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  • Other Sources  (5,523)
  • LUNAR AND PLANETARY EXPLORATION  (3,682)
  • COMMUNICATIONS AND RADAR  (989)
  • ASTRONAUTICS (GENERAL)  (852)
  • Cell & Developmental Biology
  • General Chemistry
  • Inorganic Chemistry
  • 1975-1979  (5,516)
  • 1960-1964  (7)
  • 1940-1944
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  • 1
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    Some unique meteorites found in Antarctica and their relation to asteroids (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Two unique meteorites were identified by means of a mineralogical examination of the smaller-sized Yamato achondrites. Yamato-74130 is the most iron-rich ureilite with Na, Cr-rich augite instead of pigeonite. Yamato-74160 was extensively recrystallized, but the composition and proportion of olivine, orthopyroxene, augite, and plagioclase is consistent with LL7 chondrites. ALHA77005 is a unique achondrite with olivine, possibly three pyroxene assemblages, and maskelynite. These meteorites provide evidence that there may be other 'thermalized' asteroids than the howardite parent body. Detailed petrologic descriptions of the unique achondrites, recrystallized diogenite Yamato-74013, and the rapidly cooled eucrite Yamato-74450 with pyroxene phenocrysts are given. It is inferred from the bulk chemistry and the mineralogical reexamination of Yamato-75028 that it is composed of the H5-type clasts and chondrule-rich H(L)3-like matrix with the H5 fragments. A close relationship in the collisional evolution of some asteroids with these materials is inferred.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: National Institute of Polar Research, Memoirs (ISSN 0386-0744); 15, 1; 54-76
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  • 2
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    Propagation predictions for the HF-range by the Research Institute of the Deutsche Bundespost (1979)
    In:  CASI
    Details
    Publication Date: 2009-11-16
    Description: Long term and short term HF propagation prediction service is described. The long term prediction method is computer based. The short term prediction method is still a manual method which relies mainly on a number of continuous field strength recordings and on the forecaster's ability to interpret the recordings and to combine this information with all available solar-geophysical data. Examples of the predictions are given and are compared with actually observed HF propagation conditions.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 25-43
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  • 3
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    Metallurgical processing (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: The metallurgical processing experiments on Skylab were chosen to: (1) elucidate the unknown effects of a low gravity environment on certain processes; (2) determine to what extent nongravitational driven flows operate in the processes; and (3) explore the possibilities of containerless solidification. Welding and brazing experiments were conducted to provide an understanding of solidification mechanics in a weightless environment.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 37 p
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  • 4
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    Early space experiments in materials processing: Future programs (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: A list of the present state of knowledge in materials processing is presented. The fluid behavior in a low gravity environment is summarized. Materials processing in the Space Transportation System facility is discussed. Prospects for space commercialization are reported.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 16 p
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  • 5
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    Post-Skylab activities (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: The Apollo Soyuz Test Program is described. A modification of the Skylab furnace was developed for the ASTP mission that had a maximum temperature of 1200 C, a programmed cool down to give more uniform growth rates, and a He quench system to shorten the time required to reach allowable touch temperature. The Space Processing Applications Rocket (SPAR) program was initiated to provide some continuity in flight experimentation. Liquid mixing, immiscible alloy solidification, composite materials, bubbles and dispersed particles during solidification, and containerless processing techniques were studied in the SPAR program.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 45 p
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  • 6
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    Fluid behavior in low g (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: Several experiments and a number of demonstrations were performed during Skylab to elucidate the behavior of fluids in space. The purposes of these experiments were to confirm hypotheses on how systems would behave in a low-g environment, determine to what extent residual accelerations and nongravity-driven convection affected processes, and provide graphic demonstrations of fluid behavior in space for classroom use and to stimulate new ideas for low-g research.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 33 p
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  • 7
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    Possible applications of space processing (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: Numerous applications take advantage of low gravity. These range from research, such as study of basic properties of materials or developing a better understanding of various processes and how they might be controlled, to actual production of unique materials, either in very limited quantities for research purposes to serve as paradigms for determining the limiting results of processes in which gravity effects are removed, or in large quantities, to fill certain high technology needs that cannot be met by other means. Examples of these are given in the following topics discussed: (1) crystal growth; (2) metals, alloys and composite materials (metallurgy); (3) glass and ceramics (containerless processing); (4) fluid and chemical processes; and (5) processing of biological materials.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 60 p
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  • 8
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    The evolution of apparatus for materials processing on Skylab (1979)
    In:  CASI
    Details
    Publication Date: 2006-07-06
    Description: The following topics are discussed: (1) the inception of space processing; (2) earth-based experimental activities prior to Skylab (drop tower and research aircraft experiments); (3) preliminary experiments in space (Apollo and sounding rocket experiments); and (4) Skylab experimental facilities. Apparatus for contained materials processing; for brazing in space; and containerless processing are presented and discussed. The Skylab materials processing system and miscellaneous design considerations are also discussed.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 48 p
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  • 9
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    Meteoroid protection for the Comet Halley probe (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: The high closing speed of 57km/s between the spacecraft and Halley poses special problems in the design of the required meteoroid protection. A double wall structure with a total thickness equal to 0.1 to 1 times the diameter of the largest meteoroid encountered is sufficient to stop that meteoroid. However, the unusually high number of meteoroid impacts on the Halley probe will cause significant erosion of the outer wall so that failure of the second wall is more likely to occur from a small meteoroid passing through a previously created hole in the outer wall and then penetrating the second wall. Calculations of the shielding required based on this failure mode, show that a double wall structure must actually have a total thickness 1.2 to 7.3 times the diameter of the largest meteoroid encountered, depending on the size distribution of the meteoroids.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: ESA Comet Halley Micrometeoroid Hazard Workshop; p 73-76
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  • 10
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    NASA workshop on outgassing (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-20
    Description: The materials and processing constraints that are involved in the construction of a molecular wake shield for the shuttle orbiter are discussed. Stainless steel, having outgassing rates less than the required 10 to the minus 12th power Torr-liters/sq cm per second was the primary material suggested for the construction of the shield.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Proc. of Workshops to Define Eng. Requirements for a Space Vacuum Res. Facility; 17 p
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  • 11
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    Report of the Ad Hoc Committee on the assessment of models of a wake shield environment around various spacecraft, Universities Space Research Association (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-20
    Description: Models depicting the ambient atmosphere which can overtake the spacecraft vacuum shield are presented. The subject areas discussed are: possible changing effects on the wake shield environment; possible utilization of the induced environmental contamination monitor; present state of the knowledge of the parameters used to describe the intermolecular collisions; the possibility of using simple models to describe the wake shield environment; possible errors associated with using kinetic theory to calculate that part of the atmosphere overtaking the shield; and a general assessment of the Monte Carlo techniques used to calculate the shield environment.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: NASA. Marshall Space Flight Center Proc. of Workshops to Define Eng. Requirements for a Space Vacuum Res. Facility; 6 p
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  • 12
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    Proceedings of workshops to define engineering requirements for a space vacuum research Facility: Summary (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-20
    Description: Models depicting the collision dynamics in the near vicinity of a body orbiting in the upper atmosphere were studied to investigate degassing techniques for a vacuum facility.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Proc. of Workshops to Define Eng. Requirements for a Space Vacuum Res. Facility; 3 p
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  • 13
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    A circuit model for electromagnetic properties of waveguide arcs (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: A dielectric model of waveguide arcs is presented to relate measurable electromagnetic quantities to the physical parameters characterizing the breakdown process.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 193-195
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  • 14
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    Assessment of 20 kW S-band transmitter (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: The performance history of the 20-kW S-band transmitter, installed at three 64-meter antennas and six 26-meter antennas in the DSN, is reviewed. A number of failures and discrepancy reports are characteristic of the wearout phase of a failure curve. The type of failures are reviewed and four options toward reducing the number and cost of failures are reviewed. These are: existing (no change), refurbish, redesign and replacement. The options are compared on a ten year life cycle cost basis using FY77 expenditures for existing equipment as a base. It was concluded that benefits, in terms of reduction of outrage time, increase with an increase of expenditure toward improvement.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 186-192
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  • 15
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    Microwave time delays in the DSN 34- and 64-meter antennas (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: The results and methods used to derive data for the recent changes to the DSN 34- and 64-m stations at both S- and X-band frequencies are presented.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 183-185
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  • 16
