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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 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Reentry thermal protection from Pioneer F RTG insulation material

Ablation tests were performed on the insulation material used in the Pioneer F radioisotope thermoelectric generator (RTG) in the Ames Arc-Heated Planetary-Gas Wind Tunnel. Test results indicate that the material, trade name Min-K 1301, should experience little ablation for heat transfer rates below 40 BTU/sq ft-sec. If the current design were to be changed so that the various pieces of Min-K were fastened or interlocked together the total amount of heat delivered to the RTG heat source during an earth orbital decay reentry would be reduced by at least 22.7%.

Vorreiter, J. W.↗
NASA NTRS1972

Pioneer F mission to Jupiter

The experimental designs for the Pioneer F mission to Jupiter are described. The spacecraft is designed to make measurements of the planet's atmosphere, radiation belts, heat balance, magnetic fields, moons, and other related phenomena. The mission also characterizes the heliosphere, the interstellar gas, cosmic rays, asteroids, and meteoroids between the earth and 2.4 billion kilometers from the sun.

Allaway, H. G.↗
NASA NTRS1972

Flight-determined characteristics of an air intake system on an F-111A airplane

Flow phenomena of the F-111A air intake system were investigated over a large range of Mach number, altitude, and angle of attack. Boundary-layer variations are shown for the fuselage splitter plate and inlet entrance stations. Inlet performance is shown in terms of pressure recovery, airflow, mass-flow ratio, turbulence factor, distortion factor, and power spectral density. The fuselage boundary layer was found to be not completely removed from the upper portion of the splitter plate at all Mach numbers investigated. Inlet boundary-layer ingestion started at approximately Mach 1.6 near the translating spike and cone. Pressure-recovery distribution at the compressor face showed increasing distortion with increasing angle of attack and increasing Mach number. The time-averaged distortion-factor value approached 1300, which is near the distortion tolerance of the engine at Mach numbers above 2.1.

Hughes, D. L.↗
NASA NTRS1971

NASA, John F. Kennedy Space Center environmental impact statement

The probable total impact of the John F. Kennedy Space Center (KSC) operations on the environment is discussed in terms of launch operations emissions and environmental quality. A schedule of planned launches through 1973 is included with a description of the systems for eliminating harmful emissions during launch operations. The effects of KSC on wild life and environmental quality are discussed along with the irreversible and irretrievable commitments of natural resources.

Source record↗
NASA NTRS1972

Advanced airbreathing engine lubricants study with a tetraester fluid and a synthetic paraffinic oil at 492 K (425 F)

Groups of 120-mm-bore angular-contact ball bearings made from AISI M-50 steel were fatigue tested with a tetraester and a synthetic paraffinic oil at a bearing temperature of 492 K (425 F) in an air environment. Bearing life exceeded AFBMA-predicted (catalog) life by factors in excess of 4 and 10 for the tetraester and synthetic paraffinic fluids, respectively. The final viscosities after 500 hours of operation were 14 and 6 times the initial values, respectively. During the same time period, when the test oil is replaced at a rate approximating the replenishment rate in actual commerical engine usage, no significant increase in lubricant viscosity with time was observed.

Zaretsky, E. V.↗
NASA NTRS1972

Parameters of small scale ionization inhomogeneities in the F region of the ionosphere

The results of the parameters of small-scale ionization inhomogeneities study of the ionosphere's F-region for October-November 1965 and January-February 1966 are presented. It is shown that the most probable values of the inhomogeneity parameters are as follows: degree of anisotropy 1.4-2; vertical dimension 200-400 m; horizontal dimensions along major and minor axes 400-1000 and 200-600 m, respectively; rate of chaotic motions 30-60 m/sec; lifetime 6-9 sec.

Drobzhev, V. I.↗
NASA NTRS1972

IMP F and G phase 1 magnetic field analysis

The program developed to analyze magnetic field data from the magnetic field experiment flown in IMP F is reported. The analysis converts the raw X, Y, Z sensor data as received on the magnetic field experiment tape into vector measurements of the ambient magnetic field observed by the experiment. These data are computed for four frames of reference -- apparent, payload, solar ecliptic and solar magnetospheric. In addition 20.45 second statistics are computed for the last three coordinate systems. Finally, a summary tape is produced containing detailed data and sequence statistics as well as the output from the autocorrelation computer, trajectory data and identification information.

