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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Future activity in astrophysics

An overview is given of the NASA astrophysics program with emphasis on missions which are likely to be started or flown within the next five to seven years. Included in this summary are descriptions of approved future missions such as the Infrared Astronomical Satellite, the Space Telescope and the HEAO-B and HEAO-C satellites, as well as of missions which are now in the planning stage. Such missions include the Cosmic Background and Extreme Ultraviolet Explorers, the Gamma Ray and Cosmic Ray Observatories, the Advanced X-ray Astrophysics Facility, infrared and optical/ultraviolet telescopes to be used on the Space Shuttle, and the orbiting gyroscope experiment (GP-B). The current state-of-the-art, as well as future requirements in astrophysical sensing techniques, are highlighted.

Rosendhal, J. D.↗
NASA NTRS1986

A multidisciplinary study of planetary, solar and astrophysical radio emissions

Combination of the related fields of planetary, solar, and astrophysical radio emissions was attempted in order to more fully understand the radio emission processes. Topics addressed include: remote sensing of astrophysical plasma turbulence; Alfven waves; astrophysical shock waves; surface waves; very long base interferometry results; very large array observations; solar magnetic flux; and magnetohydrodynamic waves as a tool for solar corona diagnostics.

Gurnett, D. A.↗
NASA NTRS1985

Astrophysics and the Space Station - Executive summary of the NASA Working Group

Current plans for astrophysics experiments using the Space Station are summarized. The planning history is briefly traced; the fundamental roles of the Station as observatory, assembly plant, and service point for free-flying astrophysics platforms are considered; the NASA astrophysics programs are described; the chief outstanding problems are listed; and the need for smaller experiments is stressed. Lists of desired Station performance parameters and charts showing projected completion dates for Station components are provided.

Pellerin, C. J.↗
NASA NTRS1988

Generation of dynamo magnetic fields in protoplanetary and other astrophysical accretion disks

A computational method for treating the generation of dynamo magnetic fields in astrophysical disks is presented. The numerical difficulty of handling the boundary condition at infinity in the cylindrical disk geometry is overcome by embedding the disk in a spherical computational space and matching the solutions to analytically tractable spherical functions in the surrounding space. The lowest lying dynamo normal modes for a 'thick' astrophysical disk are calculated. The generated modes found are all oscillatory and spatially localized. Tha potential implications of the results for the properties of dynamo magnetic fields in real astrophysical disks are discussed.

Stepinski, T. F.↗
NASA NTRS1988

Design of an expert system for estimating the cost of new knowledge in high energy astrophysics

The High Energy Astrophysics Costing Tool (HEACT) is a combined Expert System/Numerical Simulation to evaluate sensors and experiments proposed for space platforms in order to determine their expected performance and to assess the amount and quality of scientific information likely to be gathered by such experiments. The end product of this tool will be both a cost estimate for the experiment package as deployed and also an estimate of the amount of new scientific knowledge (both new data and reductions in the uncertainties of previous measurements) which would result from the actual deployment and operation of that experiment package. The numerical simulation part of HEACT will contain components to: (1) calculate the high energy signatures of both actual and proposed classes of astrophysical objects, and (2) model the response and resolution of the candidate sensors for observing those objects. The rule based part of the HEACT will be based on knowledge in the areas of experiment design, instrument selection, and system integration developed from experience with existing high energy astrophysics observatories, both orbiting and lofted by rockets or balloons. This paper presents mainly results from the design of the rule-based part of HEACT. It focuses on the structure of the rules and the structures used to represent the knowledge related to the design and integration of such experiments. Methods for integrating the results from numerical simulations into the expert system will also be discussed.

Bosworth, Edward L., Jr.↗
NASA NTRS1989

The Nuclear Astrophysics Explorer

The Nuclear Astrophysics Explorer was proposed in 1986 for NASA's Explorer Concept Study Program by an international collaboration of 25 scientists from nine institutions. The one-year feasibility study began in June 1988. The Nuclear Astrophysics Explorer would obtain high resolution observations of gamma-ray lines, E/Delta E about 1000, at a sensitivity of about 0.000003 ph/sq cm s, in order to study fundamental problems in astrophysics such as nucleosynthesis, supernovae, neutron star and black-hole physics, and particle acceleration and interactions. The instrument would operate from 15 keV to 10 Mev and use a heavily shielded array of nine cooled Ge spectrometers in a very low background configuration. Its 10 deg FWHM field of view would contain a versatile coded mask system which would provide two-dimensional imaging with 4 deg resolution, one-dimensional imaging with 2 deg resolution, and efficiendt measurements of diffuse emission. An unshielded Ge spectrometer would obtain wide-field measurements of transient gamma-ray sources. The earliest possible mission would begin in 1995.

