Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “10-Be”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37

Experimental wake survey behind Viking 75 entry vehicle at angles of attack of 0 deg, 5 deg, and 10 deg, Mach numbers from 0.20 to 1.20, and longitudinal stations from 1.50 to 11.00 body diameters

An investigation was conducted to obtain flow properties in the wake of a preliminary configuration of the Viking '75 Entry Vehicle at Mach numbers from 0.20 to 1.20 and at angles of attack of 0 deg, 5 deg, and 10 deg. The wake flow properties were calculated from total and static pressures measured with a pressure rake at longitudinal stations varying from 1.50 to 11.00 body diameters, and are presented in tabulated and plotted form. The wake properties were essentially symmetrical about the X-axis at alpha = 0 deg and the profiles were shifted away from the X-axis at angles of attack. An unexpected reduction in wake property ratios occurred as the Mach number increased from 0.60 to 1.00; these ratios then increased as the Mach number increased to 1.20. The reduction was present for all the longitudinal stations of the tests and decreased with increased longitudinal distance.

Brown, C. A., Jr.↗

The computation of 15 deg and 10 deg equal area block terrestrial free air gravity anomalies

Starting with the set of 23,355 1 deg x 1 deg mean free air gravity anomalies used in Rapp (1972) to form a 5 deg equal area block terrestrial gravity field, the computation of 15 deg equal area block mean free air gravity anomalies is described along with estimates of their standard deviations. A new scheme of an integral division of a 15 deg block into 9 component 300 n. m. blocks, and each 300 n. m. block being subdivided into 25 60 n.mi. blocks, is used. This insures that there is no loss in accuracy, which would have resulted if proportional values according to area were taken of the 5 deg equal area anomalies to form the 15 deg block anomalies. A similar scheme is used for the computation of 10 deg equal area block mean free air gravity anomalies with estimates of their standard deviations. The scheme is general enough to be used for a 30 deg equal area block terrestrial gravity field.

Hajela, D. P.↗

Pioneer 10 observations of the solar wind interation with Jupiter

Pioneer 10 Plasma Analyzer experiment flight data during the Jupiter flyby are presented. The observations show that the interaction of Jupiter's magnetic field with the solar wind is similar in many ways to that at earth, but the scale size is over 100 times larger. Jupiter is found to have a detached standing bow shock wave of high Alfven Mach number. Jupiter has a prominent magnetopause which deflects the magnetosheath plasma and excludes its direct entry into the Jovian magnetosphere. The sunward hemisphere of Jupiter's outer magnetosphere is found to be highly inflated with thermal plasma and a high beta region which is highly responsive to changes in solar wind dynamic pressure. Observational arguments are presented which tend to discount a thin disklike magnetosphere but, rather, favor a Jovian magnetosphere, albeit probabily considerably flattened as compared to the earth's magnetosphere, yet still with reasonable thickness. Results concerning the shock jump conditions, the magnetosheath flow field and inferred internal magnetospheric plasma are presented.

Wolfe, J. H.↗

Magnetic field observations near Mercury: Preliminary results from Mariner 10

Results are presented from a preliminary analysis of data obtained near Mercury by the NASA/GSFC Magnetic Field Experiment on Mariner 10. A very well developed, detached bow shock wave, which developed as the super-Alfvenic solar wind interacted with the planet Mercury was observed. A magnetosphere-like region, with maximum field strength of 98 gamma at closest approach (704 km altitude) was also observed, and was contained within boundaries similar to the terrestrial magnetopause. The obstacle deflecting the solar wind flow was global in size, but the origin of the enhanced magnetic field was not established. The most plausible explanation, considering the complete body of data, favored the conclusion that Mercury has an intrinsic magnetic field.

Ness, N. F.↗

The transit of Mercury of 10 November 1973

The transit of Mercury of November 10, 1973 was observed from Silver Spring, Maryland (76 deg 58' W, 39 deg 01' N) for the period 6:48:00 EST, near sunrise, to 8:17:18 (contact 4). A total of 24 frames of 35mm Pan X film were taken through a Questar telescope equipped with a sun filter of 40mm aperture. The diameter of the solar image is 13mm on the film. Transit photographs from the observation are included.

