assymetrics. An effective load relief technique reduces aerodynamic loads on both the booster and the orbiter. Reducing aerodynamic loads permits decreasing the structural weight of the lifting and stabilizing surfaces. An orbiter payload penalty is caused by trajectory deviations resulting from load relief. However, the net effect of an effective load relief technique is an increase in payload capability. Atmospheric launch dynamics investigations have been carried out for different configuration types, which include expendable, straight wing, delta wing, and ballistic recoverable boosters.

Patha, J. T.↗
NASA NTRS1972

Hydrogen planets and high-pressure physics

A theoretical discussion of the composition of the major planets is presented. A simplistic physical model of the giant planets is described. The conclusions of several theoretical explanations of the planetary structure are explained. Curves are developed to show the mass-radius relation for zero temperature spheres of various chemical compositions. The density of isothermal atmospheres of hydrogen as a function of the elevation above a surface of solid hydrogen.

Wildt, R.↗
NASA NTRS1990

Entry-probe studies of the atmospheres of earth, Mars, and Venus - A review (Von Karman Lecture)

This paper overviews the history (since 1963) of the exploration of planetary atmospheres by use of entry probes. The techniques used to measure the compositions of the atmospheres of the earth, Mars, and Venus are described together with the key results obtained. Attention is also given to the atmosphere-structure experiment aboard the Galileo Mission, launched on October 17, 1989 and now under way on its 6-yr trip to Jupiter, and to future experiments.

Seiff, Alvin↗
NASA NTRS1992

Atmospheric measurements of peroxyacetyl nitrate and other organic nitrates at high latitudes - Possible sources and sinks

Measurements of PAN and other reactive nitrogen species during the NASA Arctic Boundary Layer Expedition (ABLE 3A) are described, their north-south and east-west gradients in the free troposphere are characterized, and the sources and sinks of PAN and NO(y) are assessed. Large concentrations of PAN and NO(y) are present in the Arctic/sub-Arctic troposphere of the Northern Hemisphere during the summer. Mixing ratios of PAN and a variety of other molecules are more abundant in the free troposphere compared to the boundary layer. Coincident PAN and O3 atmospheric structures suggest that phenomena that define PAN also define the corresponding O3 behavior. Model calculations, correlations between NO(y) and anthropogenic tracers, and the compositions of NO(y) itself suggest that the Arctic/sub-Arctic reactive nitrogen measured during ABLE 3A is predominantly of anthropogenic origin with a minor component from the stratosphere.

Singh, H. B.↗
NASA NTRS1992

Conceptual design and structural analysis of the spectroscopy of the atmosphere using far infrared emission (SAFIRE) instrument

The conceptual design and structural analysis for the Spectroscopy of the Atmosphere using Far Infrared Emission (SAFIRE) Instrument are provided. SAFIRE, which is an international effort, is proposed for the Earth Observing Systems (EOS) program for atmospheric ozone studies. A concept was developed which meets mission requirements and is the product of numerous parametric studies and design/analysis iterations. Stiffness, thermal stability, and weight constraints led to a graphite/epoxy composite design for the optical bench and supporting struts. The structural configuration was determined by considering various mounting arrangements of the optical, cryo, and electronic components. Quasi-static, thermal, modal, and dynamic response analyses were performed, and the results are presented for the selected configuration.

Moses, Robert W.↗
NASA NTRS1976

Biology on the outer planets

A brief review is given of information on the structure and composition of the outer planets and the organic reactions that may be occurring on them. The possibility of life arising or surviving in the atmospheres of these planets is considered, and the problem of contamination during future unmanned missions is assessed. Atmospheric models or available atmospheric data are reviewed for Jupiter, Saturn, Uranus, Neptune, Pluto, the Galilean satellites, and Titan. The presence of biologically interesting gases on Jupiter and Saturn is discussed, requirements for life on Jupiter are summarized, and possible sources of biological energy are examined. Proposals are made for protecting these planets and satellites from biological contamination by spacecraftborne terrestrial organisms.