Mish, W. H.↗
NASA NTRS1972

Flight measurements of buffet characteristics of the F-104 airplane for selected wing-flap deflections

A flight program was conducted on the F-104 airplane to investigate the effects of moderate deflections of wing leading- and trailing-edge flaps on the buffet characteristics at subsonic and transonic Mach numbers. Selected deflections of the wing leading and trailing-edge flaps, individually and in combination, were used to assess buffet onset, intensity, and frequency; lift curves; and wing-rock characteristics for each configuration. Increased deflection of the trailing-edge flap delayed the buffet onset and buffet intensity rise to a significantly higher airplane normal-force coefficient. Deflection of the leading-edge flap produced some delay in buffet onset and the resulting intensity rise at low subsonic speeds. Increased deflection of the trailing-edge flap provided appreciable lift increments in the angle-of-attack range covered, whereas the leading-edge flap provided lift increments only at high angles-of-attack. The pilots appreciated the increased maneuvering envelope provided by the flaps because of the improved turn capability.

Friend, E. L.↗
NASA NTRS1970

Energetic particles experiment instrumentation packaging program for IMP-F (Explorer 34) and IMP-G (Explorer 41) NASA Interplanetary Monitoring Platform program

The package design and assembly techniques for the IMP-F and IMP-G space-physics experiments, provided for the NASA Interplanetary Monitoring Platform Program are described. Thin-film, hybrid, integrated circuits used in these instruments to increase component density and reliability, and special procedures and precautions for the fabrication of space hardware are described.

Source record↗
NASA NTRS1972

Time-dependent edge notch sensitivity of Inconel 718 sheet in the temperature range 900 to 1400 F (482 to 760 C)

Time-dependent notch sensitivity of Inconel 718 sheet occurred at 900 to 1200 F when notched specimens were loaded below the yield strength, and tests on smooth specimens showed that small amounts of creep consumed large fractions of creep-rupture life. The severity of the notch sensitivity decreased with decreasing solution treatment temperature and increasing time and/or temperature of the aging treatment. Elimination of the notch sensitivity was correlated with a change in the dislocation mechanism from shearing to by-passing precipitate particles.

Wilson, D. J.↗
NASA NTRS1972

Measurements of O(1 D) quenching rates in the F-region

In-situ determinations of the quenching of O(1 D) atoms by N2 and O2 molecules were made from observations of 6300 A nightglow intensity enhancements produced by the Platteville 1.6 MW transmitter. The heating of F-region electrons near the point of reflection of the RF wave leads to electron impact excitation of oxygen atoms to the O(1 D) state. It is shown that the resulting region of enhance 6300 A emission is localized to the region of electron energy absorption for heating at the lower altitudes. At 225 km the measured time constants for intensity buildup following transmitter turn-on and for intensity decay following turn-off are identical and equal to (13 plus or minus 1) sec. Time constants varying from 30 to 80 sec are found for the altitude range 260 to 300 km. The inferred quenching coefficient for the whole altitude range, 225 to 300 km, is 4.4 + 2 or - 1 x 10 to the minus 11th power cu cm/sec at 950 K, in good agreement with laboratory data. The quenching frequency obtained at 225 km, when referred to the altitude 120 km, is equal to (21 plus or minus 2)/sec, in agreement with less direct ionospheric determinations.

Sipler, D. P.↗
NASA NTRS1971

Oxidation screening at 1204 C /2200 F/ of candidate alloys for the space shuttle thermal protection system.

Evaluation of the oxidation resistance of 15 alloys under some of the environmental conditions that might be encountered by the shuttle thermal protection system. The alloys included nickel-, iron-, and cobalt-base wrought alloys. Specimens were self-resistively heated to 1204 C (2200 F) in a 10-torr still-air environment for 100 thirty-minute cycles. Specimen weight, thickness, and microstructural changes were noted, and surface scales were identified by room-temperature X-ray diffraction. Based on these observations, the behavior of the alloys was evaluated in terms of overall amount of metal consumption due to oxide formation and relative tendency toward oxide spalling and scale vaporization.