Feibelman, W. A.↗

Magnetic coordinates for the Pioneer 10 Jupiter encounter

The magnetic coordinates of the Pioneer 10 spacecraft and the five innermost satellites are reported for the Jupiter encounter. The D sub 2 offset is used to make the calculations. Magnetic coordinates are needed for the interpretation of the trapped particle measurements, including the absorption effects of the satellites. Contours of constant field magnitude and magnetic latitude are given at the surface of Jupiter for the D sub 2 model. The system 3 longitude of a spacecraft at Jupiter is derived, and formulas given for the relationships between system 1, 2, and 3 longitudes. The longitude of the magnetic dipole increases by about 3 deg per year, due to the inaccurate rotation rate used to define system 3 longitude.

Mead, G. D.↗

Investigations to the space shuttle orbiter 2A configuration 0.015-scale model in the NASA Ames Research Center 3.5-foot hypersonic wind tunnel at Mach numbers 5, 7 and 10 (OA11B)

The results of a wind tunnel test to determine the force, moment, and hinge-moment characteristics of the Configuration 2A Space Shuttle Vehicle Orbiter at Mach numbers 5, 7 and 10 are presented. The model was an 0.015-scale representation of the Orbiter Configuration 2A used in test 0A11A and later tests. Six-component aerodynamic force and moment data were recorded from a 1.50-inch internal strain-gage balance, and base pressures were taken for axial and drag force corrections. Hinge-moment data were obtained for the rudder and the inboard and outboard elevon panels of the starboard wing.

Mellenthin, J. A.↗

Primary cosmic ray electrons above 10 GeV - Measurements using a thick detector

A balloon-borne measurement of the cosmic ray electron spectrum from 10 to 200 GeV is reported in which two new techniques have been used to remove proton background contamination. First, the depth of the spectrometer was more than 40 radiation lengths, the equivalent of more than 3 mean free paths of material, enabling hadronically and electromagnetically induced cascades to be differentiated for a subset of the data. Second, electromagnetic cascade starting points were determined to within plus or minus 0.1 radiation lengths on the basis of a calibration with electrons from 5.4 to 18 GeV at the Stanford Linear Accelerator, greatly reducing the chances for a proton to simulate an electron. The resulting spectrum, when fitted with a power law, is quite steep, -3.2 plus or minus 0.1, but the fit to a power law is marginal.

Silverberg, R. F.↗

Jupiter's radiation belts - Can Pioneer 10 survive

Recent calculations suggest that three of the Galilean satellites are very effective in limiting the fluxes of energetic electrons and protons diffusing inward from Jupiter's outer magnetosphere. Electron and proton densities with and without lunar effects are plotted as functions of the distance from the center of the planet in units of Jupiter radii. Both electrons and protons in the model come from the solar wind. The trajectory of Pioneer 10 in magnetic coordinates is examined and the period of greatest danger to the spacecraft is discussed.

Hess, W. N.↗

Spectrum of atmospheric gamma rays to 10 MeV at lambda = 40 deg

Results of measurements of the differential counting rate spectra due to atmospheric gamma rays as a function of altitude to 3.6 g/sq cm over Texas. Two gain settings and a 128-channel pulse height analyzer were used to cover the range from 0.2 to 10 MeV. The detector was a 7.6 x 7.6 cm NaI crystal, which was surrounded on five sides by a 2-cm-thick plastic anticoincidence shield for charged particle rejection. The system had a nearly isotropic response to photons above 0.2 MeV. The spectrum at ceiling appeared as a steep continuum with a power-law index of about 1.4. The only obvious feature was the 0.51-MeV positron annihilation line. The spectral shape was independent for depths less than 20 g/sq cm, the absolute intensity varying in proportion to the intensity of the cosmic ray secondary charged particles. Also, at depths less than 30 g/sq cm the observed flux variation with altitude can be described in terms of an empirical depth-dependent source function.

Peterson, L. E.↗

Energy spectrum and flux of 3- to 20-Mev neutrons and 1- to 10-Mev gamma rays in the atmosphere

An experiment is described which was designed to measure the neutron and gamma ray energy spectrums and fluxes in the energy intervals 3 to 20 MeV and 1 to 10 MeV, respectively. In addition, from the 3 to 20-MeV proton recoil spectrums it is possible to infer the shape of the neutron energy spectrum from 20 to 50 MeV. The detecting system utilized a separate charged particle rejection scheme and a two-parameter display system for the output from the pulse shape discrimination which separated gamma rays from neutrons (n). Two long-duration flights were made with this detector in 1970 at Palestine, Tex. (P sub c = 4.6 Gv) and at Ft. Churchill, Canada (P sub c = 0.3 Gv).

