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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

A distributed analysis and visualization system for model and observational data

The objective of this proposal is to develop an integrated and distributed analysis and display software system which can be applied to all areas of the Earth System Science to study numerical model and earth observational data from storm to global scale. This system will be designed to be easy to use, portable, flexible and easily extensible and designed to adhere to current and emerging standards whenever possible. It will provide an environment for visualization of the massive amounts of data generated from satellites and other observational field measurements and from model simulations during or after their execution. Two- and three-dimensional animation will also be provided. This system will be based on a widely used software package from NASA called GEMPAK and prototype software for three-dimensional interactive displays built at NCSA. The underlying foundation of the system will be a set of software libraries which can be distributed across a UNIX based supercomputer and workstations.

Wilhelmson, Robert↗
NASA NTRS2001

The Altus Cumulus Electrification Study (ACES): A UAV-based Investigation of Thunderstorms

The Altus Cumulus Electrification Study (ACES) is a NASA-sponsored and -led science investigation that utilizes an uninhabited aerial vehicle (UAV) to investigate thunderstorms in the vicinity of the NASA Kennedy Space Center, Florida. As part of NASA's UAV-based science demonstration program, ACES will provide a scientifically useful demonstration of the utility and promise of UAV platforms for Earth science and applications observations. ACES will employ the Altus 11 aircraft, built by General Atomics-Aeronautical Systems, Inc. By taking advantage of its slow flight speed (70 to 100 knots), long endurance, and high-altitude flight (up to 55,000 feet), the Altus will be flown near, and when possible, above (but never into) thunderstorms for long periods of time, allowing investigations to be conducted over entire storm life cycles. Key science objectives simultaneously addressed by ACES are to: (1) investigate lightning-storm relationships, (2) study storm electrical budgets, and (3) provide Lightning Imaging Sensor validation. The ACES payload, already developed and flown on Altus, includes electrical, magnetic, and optical sensors to remotely characterize the lightning activity and the electrical environment within and around thunderstorms. The ACES field campaign will be conducted during July 2002 with a goal of performing 8 to 10 UAV flights. Each flight will require about 4 to 5 hours on station at altitudes from 40,000 ft to 55,000 ft. The ACES team is comprised of scientists from the NASA Marshall Space Flight Center and NASA Goddard Space Flight Centers partnered with General Atomics and IDEA, LLC.

Blakeslee, Richard↗
NASA NTRS2010

Preliminary Testing of a Pressurized Space Suit and Candidate Fabrics Under Simulated Mars Dust Storm and Dust Devil Conditions

In August 2009 YAP Films (Toronto) received permission from all entities involved to create a documentary film illustrating what it might be like to be on the surface of Mars in a space suit during a dust storm or in a dust devil. The science consultants on this project utilized this opportunity to collect data which could be helpful to assess the durability of current space suit construction to the Martian environment. The NDX?1 prototype planetary space suit developed at the University of North Dakota was used in this study. The suit features a hard upper torso garment, and a soft lower torso and boots assembly. On top of that, a nylon-cotton outer layer is used to protect the suit from dust. Unmanned tests were carried out in the Martian Surface Wind Tunnel (MARSWIT) at the NASA Ames Research Center, with the suit pressurized to 10 kPa gauge. These tests blasted the space suit upper torso and helmet, and a collection of nine candidate outer layer fabrics, with wind-borne simulant for five different 10 minute tests under both terrestrial and Martian surface pressures. The infiltration of the dust through the outer fabric of the space suit was photographically documented. The nine fabric samples were analyzed under light and electron microscopes for abrasion damage. Manned tests were carried out at Showbiz Studios (Van Nuys, CA) with the pressure maintained at 20?2 kPa gauge. A large fan-created vortex lifted Martian dust simulant (Fullers Earth or JSC Mars?1) off of the floor, and one of the authors (Lee) wearing the NDX?1 space suit walked through it to judge both subjectively and objectively how the suit performed under these conditions. Both the procedures to scale the tests to Martian conditions and the results of the infiltration and abrasion studies will be discussed.