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    DSS 13 antenna monitor system (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: The development of a monitor system for the DSS 13 antenna is presented. The system checks for accumulator pressures, differential pressures, wind velocity, power supplies, fluid temperatures, and fluid levels. It was concluded that the system performed properly in high winds and correctly reported all malfunctions.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 138-140
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  • 17
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    Carrier tracking loop performance in the presence of strong CW interference (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: Research on the behavior of the carrier tracking loop exposed to a continuous wave irradiation along with Bruno's closed form of approximation for the loop phase error are described.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 130-137
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  • 18
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    Costas loop demodulation of suppressed carrier BPSK signals in the DSN environment: Experimental results obtained at TDL (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: Suppressed carrier binary phase-shift keyed (BPSK) signalling is currently being considered as a design alternative for future DSN telemetry in the multimegabit range. Carrier tracking of such signals is usually achieved by a Costas loop, as opposed to the ordinary phase lock loop. A Costas loop capable of demodulating BPSK signals with data rates up to 1 Msps was designed and constructed and its Doppler tracking performance with respect to a Block 3 receiver was tested at the Telecommunications Development Laboratory (TDL). The compatibility of suppressed carrier signalling with the current radiometric system, specifically Doppler tracking and ranging, was investigated. The experimental results obtained to-date with respect to Doppler tracking are presented.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 94-104
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  • 19
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    Feasibility of inertialess conscan utilizing modified DSN feedsystems (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: The closed-loop conical-scan (conscan) technique has proven to be a useful method for pointing the DSN antennas more accurately than is possible by open-loop methods. As presently implemented, the antenna beam is scanned about the received signal direction by physical movement of the antenna. While straightforward, this approach has at least two disadvantages. Firstly, because of structural distortions, finite angle encoder resolution, and drive servo response, the actual antenna beam direction only approximates the commanded beam direction. Secondly, because of the large mass moved during scan, the rate of scan is severely restricted. If there are significant gain or signal level variations during a scan period, the conscan system interprets these variations as antenna pointing error. Both of these disadvantages would be alleviated in an inertialess conscan system in which the beam scanning was performed electronically. Recently, standard JPL antenna feedhorn software was upgraded to calculate, among other things, asymmetric corrugated horn radiation patterns of the type that would be needed for electronic beam scan. The required horn excitation is discussed and the results were described.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 85-93
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  • 20
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    Antenna feedhorn software upgrade (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: The HYBRIDHORN computer program was developed to serve as an item of general purpose antenna feedhorn design and analysis software. The formulation contains a small flare angle approximation which is subject to question for designs such as the S- and X-band feedhorn. Additionally, the original formulation did not allow azimuthal variation indexes other than unity. The HYBRIDHORN program was upgraded to correct both of these deficiencies. A large flare angle formulation was found. In the upgrade, all of the major program elements were converted to Univac 1108 compatible structured FORTRAN (SFTRAN) for ease of software maintenance. The small and large angle formulations are described and sample numerical results are presented.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 75-84
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  • 21
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    Some effects of quantization on a noiseless phase-locked loop (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: If the VCO of a phase-locked receiver is to be replaced by a digitally programmed synthesizer, the phase error signal must be sampled and quantized. Effects of quantizing after the loop filter (frequency quantization) or before (phase error quantization) are investigated. Constant Doppler or Doppler rate noiseless inputs are assumed. The main result gives the phase jitter due to frequency quantization for a Doppler-rate input. By itself, however, frequency quantization is impractical because it makes the loop dynamic range too small.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 58-66
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  • 22
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    Recovering the spectrum of a narrow-band process from syncopated samples (1979)
    In:  CASI
    Details
    Publication Date: 2006-06-01
    Description: A nonuniform sampling strategy, phase quadrature sampling, in which a process of bandwith B is sampled at rate B in each of two channels where the two channels are pi/2 out of phase at frequency B is described. Phase quadrature sampling is a special case of sampling, where the phase between channels is fixed but arbitrary. A simple method for recovering the spectrum of the input process from syncopated samples is derived. The derivation indicates what values of phase between channels result in lossless sampling.
    Keywords: COMMUNICATIONS AND RADAR
    Type: The Deep Space Network; p 47-50
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  • 23
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    Effects of D region ionization on radio wave propagation (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The effects of anomalous D region ionization upon radio wave propagation are described for the main types of disturbances: sudden ionospheric disturbances, relativistic electron events, magnetic storms, auroral disturbances, polar cap events, and stratospheric warmings. Examples of radio wave characteristics for such conditions are given for the frequencies between the extremely low (3-3000 Hz) and high (3-30 MHz) frequency domains. Statistics on the disturbance effects and radio wave data are given in order to contribute towards the evaluation of possibilities for predicting the radio effects.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 617-654
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  • 24
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    Forecasts of geomagnetic activities and HF radio propagation conditions made at Hiraiso/Japan (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The Hiraiso Branch of RRL prediction techniques are summarized separately for the 27 day recurrent storm and the flare-associated storm. The storm predictions are compared with the actual geomagnetic activities in two ways. The first one is the comparison on a day to day basis. In the second comparison, the accuracy of the storm predictions during 1965-1976 are evaluated. In addition to the storm prediction, short-term predictions of HF radio propagation conditions are conducted at Hiraiso. The HF propagation predictions are briefly described as an example of the applications of the magnetic storm prediction.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 182-204
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  • 25
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    Estimation of solar flame influence on radio circuit transmission loss (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: A provisional method for determining the hours and frequencies at which solar flares cause major radiopath absorption increase is presented. This technique is incorporated in a computer program for monthly radio propagation prediction.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 67-71
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  • 26
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    Platforms in space: Evolutionary trends (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-12
    Description: The problem of physical crowding and the proliferation of separate communication links and ground support systems for multiple free-flying satellites can be overcome by using space platforms and multiplexing the data streams. Pertinent features of the space shuttle orbiter payloads, the solar power satellite, and geostationary and geosynchronous platforms are discussed. Typical payload requirements data which are needed to allow meaningful study of payloads as candidates for platform implementation are cited and factors affecting the compatibility/grouping of payloads are outlined.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Proc.: Workshop on the Need for Lightning Observations from Space; p 159-182
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  • 27
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    PROPHET: An applicaton of propagation forecasting principles (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: A propagation assessment and forecasting terminal, PROPHET, is described. The terminal is a key element of the environmental prediction and assessment system which uses real time solar/geophysical data to provide real time knowledge of propagation conditions. The terminal uses models to translate data from satellite and ground based sources into performance predictions for specific systems.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 312-321
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  • 28
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    Radio disturbance warning issuance system (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: A radio disturbance warning issuance system was introduced in the Hiraiso Branch of the Radio Research Laboratories in 1972 to reconstruct the current radio disturbance warning service as a social information service. A description of the new ideas which were experimentally systematized by means of an electronic computer is presented.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 223-228
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  • 29
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    Extraction processes for the production of aluminum, titanium, iron, magnesium, and oxygen and nonterrestrial sources (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-12
    Description: The suitability of existing terrestrial extractive metallurgical processes for the production of Al, Ti, Fe, Mg, and O2 from nonterrestrial resources is examined from both thermodynamic and kinetic points of view. Carbochlorination of lunar anorthite concentrate in conjunction with Alcoa electrolysis process for Al; carbochlorination of lunar ilmenite concentrate followed by Ca reduction of TiO2; and subsequent reduction of Fe2O3 by H2 for Ti and Fe, respectively, are suggested. Silicothermic reduction of olivine concentrate was found to be attractive for the extraction of Mg becaue of the technological knowhow of the process. Aluminothermic reduction of olivine is the other possible alternative for the production of magnesium. The large quantities of carbon monoxide generated in the metal extraction processes can be used to recover carbon and oxygen by a combination of the following methods: (1) simple disproportionation of CO,(2) methanation of CO and electrolysis of H2O, and (3) solid-state electrolysis of gas mixtures containing CO, CO2, and H2O. The research needed for the adoption of earth-based extraction processes for lunar and asteroidal minerals is outlined.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: NASA. Ames Res. Center Space Resources and Space Settlements; p 257-274
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  • 30
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    The initial lunar supply base (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-12
    Description: The first lunar supply base should have a mass less than 1000 tons, be deployed by 24 persons in 4 months, and be maintained by 10 persons. Output could be expanded 20 times in 5 years to 600,000 tons/yr by a factor of 10 expansion of the area of the solar array on the lunar surface, using low power soil beneficiation, increasing the fleet of mining vehicles, and illuminating the base continuously at night with lunar orbiting mirrors. The space manufacturing facility (SMF) will supply most of the mass (solar cells and orbiting mirrors) necessary for expansion. Several devices and procedures are suggested for development which could further reduce the total mass necessary to transport to the Moon to establish the initial lunar supply base.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: NASA. Ames Res. Center. Space Resources and Space Settlements; p 207-224