Klumpar, D. M.↗

Io-accelerated electrons - Predictions for Pioneer 10 and Pioneer 11

Based on a model in which electrons are accelerated to energies of 100 kiloelectron volts through sheaths associated with Io, predictions are made about energetic electrons to be observed by Pioneer 10 and Pioneer 11 in the Jovian magnetosphere. This energetic electron source may be distinguishable from the solar wind diffusion source by the radial flux profile and by the characteristic electron energies.

Shawhan, S. D.↗

Preliminary Pioneer 10 encounter results from the Ames Research Center plasma analyzer experiment

Preliminary results from the Ames Research Center plasma analyzer experiment for the Pioneer 10 Jupiter encounter indicate that Jupiter has a detached bow shock and magnetopause similar to the case at Earth but much larger in spatial extent. In contrast to Earth, Jupiter's outer magnetosphere appears to be highly inflated by thermal plasma and therefore highly responsive in size to changes in solar wind dynamic pressure.

Wolfe, J. H.↗

Protons and electrons in Jupiter's magnetic field - Results from the University of Chicago experiment on Pioneer 10

Fluxes of high energy electrons and protons are found to be highly concentrated near the magnetic equatorial plane from distances of about 30 to about 100 Jovian radii. The 10-hour period of planetary rotation is observed as an intensity variation, which indicates that the equatorial zone of high particle fluxes is inclined with respect to the rotation axis of the planet. At radial distances below 20 Jovian radii, the synchrotron-radiation-producing electrons with energies above 3 MeV rise steeply to a maximum intensity near the periapsis at 2.8 Jovian radii. The flux of protons with energies above 30 MeV reaches a maximum intensity at 3.5 Jovian radii, with the intensity decreasing inside this radial distance.

Simpson, J. A.↗

Gravitational parameters of the Jupiter system from the Doppler tracking of Pioneer 10

Preliminary analyses of Doppler data from Pioneer 10 during its encounter with Jupiter indicate that the mass of Io is about 20% greater than previously thought and that Io's mean density is about 3.5 grams per cubic centimeter. A determination of the dynamical flattening of Jupiter (a - b)/a (where a is the semimajor axis and b is the semiminor axis) is found to lie in the neighborhood of 0.065, which agrees with the value determined from satellite perturbations.

Anderson, J. D.↗

Mariner 10 Venus encounter

Review of the scientific objectives of the Mariner 10 mission with regard to observations of Venus during a flyby, and description of the equipment installed on the spacecraft to fulfill these objectives. A detailed description is given of the hardware modifications made to the payload specifically for the Venus sequence. In discussing the encounter operations, two spacecraft problems which significantly affected the Venus encounter sequence are cited - namely, a failure of the television optic heaters to come on shortly after launch, and the occurrence of a roll gyro oscillation.

Dunne, J. A.↗

Magnetic field observations near Venus - Preliminary results from Mariner 10

The NASA-GSFC magnetic field experiment on Mariner 10 is the first flight of a dual magnetometer system conceived to permit accurate measurements of weak magnetic fields in space in the presence of a significant and variable spacecraft magnetic field. Results from a preliminary analysis of a limited data set are summarized in this report, which is restricted primarily to Venus encounter. A detached bow shock wave that develops as the super Alfvenic solar wind interacts with the Venusian atmosphere has been observed. However, the unique coincidence of trajectory position and interplanetary field orientation at the time of bow shock crossing led to a very disturbed shock profile with considerably enhanced upstream magnetic fluctuations. At present it is not possible to ascertain the nature and characteristics of the obstacle responsible for deflecting the solar wind flow. Far downstream disturbances associated with the solar wind wake have been observed.

Ness, N. F.↗

Venus - Atmospheric motion and structure from Mariner 10 pictures

The Mariner 10 television cameras imaged the planet Venus in the visible and near ultraviolet for a period of 8 days at resolutions ranging from 100 meters to 130 kilometers. The general pattern of the atmospheric circulation in the upper tropospheric/lower stratospheric region is displayed in the pictures. Atmospheric flow is symmetrical between north and south hemispheres. The equatorial motions are zonal (east-west) at approximately 100 meters per second, consistent with the previously inferred 4-day retrograde rotation. Angular velocity increases with latitude. The subsolar region, and the region downwind from it, show evidence of large-scale convection that persists in spite of the main zonal motion. Dynamical interaction between the zonal motion and the relatively stationary region of convection is evidenced by bowlike waves.

Murray, B. C.↗