Gaier, James R.↗
NASA NTRS2010

Preliminary Testing of a Pressurized Space Suit and Candidate Fabrics Under Simulated Mars Dust Storm and Dust Devil Conditions

In August 2009 YAP Films (Toronto) received permission from all entities involved to create a documentary film illustrating what it might be like to be on the surface of Mars in a space suit during a dust storm or in a dust devil. The science consultants on this project utilized this opportunity to collect data which could be helpful to assess the durability of current space suit construction to the Martian environment. The NDX-1 prototype planetary space suit developed at the University of North Dakota was used in this study. The suit features a hard upper torso garment, and a soft lower torso and boots assembly. On top of that, a nylon-cotton outer layer is used to protect the suit from dust. Unmanned tests were carried out in the Martian Surface Wind Tunnel (MARSWIT) at the NASA Ames Research Center, with the suit pressurized to 10 kPa gauge. These tests blasted the space suit upper torso and helmet, and a collection of nine candidate outer layer fabrics, with wind-borne simulant for five different 10 min tests under both terrestrial and Martian surface pressures. The infiltration of the dust through the outer fabric of the space suit was photographically documented. The nine fabric samples were analyzed under light and electron microscopes for abrasion damage. Manned tests were carried out at Showbiz Studios (Van Nuys, California) with the pressure maintained at 20 2 kPa gauge. A large fan-created vortex lifted Martian dust simulant (Fullers Earth or JSC Mars-1) off of the floor, and one of the authors (Lee) wearing the NDX-1 space suit walked through it to judge both subjectively and objectively how the suit performed under these conditions. Both the procedures to scale the tests to Martian conditions and the results of the infiltration and abrasion studies will be discussed.

Gaier, James R.↗
NASA NTRSDate not supplied

The Effect of Drag Model on Heatshield Recession due to Particle Impacts for Martian Spacecraft

A spacecraft entering the Martian atmosphere during a dust storm may experience recession to the heatshield due to dust particle impacts. Aerodynamic drag is the primary force that determines the trajectory of the dust particles through the shock layer. This paper examines the effect of particle drag model on the heatshield recession. Three particle drag models are assessed including two that are intended to be applicable over a wide range of particle flow conditions. Particle trajectories are computed in conditions measured during the 2007 major global dust storm. It was found that accounting for Knudsen number and compressibility effects made a large difference in the estimated particle impact velocity. The two drag models that were valid for transitional, compressible particle flow environments predicted only slightly-different amounts of heatshield recession due to dust particle impacts. A brief description of the effects of non-spherical particles on drag coefficients is provided.

Heatshield↗
NASA NTRSDate not supplied

The Effect of Drag Model on Heatshield Recession due to Particle Impacts for Martian Spacecraft

A spacecraft entering the Martian atmosphere during a dust storm may experience recession to the heatshield due to dust particle impacts. Aerodynamic drag is the primary force that determines the trajectory of the dust particles through the shock layer. This paper examines the effect of particle drag model on the heatshield recession. Three particle drag models are assessed including two that are intended to be applicable over a wide range of particle flow conditions. Particle trajectories are computed in conditions measured during the 2007 major global dust storm. It was found that accounting for Knudsen number and compressibility effects made a large difference in the estimated particle impact velocity. The two drag models that were valid for transitional, compressible particle flow environments predicted only slightly-different amounts of heatshield recession due to dust particle impacts. A brief description of the effects of non-spherical particles on drag coefficients is provided.

Heatshield↗
NASA NTRS2023

Mesoscale Phenomena and Their Contribution to the Global Response: A Focus on the Magnetotail Transition Region and Magnetosphere-Ionosphere Coupling

An important question that is being increasingly studied across subdisciplines of Heliophysics is “how do mesoscale phenomena contribute to the global response of the system?” This review paper focuses on this question within two specific but interlinked regions in Near-Earth space: the magnetotail’s transition region to the inner magnetosphere and the ionosphere. There is a concerted effort within the Geospace Environment Modeling (GEM) community to understand the degree to which mesoscale transport in the magnetotail contributes to the global dynamics of magnetic flux transport and dipolarization, particle transport and injections contributing to the storm-time ring current development, and the substorm current wedge. Because the magnetosphere-ionosphere is a tightly coupled system, it is also important to understand how mesoscale transport in the magnetotail impacts auroral precipitation and the global ionospheric system response. Groups within the Coupling, Energetics and Dynamics of Atmospheric Regions Program (CEDAR) community have also been studying how the ionosphere-thermosphere responds to these mesoscale drivers. These specific open questions are part of a larger need to better characterize and quantify mesoscale “messengers” or “conduits” of information—magnetic flux, particle flux, current, and energy—which are key to understanding the global system. After reviewing recent progress and open questions, we suggest datasets that, if developed in the future, will help answer these questions.