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  • 31
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    Ionosphere-reflected propagation (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: The predictability of those ionospheric parameters relevant to ionosphere-reflected communications is considered along with their optimum utilization. Several excellent original articles and review papers which have been published from time to time dealing with the long term and short term forecasting of ionospheric parameters, radio systems, and modelling needs for ionospheric communications, are covered.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 203-216
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  • 32
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    Transionospheric propagation predictions (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The current status and future prospects of the capability to make transionospheric propagation predictions are addressed, highlighting the effects of the ionized media, which dominate for frequencies below 1 to 3 GHz, depending upon the state of the ionosphere and the elevation angle through the Earth-space path. The primary concerns are the predictions of time delay of signal modulation (group path delay) and of radio wave scintillation. Progress in these areas is strongly tied to knowledge of variable structures in the ionosphere ranging from the large scale (thousands of kilometers in horizontal extent) to the fine scale (kilometer size). Ionospheric variability and the relative importance of various mechanisms responsible for the time histories observed in total electron content (TEC), proportional to signal group delay, and in irregularity formation are discussed in terms of capability to make both short and long term predictions. The data base upon which predictions are made is examined for its adequacy, and the prospects for prediction improvements by more theoretical studies as well as by increasing the available statistical data base are examined.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 217-245
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  • 33
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    Solar-induced variations of environment affecting manned space flight and spacecraft operations (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: Estimates of short and long term solar activity are required for calculating variations in the environment with regard to spacecraft charging, radiation effects, and orbital lifetime. Correlations appear to exist between the time of solar activity and the time of operational anomalies due to electrical discharges when the dielectric surfaces of geosynchronous spacecraft are charged by interaction with the ambient plasma to levels above breakdown voltage. An ability to predict the solar induced variation variability of the plasmas could permit refinement of design criteria. The influence of the radiation on spacecraft materials, systems, and manned operations is summarized. Solar radition effects on the orbital altitude atmospheric density environment and spacecraft lifetimes are also considered.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Solar-Terrest. Predictions Proc., Vol. 2; p 89-103
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    User requirements of solar-terrestrial predictions for spacecraft applications (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: Areas which are influenced by solar-terrestrial coupling effects and which are internal to the Earth's magnetosphere are of interest to mission planners, spacecraft hardware designers, and those engaged in the operation of already orbiting manned or unmanned spacecraft. Accurate models are needed to predict energetic particle flux density, interactions between low energy (10 eV to 100 eV) near-Earth plasma and space systems, and neutral atmospheres. Parameters required for each of these areas are discussed.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2; p 1-20
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    Space vehicle meteoroid shielding design (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: Design principles of spaced, multiwall meteoroid protection are investigated in the light of experimental data generated during the Apollo Program. The outer wall or shield is shown to be the most important element in the meteoroid-spacecraft interaction. The condition of the debris is primarily a function of the shock pressure, the melting points of the meteoroid and the shield, and the length of the meteoroid and thickness of the shield. Spacing between the walls is effective up to approximately 100 times the length of the meteoroid. The required thickness of the second wall is shown to be proportional to the meteoroid mass, velocity, and density, and to the spacing between the walls, taken with exponents dependent upon the condition of the debris. The effects of placing additional elements (insulation or honeycomb cells) between the two walls are discussed, and the efficiency of various protective configurations is presented. An analysis of the meteoroid protection proposed for the Comet Halley probe is included as an appendix.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: ESA Comet Halley Micrometeoroid Hazard Workshop; p 85-92
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    Radio propagation prediction services in Japan (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: Japanese prediction services for HF radio communications are outlined in relation to prediction method, performance and evaluation. The current prediction is based on the CCIR interim method with some modifications matching to a computer system. The principal service is the monthly median prediction issued regularly three months in advance for various communication circuits. A daily prediction for short distance circuits is being prepared by using real time ionospheric sounding data. An evaluation theory and practice is expected to be introduced in the future prediction service.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 212-222
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    Long term solar activity and ionospheric prediction services rendered by the National Physical Laboratory, New Delhi (1979)
    In:  CASI
    Details
    Publication Date: 2006-01-16
    Description: The data base used in solar and ionospheric prediction services is described. Present prediction techniques are discussed and compared with actual observations. Future prediction techniques using computers are also discussed.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 118-133
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    The French short term radiopropagation predictions in the decameter band (1979)
    In:  CASI
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    Publication Date: 2006-01-16
    Description: Weekly and daily predictions of the ionospheric characteristics relevant to radio propagation are considered. A description of the techniques involved is given as well as examples showing how the prediction messages are prepared. The short term predictions are confined to restricted geographical areas and are relevant to radio circuits whose terminators are both located inside the same zone. They can be used with a reasonable approximation for circuits less than 3000 km of length whose reflection point lies within a given zone.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NOAA Solar-Terrest. Predictions Proc., Vol. 1; p 12-24
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    Extraterrestrial fiberglass production using solar energy (1979)
    In:  CASI
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    Publication Date: 2006-01-12
    Description: A conceptual design is presented for fiberglass production systems in both lunar and space environments. The raw material, of lunar origin, will be plagioclase concentrate, high silica content slag, and calcium oxide. Glass will be melted by solar energy. The multifurnace in the lunar plant and the spinning cylinder in the space plant are unique design features. Furnace design appears to be the most critical element in optimizing system performance. A conservative estimate of the total power generated by solar concentrators is 1880 kW; the mass of both plants is 120 tons. The systems will reproduce about 90 times their total mass in fiberglass in 1 year. A new design concept would be necessary if glass rods were produced in space.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: NASA. Ames Res. Center Space Resources and Space Settlements; p 225-232
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    Mining and beneficiation of lunar ores (1979)
    In:  CASI
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    Publication Date: 2006-01-12
    Description: The beneficiation of lunar plagioclase and ilmenite ores to feedstock grade permits a rapid growth of the space manufacturing economy by maximizing the production rate of metals and oxygen. A beneficiation scheme based on electrostatic and magnetic separation is preferred over conventional schemes, but such a scheme cannot be completely modeled because beneficiation processes are empirical and because some properties of lunar minerals have not been measured. To meet anticipated shipping and processing needs, the peak lunar mining rate will exceed 1000 tons/hr by the fifth year of operation. Such capabilities will be best obtained by automated mining vehicles and conveyor systems rather than trucks. It may be possible to extract about 40 kg of volatiles (60 percent H2O) by thermally processing the less than 20 micron ilmenite concentrate extracted from 130 tons of ilmenite ore. A thermodynamic analysis of an extraction process is presented.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Space Resources and Space Settlements; p 275-288
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    A geologic assessment of potential lunar ores (1979)
    In:  CASI
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    Publication Date: 2006-01-12
    Description: Although bulk lunar soil is not a suitable feedstock for extracting metals, certain minerals such as anorthite and ilmenite can be separated and concentrated. These minerals can be considered as potential ores of aluminum, silicon, titanium, andiron. A separation and metal extraction plant could also extract large amounts of oxygen and perhaps hydrogen from these minerals. Anorthie containing 19 percent aluminum and 20 percent silicon can be concentrated from some highland soils where it is present in amounts up to 60 percent. Ilmenite containing 32 percent titanium and 37 percent iron can be concentrated from some mare soils where it is present in amounts up to 10 percent. The ideal mining site would be located at the boundary between a high-titanium mare and a high-aluminum highlands. Such area may exist around the rims of some eastern maria, particularly Tranquilitatis. A location on Earth with raw materials as described above would be considered an economically valuable ore deposit if conventional terrestrial resources were not available.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Ames Res. Center Space Resources and Space Settlements; p 243-255
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    The processing of semiconductor materials (1979)
    In:  CASI
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    Publication Date: 2006-07-06
    Description: Five experiments involving the processing of semiconductor materials were performed during the Skylab mission. After discussions on semiconductors and their unique electronic properties, and techniques of crystal growth, these five experiments are presented. Four melt growth experiments were attempted: (1) steady state growth and segregation under zero gravity (InSb); (2) seeded, containerless solidification of InSb; (3) influence of gravity-free solidification on microsegregation; and (4) directional solidification of InSb-GaSb alloys. One vapor growth experiment, crystal growth by vapor transport, was attempted.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 45 p
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    The promise of space processing (1979)
    In:  CASI
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    Publication Date: 2006-07-06
    Description: The long exposure to a virtually zero-gravity environment is a truly unique situation that cannot be duplicated or even approximated for any length of time on earth. The topics discussed are: (1) low gravity; (2) atmospheric effects; (3) potential advantages of materials processing in space; (4) the absence of buoyancy-driven convection; (5) the absence of hydrostatic pressure; (6) the absence of sedimentation and buoyancy; (7) containerless processing; and (8) ultrahigh vacuum processing.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Early Space Expt. in Mater. Process.; 37 p
