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At least 613 records · Page 34

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NASA NTRS1972

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 97

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

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NASA NTRS1972

Aerospace medicine and biology: A continuing bibliography with indexes, supplement

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NASA NTRS1972

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 100)

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. Reference describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Source record↗

NASA NTRS1972

Subsatellite measurements of plasmas and solar particles

The experiment with the small scientific subsatellite which was launched into lunar orbit from Apollo 15 is described. The subsatellite was designed to measure plasma and energetic-particle fluxes, vector magnetic fields, and velocity of the subsatellite for determining lunar gravitational anomalies. The theory of particle-shadow formation by the moon solar wind electrons, and energetic-electron fluxes in interplanetary space are discussed along with an analysis of the initial data.

Anderson, K. A.↗

NASA NTRS1972

Energy loss of cosmic rays in the interplanetary

The problems associated with determining the loss of energy by interstellar cosmic ray particles as they pass through interplanetary space to earth are discussed.

Fisk, L. A.↗

NASA NTRS1972

Anisotropies in the interplanetary intensity of solar protons E sub p 0.3 MeV

From the data on solar protons with energy 0.3 MeV obtained by Explorer 35 since July 1967, ten events were selected for the study of intensity vs time and of angular distributions of intensity in interplanetary space near the earth. The bases of selection were that the events be of adequate intensity for statistically satisfactory study and that they be attributable to a single solar flare so that their time histories were not complicated by overlapping emissions of particles. The principal findings for these events are presented.

Innanen, W. G.↗

NASA NTRS1972

A cumulative index to a continuing bibliography on aerospace medicine and biology, January 1972

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NASA NTRS1972

Energetic electrons from solar flares and associated type 3 radio bursts from metric to hectometric wave frequencies

Distinct Kev electron events as observed by satellites near the earth are, in general, associated with solar flares which are accompained by the emission of both metric and hectometric type 3 radio bursts. The positions of these flares are mainly on the western hemisphere of the sun. These results show that Kev electrons propagate under the control of the magnetic field in the interplanetary space and that, while propagating through this space, these electrons excite type 3 radio bursts from metric to hectometric wave frequencies. Emission characteristics of hectometric type 3 bursts are briefly considered in relation to the positions of associated flares.

Sakurai, K.↗

NASA NTRS1972

Nonlinear estimation theory applied to orbit determination

The development of an approximate nonlinear filter using the Martingale theory and appropriate smoothing properties is considered. Both the first order and the second order moments were estimated. The filter developed can be classified as a modified Gaussian second order filter. Its performance was evaluated in a simulated study of the problem of estimating the state of an interplanetary space vehicle during both a simulated Jupiter flyby and a simulated Jupiter orbiter mission. In addition to the modified Gaussian second order filter, the modified truncated second order filter was also evaluated in the simulated study. Results obtained with each of these filters were compared with numerical results obtained with the extended Kalman filter and the performance of each filter is determined by comparison with the actual estimation errors. The simulations were designed to determine the effects of the second order terms in the dynamic state relations, the observation state relations, and the Kalman gain compensation term. It is shown that the Kalman gain-compensated filter which includes only the Kalman gain compensation term is superior to all of the other filters.

Choe, C. Y.↗

NASA NTRS1971

The extended coronal magnetic field.

The coronal magnetic field should contain many field lines connecting the photosphere to interplanetary space. A sharp boundary separates two adjacent sectors of opposite polarity. The large-scale structure of the corona is related to the photospheric sector pattern. The corona may frequently contain transient magnetic loops reaching out to five to ten solar radii.

Wilcox, J. M.↗

NASA NTRS1971

What can nuclear energy do for society.

Nuclear fuel is a compact and abundant source of energy. Its cost per unit of energy is less than that of fossil fuel. Disadvantages of nuclear fuel are connected with the high cost of capital equipment required for releasing nuclear energy and the heavy weight of the necessary shielding. In the case of commercial electric power production and marine propulsion the advantages have outweighed the disadvantages. It is pointed out that nuclear commercial submarines have certain advantages compared to surface ships. Nuclear powerplants might make air-cushion vehicles for transoceanic ranges feasible. The problems and advantages of a nuclear aircraft are discussed together with nuclear propulsion for interplanetary space voyages.

Rom, F. E.↗

NASA NTRS1972

Relativistic electrons from the sun observed by IMP-4.