transition region↗
NASA NTRS2011

The Electrostatic Environments of Mars and the Moon

The electrical activity present in the environment near the surfaces of Mars and the moon has very different origins and presents a challenge to manned and robotic planetary exploration missions. Mars is covered with a layer of dust that has been redistributed throughout the entire planet by global dust storms. Dust, levitated by these storms as well as by the frequent dust devils, is expected to be electrostatically charged due to the multiple grain collisions in the dust-laden atmosphere. Dust covering the surface of the moon is expected to be electrostatically charged due to the solar wind, cosmic rays, and the solar radiation itself through the photoelectric effect. Electrostatically charged dust has a large tendency to adhere to surfaces. NASA's Mars exploration rovers have shown that atmospheric dust falling on solar panels can decrease their efficiency to the point of rendering the rover unusable. And as the Apollo missions to the moon showed, lunar dust adhesion can hinder manned and unmanned lunar exploration activities. Taking advantage of the electrical activity on both planetary system bodies, dust removal technologies are now being developed that use electrostatic and dielectrophoretic forces to produce controlled dust motion. This paper presents a short review of the theoretical and semiempirical models that have been developed for the lunar and Martian electrical environments.

Calle, Carlos I.↗
NASA NTRS1991

Thermal environment of Mars

Thermal observations of Mars are reviewed focusing on surface and atmospheric temperatures. Data obtained indicate that the effect of increasing dust in the atmosphere is to reduce diurnal temperature variation at the surface, while enhancing atmospheric thermal variation. Atmospheric thermal effects can be induced by global dust storms even in regions of polar night. Maximum temperatures occur near the equator in summer or at local sites with sunward facing slopes, where low surface thermal inertias make it possible to achieve values up to about 310 K. Radiation and convection in the daytime affect atmospheric temperatures near the surface, which are limited by radiation at night. Results of thermal observations confirm that Mars' thermal state and climate can significantly vary from year to year, due to the variation in dust activity.

Martin, T. Z.↗
NASA NTRSDate not supplied

Changes in Lightning Characteristics as Hurricane Dorian (2019) Reached Peak Intensity

Previous work using land-based lightning detection networks and lightning imagers in low Earth orbit has established that lighting is a useful predictor of TC intensification. Increases in the number of lightning flashes in both the inner core and outer rainbands of hurricanes are linked to hurricane intensification. Sometimes, however, lightning outbreaks can occur in storms that weaken during or after the outbreak. Environmental conditions such as vertical wind shear and land interaction or inner-core structural changes such as secondary eyewall formation can account for some of this discrepancy. Hurricane Dorian (2019), however, exhibited a distinct inner-core lightning outbreak in a low-shear environment with minimal land interaction. The lightning flashes during this outbreak were located on the inner edge of the eyewall, which is not the expected location of enhanced convection during secondary eyewall formation. Regardless, Dorian weakened during and after this lightning outbreak. This presentation will analyze Dorian’s lightning evolution using data from the Geostationary Lightning Mapper (GLM) aboard the GOES-16 satellite. GLM provides continuous observations of not only the number and polarity of lightning flashes, but also the size and optical energy of the flashes. Here we show marked differences in the distributions of average flash area and total optical energy between the two most pronounced lightning outbreaks in Dorian’s lifetime: one while the storm was rapidly intensifying and another while the storm began to weaken. During intensification, lightning flashes were fewer but larger and more energetic, whereas during weakening, lightning flashes were much more numerous, but were smaller and less energetic. We present evidence that barotropic mixing between the eye and eyewall could have contributed to both the increase in inner-core lightning and the weakening of Dorian’s storm-scale maximum wind speed. These results suggest that average flash area and total optical energy could help to distinguish between lightning outbreaks that correspond to intensification and outbreaks that correspond to weakening.

Hurricanes↗
NASA NTRS2013

Understanding the Relationships Between Lightning, Cloud Microphysics, and Airborne Radar-derived Storm Structure During Hurricane Karl (2010)

