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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Simulation evaluation of transition and hover flying qualities of the E-7A STOVL aircraft

The generalized simulation model developed for the E-7A STOVL fighter-type aircraft configuration has attempted to define the limits of acceptibility for a vertical-to-horizontal-to-vertical flight transition envelope. An effort was also made to determine the control power required during hover and transition, and to evaluate whether the integration of flight and propulsion controls thus far effected achieves good flying qualities throughout the low-speed flight envelope. The results thus obtained furnish a general view of the acceptable transition corridor, expressed in terms of the minimum-climb capability.

Franklin, James A.↗
NASA NTRS1989

Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix E: Pressure-fed booster test bed for the liquid rocket booster study

The stress analysis/structural design of the Pressure-Fed Booster Engine Test Bed using the existing F-1 Test Facility Test Stand at Huntsville, Alabama is described. The analysis has been coded and set up for solution on NASTRAN. A separate stress program was established to take the NASTRAN output and perform stress checks on the members. Joint checks and other necessary additional checks were performed by hand. The notes include a brief description of other programs which assist in reproducing and reviewing the NASTRAN results. The redesign of the test stand members and the stress analysis was performed per the A.I.S.C. Code. Loads on the stand consist of the loaded run tanks; wind loads; seismic loads; live loads consisting of snow and ice: live and dead loads of steel; and loaded pressurant bottle. In combining loads, wind loads and seismic loads were each combined with full live loads. Wind and seismic loads were not combined. No one third increase in allowables was taken for the environmental loads except at decks 147 and 214, where the increase was used when considering the stay rods, brackets and stay beams. Wind and seismic loads were considered from each of the four coordinate directions (i.e. N,S,E,W) to give eight basic conditions. The analysis was run with the pressurant tank mounted at level 125. One seismic condition was also run with the tank mounted at levels 169 and 214. No failures were noted with mounting at level 169, but extensive deck failure with mounting at level 214 (the loadsets used are included on the tape, but no detailed results are included in the package). Decking support beams at levels 147 and 214 are not included in the model. The stress program thus does not reduce strut lengths to the length between support beams (the struts are attached to the beams at intersection points) and gives stress ratios larger than one for some of the struts. The affected members were therefore checked by hand.

Source record↗
NASA NTRS1990

Reflectance spectra of 'featureless' materials and the surface mineralogies of M- and E-class asteroids

In a search for diagnostic spectral parameters which can be used to distinguish different materials on the surface of asteroids and to provide information on the detection limits for mafic silicates, the 0.3- to 2.6-micron reflectance spectra of meteoritic enstatite (nearly pure MgSiO3), iron meteorite metal, magnetite, and amorphous carbon as well as various mixtures of these materials with mafic silicates were examined. Results are presented on the dependence of the spectral detectability of mafic silicates associated with metal, carbon, and magnetite on the particle sizes of the phases, their chemistries, crystal structures, and abundances. It is shown that the observational data for a representative M-class asteroid, (16) Psyche, are largely consistent with a fine-grained metal-rich surface assemblage, whereas data for the E-class asteroid (44) Nysa indicate that its surface is composed of fine-grained material similar to enstatite achondrites, with a small amount of material comparable to the chondritic inclusions found in the Cumberland Falls aubrite.

Cloutis, Edward A.↗
NASA NTRS1990

Complex-coordinate calculation of 1D(e) resonances using Hylleraas functions

The lowest 1D(e) resonances below the n = 2 and n = 3 thresholds are calculated using a method of complex-coordinate rotation. The results, obtained with the use of Hylleraas functions, are believed to be of high accuracy. This work should serve as a useful reference for other investigations.

Bhatia, A. K.↗
NASA NTRS1990

Differences in the solar modulation of E greater than 60 MeV cosmic rays at earth and 18 AU during a complete 11-year cycle from 1977 to 1988

The cosmic ray intensities for E greater than 60 MeV particles at a constant radius of 18 AU using data from the IMP, Voyager and Pioneer spacecraft. These intensities are compared with the intensities at earth for a complete 11-year cycle from 1977 to 1988. It is found that the variations at 1 AU and 18 AU track very closely during the decreasing portion of the cycle from 1977 to 1982 but during the recovery the intensity at 18 AU increases much less than at earth with the result that in 1987 the intensity is only 82 percent of that at the previous minimum in 1977. These results imply that the integral radial gradient between 1 and 18 AU is constant in time from 1977 to 1982 but decreases from 1982 to 1988. Thus, the amplitude of the 11-year variation observed at a fixed energy is quite strongly radially dependent, with the amplitude becoming less at larger radii.