Matteson, J. L.↗
NASA NTRS1988

Astrophysical implications of presolar grains

The widely accepted hypothesis that presolar materials survive intact in meteorites and can be studied in our laboratories is of great potential astrophysical significance. Two first-order conclusions have been drawn from the evidence supporting this hypothesis: graphitic grains are rare in the interstellar medium and grain lifetimes are considerably longer than 100 million yr. Both conclusions are in conflict with currently accepted astrophysical models, but might still be consistent with astronomical observations. Many more astrophysical revelations could be concealed within the meteorites, but until astronomers are again given some training in meteoritics, only the meteoritics community has the tools necessary to decipher the message.

Nuth, Joseph A., III↗
NASA NTRS1987

Long-lived space observatories for astronomy and astrophysics

NASA's plan to build and launch a fleet of long-lived space observatories that include the Hubble Space Telescope (HST), the Gamma Ray Observatory (GRO), the Advanced X Ray Astrophysics Observatory (AXAF), and the Space Infrared Telescope Facility (SIRTF) are discussed. These facilities are expected to have a profound impact on the sciences of astronomy and astrophysics. The long-lived observatories will provide new insights about astronomical and astrophysical problems that range from the presence of planets orbiting nearby stars to the large-scale distribution and evolution of matter in the universe. An important concern to NASA and the scientific community is the operation and maintenance cost of the four observatories described above. The HST cost about $1.3 billion (1984 dollars) to build and is estimated to require $160 million (1986 dollars) a year to operate and maintain. If HST is operated for 20 years, the accumulated costs will be considerably more than those required for its construction. Therefore, it is essential to plan carefully for observatory operations and maintenance before a long-lived facility is constructed. The primary goal of this report is to help NASA develop guidelines for the operations and management of these future observatories so as to achieve the best possible scientific results for the resources available. Eight recommendations are given.

Savage, Blair D.↗
NASA NTRS1990

Transition regions in solar system and astrophysical plasmas

A brief review is presented of basic particle and field characteristics of plasmas observed within the solar system, especially near transition regions, and their parameter ranges are compared with those inferred for stellar winds and the interstellar medium. Parameter ranges for solar system and astrophysical plasmas are found to have considerable overlap. In addition, astrophysics provides unique, global perspectives of large-scale systems, whereas solar-system space physics provides for direct quantitative testing of physical processes. Astrophysics and solar-system space physics studies thus have complementary and synergistic roles.

Eastman, Timothy E.↗
NASA NTRS1991

Theory and laboratory astrophysics

Science opportunities in the 1990's are discussed. Topics covered include the large scale structure of the universe, galaxies, stars, star formation and the interstellar medium, high energy astrophysics, and the solar system. Laboratory astrophysics in the 1990's is briefly surveyed, covering such topics as molecular, atomic, optical, nuclear and optical physics. Funding recommendations are given for the National Science Foundation, NASA, and the Department of Energy. Recommendations for laboratory astrophysics research are given.

Schramm, David N.↗
NASA NTRS1991

Workshop Proceedings: Sensor Systems for Space Astrophysics in the 21st Century, Volume 2

In 1989, the Astrophysics Division of the Office of Space Science and Applications initiated the planning of a technology development program, Astrotech 21, to develop the technological base for the Astrophysics missions developed in the period 1995 to 2015. The Sensor Systems for Space Astrophysics in the 21st Century Workshop was one of three Integrated Technology Planning workshops. Its objectives were to develop an understanding of the future comprehensive development program to achieve the required capabilities. Program plans and recommendations were prepared in four areas: x ray and gamma ray sensors, ultraviolet and visible sensors, direct infrared sensors, and heterodyne submillimeter wave sensors.

