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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Deep Space Mission Trend Analyses: A Briefing to the Next Generation EBRE Study Team

Determination of stakeholder needs for next generation implementations necessitates a multi ]pronged approach. . Future mission set analyses provide a lower gbound h for some of these needs. . Earth ]based analogies provide an upper gbound h for some of these needs. . Interpreting the results requires being mindful of both the near ]term contextual factors and long ]term factors that are in play. . In the context of last year fs analyses, the current budget environment, the potential Pu ]238 shortage, and SMD fs gsingle 34m only h policy may, collectively, create a future deep space mission set that, from a capacity and end ]to ]end link difficulty standpoint, is no more challenging than it is today. . Nonetheless, data rates and volumes continue to increase, suggesting capability and spectrum challenges ahead. These results agree with the results from the Earthbased analogies. . Emerging developments such as smallsats and distributed spacecraft could significantly change the capacity and end ]to ]end link difficulty picture.

future mission analysis↗
NASA NTRS2014

Non-Detection of Methane in the Mars Atmosphere by the Curiosity Rover

By analogy with Earth, methane in the atmosphere of Mars is a potential signature of ongoing or past biological activity on the planet. During the last decade, Earth-based telescopic and Mars orbit remote sensing instruments have reported significant abundances of methane in the Martian atmosphere ranging from several to tens of parts-per-billion by volume (ppbv). Observations from Earth showed plumes of methane with variations on timescales much faster than expected and inconsistent with localized patches seen from orbit, prompting speculation of sources from sub-surface methanogen bacteria, geological water-rock reactions or infall from comets, micro-meteorites or interplanetary dust. From measurements on NASAs Curiosity Rover that landed near Gale Crater on 5th August 2012, we here report no definitive detection of methane in the near-surface Martian atmosphere. Our in situ measurements were made using the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite6 that made three separate searches on Martian sols 79, 81 and 106 after landing. The measured mean value of 0.39 plus or minus 1.4 ppbv corresponds to an upper limit for methane abundance of 2.7 ppbv at the 95 confidence level. This result is in disagreement with both the remote sensing spacecraft observations taken at lower sensitivity and the telescopic observations that relied on subtraction of a very large contribution from terrestrial methane in the intervening observation path. Since the expected lifetime of methane in the Martian atmosphere is hundreds of years, our results question earlier observations and set a low upper limit on the present day abundance, reducing the probability of significant current methanogenic microbial activity on Mars.

Curiosity Rover↗
NASA NTRS2016

Characterization of Evidence for Human System Risk Assessment

Understanding the kinds of evidence available and using the best evidence to answer a question is critical to evidenced-based decision-making, and it requires synthesis of evidence from a variety of sources. Categorization of human system risks in spaceflight, in particular, focuses on how well the integration and interpretation of all available evidence informs the risk statement that describes the relationship between spaceflight hazards and an outcome of interest. A mature understanding and categorization of these risks requires: 1) sufficient characterization of risk, 2) sufficient knowledge to determine an acceptable level of risk (i.e., a standard), 3) development of mitigations to meet the acceptable level of risk, and 4) identification of factors affecting generalizability of the evidence to different design reference missions. In the medical research community, evidence is often ranked by increasing confidence in findings gleaned from observational and experimental research (e.g., "levels of evidence"). However, an approach based solely on aspects of experimental design is problematic in assessing human system risks for spaceflight. For spaceflight, the unique challenges and opportunities include: (1) The independent variables in most evidence are the hazards of spaceflight, such as space radiation or low gravity, which cannot be entirely duplicated in terrestrial (Earth-based) analogs, (2) Evidence is drawn from multiple sources including medical and mission operations, Lifetime Surveillance of Astronaut Health (LSAH), spaceflight research (LSDA), and relevant environmental & terrestrial databases, (3) Risk metrics based primarily on LSAH data are typically derived from available prevalence or incidence data, which may limit rigorous interpretation, (4) The timeframe for obtaining adequate spaceflight sample size (n) is very long, given the small population, (5) Randomized controlled trials are unattainable in spaceflight, (6) Collection of personal and environmental data on the astronaut population may create opportunities for advanced analytics and human-environment modeling that goes beyond that achieved in isolated experimental designs; and (7) Translation of relevant research to operations is a complex, transdisciplinary enterprise in which the approach must apply across the physical, biological, behavioral, and social sciences. The approach to synthesizing evidence must address both source and fidelity of data, and reflect the most general attributes of quality of evidence in science and engineering: reliability and validity. The authors are developing a two-factor approach which includes the various kinds of evidence required to understand risks and for the integrated interpretation of all evidence that is essential to develop standards and countermeasures. A unified framework for aggregating and assessing different kinds of evidence provides a consistent, traceable, evidence-based decision-making process to translate research to operations in an environment where engineers, scientists, physicians, and managers all engage in analyzing the trade space of vehicle design, standards, requirements and solutions for spaceflight.