Lockwood, J. A.↗
NASA NTRS1990

Electric currents in E-like planetary ionospheres

In this paper an MHD approach is used to consider the conduction of electric current in a lightly ionized gas, taking into account the gradients of pressure in the ion and electron gases, in addition to the electric field. The coefficients of electrical conductivity are found for each driver of current. New expressions for the components of heat dissipation associated with each driver of current are developed, which are fully consistent with kinetic theory. The relationship of the results to those obtained by kinetic theory is discussed. New components of currents associated with planetary equatorial electrojets are found. A new diffusion equation for magnetic induction is found, applicable in E-like regions of planetary ionospheres, and stellar photospheres.

Cole, K. D.↗
NASA NTRS1991

ISEE 1 observations of electrostatic ion cyclotron waves in association with ion beams on auroral field lines from about 2.5 to 4.5 R(E)

Quasi-monochromatic waves at about the hydrogen cyclotron frequency were observed as the ISEE 1 satellite traversed auroral field lines at radial distances of about 2.5-4.5 R(E) near midnight on June 19, 1981. Waves and both lower and higher frequencies were observed at higher altitudes, and possible electrostatic helium cyclotron and oxygen cyclotron waves occurred at lower altitudes. Upflowing hydrogen and oxygen beams and field-aligned currents occurred simultaneously. The features of the waves are most consistent with the current-driven mode. In addition, numerical studies of the linear dispersion relation, using parameters based on the observations, show that both the parallel and oblique two-stream modes and the ion-beam-driven modes were stable while oblique current-driven modes were unstable. The O(+) and H(+) distributions provide evidence for interactions with local electrostatic ion cyclotron waves and for the H(+)-O(+) two-stream instability at altitudes below the satellite.

Catell, C. A.↗
NASA NTRS1992

The e-Beam Sustained Laser Technology for Space-based Doppler Wind Lidar

An overview is presented of GEC Avionics activities relating to the Spaceborne Doppler Wind Lidar. In particular, the results of design studies into the use of an e-beam sustained CO2 laser for spaceborne applications, and experimental work on a test bed system are discussed.

Brown, M. J.↗
NASA NTRS1991

Discovery of a low-redshift ultraluminous 'E + A' galaxy

The serendipitous discovery is reported of a relatively low redshift (z = 0.0875) 'E + A' (poststarburst) galaxy. The galaxy is remarkable for its extremely high luminosity, strong Balmer absorption lines, and morphology, indicating that a merger precipitated the starburst about 1 Gyr ago.

Oegerle, William R.↗
NASA NTRS1991

Structure and particle properties of Saturn's E Ring

The present systematic reanalysis of a substantial portion of extant photometric data on the Saturn E Ring has calibrated every observation on the basis of a common 3D model. A simple power-law model is found to describe the ring's normal optical depth profile with orbital radius; this trend is departed from, however, near the density peak, where there emerges a 30-percent localized decrease in thickness. No power-law size distribution is found to be compatible with available photometry. The peculiar size distribution points to a ring origin in a process that was not collisional or disruptive.

Showalter, Mark R.↗
NASA NTRS1992

The dynamics of Saturn's E ring particles

An analytical and numerical investigation is conducted of the motions of the 1-micron grains launched from Enceladus as they evolve under the influence of the Saturn oblate gravity field, solar radiation pressure, and EM forces. By plotting the position of a single particle over time, the distribution of 1-micron rains thus injected is shown in the course of swift movement under these forces; the distribution is noted to exhibit many of the characteristics of the Saturn E ring. Particles with slightly different grain sizes are found to achieve much smaller eccentricities.

