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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 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Kinetic modeling of O(+) upflows resulting from E x B convection heating in the high-latitude F region ionosphere

We report here the results of modeling work aimed at understanding the development of ionospheric O(+) field-aligned upflows that develop in response to high-latitude E x B drift induced frictional heating. The model used is a collisional semikinetic model which includes ion-neutral resonant charge exchange and polarization collisions as well as Coulomb self-collisions. It also includes the process of chemical removal of O(+) as well as all of the macroscopic forces: ambipolar electric, gravity, magnetic mirror, and centripetal. Model results show the development of several types of non-Maxwellian velocity distributions including toroids at low altitude, distributions with large heat flow in the perpendicular component at intermediate altitudes, and distributions with a separate upflowing population or upward superthermal tail at high altitudes. Whenever the convection electric field increases from a small value (less than 25 mV/m) to a large value (100-200 mV/m) in 6 min or less large upflows develop with parallel drift speeds which peak (below 1000 km) at values between 500 m/s and 2 km/s, parallel fluxes which peak between 6.0 x 10(exp 8) and 3.2 x 10(exp 9)/sq cm/s, and parallel per particle heat flows which peak between 8.0 x 10(exp -9) and 8.0 x 10(exp -8) ergs cm/s. The higher values in these ranges occur for a cooler neutral atmosphere, with a larger convection electric field that is turned on quickly. The model produces field-aligned O(+) flow speeds that are larger than those produced by a 20-moment generalized transport model but smaller then those produced by an isotropic hydrodynamic model for comparable values of the convection turn on times. The model results compare favorably with some topside satellite and radar data.

Wilson, G. R.↗
NASA NTRS1992

The envelope of B(e) supergiants in the Magellanic Clouds

We have obtained linear polarization data of B(e) supergiants in the Magellanic Clouds. Our analysis shows that they have non-spherically symmetric envelopes, with a range of intrinsic polarizations. Comparisons of our data with spectroscopic data in the literature agrees with this interpretation. The polarization correlates best with the IR excess due to dust, suggesting dust scattering as the main polarization mechanism. Comparision of our data with data uncovered from the literature for four stars indicate that the envelopes are stable.

Magalhaes, Antonio Mario↗
NASA NTRS1995

Electrical structure and E-fields in the high-latitude mesosphere

A description of the electric structure as observed during a rocket sounding noctilucent cloud (NLC) observation program in the summer of 1991, is presented. Both NLC and polar mesosphere summer echo (PMSE) conditions were determined. The observable effects on ions and electrons were measured in the NLC and PMSE regions and associated electric field (E-fields) measurements indicated small alternating current vertical fields. The following findings are reported: small and large scale electron density structure is noticeable in the NLC regions; above 82 km, the occurrence of very low-mobility positive ions directly demonstrates the existence of charged aerosols, and small alternating current vertical electric fields were observed in the NLC and PMSE region.

Mitchell, John D.↗
NASA NTRS1998

The Distant Tail at 200 R(sub E): Comparison Between Geotail Observations and the Results from a Global Magnetohydrodynamic Simulation

This paper reports a comparison between Geotail observations of plasmas and magnetic fields at 200 R(sub E) in the Earth's magnetotail with results from a time-dependent, global magnetohydrodynamic simulation of the interaction of the solar wind with the magnetosphere. The study focuses on observations from July 7, 1993, during which the Geotail spacecraft crossed the distant tail magnetospheric boundary several times while the interplanetary magnetic field (IMF) was predominantly northward and was marked by slow rotations of its clock angle. Simultaneous IMP 8 observations of solar wind ions and the IMF were used as driving input for the MHD simulation, and the resulting time series were compared directly with those from the Geotail spacecraft. The very good agreement found provided the basis for an investigation of the response of the distant tail associated with the clock angle of the IMF. Results from the simulation show that the stresses imposed by the draping of magnetosheath field lines and the asymmetric removal of magnetic flux tailward of the cusps altered considerably the shape of the distant tail as the solar wind discontinuities convected downstream of Earth. As a result, the cross section of the distant tail was considerably flattened along the direction perpendicular to the IMF clock angle, the direction of the neutral sheet following that of the IMF. The simulation also revealed that the combined action of magnetic reconnection and the slow rotation of the IMF clock angle led to a braiding of the distant tail's magnetic field lines along the axis of the tail, with the plane of the braid lying in the direction of the IMF.