Steinberg, S. L.↗
NASA NTRS2018

The Impact of Stellar Variability on the Detection of Transiting Earth-like Planets

Stellar variability represents a key limitation on the detectability of weak transit signatures of small, Earth-size planets with space-based missions such as NASA's Kepler Mission or ESA's PLATO Mission. The expectations for the performance of the Kepler Mission in the face of solar-like variability were predicated on observations of the Sun with the Variability of Solar Irradiance and Gravity Oscillations (VIRGO) instrument aboard NASA and ESA's joint Solar and Heliospheric Observatory (SOHO) mission, which was launched in December 1995. Analyses of SOHO data indicated that solar-like variability would contribute approx.10 ppm to Kepler's noise budget at 6.5 ours, a typical grazing transit timescale. This proved to be optimistic as the typical 12th mag G2V star in the Kepler field of view exhibited 20 ppm of stellar variability-related noise at 6.5 hours, making the detection of true Earth-Sun analogs more difficult. While the consequent increase in the total noise at 6.5 hours from 20 ppm to 30 ppm could have been overcome by extending the mission to a total duration of 7 to 8 years. Unfortunately, a second reaction wheel failed in May 2013, ending the Kepler primary mission. Nevertheless, Kepler proved to be a veritable cornucopia of science results, both for exoplanets and for astrophysics. The phenomenal photometric precision and continuous observations required in order to identify small, rocky transiting planets enables the study of a large range of phenomena contributing to stellar variability for many thousands of solar-like stars in Kepler's field of view in exquisite detail. These effects range from less than 1 ppm acoustic oscillations on timescales from a few minutes and longward, to flares on timescales of hours, to spot-induced modulation on timescales of days to weeks to activity cycles on timescales of months to years. Kepler discovered over 2600 validated and confirmed exoplanets, and measured the pressure-mode oscillations of over 15000 stars over the course of its mission and the reconstituted K2 mission. We present the adaptive, wavelet-based matched filter used for both the Kepler and the TESS missions, and discuss the connections between this detection algorithm and fundamental detection theory, which allows the detector to function as a noise characterization engine. This provides a dynamical measurement of the photometric noise at transit timescales and thus, a key performance metric for missions like PLATO and Kepler. We give an overview of the stellar variability we see across the full range of spectral types observed by Kepler, from the cool, small red M stars to the hot, large late A stars, both in terms of amplitude as well as timescale.

transit surveys↗
NASA NTRS2019

Giant Planet Effects on Terrestrial Planet Formation and System Architecture

Using an updated collision model, we conduct a suite of high-resolution N-body integrations to probe the relationship between giant planet mass and terrestrial planet formation and system architecture. We vary the mass of the planets that reside at Jupiter's and Saturn's orbit and examine the effects on the interior terrestrial system.We find that massive giant planets are more likely to eject material from the outer edge of the terrestrial disc and produce terrestrial planets that are on smaller, more circular orbits. We do not find a strong correlation between exterior giant planet mass and the number of Earth analogues (analogous in mass and semi-major axis) produced in the system. These results allow us to make predictions on the nature of terrestrial planets orbiting distant Sun-like star systems that harbour giant planet companions on long orbits - systems that will be a priority for NASA's upcoming Wide-Field Infrared Survey Telescope (WFIRST) mission.