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    Sample fields of the Viking landers, physical properties, and aeolian processes (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Surface sampler activities on Mars during the Viking extended mission are considered, including excavation of deep trenches, construction of conical piles of materials, backhoe touchdown experiments, and acquisition of contiguous pictures of the surface beneath number 2 terminal descent engines using mirrors. Results of the Physical Properties Investigation that are relevant to aeolian processes are also discussed. Both pictures and surface sampler data indicate that the surface materials in the sample fields of the Viking landers may be grouped, in order of increasing strength, into drift material, crusty to cloddy material, blocky material and rocks.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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    Pitted and fluted rocks in the Western Desert of Egypt - Viking comparisons (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The Western Desert of Egypt is one of the most arid regions on earth and is probably the closest terrestrial analog to the surface of Mars. An expedition to the area in 1978 revealed an abundance of quartzite and basalt rocks that have been pitted and fluted by wind erosion and deflation of the desert surface. These pitted rocks are internally homogeneous, show no internal holes or vesicles, and are considered an important but neglected type of ventifact. They bear a striking resemblance to the pitted and fluted rocks seen by the Viking Landers, rocks that have generally been interpreted as vesicular basalts only slightly modified by wind erosion. Wind tunnel studies of the air flow over and around nonstreamlined hand specimens from the Western Desert show that windward abrasion coupled with negative flow, secondary flow, and vorticity in a unidirectional wind can explain the complex arrays of pits and flutes. These field and laboratory observations suggest that the pitted rocks at the Viking Lander sites are also ventifacts, and thus the Martian surface may be far more wind eroded than previously thought.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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    Morphology and distribution of common 'sand' dunes on Mars - Comparison with the earth (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A comparative study of Martian and terrestrial dunes was made based on Viking Orbiter pictures and aerial pictures of terrestrial deserts. The morphological similarity between the Martian dunes and terrestrial crescentic dunes implies that the dynamics of dune formation are similar on the two planets, despite Martian constraints on dune formation that include much higher velocity winds required to move 'sand' in saltation, the possible inhibition of sand movement by absorbed water vapor, the seasonal 'snow' cover in the north circumpolar erg, and a probably sparse sand supply. The absence of longitudinal dunes and the restriction of massive crescentic dunes to a few sites on Mars suggests that Mars may have a long eolian history in which much of the sand suitable for saltation has already been transported to the north polar erg and crater floor fields.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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    Future exploration of the asteroids (1979)
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    Publication Date: 2011-08-17
    Description: Future possibilities for the further study of the asteroids are reviewed, with particular attention paid to space missions for their direct exploration. The role of traditional ground-based and earth orbiting techniques is examined briefly, and it is concluded that although astronomical techniques are presently at their peak, and despite the opportunities provided by the Infrared Astronomical satellite, the Space Telescope and Spacelab Infrared Telescope Facility, the next major step will require direct exploration by space probes to obtain information on asteroid surface chemistry, geology and bulk properties. Various mission modes and propulsion systems for a first multi-target asteroid mission are discussed, including flyby, rendezvous, landing and sample return, and ion-drive propulsion systems. Science payloads for a basic rendezvous mission are considered, and target selection for multi-asteroid flyby tours and rendezvous tours is discussed. Consideration is also given to sample return missions for the evaluation of the asteroid as potential resources.
    Keywords: ASTRONAUTICS (GENERAL)
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    Viking magnetic properties experiment - Extended mission results (1979)
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    Publication Date: 2011-08-17
    Description: The backhoe magnets on Viking Lander (VL) 2 were successfully cleaned, followed by a test involving successive insertions of the cleaned backhoe into the surface. Rapid saturation of the magnets confirmed evidence from primary mission results that the magnetic mineral in the Martian surface is widely distributed, most probably in the form of composite particles of magnetic and nonmagnetic minerals. An image of the VL 2 backhoe taken via the X4 magnifying mirror demonstrates the fine-grained nature of the attracted magnetic material. The presence of maghemite and its occurrence as a pigment in, or a thin coating on, all mineral particles or as discrete, finely divided and widely distributed crystallites, are consistent with data from the inorganic analysis experiments and with laboratory simulations of results of the biology experiments on Mars.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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    Primordial heating of asteroidal parent bodies (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Most meteorites show evidence of thermal processing either because of metamorphic changes or as a result of melting and differentiation. Proposed mechanisms for supplying this energy generally rely upon short-lived radioisotopes or electrical induction, though accretion is sometimes mentioned, and more exotic models have been discussed. Interest in isotopic heating has been heightened by the discovery of Al-26 in Allende inclusions and also by the proposal that a lunar core and dynamo resulted from the radioactive decay of superheavy elements during the early solar system. Electrical induction as a heat source can be scaled to a broad range of solar system conditions, but corroborative evidence for these conditions is inconclusive. The accretion mechanism is probably not viable for the asteroidal and meteorite parent bodies, because the high kinetic energy requirement is inconsistent with the formation of the objects and their regoliths in the presence of a weak gravitational field.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Aqueous activity on asteroids - Evidence from carbonaceous meteorites (1979)
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    Publication Date: 2011-08-17
    Description: Carbonaceous chondrites of groups CI and CM were formed by impact brecciation and aqueous alteration of earlier generations of mineral phases within the surface regions of two or more parent bodies. Those parent bodies were probably asteroids, rather than comets, although a problem still exists in delivering such material safely to earth. Aqueous activity may have been widespread on asteroids.
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    Diverse puzzling asteroids and a possible unified explanation (1979)
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    Publication Date: 2011-08-17
    Description: Recent observations have led to unconventional models of certain asteroids, suggesting previously unsuspected forms. Some of these include binary asteroids (e.g., 532 Herculina, 18 Melpomene), very irregular asteroids (e.g., the Mars-crossing 1580 Betulia), and very elongated asteroids, unlikely to be collisional fragments (e.g., 624 Hector). A connection is suggested between this observational work and ongoing theoretical work concerning collisions of large comparable-sized asteroids. Such collisions have different consequences from the collisions usually considered. The new work suggests possible sources of elongated and binary asteroids.
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    Radio observations of asteroids - Results and prospects (1979)
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    Publication Date: 2011-08-17
    Description: Radio observations of the asteroids can provide information on the thermal and dielectric properties of the surface materials and, because the radio emission arises somewhat below the surface, the data give some indication of layering. Observational difficulty has limited the investigations to only 6 asteroids. 1 Ceres and 324 Bamberga appear to have a layer of dust covering a more compacted material; the data on 4 Vesta cannot be matched by any current models for the surface; and the results for 18 Melpomene, 31 Euphrosyne and 433 Eros are too incomplete for firm conclusions. Future possibilities include more accurate radiometry of a few selected asteroids of different taxonomic classes and actual resolution of some of the larger objects by aperture synthesis techniques.
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    Optical polarimetry of asteroids and laboratory samples (1979)
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    Publication Date: 2011-08-17
    Description: Interpretations of astronomical polarization data for more than 100 minor planets are summarized with reference to laboratory data for lunar, meteoritic, and terrestrial samples. All observed asteroids, including objects only a few kilometers in diameter, have microscopically intricate surfaces. Detailed comparisons between laboratory measurements of basaltic achondrites and telescopic results for Vesta show that its surface is particulate with a broad range of particle sizes, including a component of fine (1-5 micron) dust. The surface soils have not, however, undergone marked optical alterations as is the case for the lunar fines. For albedos greater than about 0.06, the albedo and hence the diameter can be determined with some reliability from the slope of the ascending branch of the polarization-phase curve. Many minor planets have surfaces that are remarkably uniform in albedo and texture on a hemispheric scale. A notable exception is 4 Vesta, which shows about ten percent albedo variegation between hemispheres.
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    The asteroids - Nature, interrelations, origin, and evolution (1979)
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    Publication Date: 2011-08-17
    Description: The paper deals with the physical and chemical nature of the asteroids and with their physical and orbital distributions and interrelationships. Existing hypotheses about the formation and evolution of asteroids are examined. A thematic synopsis of these topics is presented, and accepted interpretations are discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Review of the metallographic cooling rates of meteorites and a new model for the planetesimals in which they formed (1979)
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    Publication Date: 2011-08-17
    Description: The cooling rates of meteorites through approximately 900 -650 K, as read from their metal alloy compositions, are reviewed. Metallographic cooling rates are compared with the cooling rates that appear to be required by the K/Ar and Ar-40/Ar-39 ages of five meteorite classes, and discrepancies are found in all cases. Either (1) the metallographic cooling rates (and also Pu-244 fission cooling rates) are systematically in error, being too slow by a factor of approximately 6; or (2) the traditional thermal model for parent meteorite planets (having constant dimension and uniform physical properties) is oversimplified and the Ar closure temperatures for chondrites derived by Turner et al. (1978) are too low. An alternative parent planet model is proposed and numerically modeled, in which accretion of thermally insulating particulate matter, heat generation by Al-26 decay, melting or sintering of the particulate matter into conductive rock, and establishment of the properties of the meteorites occurred concurrently. Meteorite chronologies are somewhat easier to understand in this context, since the initially small, hot (thus sintered and conductive) bodies would have cooled rapidly to isotopic closure, but later cooling might have been much slower as a result of the continued accretion of insulating particulate matter.