Berchem, J.↗
NASA NTRS1999

Construction of a Specialized Cloning Strain of E. Coli for the Nitrate Reductase Genes of Haloferax Denitrificans

This is the final report on Joint Research Interchange (NCC2-5011) "Construction of a Specialized Cloning Strain of E.. coli for the Nitrate Reductase Genes of Haloferax denitrificans." Originally the award was 11/l/93-10/31/95, but there were no-cost extensions made, because of a year Sabbatical at the Pasteur Institute in Paris and other leaves of 3 months each at the Pasteur Institute, during which work could not be done on this project, which extended the closing date to 10/30/98.

Johnson, Emmett↗
NASA NTRS1998

Auroral Kilometric Radiation Integrated Power Flux as a Proxy for A E

We propose to use the integrated intensity of auroral kilometric radiation from Polar measurements as a proxy for the auroral electrojet index A(sub E) in support of studies of the response of the magnetosphere and the geomagnetic tail to changes in magnetic activity. In addition to providing event timing information to understand the effects of perturbations and substorms, the resulting space-based auroral kilometric radiation index would be useful as an input to space weather efforts as an auroral activity metric.

Kurth, W. S.↗
NASA NTRS1999

The Astro-E/XRS Calibration Program and Results

XRS is the microcalorimeter X-ray detector aboard the US-Japanese ASTRO-E observatory, which is scheduled to be launched in early 2000. XRS is a high resolution spectrometer- with less than 9 eV resolution at 3 keV and better than 14 eV resolution over its bandpass ranging from about 0.3 keV to 15 keV. Here we present the results of our first calibration of the XRS instrument. We describe the methods used to extract detailed information about the detection efficiency and spectral redistribution of the instrument. We also present comparisons of simulations and real data to test our detector models.

Gendreau, Keith C.↗
NASA NTRS1999

The Astro-E High Resolution X-Ray Spectrometer

The Astro-E High Resolution X-ray Spectrometer (XRS) was developed jointly by the NASA/Goddard Space Flight Center and the Institute of Space and Astronautical Science in Japan. The instrument is based on a new approach to spectroscopy, the X-ray microcalorimeter. This device senses the energies of individual X-ray photons as heat with extreme precision. A 32 channel array of microcalorimeters is being employed, each with an energy resolution of about 12 eV at 6 keV (the Fe-K region). This will provide spectral resolving power 10 times higher than any other non-dispersive X-ray spectrometer. The instrument incorporates a three stage cooling system capable of operating the array at 60 mK for about two years in orbit. The array sits at the focus of a grazing incidence conical mirror. The quantum efficiency of the microcalorimeters and the reflectivity of the X-ray mirror system combine to give high throughput over the 0.3-12 keV energy band. This new capability will enable the study of a wide range of high-energy astrophysical sources with unprecedented spectral sensitivity. This paper presents the basic design requirements and implementation of the XRS, and also describes the instrument parameters and performance.

Kelley, Richard L.↗
NASA NTRS1999

S-Wave Dispersion Relations: Exact Left Hand E-Plane Discontinuity from the Born Series

We show, for a superposition of Yukawa potentials, that the left hand cut discontinuity in the complex E plane of the (S-wave) scattering amplitude is given exactly, in an interval depending on n, by the discontinuity of the Born series stopped at order n. This also establishes an inverse and unexpected correspondence of the Born series at positive high energies and negative low energies. We can thus construct a viable dispersion relation (DR) for the partial (S-) wave amplitude. The high numerical precision achievable by the DR is demonstrated for the exponential potential at zero scattering energy. We also briefly discuss the extension of our results to Field Theory.

Bessis, D.↗
NASA NTRS1999

The Astro-E/XRS Calibration Program and Results

XRS is the microcalorimeter X-ray detector aboard the US-Japanese ASTRO-E observatory, which is scheduled to be launched in early 2000. XRS is a high resolution spectrometer- with less than 9 eV resolution at 3 keV and better than 14 eV resolution over its bandpass ranging from about 0.3 keV to 15 keV. Here we present the results of our first calibration of the XRS instrument. We describe the methods used to extract detailed information about the detection efficiency and spectral redistribution of the instrument. We also present comparison of simulations and read data to test our detector models.

