Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Expedition”

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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Photographs of the front of the expanding auroral bulge during an auroral substorm.

Selected photographs from a 1968 NASA airborne expedition of the spectacular and theoretically intriguing poleward expansive phase of auroral substorms are presented. They illustrate many of the common features of the front of the expanding auroral bulges, such as violent curl motions, the formation of new arcs at the front, and north-south aligned arcs just inside the bulge. A simultaneous magnetic record is also presented and briefly discussed.

Akasofu, S.-I.↗
NASA NTRS1973

The hydroxyl emissions in relation to the dynamical processes of the atmosphere

Ground and airborne hydroxyl emission observations were made in the northern polar regions. The ground observations were made at Ester Dome, Alaska, and the airborne observations were made during the 1969 NASA Airborne Expedition. The analysis of some of the data that were acquired has lead to the following conclusions: (1) Airglow OH measurements show no appreciable change with latitude or longitude. (2) Diurnal changes at northern latitudes are similar to those observed in midlatitude regions. (3) Two types of OH enhancements were observed photometrically in the 9370 A region - one associated with visible aurora, and the other uncorrelated with visible aurora. High resolution spectra under both inactive and active conditions indicate that the OH enhancements seen photometrically in active aurorae are probably due to contamination of the filter pass bands by the unexpected enhancement of the NI multiplet lines at 9387 A and 9393 A. All previously reported aurorally associated enhancements are consequently suspect.

Romick, G. J.↗
NASA NTRS1973

Universal obturator shutter

The construction and electrical circuit of a rotating photoshutter are described. The photoshutter can operate, using both stationary and expeditional astronomical instruments under one of three conditions: (1) short exposures from 0.01 to 0.06 sec, controlled by a mobile sector; (2) exposures from 1 sec and more, fixed by hand; and (3) exposures fixed by an electronic or electromechanical timer. The working aperture of the shutter is 150 x 150 mm.

Skorik, K. Y.↗
NASA NTRS1973

Evaluate the application of ERTS-A data for detecting and mapping sea ice

The author has identified the following significant results. The results of the analysis of data collected during the spring and summer demonstrate that ERTS-1 imagery has a high potential for monitoring arctic sea ice conditions during the time for maximum ice extent through ice-breakup season. In the eastern Beaufort Sea area, the combination of ERTS-1 orbital overlap and a high incidence of cloud-free conditions during the spring assures a high frequency of repetitive satellite coverage. In the mid-Beaufort Sea, numerous fractures and leads can be identified, even in the early spring data. Ice features that can be identified include: development of fractures leading to the formation of distinct ice floes; growth and deterioration of leads; evidence of shearing movements of ice masses; formation of new grey ice within leads; distinction between grey, grey-white, and older forms of ice; and the deterioration of the ice surface evidenced by the formation of puddles, thaw holes, and drainage patterns. Ice conditions in the Bering Sea near St. Lawrence Island reported by aircraft observers participating in the Bering Sea Expedition are in close agreement with the ice conditions mapped from the corresponding ERTS-1 imagery. Ice features identified were: boundaries between grey ice and first year ice, shear leads, and occurrence of open water.

Barnes, J. C.↗
NASA NTRS1973

Apollo 17: At Taurus Littrow

A summation, with color illustrations, is presented on the Apollo 17 mission. The height, weight, and thrust specifications are given on the launch vehicle. Presentations are given on: the night launch; earth to moon ascent; separation and descent; EVA, the sixth lunar surface expedition; ascent from Taurus-Littrow; the America to Challenger rendezvous; return, reentry, and recovery; the scientific results of the mission; background information on the astronauts; and the future projects.

Anderton, D. A.↗
NASA NTRS1972

Space exploration and the origin of life.

An important aspect of space exploration is connected with investigations regarding the existence of life on other celestial bodies. The most important objects to be studied for this purpose include the planets, the satellites of planets, meteorites, asteroids, and comets. The exploration of Mars, in particular, beginning with the telescope, fly-by and orbiting spacecraft, followed by landed laboratories, and perhaps culminating eventually in manned expeditions, may well provide a significant portion of the data we seek about the origin of life and introduce a new era of understanding of man's place in the universe.

Young, R. S.↗
NASA NTRS1973

Analysis of aircraft microwave measurements of the ocean surface

A data system was developed to process, from calibrated brightness temperature to computation of estimated parameters, the microwave measurements obtained by the NASA CV-990 aircraft during the 1972 Meteorological Expedition. A primary objective of the study was the implementation of an integrated software system at the computing facility of NASA/GSFC, and its application to the 1972 data. A single test case involving measurements away from and over a heavy rain cell was chosen to examine the effect of clouds upon the ability to infer ocean surface parameters. The results indicate substantial agreement with those of the theoretical study; namely, that the values obtained for the surface properties are consistent with available ground-truth information, and are reproducible except within the heaviest portions of the rain cell, at which nonlinear (or saturation) effects become apparent. Finally, it is seen that uncorrected instrumental effects introduce systematic errors which may limit the accuracy of the method.

Willand, J. H.↗
NASA NTRS1973

Techniques development for whale migration tracking

Effort leading to the completion of development and fabrication of expansible whale harnesses and whale-carried instrument pods is described, along with details of the gear. Early preparative effort for a January-February 1974 field expedition is reported.

Goodman, R. M.↗
NASA NTRS1973

Substorm effects in auroral spectra

A substorm time parameter is defined and used to order a large body of photometric data obtained on aircraft expeditions at high latitudes. The statistical analysis demonstrates hardening of the electron spectrum at the time of substorm, and it is consistent with the accepted picture of poleward expansion of aurora at the time of substorm and curvature drift of substorm-injected electrons. These features are not evident from a similar analysis in terms of magnetic time. We conclude that the substorm time concept is a useful ordering parameter for auroral data.