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    Asteroid taxonomy and the distribution of the compositional types (1979)
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    Publication Date: 2011-08-17
    Description: Physical observations of minor planets documented in the TRIAD computer file are used to classify 752 objects into the broad compositional types C, S, M, E, R, and U (unclassifiable) according to the prescriptions adopted by Bowell et al. (1978). Diameters are computed from the photometric magnitude using radiometric and/or polarimetric data where available, or else from albedos characteristic of the indicated type. An analysis of the observational selection effects leads to tabulation of the actual number of asteroids, as a function of type and diameter, in each of 15 orbital element zones. For the whole main belt the population is 75% of type C, 15% of type S, and 10% of other types, with no belt-wide dependence of the mixing ratios on diameter. In some zones the logarithmic diameter-frequency relations are decidedly nonlinear. The relative frequency of S-type objects decreases smoothly outward through the main belt, with exponential scale length 0.5 AU. The rarer types show a more chaotic, but generally flatter, distribution over distance. Characteristic type distributions, contrasting with the background population, are found for the Eos, Koronis, Nysa and Themis families.
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    Phobos and Deimos - A preview of what asteroids are like (1979)
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    Publication Date: 2011-08-17
    Description: The surfaces of Phobos and Deimos are discussed, as the best available examples of what asteroid surfaces may be like. Attention is given to shape, regolith properties, crater densities, albedo markings and surface gravities. It is found that although the surfaces of these two similarly-sized asteroid-like bodies are nearly identical in terms of many disk-integrated properties, they are strikingly different in surface morphology.
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    Radar observations of asteroids (1979)
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    Publication Date: 2011-08-17
    Description: Radar observations of asteroids use simple CW waveforms, the transmissions lasting for the duration of the round-trip delay. The echo is received, spectrum-analyzed, and integrated for a similar period. Since radar coherently illuminates the target, the surface scattering properties at radio wavelengths are directly determined as a function of angle and polarization. The distance and radial velocity obtained with radar complement the angular position of the object as determined from telescope measurements. Radar cross sections, scattering law, and radius are given for radar-observed asteroids.
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    Masses and densities of asteroids (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Ceres, Pallas, and Vesta allow a determination of mass from gravitational effects in the motion of another asteroid. An extended and partly corrected set of observations of 197 Arete leads to an increase of 15% in the resulting mass of Vesta that was first determined by Hertz. Other possibilities of mass determination and estimates of the total mass of asteroids are mentioned. The available diameter determinations and adopt preferred values are reviewed. The densities for Ceres, Pallas, and Vesta are respectively 2.3 plus or minus 1.1 g/cu cm, 2.6 plus or minus 0.9 g/cu cm and 3.3 plus or minus 1.5 g/cu cm.
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    On the origin of asteroids (1979)
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    Publication Date: 2011-08-17
    Description: A general scenario is described for the early history of the solar system. The primitive solar nebula is formed from the infall of gas from a collapsing interstellar cloud fragment. It becomes repeatedly unstable against collapse to form giant gaseous protoplanets. In the course of protoplanet evolution the center of the protoplanet enters a thermodynamic regime in which common rocky minerals become liquids; convection brings solids to the central region where a substantial fraction of them rain out to form a protoplanetary core. In the inner solar system protoplanetary envelopes are tidally stripped away, thus injecting into the solar nebula large equantities of chondrules and inclusions. Late in the development of the solar nebula, after most of the gas has disappeared, turbulence dies out and the small solids settle into a thin layer at midplane of the nebula. Gravitational instabilities in this layer form asteroidal and cometary bodies. Some further consequences of this scenario are discussed.
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    Geochemical evolution of the eucrite parent body - Possible nature and evolution of asteroid 4 Vesta (1979)
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    Publication Date: 2011-08-17
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    Infrared spectral reflectances of asteroid surfaces (1979)
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    Publication Date: 2011-08-17
    Description: This review compares the types of compositional information produced by three complementary techniques used in infrared observations of asteroid surfaces: broadband JHKL photometry, narrow band photometry, and multiplex spectroscopy. The high information content of these infrared observations permits definitive interpretations of asteroid surface compositions in terms of the major meteoritic minerals (olivine, pyroxene, plagioclase feldspar, hydrous silicates, and metallic Ni-Fe). These studies emphasize the individuality of asteroid surface compositions, the inadequacy of simple comparisons with spectra of meteorites, and the need to coordinate spectral measurements of all types to optimize diagnostic capabilities.
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    The nature and effects of impact cratering on small bodies (1979)
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    Publication Date: 2011-08-17
    Description: Collisions between asteroids and other forms of solar system debris are discussed, especially relatively high-energy, non-catastrophic collisions, the resulting craters, and the effects they should have on the surfaces and interiors of target bodies. Attention is given to the nature and formation of impact craters, as well as to shock waves and the energy (kinetic, internal) imparted through them, crater scaling, stress wave-surface interactions, impact melt, and the effects of non-escaping ejecta on the surface of the target body (rock, fine-grained regolith, porous media).
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Regolith development and evolution on asteroids and the moon (1979)
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    Publication Date: 2011-08-17
    Description: Early descriptions of regoliths on small bodies were devised to account for observations of asteroids (Chapman 1971, 1976) and the gas-rich meteorites (Anders 1975). Lack of agreement between these approaches prompted Housen et al. (1978, 1979) to examine the problem in detail. The resulting model predicted that moderate-sized (100-300 km) asteroids should evolve regoliths up to a few kilometers deep which could be source regions of gas-rich meteorites. Smaller objects should have regoliths ranging from dust coatings to meters-thick layers depending on the strength of the object. The earlier model could not treat asteroids larger than 300 km in diameter. The model, now modified to treat larger-sized objects, predicts regolith depths, on asteroids larger than 300 km, which decrease with increasing size. A regolith depth of 7 m is predicted for the lunar maria in reasonable agreement with the observed depths of 5 m.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Distant asteroids and outer Jovian satellites (1979)
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    Publication Date: 2011-08-17
    Description: Sixty percent of the sampled objects in the Hilda, Trojan and outer Jovian satellite locations belong to C-type and another 30% belong to a new group called RD-type (reddish and dark), sometimes referred to simply as D-type. Objects in this group have low albedo values between 2 and 4% and steep reflection spectra between 0.7 micron and 0.9 micron. Furthermore, 944 Hidalgo belongs to this group but shows color variation over its surface. Meteoritic minerals with similar optical reflection spectra are discussed. Trojans with sizes down to 15 km in the cloud preceding Jupiter are about 3.5 times more numerous than those in the following cloud. RD-type Trojans appear more often in the preceding cloud. There is a resemblance of spectrum, albedo and phase relation among the majority of Trojans and the outer Jovian satellites.
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    Rb-Sr age of the Shergotty achondrite and implications for metamorphic resetting of isochron ages (1979)
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    Publication Date: 2011-08-17
    Description: The age of the Shergotty achondrite is determined by Rb-Sr isotope analysis and the metamorphic resetting of isochron ages, which is presumed to have occurred during a shock event in the history of the meteorite, is discussed. The isochron best fitting the Rb-Sr evolution diagram is found to correspond to an age of 165 million years, with an initial Sr-87/Sr-86 value of 0.72260. Different apparent ages obtained by the K-Ar and Sm-Nd methods are interpreted in terms of a model which quantifies the degree of resetting of internal isochron ages by low temperature solid state diffusion. On the basis of these considerations, it is concluded that Shergotty crystallized from a melt 650 million years ago, was shock heated to 300 to 400 C after its parent body was involved in a collision 165 million years ago, and was first exposed to cosmic rays two million years ago.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geochimica et Cosmochimica Acta; 43; July 197
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    Voyager spacecraft radio observations of Jupiter - Initial cruise results (1979)
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    Publication Date: 2011-08-17
    Description: Low frequency (below 1326 kHz) observations of Jupiter obtained from November, 1977 through June, 1978 by the radio astronomy receivers carried by the two Voyager spacecraft are reported and compared with a large body of higher-frequency ground-based observations. Although the morphology of hectometric wavelength (HOM) emissions strongly resembles that of decametric (DAM) wavelength radio noise, they display opposite polarization. DAM emissions are strongly modulated by Io, whereas HOM emissions exhibit little or no influence from any satellite and appear to be modulated by the rotation phase of the planet. Several single-source models could possibly account for these results, including a model assuming emission at two well-separated frequencies above and below the local electron plasma frequency and the model proposed by Barbosa (1976) in which electrostatic waves at twice the upper hybrid frequency couple to both the ordinary and extraordinary electromagnetic modes. However, neither of these is entirely satisfactory.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters; 6; June 197
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    Airborne East Coast/Midwest urban survey at 121.5/243 MHz (1979)
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    Publication Date: 2011-08-17
    Description: Results of an airborne RF interference measurement survey of the emergency-distress, Search and Rescue frequency bands at 121.5 and 243 MHz at an altitude of 25,000 ft over the U.S. East Coast and Midwest urban areas are presented. Included are a series of minutely median profile plots of antenna-noise temperature computed from RF interference power measurements at the output terminal of a quarter-wavelength monopole antenna, for both daytime and nighttime observations. The greatest value, 450,000 K, of minutely median temperature was recorded over New York City at 121.5 MHz during the day. East Coast urban areas exhibited a day-night effect at 121.5 MHz, where nighttime observations had a median value of 8.6-dB below daytime values; Midwest counterparts did not exhibit a significant day-night effect at 121.5 MHz.