High-Resolution N-Body Integrations↗
NASA NTRS2018

The Impact of Stellar Variability on the Detection of Transiting Earth-Like Planets

Stellar variability represents a key limitation on the detectability of weak transit signatures of small, Earth-size planets with space-based missions such as NASA's Kepler Mission or ESA's PLATO Mission. The expectations for the performance of the Kepler Mission in the face of solar-like variability were predicated on observations of the Sun with the Variability of Solar Irradiance and Gravity Oscillations (VIRGO) instrument aboard NASA and ESA's joint Solar and Heliospheric Observatory (SOHO) mission, which was launched in December 1995. Analyses of SOHO data indicated that solar-like variability would contribute ~10 ppm to Kepler's noise budget at 6.5 ours, a typical grazing transit timescale. This proved to be optimistic as the typical 12th mag G2V star in the Kepler field of view exhibited 20 ppm of stellar variability-related noise at 6.5 hours, making the detection of true Earth-Sun analogs more difficult. While the consequent increase in the total noise at 6.5 hours from 20 ppm to 30 ppm could have been overcome by extending the mission to a total duration of 7 to 8 years. Unfortunately, a second reaction wheel failed in May 2013, ending the Kepler primary mission. Nevertheless, Kepler proved to be a veritable cornucopia of science results, both for exoplanets and for astrophysics. The phenomenal photometric precision and continuous observations required in order to identify small, rocky transiting planets enables the study of a large range of phenomena contributing to stellar variability for many thousands of solar-like stars in Kepler's field of view in exquisite detail. These effects range from <1 ppm acoustic oscillations on timescales from a few minutes and longward, to flares on timescales of hours, to spot-induced modulation on timescales of days to weeks to activity cycles on timescales of months to years. Kepler discovered over 2600 validated and confirmed exoplanets, and measured the pressure-mode oscillations of over 15000 stars over the course of its mission and the reconstituted K2 mission. We present the adaptive, wavelet-based matched filter used for both the Kepler and the TESS missions, and discuss the connections between this detection algorithm and fundamental detection theory, which allows the detector to function as a noise characterization engine. This provides a dynamical measurement of the photometric noise at transit timescales and thus, a key performance metric for missions like PLATO and Kepler. We give an overview of the stellar variability we see across the full range of spectral types observed by Kepler, from the cool, small red M stars to the hot, large late A stars, both in terms of amplitude as well as timescale.

exoplanets↗
NASA NTRS2019

Giant Planet Effects on Terrestrial Planet Formation and System Architecture

Using an updated collision model, we conduct a suite of high-resolution N-body integrations to probe the relationship between giant planet mass and terrestrial planet formation and system architecture. We vary the mass of the planets that reside at Jupiter’s and Saturn’s orbit and examine the effects on the interior terrestrial system.We find that massive giant planets are more likely to eject material from the outer edge of the terrestrial disc and produce terrestrial planets that are on smaller, more circular orbits. We do not find a strong correlation between exterior giant planet mass and the number of Earth analogues (analogous in mass and semimajor axis) produced in the system. These results allow us to make predictions on the nature of terrestrial planets orbiting distant Sun-like star systems that harbour giant planet companions on long orbits – systems that will be a priority for NASA’s upcoming Wide-Field Infrared Survey Telescope (WFIRST) mission.

Anna C. Childs↗
NASA NTRSDate not supplied

Considerations for Health and Performance During Surface Extravehicular Activities

BACKGROUND: NASA’s objectives for expanding human presence beyond low Earth orbit will require Extravehicular Activities (EVAs) on lunar and planetary surfaces. Given the physiological and functional demands of conducting surface EVAs in a pressurized spacesuit in reduced gravity environments, there is a possibility that crew injury and compromised physiological and/or functional performance may present. OVERVIEW: Many human health and performance knowledge gaps exist in regards to exploration EVA that require characterization to ensure safety, reliability, and mission success. To address knowledge gaps, EVA simulations in Earth-based analog environments and/or spacesuit simulators can be utilized to provide valuable insights into task-based physiologic and metabolic costs, cognitive loads, and associated operational limitations to inform future mission concepts. Physical workloads approaching 60% of maximum metabolic rates and 85% age-predicted heart rate maxima; core body temperatures approaching 100o F; and subjective responses indicating limited spare cognitive capacity via Bedford scale have been observed during ground-based exploration EVA simulations in the NASA Active Response Gravity Offload Simulator (ARGOS) and Neutral Buoyancy Lab (NBL) during simulated planetary EVAs in pressurized suits. Further, ground-based EVA analogs vary in their ability to simulate planetary EVA and resulting physical workloads. DISCUSSION: Metabolic costs, thermal burdens, functional strength, and cognitive impacts have been and must continue to be assessed in ground-based analogs to fully characterize operational demands and crew readiness levels for exploration EVA. Considerations should be given to enabling a new concept of high-tempo surface EVA operations and associated work-rest intervals, understanding human health and performance impacts of evolving commercial suit designs and capabilities, and predictive modeling and decision support capabilities to enable safe and successful EVA operations.