Gendreau, Keith C.↗
NASA NTRS1999

STS-99 Crew Interviews: Janice E. Voss

Live footage of a preflight interview with Mission Specialist Janice E. Voss is seen. The interview addresses many different questions including why Voss became an astronaut, the events that led to her interest, and her career path. Other interesting information that this one-on-one interview discusses is the purpose for the Shuttle Radar Topography Mission (SRTM). Specific interest is on the importance of this SRTM flight, the knowledge that we will gain from the 3D topographic map of the Earth, and the reason why this 3D data is being recorded instead of down-linked. The two antennas that will be taking the pictures, the deployment and retraction of the mass, the involvement of the International partners in processing the data (C-band and X-band), and Voss' responsibility during this 24 hour mission are also discussed.

Source record↗
NASA NTRS2000

Ion Layer Separation and Equilibrium Zonal Winds in Midlatitude Sporadic E

In-situ observations of a moderately strong mid-latitude sporadic-E layer show a separation in altitude between distinct sublayers composed of Fe(+), Mg(+), and NO(+). From these observations it is possible to estimate the zonal wind field consistent with diffusive equilibrium near the altitude of the layer. The amplitude of the zonal wind necessary to sustain the layer against diffusive effects is less than 10 meters per second, and the vertical wavelength is less than 10 km.

Earle, G. D.↗
NASA NTRS1991

STS-43 Atlantis/Breakfast & Suit-Up, Depart O&C, Ingress, Launch with Isolated Views, TDRS-E Deploy, and Landing with Isolated Views

Footage of various stages of the STS-43 Atlantis launch is shown, including shots of the crew at breakfast, getting suited up, and departing to board the Orbiter. The launch is shown from many vantage points, as is the landing. Atlantis is shown from space and the deployment of the fifth Tracking and Data Relay Satellite (TDRS-E) is also shown.

Source record↗
NASA NTRS1998

Clementine High Resolution Camera Mosaicking Project: CL 6012; 0 deg N to 80 deg N Latitude, 240 deg to 270 deg E Longitude - Volume 12

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael↗
NASA NTRS1998

Clementine High Resolution Camera Mosaicking Project: CL 6013; 0 deg S to 80 deg S Latitude, 240 deg to 270 deg E Longitude - Volume 13

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael↗
NASA NTRS1998

Clementine High Resolution Camera Mosaicking Project: CL 6009; 80 deg N to 80 deg S Latitude, 180 deg to 210 deg E Longitude - Volume 9

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael↗
NASA NTRS1998

Clementine High Resolution Camera Mosaicking Project: CL 6017; 0 deg to 80 deg S Latitude, 330 deg E Longitude - Volume 17

This compact disk (CD) is part of the Malin Space Science Systems (MSSS) effort to mosaic Clementine I high resolution (HiRes) camera lunar images. These mosaics were developed through calibration and semi-automated registration against the recently released geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic, which is available through the PDS, as CD-ROM volumes CL_3001-3015. The HiRes mosaics are compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution observations from the HiRes imaging system onboard the Clementine Spacecraft. These mosaics are spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel. The geometric control is provided by the 100 m/pixel U.S. Geological Survey (USGS) Clementine Basemap Mosaic compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Calibration was achieved by removing the image nonuniformity largely caused by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap that approximately transform the 8-bit HiRes data to photometric units. The mosaics on this CD were compiled from sub-polar data (latitudes 80 degrees South to 80 degrees North; -80 to +80) within the longitude range 0-30 deg E. The mosaics are divided into tiles that cover approximately 1.75 degrees of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. This CD contains ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files. For more information on the contents and organization of the CD volume set refer to the "FILES, DIRECTORIES AND DISK CONTENTS" section of this document. The image files are organized according to NASA's Planetary Data System (PDS) standards. An image file (tile) is organized as a PDS labeled file containing an "image object".

Malin, Michael↗