    Keywords: COMMUNICATIONS AND RADAR
    Type: IEEE Transactions on Electromagnetic Compatibility; EMC-21; May 1979
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    Gravitational influences on the liquid-state homogenization and solidification of aluminum antimonide (1979)
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    Publication Date: 2011-08-17
    Description: Typical commercial or laboratory-prepared samples of polycrystalline AlSb contain microstructural inhomogeneities of Al- or Sb-rich phases in addition to the primary AlSb grains. The paper reports on gravitational influences, such as density-driven convection or sedimentation, that cause microscopic phase separation and nonequilibrium conditions to exist in earth-based melts of AlSb. A triple-cavity electric furnace is used to homogenize the multiphase AlSb samples in space and on earth. A comparative characterization of identically processed low- and one-gravity samples of commercial AlSb reveals major improvements in the homogeneity of the low-gravity homogenized material.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: Metallurgical Transactions A - Physical Metallurgy and Materials Science; 10A; May 1979
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    Io - An intense brightening near 5 micrometers (1979)
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    Publication Date: 2011-08-17
    Description: Spectrophotometric observations of the Jovian satellite Io on February 20 and 21, 1978, (Universal Time) were made from 1.2 to 5.4 micrometers. Io's brightness at 4.7 to 5.4 micrometers was found to be three to five times greater at an orbital phase angle of 68 deg than at orbital phase angles of 23 deg (5.5 hours before the brightening) and 240 deg (20 hours after the brightening). Since the 5-micrometer albedo of Io is near unity under ordinary conditions, the observed transient phenomenon must have been the result of an emission mechanism. Although several such mechanisms were examined, the actual choice is not clear.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 203; Feb. 16
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    Encounter with Venus (1979)
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    Publication Date: 2011-08-17
    Description: The orbiter and multiprobe components of the Pioneer Venus mission are briefly described. The orbiter was launched on May 20, 1978 and was placed into a highly eccentric near-polar orbit around Venus on December 4, 1978, while the multiprobe was launched on August 8, 1978 and reached Venus on December 9, 1978. Parameters of the orbiter orbit are presented, and modifications of the periapsis altitude are described. The time sequences of the probe entry events are reported for the large probe, north probe, day probe, and night probe, which, along with the bus, are the components of the multiprobe. The multiprobe entry and impact locations as well as related data are reported.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 203; Feb. 23
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    Venus upper atmosphere neutral composition - Preliminary results from the Pioneer Venus orbiter (1979)
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    Publication Date: 2011-08-17
    Description: Measurements in situ of the neutral composition and temperature of the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer Venus orbiter. The presence of many gases, including the major constituents CO2, CO, N2, O, and He has been confirmed. Carbon dioxide is the most abundant constituent at altitudes below about 155 kilometers in the terminator region. Above this altitude atomic oxygen is the major constituent, with O/CO2 ratios in the upper atmosphere being greater than was commonly expected. Isotope ratios of O and C are close to terrestrial values. The temperature inferred from scale heights above 180 kilometers is about 400 K on the dayside near the evening terminator at a solar zenith angle of about 69 deg. It decreases to about 230 K when the solar zenith angle is about 90 deg.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 203; Feb. 23
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    Electron temperatures and densities in the Venus ionosphere - Pioneer Venus orbiter electron temperature probe results (1979)
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    Publication Date: 2011-08-17
    Description: The Pioneer Venus orbiter electron temperature probe was used to obtain altitude profiles of electron temperature and density in the ionosphere of Venus. Elevated temperatures at times of low solar wind flux might indicate support for a certain model. According to this model, less than 5% of the solar wind energy is deposited at the ionopause and is conducted downward through an unmagnetized ionosphere to the region below 200 km where electron cooling to the neutral atmosphere proceeds rapidly. The patterns of electron temperatures and densities at higher solar wind fluxes are considered, the variability of the ionopause height in the late afternoon is noted, and the role of an induced magnetic barrier in the neighborhood of the ionopause is discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 203; Feb. 23
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    CO2 and CO electron vibrational cooling rates (1979)
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    Publication Date: 2011-08-17
    Description: Electron cooling rates for electron vibrational excitation of CO2 and CO and rotational excitation of CO are calculated. Results of the calculation are expressed as closed form analytic relations that are both convenient for numerical calculations and valid over a wide range of electron and neutral temperatures. It is found that the cooling rates and their temperature dependences differ significantly from other calculations. For CO2, these differences are related mainly to the assumptions about the approach to equilibrium and not to the actual cross-section choices. For electron temperatures below 1000 K and gas temperatures near 300 K (representative of conditions in the Venus atmosphere, where collisional cooling of the electrons dominates), the CO2 cooling rate is as much as an order of magnitude larger than previously considered in ionospheric models.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Nov. 1
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    Solving the current element problem over lossy half-space without Sommerfeld integrals (1979)
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    Publication Date: 2011-08-17
    Description: An approach is presented for efficient computation of the vector potentials arising in the problem of a current element radiating over a lossy half-space. The present approach departs from the conventional ones in that it works primarily with the transform domain representations rather than with the Sommerfeld integrals which are the corresponding spatial domain counterparts. The key step in the present method is to approximate the transforms using a suitable approximation which is valid for a wide range of parameters of practical interest. The approximated transforms can be inverted in a closed form for the horizontal component of the vector potentials and can be expressed in a computationally efficient form for the vertical component. Numerical results illustrating the accuracy of the method are presented and some estimates of comparative computational times are also included.
    Keywords: COMMUNICATIONS AND RADAR
    Type: IEEE Transactions on Antennas and Propagation; AP-27; Nov. 197
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    The magnetosphere of Mercury (1979)
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    Publication Date: 2011-08-17
    Description: According to Mariner 10 data on Mercury's magnetosphere, the bow shock and magnetosheath signatures in the magnetic field are entirely consistent with the geometry expected for interaction between a planet-centered magnetic dipole and the solar wind. The geometrically determined distance to the magnetopause stagnation point of solar wind flow was 1.45 plus or minus 0.15 Mercury radii. Comparative scaling of the magnetosphere of Mercury to earth shows that Mercury itself occupies a much larger fraction of the magnetosphere than does the earth. While there is no evidence for the permanent existence of a trapped charged particle radiation belt, intense transient bursts of energetic electrons indicate that a local acceleration process must be active. It is reasonable to assume that this process occurs in the magnetic tail. The interior plasma features compare well with those in the earth's magnetosphere. Characteristic time scales for transient phenomena at Mercury should be reduced by a factor of about 20 in comparison with those on earth - i.e., a few minutes for substorms vs an hour at earth. The origin of the magnetic field is unclear.
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    Planetary geodesy (1979)
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    Publication Date: 2011-08-17
    Description: The results of investigations of the geodesy of the planets and their satellites conducted during the period 1975 - 1978 are surveyed. Analysis of the photographic data of Mercury taken by Mariner 10 have revealed the mass, oblateness, radius rotation period and density of the panet, and allowed the high-resolution mapping of the surface. Earth-based radar imagery has permitted the identification of large-scale topographic features on Venus. Knowledge of the gravitational field of Mars has been improved by Mariner 9 and Viking tracking data, and the global topography and geometric figure of Mars have been derived. Doppler and ranging tracking data from the Viking landers have provided data for the precise determination of Martian rotational dynamics and the topographic features and figures of Phobos and Deimos have been observed. Pioneer 10 and 11 data have yielded information on the mass, gravitational field and dynamic parameters of Jupiter. Discoveries of a satellite of Pluto and a set of rings around Uranus have been made, the rotation of Uranus and Neptune have been measured, and the geodetic properties of the rings and satellites of Saturn have been investigated. Future developments in planetary geodesy are expected from continued Viking data and the Pioneer Venus probe and Voyager probes to Jupiter and Saturn.