EVA↗
NASA NTRS2024

Considerations for Health and Performance during Surface Extravehicular Activities

BACKGROUND: NASA’s objectives for expanding human presence beyond low Earth orbit will require Extravehicular Activities (EVAs) on lunar and planetary surfaces. Given the physiological and functional demands of conducting surface EVAs in a pressurized spacesuit in reduced gravity environments, there is a possibility that crew injury and compromised physiological and/or functional performance may present. OVERVIEW: Many human health and performance knowledge gaps exist in regards to exploration EVA that require characterization to ensure safety, reliability, and mission success. To address knowledge gaps, EVA simulations in Earth-based analog environments and/or spacesuit simulators can be utilized to provide valuable insights into task-based physiologic and metabolic costs, cognitive loads, and associated operational limitations to inform future mission concepts. Physical workloads approaching 60% of maximum metabolic rates and 85% age-predicted heart rate maxima; core body temperatures approaching 100° F; and subjective responses indicating limited spare cognitive capacity via Bedford scale have been observed during ground-based exploration EVA simulations in the NASA Active Response Gravity Offload Simulator (ARGOS) and Neutral Buoyancy Lab (NBL) during simulated planetary EVAs in pressurized suits. Further, ground-based EVA analogs vary in their ability to simulate planetary EVA and resulting physical workloads. DISCUSSION: Metabolic costs, thermal burdens, functional strength, and cognitive impacts have been and must continue to be assessed in ground-based analogs to fully characterize operational demands and crew readiness levels for exploration EVA. Considerations should be given to enabling a new concept of high-tempo surface EVA operations and associated work-rest intervals, understanding human health and performance impacts of evolving commercial suit designs and capabilities, and predictive modeling and decision support capabilities to enable safe and successful EVA operations.

P Estep↗
NASA NTRS2026

NASA JSC’s Simulant Development Lab Capabilities and Artemis Testing

The Simulant Development Lab (SDL) is a multifunctional collaborative workspace that supports the development, curation, analysis, testing, and distribution of planetary regolith simulants – including lunar, Martian, asteroidal, and other granular materials. The lab provides a multidisciplinary setting for scientific characterization of simulant physical properties and for engineering evaluations conducted with simulant test beds. To enable this work, the SDL curates and maintains a stock of more than 35 metric tons of simulant material. To evaluate these materials and support testing goals, the lab is equipped with a comprehensive suite of processing tools and analytical instruments. These capabilities enable the SDL’s mission at NASA’s Johnson Space Center to distribute, develop, process, characterize, and test regolith simulants for mission relevant applications. Through controlled and repeatable testing environments that replicate the physical and compositional properties of lunar regolith, the SDL supports Artemis hardware maturation, providing safe, Earth‑based analogs for evaluating systems that must withstand regolith dust interactions, physical wear and abrasion, and operational loads. The facility’s extensive simulant inventory and integrated geological and engineering test infrastructure accelerate technology readiness for Artemis and future exploration campaigns (e.g., future crewed or robotic missions to Mars).

Simulant Development Lab↗
NASA NTRSDate not supplied

Using Earth-based Operational Field Tests as High-Fidelity Analogs for Planetary Surface Exploration

NASA is preparing to land the first woman and first person of color on the Moon within the next decade and establish a permanent sustainable human presence before sending humans onto Mars. To ensure the success of these missions, NASA has performed operational testing in terrestrial, aquatic, and laboratory analog environments that simulate Lunar and Martian environmental characteristics to evaluate exploration concepts of operations (ConOps), engineering design requirements, science support needs, mission operations techniques, and crew training. Terrestrial analogs include Desert Research and Technology Studies (D-RATS), Biologic Analog Science Associated with Lava Terrains (BASALT), and Next Space Technologies for Exploration Partnerships (NextSTEP)Habitat Ground Testing. Aquatic analogs include NASA Extreme Environment Mission Operations (NEEMO) and Pavilion Lake Research Project (PLRP).Laboratory analogs include the Neutral Buoyancy Laboratory (NBL), Active Response Gravity Offload System(ARGOS), rock yards, and virtual and hybrid reality simulation environments. While no single Earth-based analog environment is perfect for simulating all characteristics of other planetary surfaces, testing across multiple locations leverages the strengths of each to provide an integrated understanding of how to best conduct real spaceflight surface exploration missions.