Sanders, W. A.↗
NASA NTRS1971

Relationship between Fe /+/ ions and equatorial spread F.

Evaluation of observations from the retarding potential analyzer on Ogo 6 near the magnetic equator, demonstrating an intimate relationship between the presence of Fe(+) ions and irregularities in the total ion concentration. The ionospheric irregularities (or structure) are probably another manifestation of equatorial spread F, although this has not yet been verified. Nearly half the nighttime equatorial crossings below 700 km exhibit both Fe(+) and structure, but only 10% of the passes without Fe(+) have structure. Approximately one-third of the passes with Fe(+) are not structured, which indicates that Fe(+) may be a necessary but not sufficient condition for structure formation. The Atlantic region shows an extremely high and detailed correlation between Fe(+) ions and the irregularities.

Hanson, W. B.↗
NASA NTRS1971

Investigation of an r-f radiant energy source with uranium hexafluoride and tungsten hexafluoride injection.

An experimental investigation was conducted using the UARL 1.2-megw r-f induction heater to simulate thermal environment and fuel region characteristics expected in nuclear light bulb reactors. Argon was injected at the ends of the test chamber to provide radial-inflow vortex flow pattern. In some tests, simulated fuel consisting of a mixture of argon gas with either tungsten hexafluoride gas, uranium hexafluoride gas, or tungsten particles was injected into the discharge region from probes located at the centers of the end walls. The encouraging initial results obtained are discussed.

Roman, W. C.↗
NASA NTRS1971

The temperatures, abundances and gravities of F dwarf stars.

Theoretical colors computed from laboratory line data and from model stellar atmospheres have been used to interpret the colors of about 150 F and early G dwarfs. Effective temperatures have been derived from the H-beta index and from R-I, abundances have been obtained from m(sub 1) and from b-y, and gravities have been obtained from c(sub 1) and from b-y. The effective temperatures and gravities are in good agreement with values obtained from spectral scans. Absolute magnitudes have been obtained from the effective temperatures and gravities, the latter being used with assumed stellar masses to yield radii. The present results provide theoretical justification of the empirical formulas given by Crawford and by Stroemgren for the determination of absolute magnitudes and abundances from uvby photometry.

Bell, R. A.↗
NASA NTRS1972

6300 A quantum efficiency of the recombination mechanism in the night-time F layer.

Simultaneous airglow and electron content measurements made at Hawaii are used to infer the number of 6300 and 6364 A quanta produced per electron lost in the nighttime F layer of the ionosphere. The equation of continuity of electrons is then solved numerically to obtain the electron density profile, and the amount of quenching is estimated. This leads to the number of excitations of O(super-1 D) per O2(+) recombination (epsilon). We find, for an exospheric temperature of 1100 K, epsilon is equal to 1.1 plus or minus 0.6, in good agreement with Zipf's laboratory measurement at 300 K.

Brown, W. E.↗
NASA NTRS1971

Theoretical colours for F and G dwarf stars.

Synthetic spectra have been computed for F and G dwarf stars, using a number of values of chemical abundance, Doppler broadening velocity, and damping constant. Metal abundances for a number of such stars have been obtained using computed and observed m(sub 1) and 40-52 colors. These abundances are in good agreement with spectroscopically determined ones. The c(sub 1) colors of such stars with exactly known trigonometric parallaxes have been used in order to determine how accurately absolute magnitudes can be predicted from the colors. Generally reasonable agreement can be obtained between observed and predicted absolute magnitudes for certain of these stars. The effects of interstellar reddening on the colors of the models are examined.

Bell, R. A.↗
NASA NTRS1972

Applications Technology Satellites -F and -G.

The objectives of the Applications Technology Satellite (ATS) Program are to advance space technology in areas of importance to mankind. A brief description of the planned satellites and experiments is presented. The experiments include instructional television, communications, navigation, meteorology, spacecraft technology and science. The ATS-F and -G satellites will have 30-foot deployable antennas and will serve as three-axis stabilized platforms in geostationary orbit with 0.1 degree pointing accuracy.

Gerwin, H. L.↗