Evaluation of data obtained from the IMP-4 satellite concerning 0.3- to 12-MeV electrons from the sun between May 24, 1967, and May 2, 1969. Correlations with contemporary proton intensity increases at energies above 1 MeV are studied. The results of this study are the following: (1) the differential electron energy spectrum (0.3 to 12 keV) from solar flares appears to be a constant of the flare process, with the spectral index gamma = (-) 3.0 plus or minus 0.2; (2) particle emission from solar flares contains a prompt component, which is injected into the interplanetary medium beyond the sun and which is responsible for the diffusion characteristics of solar particle events, and a delayed component which is effectively contained in the lower solar atmosphere where it diffuses typically less than or equal to plus or minus 100 deg in longitude and gradually escapes into interplanetary space; the delayed component gives rise to the corotating features commonly observed after the impulsive and diffusive onset from the prompt component; (3) storage of electrons greater than 300 keV and protons greater than 1 MeV is essential to explain emission and propagation characteristics of solar particle events; and (4) the events with low proton/electron ratios all occur at least three weeks after the previous relativistic electron producing flare.

Simnett, G. M.↗

NASA NTRS1972

A solar-wind model including proton thermal anisotropy.

A model of the solar wind is presented which divides the interplanetary space into two regions. It assumes that the solar wind is one-fluid in an 'inner region' of radius less than 0.4 A, and two-fluid and collisionless in an 'outer region' of radius greater than 0.4 A. The second and third moment equations of the Vlasov equation together with conservation equations are used to govern the solar wind flow in the outer region. The model produces solutions for all macroscopic quantities as well as for the microscopic proton distribution function, both as functions of heliocentric distances up to 50 A. Calculated results at 1 A include the solar wind velocity, electron temperature, proton temperature, proton thermal anisotropy and magnetic field magnitude. They are in good agreement with observations.

Whang, Y. C.↗

NASA NTRS1972

A classification of magnetic field configurations associated with solar flares.

On the assumption that solar flares are due to instabilities which occur in current sheets in the sun's atmosphere, one may classify magnetic-field configurations associated with flares into two types. One is characterized by 'closed' current sheets, magnetic-field lines adjacent to these sheets beginning and ending at the sun's surface. The other is characterized by 'open' current sheets, magnetic-field lines adjacent to these sheets beginning at the sun's surface but extending out into interplanetary space. Flares associated with open current sheets can produce Type III radio bursts and high-energy-particle events, but flares associated with closed current sheets cannot. The flare of July 6, 1966 apparently consisted of one flare of each type.

Sturrock, P. A.↗

NASA NTRS1972

Maneuver design and implementation for the Mariner 9 mission.

The maneuver strategy and operational techniques employed in controlling the Mariner 9 flight path from earth launch, through interplanetary space, Mars orbit insertion, and the subsequent orbital trim maneuvers are presented. It is shown how the maneuver strategy was tailored to meet the mission requirements with maximum reliability in the presence of launch vehicle injection, orbit determination, and spacecraft maneuver execution errors as great as 3 sigma. The major error sources and constraints are discussed. The in-flight results are summarized and are compared with the preflight predictions.

Mitchell, R. T.↗

NASA NTRS1972

Properties of nearby interstellar hydrogen deduced from Lyman-alpha sky background measurements

For a sufficiently rapid relative motion of the solar system and the nearby interstellar gas, neutral atoms may be expected to penetrate the heliosphere before becoming ionized. Recent satellite measurements of the Lyman alpha emission above the geocorona indicate such an interstellar wind of neutral hydrogen emerging from the direction of Sagittarius and reaching to within a few astronomical units of the sun. A detailed model of the scattering of solar Lyman alpha from the spatial distribution of neutral hydrogen in interplanetary space is presented. This asymmetric distribution is established by solar wind and solar ultraviolet ionization processes along the trajectories of the incoming hydrogen atoms. The values of the interstellar density, the relative velocity, and the gas temperature are adjusted to agree with the Lyman alpha measurements. The results may be interpreted in terms of two models, the cold model and the hot model of the interstellar gas, depending on whether galactic Lyman alpha emission is present at its maximum allowable value or negligibly small.

Thomas, G. E.↗

NASA NTRS1972

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 107, October 1972

This Supplement of Aerospace Medicine and Biology lists 353 reports, articles, and other documents announced during September 1972 in Scientific and Technical Aerospace Reports or in International Aerospace Abstracts. In its subject coverage, Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. In general, emphasis is placed on applied research, but references to fundamental studies and theoretical principles related to experimental development also qualify for inclusion.

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NASA NTRS1973

Barium release system

A chemical system is described for releasing a good yield of free barium neutral atoms and barium ions in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium. The barium is released in the vapor phase so that it can be ionized by solar radiation and also be excited to emit resonance radiation in the visible range. The ionized luminous cloud of barium becomes a visible indication of magnetic and electrical characteristics in space and allows determination of these properties over relatively large areas at a given time.

Lewis, B. W.↗