B A Janoiko↗
NASA NTRS1991

Energetic particles at Uranus

The energetic particle measurements by the low-energy charged-particle and cosmic-ray instruments on the Voyager 2 spacecraft in the magnetosphere of Uranus are reviewed. Upstream events were observed outside the Uranian bow shock, probably produced by ion escape from the magnetosphere. Evidence of earthlike substorm activity was discovered within the Uranian magnetosphere. A proton injection event was observed within the orbit of Umbriel and proton events were observed in the magnetotail plasma-sheet boundary layer that are diagnostic of earthlike substorms. The magnetospheric composition is totally dominated by protons, with only a trace abundance of H(2+) and no evidence for He or heavy ions; the Uranian atmophere is argued to be the principal plasma source. Phase-space densities of medium energy protons show inward radial diffusion and are quantitatively similar to those observed at the earth, Jupiter, and Saturn. These findings and plasma wave data suggest the existence of structures analogous to the earth's plasmasphere and plasmapause.

Cheng, Andrew F.↗
NASA NTRS2007

Aqueous Alteration of Basalts: Earth, Moon, and Mars

The geologic processes responsible for aqueous alteration of basaltic materials on Mars are modeled beginning with our knowledge of analog processes on Earth, i.e., characterization of elemental and mineralogical compositions of terrestrial environments where the alteration and weathering pathways related to aqueous activity are better understood. A key ingredient to successful modeling of aqueous processes on Mars is identification of phases that have formed by those processes. The purpose of this paper is to describe what is known about the elemental and mineralogical composition of aqueous alteration products of basaltic materials on Mars and their implications for specific aqueous environments based upon our knowledge of terrestrial systems. Although aqueous alteration has not occurred on the Moon, it is crucial to understand the behaviors of basaltic materials exposed to aqueous environments in support of human exploration to the Moon over the next two decades. Several methods or indices have been used to evaluate the extent of basalt alteration/weathering based upon measurements made at Mars by the Mars Exploration Rover (MER) Moessbauer and Alpha Particle X-Ray Spectrometers. The Mineralogical Alteration Index (MAI) is based upon the percentage of total Fe (Fe(sub T)) present as Fe(3+) in alteration products (Morris et al., 2006). A second method is the evaluation of compositional trends to determine the extent to which elements have been removed from the host rock and the likely formation of secondary phases (Nesbitt and Young, 1992; Ming et al., 2007). Most of the basalts that have been altered by aqueous processes at the two MER landing sites in Gusev crater and on Meridiani Planum have not undergone extensive leaching in an open hydrolytic system with the exception of an outcrop in the Columbia Hills. The extent of aqueous alteration however ranges from relatively unaltered to pervasively altered materials. Several experimental studies have focused upon the aqueous alteration of lunar materials and simulants (e.g., Keller and Huang, 1971; Eick et al., 1996). Lunar basalts are void of water and highly reduced, hence, these materials are initially very reactive when exposed to water under oxidizing conditions.