Eather, R. H.↗
NASA NTRS1975

Multiplexing technique for computer communications via satellite channels

Multiplexing scheme combines technique of dynamic allocation with conventional time-division multiplexing. Scheme is designed to expedite short-duration interactive or priority traffic and to delay large data transfers; as result, each node has effective capacity of almost total channel capacity when other nodes have light traffic loads.

Binder, R.↗
NASA NTRS1973

The Automated Astronomic Positioning System (AAPS)

Two prototype systems of The Automated Astronomic Positioning System (AAPS) have been delivered to Defense Mapping Agency (DMA). The AAPS was developed to automate and expedite the determination of astronomic positions (latitude and longitude). This equipment is capable of defining astronomic positions to an accuracy sigma = 0.3 in each component within a two hour span of stellar observations which are acquired automatically. The basic concept acquires observations by timing stellar images as they cross a series of slits, comparing these observations to a stored star catalogue, and automatically deducing position and accuracy by least squares using pre-set convergence criteria. An exhaustive DMA operational test program has been initiated to evaluate the capabilities of the AAPS in a variety of environments (both climatic and positional). Status of the operational test is discussed.

Williams, O. N.↗
NASA NTRS1974

Optical characteristics of regolith from the Sea of Fertility, Sea of Tranquillity, and Ocean of Storms

A diffuse reflection spectra analysis is reported for regolith returned by the Luna 16 automatic station and by the Apollo 11 and Apollo 12 expeditions. The spectra of the specular reflection of Sea of Fertility regolith, as well as the spectra of diffuse reflection from polished sections of lunar rocks from the Sea of Tranquillity and the Ocean of Storms have no well-defined structures and are close to each other. The lowest reflectivity is exhibited by the Sea of Tranquillity regolith, and the highest -- by the Ocean of Storms regolith. A weak absorption band with a maximum near 1 nm is noted in the spectra, corresponding to the Fe-2(+) ion in the octahedral position in the lattice of regolith mineral constituents. When the indicatrix of scattering of the regolith was recorded, a specular component was detected.

Antipova-Karatayeva, I. I.↗
NASA NTRS1974

The problem of organization of a coastal coordinating computer center

The fundamental principles of the operation of a coastal coordinating and computing center under conditions of automation are presented. Special attention is devoted to the work of Coastal Computer Center of the Arctic and Antarctic Scientific Research Institute. This center generalizes from data collected in expeditions and also from observations made at polar stations.

Dyubkin, I. A.↗
NASA NTRS1974

The NSF/RANN FY 1975 program for geothermal resources research and technology

The specific goal of the NSF geothermal program is the rapid development by industry of the nation's geothermal resources that can be demonstrated to be commercially, environmentally and socially acceptable as alternate energy sources. NSF, as the lead agency for the federal geothermal energy research program, is expediting a program which encompasses the objectives necessary for significant utilization. These include: acceleration of exploration and assessment methods to identify commercial geothermal resources; development of innovative and improved technology to achieve economic feasibility; evaluation of policy options to resolve environmental, legal, and institutional problems; and support of experimental research facilities for each type of geothermal resource. Specific projects in each of these four objective areas are part of the NSF program for fiscal year 1975.

Kruger, P.↗
NASA NTRS1975

The Viking Mars lander camera

The 7.3 kg cameras for the 1976 Viking Mars expedition feature an array of 12 silicon photodiodes, including six spectral bands for color and near-infrared imaging with an angular resolution of 0.12 deg and four focus steps for broadband imaging, with an improved angular resolution of 0.04 deg. The field of view in elevation ranges from 40 deg above to 60 deg below the horizon, and in azimuth ranges to 342.5 deg. The cameras are mounted 0.8 m apart to provide a stereo view of the area accessible to a surface sampler for biological and chemical investigations. The scanning rates are synchronized to the lander data transmission rates of 16000 bits per sec to the Viking orbiters as relay stations and 250 bits per sec directly to earth. However, image data can also be stored on a lander tape recorder. About 10 million bits of image data will be transmitted during most days of the 60-day-long mission planned for each lander.

Huck, F. O.↗
NASA NTRS1975

Spectroscopic determination of the characteristics of precipitating auroral particles

A large data base obtained from NASA Convair auroral expeditions is used to illustrate the variability in 6300A/4278A and 5577A/4278A ratios in auroras. The variation is well bounded by theoretical curves for characteristic spectral energies between 0.3 and 10 keV, which are typical for auroral precipitation. Coordinated measurements with the OV1-18 satellite show good agreement between the parameters of the precipitating-proton and electron-energy spectra derived from photometric measurements and those measured directly.

Mende, S. B.↗
NASA NTRS1976

Compound solder joints

Joining technique prevents contamination, may be used to join dissimilar metal tubes, minimizes fluid and gas entrapment, expedites repairs, and can yield joints having leakage rates less than 0.000001 standard cubic cm He/min. Components of joint are solder sleeve, two solder rings, Teflon sleeve, and tubing to be joined.

Batista, R. I.↗
NASA NTRS1975

Airship construction

Forty-four years ago the first successful metal airship was completed and delivered to the United States Navy, the ZMC-2. Between those years and the present, very little effort or serious consideration has been given to the manufacture, design, construction, or economic impact of airships. It is important to retain and exploit the small but continually diminishing pool of airship talent that will expedite the success of the United States in what is now a pioneering venture. The relative simplicity of airship construction, utilizing the tremendous technical advances of the last 44 years, leads to the conclusion that this form of transportation holds great promise for reducing costs of military missions and improving the international competitive position of the United States in commercial applications.

Roda, J.↗