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    Cosmic ray ionization of the Jovian atmosphere (1979)
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    Publication Date: 2011-08-17
    Description: An approximate form of the Boltzmann equation has been used to obtain local ionization rates due to the absorption of galactic cosmic rays in the Jovian atmosphere. It is shown that the muon flux component of the cosmic-ray-induced cascade may be especially important in ionizing the atmosphere at levels where the total number density exceeds 10 to the 19th per cu cm (well below the ionospheric layers produced by solar EUV). A model containing both positive and negative ion reactions has been employed to compute electron and ion number densities. Peak electron number densities of the order of 1000 per cu cm may be expected even at relatively low magnetic latitudes. The dominant positive ions are NH4(+) and CnHm(+) cluster ions, with n at least 2; it is suggested that the absorption of galactic cosmic-ray energy at such relatively high pressures in the Jovian atmosphere (M about 10 to the 18th to 10 to the 20th per cu cm) and the subsequent chemical reactions may be instrumental in the local formation of complex hydrocarbons.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 39; Sept
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    Martian meteorology (1979)
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    Publication Date: 2011-08-17
    Description: Viking mission results concerning the structure and dynamics of the Martian atmosphere are reviewed. The large-scale variability of pressure, temperature, and zonally averaged wind at the Lander sites is described, and small-scale phenomena involving the boundary layer and internal gravity waves are discussed. Observational evidence for the existence of transient planetary-scale waves, forced quasi-stationary waves, and thermal tides on Mars is examined. Atmospheric dynamics and properties of dust storms are considered, with emphasis on dust properties and distribution, the time evolution of planetwide dust storms, and dust-storm genesis and decay. Attention is also given to the nature of past Martian climates, the sizes and composition of volatile reservoirs, and volatile escape from the atmosphere.
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    Latitudinal beaming of Jupiter's low frequency radio emissions (1979)
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    Publication Date: 2011-08-17
    Description: Observations of Jupiter's radio emissions from Jovigraphic latitudes greater than 3.3 deg are reported. The measurements were obtained from the Voyager 2 spacecraft at declinations up to 6.5 deg, and when these results are compared with simultaneous observations from Voyager 1 near the ecliptic plane (at a Jovigraphic latitude of about 3 deg), they indicate that the latitudinal-beaming effects persist and may even become stronger with higher latitudes. The results were combined with earlier low-frequency measurements from periods with De as low as -3 deg in order to show the beaming effects the occurrence of the emission over a full 10 deg range of altitude. The results of observations at frequencies near 1 MHz are also discussed, which were obtained from Voyager 1 and 2 in 1978, Rae 1 in 1969, and Imp 6 in 1971-1972. The implications of the new results for models of Jupiter's radio-emission beam pattern are considered.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Sept. 1
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    The mean Jovian temperature structure derived from spectral observations from 105 to 630 cm kaysers (1979)
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    Publication Date: 2011-08-17
    Description: Far infrared observations of the thermal emission of Jupiter are used to determine the temperature at 1 bar. High-altitude observations of the whole-disk brightness temperature of Jupiter in the range of 100 to 347 kaysers were inverted to obtain a P-T profile between 1.5 and 0.06 atm, assuming as opacity sources the H2 collisionally induced continuum and the rotation inversion bands of ammonia. The P-T profile derived from the spectrum reproduces the main features of the observed spectrum, with a slightly improved fit if the effects of ammonia haze opacity or NH3 supersaturation in the saturated region are taken into account. The Jovian temperature is found to be 160 + or - 7 K at 1 bar, and 105 + or - 3 K at the inversion level at 0.15 bar. The 1-bar temperature is shown to be consistent with Jovian interior models which match the observed gravitational moment.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 40; Oct. 197
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    Digital techniques for ULF wave polarization analysis (1979)
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    Publication Date: 2011-08-17
    Description: Digital power spectral and wave polarization analysis are powerful techniques for studying ULF waves in the earth's magnetosphere. Four different techniques for using the spectral matrix to perform such an analysis have been presented in the literature. Three of these techniques are similar in that they require transformation of the spectral matrix to the principal axis system prior to performing the polarization analysis. The differences in the three techniques lie in the manner in which determine this transformation. A comparative study of these three techniques using both simulated and real data has shown them to be approximately equal in quality of performance. The fourth technique does not require transformation of the spectral matrix. Rather, it uses the measured spectral matrix and state vectors for a desired wave type to design a polarization detector function in the frequency domain. The design of various detector functions and their application to both simulated and real data will be presented.
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    The magnetic fields of Mercury, Mars, and moon (1979)
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    Publication Date: 2011-08-17
    Description: Mariner observations have shown a significant global magnetic field at Mercury with a dipole moment at a tilt of 14 + or - 5 deg relative to the normal of the orbit plane. A presently active dynamo is the most likely origin for the planet's magnetic field. Limited evidence for an intrinsic magnetic field on Mars was obtained by USSR spacecraft in 1971 and 1974. The Martian magnetic field, if it exists, may result from either remanent magnetism or an active dynamo. On the moon, local magnetic fields have been detected by the Apollo and Lunokhod missions, but no global correlation of the steady state values has been noted.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Calculated scan characteristics of a large spherical reflector antenna (1979)
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    Publication Date: 2011-08-17
    Description: A previously published numerical method to calculate the radiation properties of parabolic reflectors has been modified to also include very large spherical reflectors. The method has been verified by comparing the calculated and the measured results for a 120-wavelength spherical reflector.
    Keywords: COMMUNICATIONS AND RADAR
    Type: IEEE Transactions on Antennas and Propagation; AP-27; May 1979
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    Ionosphere of Venus - First observations of the dayside ion composition near dawn and dusk (1979)
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    Publication Date: 2011-08-17
    Description: Independent Bennett radio-frequency ion mass spectrometers on the Pioneer Venus bus and orbiter spacecraft obtained in situ measurements of the composition of the ionosphere of Venus. The spectrometer on the bus explored the dawn region while the spectrometer on the orbiter explored the duskside region. Information on the ion composition in the topside, the lower ionosphere, and the upper ionosphere is presented. Below the O(+) peak near 200 km, the ions are found to exhibit scale heights consistent with a neutral gas temperature of about 180 K near the terminator. In the upper ionosphere, scale heights of all species reflect the effects of plasma transport.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 203; Feb. 23
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    Initial observations of the Pioneer Venus orbiter solar wind plasma experiment (1979)
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    Publication Date: 2011-08-17
    Description: The ionosphere, ionosheath, ionopause, and bow shock wave of Venus are characterized. Venus is found to have a well-defined strong standing bow shock wave. In the ionosheath, downstream from the shock, compressed and heated postshock plasma apparently interacts directly with the ionosphere. Plasma ion velocity deflections suggest that the ionopause has a blunt shape. The positions of the bow shock and ionopause are variable and appear to respond to changes in the external solar wind pressure.
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    Type: Science; 203; Feb. 23
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    Minor planets and related objects. XXVII - Lightcurves of 887 Alinda (1979)
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    Publication Date: 2011-08-17
    Description: Eleven light curves and UBV photometry of the Amor asteroid Alinda, a candidate for having a cometary origin, are analyzed. A probable rotation period of 73 h 58 m + or - 3 m (p.e.) is derived on the assumption of two maxima and two minima per cycle in a composite light curve. An absolute V magnitude of 14.10 + or - 0.08 and a phase coefficient of 0.042 + or - 0.003 mag/deg in V are obtained, along with a B-V color of 0.86 + or - 0.02 and a U-B color of 0.50 + or - 0.05, both extrapolated to zero phase. The rotation period is shown to be the longest yet observed for an asteroid. It is concluded that the colors of Alinda are not unusual for an asteroid, that Alinda is probably not an extinct cometary nucleus, that the slow rotation may be a consequence of one or more collisions, and that the pole of Alinda may be nearly perpendicular to the ecliptic.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Astronomical Journal; 84; Feb. 197
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    False lock performance of quadriphase receivers (1979)
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    Publication Date: 2011-08-17
    Description: Quadriphase receivers, like biphase receivers, have the ability to false lock on a sideband on the data modulation. The theory associated with this phenomenon for receivers of binary phase-shift-keying (BPSK), using Costas loop demodulation, has recently been documented in the literature. This paper considers the corresponding theory for receivers of balanced quadriphase-shift-keying (QPSK) employing a quadriphase Costas loop (or equivalent fourth-power loop) for demodulation. Specific closed form expressions for false lock performance are developed and numerically evaluated for the particular case of single pole arm filters and an NRZ data format for each of the two statistically independent quadrature modulations.