Horanyi, Mihaly↗
NASA NTRS1993

Surface velocity fields of Ice Streams D and E derived from repeat satellite imagery

Sequential Landsat TM images were used to map in detail the surface velocity of Ice Streams D and E by tracking small ice features in coregistered images. The majority of both ice streams have now been mapped for velocity, and in most areas, approximate strain-rates are also determined. Tracking was accomplished semiautomatically using an image-to-image cross-correlation technique. Measurement density is roughly four per sq km in regions with distinct surface features (crevasses, snow dunes, etc.), and with cloud-free image coverage.

Scambos, Ted A.↗
NASA NTRS1992

Relationship of E-type Apollo asteroid 3103 (1982 BB) to the enstatite achondrite meteorites and the Hungaria asteroids

Visible and near-IR observations are reported which confirm that Apollo asteroid 3103 (1982 BB) is a high-albedo E-type object with a reflectance spectrum consistent with the iron-free silicates, primarily enstatite, present in the aubrites. Visible and thermal IR light curves indicate that 3103 is an elongated object with no evidence of substantial surface albedo variations. It is presently in an orbital resonance with earth and is probably a relatively long-lived member of the earth-approaching population. This is consistent with the relatively long cosmic ray exposure ages of the aubrites compared to other stony meteorites. The fall geometries of the aubrites are consistent with their being derived from 3103. The ubiquitous brecciated nature of the aubrites and the indications of a single parent body for nearly all these meteorite suggest that 3103 is the sole near-earth parent body of this meteorite type.

Gaffey, Michael J.↗
NASA NTRS1993

A Study of Saturn's E-Ring Particles Using the Voyager 1 Plasma Wave Instrument

The flyby of Voyager 1 at Saturn resulted in the detection of a large variety of plasma waves, e.g., chorus, hiss, and electron cyclotron harmonics. Just before the outbound equator crossing, at about 6.1 R(sub s), the Voyager 1 plasma wave instrument detected a strong, well-defined low-frequency enhancement. Initially it was suggested that plasma waves might be responsible for the spectral feature but more recently dust was suggested as at least a partial contributor to the enhancement. In this report we present evidence which supports the conclusion that dust contributes to the low-frequency enhancement. A new method has been used to derive the dust impact rate. The method relies mainly on the 16-channel spectrum analyzer data. The few wide band waveform observations available (which have been used to study dust impacts during the Voyager 2 ring plane crossing) were useful for calibrating the impact rate from the spectrum analyzer data. The mass and, hence, the size of the dust particles were also obtained by analyzing the response of the plasma wave spectrum analyzer. The results show that the region sampled by Voyager 1 is populated by dust particles that have rms masses of up to few times 10(exp -11) g and sizes of up to a few microns. The dust particle number density is on the order of 10(exp -3) m(exp 3). The optical depth of the region sampled by the spacecraft is 1.04 x 10(exp -6). The particle population is centered about 2500 km south of the equatorial plane and has a north-south thickness of about 4000 km. Possible sources of these particles are the moons Enceladus and Tethys whose orbits lie within the E-ring radial extent. These results are in reasonable agreement with photometric studies and numerical simulations.

Tsintikidis, D.↗
NASA NTRS1993

Postflight hardware evaluation RSRM-29 (STS-54). Appendix E: Insulation postfire data

Appendix E, Insulation Postfire Data for the Final Postflight Hardware Evaluation Report RSRM-29 (STS-54) is provided. Data on the following are included: nozzle-to-case joint performance; aft dome insulation performance; aft cylinder insulation performance; forward segment star tip insulation performance; and igniter chamber and adapter insulation performance.

Source record↗
NASA NTRS1993

Radar E-O image fusion

The fusion of radar and electro-optic (E-O) sensor images presents unique challenges. The two sensors measure different properties of the real three-dimensional (3-D) world. Forming the sensor outputs into a common format does not mask these differences. In this paper, the conditions under which fusion of the two sensor signals is possible are explored. The program currently planned to investigate this problem is briefly discussed.

Oneil, William F.↗
NASA NTRS1994

External Device to Incrementally Skid the Habitat (E-DISH)

A Mars habitat transport system was designed as part of the NASA Mars exploration program. The transport system, the External Device to Incrementally Skid the Habitat (E - DISH), will be used to transport Mars habitats from their landing sites to the colony base and will be detached after unloading. The system requirements for Mars were calculated and scaled for model purposes. Specific model materials are commonly found and recommendations for materials for the Mars design are included.

Brazell, J. W.↗