This study explores relationships between lightning, cloud microphysics, and tropical cyclone (TC) storm structure in Hurricane Karl (16 September 2010) using data collected by the NASA DC-8 and Global Hawk (GH) aircraft during NASA's Genesis and Rapid Intensification Processes (GRIP) experiment. The research capitalizes on the unique opportunity provided by GRIP to synthesize multiple datasets from two aircraft and analyze the microphysical and kinematic properties of an electrified TC. Five coordinated flight legs through Karl by the DC-8 and GH are investigated, focusing on the inner-core region (within 50km of the storm center) where the lightning was concentrated and the aircraft were well coordinated. GRIP datasets are used to compare properties of electrified and nonelectrified inner-core regions that are related to the noninductive charging mechanism, which is widely accepted to explain the observed electric fields within thunderstorms. Three common characteristics of Karl's electrified regions are identified: 1) strong updrafts of 10-20ms21, 2) deep mixed-phase layers indicated by reflectivities.30 dBZ extending several kilometers above the freezing level, and 3) microphysical environments consisting of graupel, very small ice particles, and the inferred presence of supercooled water. These characteristics describe an environment favorable for in situ noninductive charging and, hence, TC electrification. The electrified regions in Karl's inner core are attributable to a microphysical environment that was conducive to electrification because of occasional, strong convective updrafts in the eyewall.

Cloud mircophysics↗
NASA NTRS2003

Warm Core Structure of Hurricane Erin Diagnosed from High Altitude Dropsondes during CAMEX-4

A combination multi-aircraft and several satellite sensors were used to examine the core of Hurricane Erin on September 10, 2001, as part of the CAMEX4 program. During the first set of aircraft passes, around 1700 UTC, Erin was still at its maximum intensity with a central pressure of 969 hpa and windspeed of 105 kts (54 m/s). The storm was moving slowly northwestward at 4 m/s, over an increasingly colder sea surface. Three instrumented aircraft, the NOAA P3 with radar, the NASA ER- 2 at 19 km, newly equipped with GPS dropwindsondes, and the NASA DC-8 with dropwindsondes flew in formation across the eye at about 1700 UTC and again 2.5 hrs later around 1930 UTC. The storm had weakened by 13 m/s between the first and second eye penetrations. The warm core had a maximum temperature anomaly of only 11 C, located at 500 hpa, much weaker and lower than active hurricanes. The core appeared to slant rearward above 400 hpa. Even on the first penetration, airborne radar showed that the eye wall cloud towers were dying. The tops fell short of reaching 15 km and a melting band was found throughout. The tropopause had a bulge to 15.8 km elevation (environment approx. 14.4 km) above the dying convection. A feature of Erin at this timt was a pronounced wave-number-one convective asymmetry with all convective activity being confined to the forward quadrants on the left side of the shear vector as calculated from analyses. This is similar to that predicted by the mesoscale numerical models, which also predict that such small amounts of shear would not affect the storm intensity. In Erin, it is remarkable that relatively small shear produced such a pronounced asymmetry in the convection. In addition, horizontal asymmetries in the low-level warm core were identified. Almost certainly, the colder ocean would kill the tall convective towers feeding the warm core, even if wind shear were absent.

Halverson, J. B.↗
NASA NTRS1997

Detecting Small-Scale Topographic Changes and Relict Geomorphic Features on Barrier Islands Using SAR

The shapes and elevations of barrier islands may change dramatically over a short period of time during a storm. Coastal scientists and engineers, however, are currently unable to measure these changes occurring over an entire barrier island at once. This three-year project, which is funded by NASA and jointly conducted by the Bureau of Economic Geology and the Center for Space Research at The University of Texas at Austin, is designed to overcome this problem by developing the use of interferometry from airborne synthetic aperture radar (AIRSAR) to measure coastal topography and to detect storm-induced changes in topography. Surrogate measures of topography observed in multiband, fully polarimetric AIRSAR (This type of data are now referred to as POLSAR data.) are also being investigated. Digital elevation models (DEM) of Galveston Island and Bolivar Peninsula, Texas obtained with Topographic SAR (TOPSAR) are compared with measurements by Global Positioning System (GPS) ground surveys and electronic total station surveys. In addition to topographic mapping, this project is evaluating the use of POLSAR to detect old features such as storm scarps, storm channels, former tidal inlets, and beach ridges that have been obscured by vegetation, erosion, deposition, and artificial filling. We have also expanded the work from the original proposal to include the mapping of coastal wetland vegetation and depositional environments. Methods developed during this project will provide coastal geologists with an unprecedented tool for monitoring and understanding barrier island systems. This understanding will improve overall coastal management policies and will help reduce the effects of natural and man-induced coastal hazards. This report summarizes our accomplishments during the second year of the study. Also included is a discussion of our planned activities for year 3 and a revised budget.