Wilson, Barbara A.↗
NASA NTRS1991

The Next Century Astrophysics Program

The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of major and moderate missions that are presently under study for flight sometime within the next 20 years. These programs include the: Advanced X Ray Astrophysics Facility; X Ray Schmidt Telescope; Nuclear Astrophysics Experiment; Hard X Ray Imaging Facility; Very High Throughput Facility; Gamma Ray Spectroscopy Observatory; Hubble Space Telescope; Lunar Transit Telescope; Astrometric Interferometer Mission; Next Generation Space Telescope; Imaging Optical Interferometer; Far Ultraviolet Spectroscopic Explorer; Gravity Probe B; Laser Gravity Wave Observatory in Space; Stratospheric Observatory for Infrared Astronomy; Space Infrared Telescope Facility; Submillimeter Intermediate Mission; Large Deployable Reflector; Submillimeter Interferometer; and Next Generation Orbiting Very Long Baseline Interferometer.

Swanson, Paul N.↗
NASA NTRS1991

Astrotech 21: A technology program for future astrophysics missions

The Astrotech 21 technology program is being formulated to enable a program of advanced astrophysical observatories in the first decade of the 21st century. This paper describes the objectives of Astrotech 21 and the process that NASA is using to plan and implement it. It also describes the future astrophysical mission concepts that have been defined for the twenty-first century and discusses some of the requirements that they will impose on information systems for space astrophysics.

Cutts, James A.↗
NASA NTRS1992

NASA's ultraviolet astrophysics branch - The next decade

We review some of the mission concepts currently being considered by NASA's Astrophysics Division to carry out future observations in the 100-3000 Angstrom region. Examples of possible future missions include UV and visible interferometric experiments, a next generation Space Telescope and lunar-based UV instrumentation. In order to match the science objectives of these future missions with new observational techniques, critical technology needs in the ultraviolet regime have been identified. Here we describe how NASA's Astrophysics Division Advanced Programs Branch is attempting to formulate an integrated technology plan called the 'Astrotech 21' program in order to provide the technology base for these astrophysics missions of the 21st century.

Welsh, Barry Y.↗
NASA NTRS1992

NASA's Ultraviolet Astrophysics Branch: Present and future detector program

The various concepts in ultraviolet detector technology currently being funded by NASA's Astrophysics Division to carry out observations in the 100 to 3000 A region are reviewed. In order to match the science objectives of future space missions with new observational techniques, critical detector technology needs in the ultraviolet regime have been identified. The attempt by NASA's Astrophysics Division Advanced Programs Branch to formulate an integrated detector technology plan as part of the ongoing 'Astrotech 21' program in order to provide the technology base for these astrophysics missions of the 21st century is described.

Welsh, Barry Y.↗
NASA NTRS1994

Astrophysical science with a spaceborne photometric telescope

The FRESIP Project (FRequency of Earth-Sized Inner Planets) is currently under study at NASA Ames Research Center. The goal of FRESIP is the measurement of the frequency of Earth-sized extra-solar planets in inner orbits via the photometric signature of a transit event. This will be accomplished with a spaceborne telescope/photometer capable of photometric precision of two parts in 100,000 at a magnitude of m(sub v) = 12.5. To achieve the maximum scientific value from the FRESIP mission, an astrophysical science workshop was held at the SETI Institute in Mountain View, California, November 11-12, 1993. Workshop participants were invited as experts in their field of astrophysical research and discussed the astrophysical science that can be achieved within the context of the FRESIP mission.

Granados, Arno F.↗
NASA NTRS1996

Current Perspectives in High Energy Astrophysics

High energy astrophysics is a space-age discipline that has taken a quantum leap forward in the 1990s. The observables are photons and particles that are unable to penetrate the atmosphere and can only be observed from space or very high altitude balloons. The lectures presented as chapters of this book are based on the results from the Compton Gamma-Ray Observatory (CGRO) and Advanced Satellite for Cosmology and Astrophysics (ASCA) missions to which the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center made significant hardware contributions. These missions study emissions from very hot plasmas, nuclear processes, and high energy particle interactions in space. Results to be discussed include gamma-ray beaming from active galactic nuclei (AGN), gamma-ray emission from pulsars, radioactive elements in the interstellar medium, X-ray emission from clusters of galaxies, and the progress being made to unravel the gamma-ray burst mystery. The recently launched X-ray Timing Explorer (XTE) and prospects for upcoming Astro-E and Advanced X-ray Astronomy Satellite (AXAF) missions are also discussed.

Ormes, Jonathan F.↗