Young, R. S.↗
NASA NTRS1981

Constraints on the composition of the Venus atmosphere from microwave measurements near 1.35 cm wavelength

The determination of the brightness temperature of Venus near 1.35 cm wavelength is reviewed. The observed brightness temperature is compared with models for the microwave emission based on the physical and chemical structure of the atmosphere as obtained from spacecraft. Upper limits are set on the concentrations of microwave-absorbing minor constituents. In particular, upper limits are determined for SO2 (180 ppm) and H2O (0.3%) for a mixing-ratio profile that is uniformly mixed up to the cloud bottom at 50 km and is rapidly depleted (scale height, approximately 1 km) at higher altitudes. The total optical depth of the cloud region at or above 50 km is less than 0.17 at 1.35 cm wavelength. The SO2 upper limit is only in marginal agreement with the spacecraft results, and it may be that the latter have been overestimated, or that the distribution of SO2 is more complex than given by the uniform mixing model.

Janssen, M. A.↗
NASA NTRS2008

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Glass, David E.↗
NASA NTRSDate not supplied

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth’s atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. The presentation will start with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the “insulated airplane” approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the presentation will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Thermal Protection Systems↗
NASA NTRSDate not supplied

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth’s atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. The presentation will start with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the “insulated airplane” approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the presentation will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

David E Glass↗
NASA NTRSDate not supplied

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth’s atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. The presentation will start with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the “insulated airplane” approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the presentation will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Thermal Protection Systems, hot structure↗
NASA NTRS1985

Specification of Surface Roughness Over Oceans in the GLAS Fourth Order GCM

The surface roughness height z sub 0 is a parameter which measures the effect of surface irregularities on the mean profiles which occur in the atmospheric surface layer. Over land surfaces, z sub 0 is a function of soil composition, plant canopy type and distribution and other factors such as buildings and structures. Over open water, z sub 0 depends only on the distribution of waves, wavelets and other surface irregularities. These, in turn, are thought to be determined by the mean wind within the surface layer. Large and Pond have derived an empirical relationship between the mean wind speed U sub 10 at the ten meter level over open water and the neutral drag coefficient C sub DN. Their relationship covers the range U sub 10 or = M/S. Earlier, Kondo had computed a relationship between U sub 10 and C sub DN on the basis of laboratory observations which extended down to the range of infinitely small wind speeds. An interpretation between the relationships of Large and Pond for large wind speed and of Kondo for small wind speed is presented.

Helfand, H. M.↗
NASA NTRSDate not supplied

Relating Lightning Activity to the Convective Evolution of Pre-Genesis Tropical Disturbances

Lightning and environmental characteristics are analyzed for National Hurricane Center (NHC) invest disturbances. For 2019-2021, Atlantic NHC invest tracks are grouped into disturbances that eventually developed into tropical cyclones (TCs) and ones that did not. Data from the NASA/NOAA Geostationary Lightning Mapper (GLM) is used to quantify potential differences in total optical energy, flash extent density, and flash area between the groups. To provide environmental context to the lightning results, vertical profiles from the NOAA Unique Combined Atmospheric Processing System (NUCAPS) dataset will be investigated. Specifically, the profiles will provide insight into the temperature and moisture structure of the invests. In addition to the composite analysis, interesting cases of tropical cyclogenesis will be examined in further detail. Overall, this work seeks to further our understanding of lightning properties and convective environments in tropical cyclogenesis.

Justin W Whitaker↗
NASA NTRS1976

Infrared spectra of molecules and materials of astrophysical interest

The vibrational spectra from 4,000 to 33/cm of several molecules which may be present in the atmosphere of the Jovian planets or exist in outer space were studied. These studies have been made to provide vibrational frequencies which can be used to: (1) determine the composition of the cloud covers of several of the planets, (2) provide structural information under favorable circumstances, (3) provide necessary data from which accurate thermodynamic data can be calculated, and (4) furnish information as to the nature of the potential energy function of the molecules and forces acting within them. Some of the molecules studied can be produced photochemically from methane, ammonia, and hydrogen sulfide which are thought to be constituents of the planets with reducing atmospheres. Some of the compounds will polymerize under ultraviolet radiation and drop out of the atmospheres. However, planets with a hot base, like that of Jupiter, may rebuild molecules destroyed photochemically. These criteria were used in selecting the compounds under study.

Durig, J. R.↗