Gibeaut, James C.↗
NASA NTRS2018

Science Service Status 2019 World Radiocommunication Conference

Science missions such as Earth-exploration and remote sensing thatuse frequencies allocated for Earth Exploration-Satellite Service(EESS) provide valuable information about, for example: (1) Air quality monitoring (2) Soil moisture mapping (3) Sensing sea salinity (4) Weather forecasting and climate models (winds, storms, clouds).Another set of science missions use Space Research Service (SRS)allocations. These space research missions can support: (1) On orbit research that for example can help in the creation of new drugsor the impact of the space environment on satellites (2) Scientific information about the universe – stars, planetary science, solarsystem, and the future evolution of the universe.

Roura, Corali↗
NASA NTRS1994

Field and data analysis studies related to the atmospheric environment

This report summarizes work on a broad array of projects including: (1) applications of meteorological and/or oceanographic satellites; (2) improvement of the current set of NASA/USAF lightning related launch commit criteria rules; (3) the design, building, testing and deployment of a set of cylindrical field mills for aircraft use; (4) the study of marginal electrification storm conditions in relationship to the current launch commit rules for the space shuttle and various other launch vehicles using an instrumented aircraft; (5) support of the DC-8 and ER-2 lightning instrument package as part of both the Tropical Ocean - Global Atmospheric/Coupled Ocean-Atmospheric Response Experiment and the Convection and Moisture Experiment; (6) design of electronic circuitry and microprocessor firmware for the NASA Advanced Ground Based Field Mill; (7) design and testing of electronic and computer instrumentation for atmospheric electricity measurements; (8) simulating observations from a lightning imaging sensor on the Tropical Rainfall Measuring satellite; and (9) supporting scientific visualization and the development of computer software tools.

Kidder, Stanley↗
NASA NTRS1986

Rapid evolution of a jet streak circulation in a pre-convective environment

An analysis of the April 10, 1979 Red River Valley severe weather outbreak, using a three-hourly rawinsonde network, indicates that the preconvection environment is influenced by upper-level and lower-level tropospheric jet streaks (ULJs and LLJs) that act to destabilize the atmosphere, and contribute to low-level heat and moisture transports and convergence that act to initiate the storm system. Transformation of an indirect circulation noted within the exit region of the ULJ at 1200 and 1500 GMT is observed within a six-hour period. Dramatic changes are found in the jet streak circulations over a short period of time as the system deviates from that approximated by the geostrophic momentum approximation, and these deviations suggest that adjustments asssociated with ULJs in this case could not be resolved using a simplified two-dimensional approach.

Kocin, P. J.↗
NASA NTRS2004

Seeing the Invisible with the IMAGE Mission

The Global Positioning System, communication, power transmission, and oil pipelines are only a few of the technologies upon which we depend in research and in everyday life. Each is at risk from invisible storms in near-Earth space. The astrophysical plasmas near our planet store and deliver vast amounts of energy from the Sun in the form of high energy particles, electric currents, and heating of the upper atmosphere. This natural plasma environment is the only one routinely measured in situ over the last 40 years and until recently one of the few we haven't been able to see. Much like atmospheric weather satellites brought global context to that field many decades ago, the IMAGE Mission is now revealing a global context for space weather. The contributions being made by the IMAGE Mission to understanding space weather will be presented along with a brief overview of this dynamic environment. Special emphasis will be placed on research involving the plasmasphere, a toroidal region of relatively dense, cold plasma surrounding the Earth that plays a key role in energy and mass transport through near-Earth space.

Gallagher, D. L.↗
NASA NTRS2016

Interplanetary Space Weather Effects on Lunar Reconnaissance Orbiter Avalanche Photodiode Performance

Space weather is a major concern for radiation-sensitive space systems, particularly for interplanetary missions, which operate outside of the protection of Earth's magnetic field. We examine and quantify the effects of space weather on silicon avalanche photodiodes (SiAPDs), which are used for interplanetary laser altimeters and communications systems and can be sensitive to even low levels of radiation (less than 50 cGy). While ground-based radiation testing has been performed on avalanche photodiode (APDs) for space missions, in-space measurements of SiAPD response to interplanetary space weather have not been previously reported. We compare noise data from the Lunar Reconnaissance Orbiter (LRO) Lunar Orbiter Laser Altimeter (LOLA) SiAPDs with radiation measurements from the onboard Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument. We did not find any evidence to support radiation as the cause of changes in detector threshold voltage during radiation storms, both for transient detector noise and long-term average detector noise, suggesting that the approximately 1.3 cm thick shielding (a combination of titanium and beryllium) of the LOLA detectors is sufficient for SiAPDs on interplanetary missions with radiation environments similar to what the LRO experienced (559 cGy of radiation over 4 years).

LOLA↗