Ming, Douglas W.↗
NASA NTRS1998

The Hadean, Through a Glass Telescopically: Observations of Young Solar Analogs

Investigations into the Earth's surface environment during the Hadean eon (prior to 3.8 Ga) are hampered by the paucity of the geological and geochemical record and the relative inaccessibility of better-preserved surfaces with possibly similar early histories (i.e., Mars). One approach is to observe nearby, young solar-mass stars as analogs to the Hadean Sun and its environment. A catalog of 38 G and early K stars within 25 pc was constructed based on main-sequence status, bolometric luminosity, lack of known stellar companions within 800 AU, and coronal X-ray luminosities commensurate with the higher activity of solar-mass stars <0.8 b.y. old. Spectroscopic data support the assignment of ages of 0.2 - 0.8 Ga for most of these stars. Observations of these objects will provide insight into external forces that influenced Hadean atmosphere, ocean, and surface evolution (and potential ecosystems), including solar luminosity evolution, the flux and spectrum of solar ultraviolet radiation, the intensity of the solar wind, and the intensity and duration of a late period of heavy bombardment. The standard model of solar evolution predicts a luminosity of 0.75 solar luminosity at the end of the Hadean, implying a terrestrial surface temperature inconsistent with the presence of liquid water and motivating atmospheric greenhouse models. An alternative model fo solar evolution that invokes mass loss, constructed to explain solar Li depletion, attenuates or reverses this luminosity evolution of the atmospheres of Earth and the other terrestrial planets. This model can be tested by Li abundance measurements. The continuum emission from stellar wind plasma during significant mass loss may be detectable at millimeter and radio wavelengths. The Earth (and Moon) experienced a period of intense bombardment prior to 3.8 Ga, long after accretion was completed in the inner solar system and possibly associated with the clearing of residual planetesimals in the outer solar system. Such a bombardment may have contributed volatiles and organics to the surface, but also have limited the appearacne of a biosphere. While planetary systems around solar systems cannot be detected directly with present technology, the thermal emission from the interplanetary dust generated during a similar heavy bombardment period can be. Midinfrared observations of a large uniform sample of solar analogs are used to constrain the frequency and duration of such events.

Gaidos, E. J.↗
NASA NTRS2010

Detecting Water on Super-Earths Using JAVST

Nearby lower train sequence stars host a class of planets known as Super-Earths, that have no analog in our own solar system. Super-Earths are rocky and/or icy planets with masses up to about 10 Earth masses, They are expected to host atmospheres generated by a number of processes including accretion of chondritic material. Water vapor should be a common constituent of super-Earth atmospheres, and may be detectable in transiting super-Earths using transmission spectroscopy during primar y eclipse, and emission spectroscopy at secondary eclipse. I will discuss the prospects for super-Earth atmospheric measurements using JWST.

Deming, D.↗
NASA NTRS2017

Kepler-1649b: An Exo-Venus in the Solar Neighborhood

The Kepler mission has revealed that Earth-sized planets are common, and dozens have been discovered to orbit in or near their host star’s habitable zone. A major focus in astronomy is to determine which of these exoplanets are likely to have Earth-like properties that are amenable to follow-up with both ground- and future space-based surveys, with an ultimate goal of probing their atmospheres to look for signs of life. Venus-like atmospheres will be of particular interest in these surveys. While Earth and Venus evolved to have similar sizes and densities, it remains unclear what factors led to the dramatic divergence of their atmospheres. Studying analogs to both Earth and Venus can thus shed light on the limits of habitability and the potential for life on known exoplanets. Here, we present the discovery and confirmation of Kepler-1649b, an Earth-sized planet orbiting a nearby M5V star that receives incident flux at a level similar to that of Venus. We present our methods for characterizing the star, using a combination of point-spread function photometry, ground-based spectroscopy, and imaging, to confirm the planetary nature of Kepler-1649b. Planets like Kepler-1649b will be prime candidates for atmospheric and habitability studies in the next generation of space missions.

Terrestrial planets↗
NASA NTRS2011

Use of Hawaii Analog Sites for Lunar Science and In-Situ Resource Utilization

In-Situ Resource Utilization (ISRU) and lunar science share similar objectives with respect to analyzing and characterizing the physical, mineral, and volatile materials and resources at sites of robotic and human exploration. To help mature and stress instruments, technologies, and hardware and to evaluate operations and procedures, space agencies have utilized demonstrations at analog sites on Earth before use in future missions. The US National Aeronautics and Space Administration (NASA), the Canadian Space Agency (CSA), and the German Space Agency (DLR) have utilized an analog site on the slope of Mauna Kea on the Big Island of Hawaii to test ISRU and lunar science hardware and operations in two previously held analog field tests. NASA and CSA are currently planning on a 3rd analog field test to be held in June, 2012 in Hawaii that will expand upon the successes from the previous two field tests.

Sanders, G. B.↗
NASA NTRS1979

Magnetospheric plasma waves

Space measurements have provided a wealth of data on wave phenomena, plasma parameters, and energetic particle characteristics within the earth's magnetosphere. In the present paper, the generation, propagation, and interaction of plasma waves are discussed, along with the interpretation of the observations. Data on plasma waves from other planetary magnetospheres and cosmic plasma systems are examined and interpreted by analogy to the earth's magnetosphere. Areas requiring continued plasma wave research are indicated.

Shawhan, S. D.↗