    Keywords: COMMUNICATIONS AND RADAR
    Type: IEEE Transactions on Communications; COM-27; Nov. 197
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    Discovery of a new Jupiter satellite (1979)
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    Publication Date: 2011-08-17
    Description: During detailed analysis of Voyager 2 pictures of the Jupiter ring, a starlike object was identified in the plane of the ring. The same object was subsequently found on a higher-resolution frame and proved to be a satellite of Jupiter. This satellite has a circular orbit whose radius is 1.8 Jupiter radii, a period of 7 hours and 8 minutes, and a diameter of less than 40 kilometers. It is located at the outer edge of the Jupiter ring.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 206; Nov. 23
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    The magnetic field of Mercury (1979)
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    Publication Date: 2011-08-17
    Description: The paper examines the magnetic field observations and their analyses relating to the determination of the Mercury magnetic field. Methods of analyzing data included: (1) comparison of bow shock and magnetopause relative positions at Mercury to the earth, (2) direct spherical harmonic analysis, (3) magnetosphere modeling by an image dipole, and (4) scaling of a mathematical model for the terrestrial magnetosphere. Dipole moments were determined using partial quadrupole and octupole terms to improve the least-square fit of models to observations; analyses by method (2) yield a convergent series of dipole moments values considered to best represent the intrinsic planetary field. Finally, it is suggested that the origin of the magnetic field of Mercury cannot be uniquely determined, but the sources of convective energy may be radiogenic decay and heat release, gravitational settling, and differentiation of processional torques.
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    Some new results on spherical dynamos (1979)
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    Publication Date: 2011-08-17
    Description: Small-scale motions in the earth's liquid core are likely to be highly anisotropic because of the effects of rotation. Guided by physical considerations, the 'alpha-effect' described by an anisotropic tensor alpha sub ik is formulated and the corresponding boundary value problem for a sphere is solved for a variety of boundary conditions. A converged solution has been obtained only in the case of the Fermi condition of an infinitely conducting exterior of the sphere. Some remarks are made on the hypothetical upper bound on magnetic field strengths in planetary cores originally proposed by Busse (1976).
    Keywords: LUNAR AND PLANETARY EXPLORATION
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    Io's surface and environs - A magmatic-volatile model (1979)
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    Publication Date: 2011-08-17
    Description: A model is proposed to account for the observed properties of Io. The crust is probably siliceous, but the outermost visible surface is composed primarily of several allotropes of elemental sulfur, plus frosts of SO2, H2S, and S2O. The 4-micron feature in Io's IR reflectance is identified as the (nu 1 + nu 3) band of SO2 frost. A possible source of the S is dissociation of iron sulfide brought up from the core by mantle convection. The SO2 is produced in the volcanoes, and the H2S by interaction of magnetospheric protons with the surface S. Delayed luminescence from S2O could cause the posteclipse brightening. The orbital torus is sustained by evaporation from molten ejecta from the volcanoes. Several additional diagnostic absorption bands and two additional minor torus species are predicted by this model.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters; 6; Oct. 197
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    Nebular condensation of Ga, Ge and Sb and the chemical classification of iron meteorites (1979)
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    Publication Date: 2011-08-17
    Description: The quantization of the Ga and Ge contents in iron meteorites, which is used as a key parameter in the chemical classification of iron meteorites, is discussed in terms of nebular condensation. The calculation of nebular equilibrium condensation is examined, taking into account the dependence of the activity coefficient on temperature and composition, and recent calculations of the condensation temperatures of Ga, Ge, Sb, Au, As and Cu are presented, noting that Ge is the most volatile siderophile, followed by Ga and Sb. The narrow intragroup ranges of Ga and Ge are interpreted in terms of minimal fractionation during core crystallization, while the larger ranges of Sb are attributed to its significantly smaller solid/liquid distribution coefficient in IIIAB meteorites.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Nature; 282; Dec
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    Albedo and color contrasts on asteroid surfaces (1979)
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    Publication Date: 2011-08-17
    Description: Asteroids in general display only small or negligible variations in spectrum or albedo during a rotational cycle. Color variations with rotation are described in the literature but are usually comparable to the noise in the measurements. Twenty-four asteroids have been systematically monitored for such color changes. Only 3 Juno, 4 Vesta, 6 Hebe, 71 Niobe, 349 Dembowska, and 944 Hidalgo display color variations larger than 0.03 mag. In each of these cases the asteroid appears redder near maximum brightness. Of seven asteroids monitored polarimetrically, only 4 Vesta shows a convincing variation, attributed to an albedo change with rotation. The lightcurve can be explained by albedo differences alone; Vesta apparently has a nearly spheroidal shape. Nothwithstanding the above results, the degree of uniformity of most asteroid surfaces is remarkable. If asteroids exist with large discrete domains of ferrosilicate, metallic, and/or carbonaceous material together on their surfaces, they have not yet been identified.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 40; Dec. 197
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  • 95
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    Digital and analog communication systems (1979)
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    Publication Date: 2011-08-17
    Description: The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.
    Keywords: COMMUNICATIONS AND RADAR
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  • 96
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    The use of the German V-2 in US for upper atmosphere research (1979)
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    Publication Date: 2011-08-17
    Description: Early U.S. space experiments involving the liquid propellant German V-2 are discussed. Although the primary objective of the experiments conducted under project Hermes after World War II was initially the development of missile technology, scientific objectives were soon given the priority. The missile was modified for scientific experiments and the payload increased from 6.8% to 47% between 1946 and 1949. Among other instruments, the payload included a cosmic ray telescope, ionosphere transmitter and spectrograph for solar spectral measurements. While the scientific success of the program established a positive public attitude towards space research, the Upper Atmosphere Research Panel, formed to coordinate the project, set a pattern for future scientific advisory bodies.
    Keywords: ASTRONAUTICS (GENERAL)
    Type: vol. 32; Dec. 197
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    Magnetic field studies at Jupiter by Voyager 2 - Preliminary results (1979)
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    Publication Date: 2011-08-17
    Description: The Voyager 2 magnetic field experiment, for which the instrumentation is identical to that on Voyager 1, operated flawlessly throughout the second Jupiter encounter. The paper presents a brief overview of the results obtained to date on the Jovian magnetosphere, the bow shock, the magnetopause, and the extended magnetic tail. The results and the magnetic field geometry confirm the earlier conclusion from Voyager 1 that Jupiter has an enormous magnetic tail, approximately 300-400 Jupiter radii in diameter, trailing behind the planet with respect to the supersonic flow of the solar wind. Additional observations of the distortion of the inner magnetosphere by a concentrated plasma show a spatial merging of the equatorial magnetodisk current with the current sheet in the magnetic tail. Disturbances near Ganymede are discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 206; Nov. 23
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    Radio science with Voyager at Jupiter - Initial Voyager 2 results and a Voyager 1 measure of the Io torus (1979)
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    Publication Date: 2011-08-17
    Description: About 22 hours after its closest approach to Jupiter, Voyager 2 passed behind the planet as viewed from the earth. Although the spacecraft was geometrically occulted for nearly two hours, the radio links between it and the earth were maintained almost continuously because of the refraction of the signals in Jupiter's south polar atmosphere. A figure shows the plane-of-the-sky geometry of this grazing occultation and preliminary data on the intensity of the spacecraft radio signals as received by the tracking station at Goldstone, California. The intensity data indicate a classic atmospheric occultation profile and the effects of turbulence and ionospheric focusing and defocusing. Analysis of the dispersive ionospheric refraction data yields preliminary profiles for the topside ionosphere at 66.7 deg S (entry in the evening) and 50.1 deg S (exit in the morning) that are reversed with respect to corresponding Voyager 1 profiles in terms of plasma concentration at a fixed altitude. Preliminary reduction of the preencounter occultation of Voyager 1 by the Io torus gives an average plasma density of about 1000 e/cu cm.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 206; Nov. 23
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    Residence lifetimes of 1.79- to 2.15-MeV protons in the equatorial region of the Jovian magnetosphere (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The magnitude of the strong flow of 1.79-2.15 MeV protons away from the Jovian magnetic equator is used to estimate the residence lifetimes of these protons in the equatorial source region. The lifetime is approximately 1.2 x 10 to the 5th/(R - 5.8)-squared sec, where R is distance in Jovian radii from Jupiter's center to the equatorial region of interest. At Europa and Ganymede (but not at Io) this lifetime is 1-2 orders of magnitude shorter than sweepup lifetimes by the moons. The fluxes of these protons, integrated over the observed range from 6 to 40 Jovian radii, amount to 3 x 10 to the 23rd particles per second, per degree of longitude and carry away about 9 x 10 to the 17th ergs per second per degree.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Oct. 1
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    Investigation of Luna-20 soil samples, using a mass spectrometer with a spark-discharge ion source (1979)
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    Publication Date: 2011-08-17
    Description: A method of analyzing soil samples with a mass spectrometer employing a spark-discharge ion source is described, and the effectiveness of the method is demonstrated by applying it to the determination of impurities, in amounts of less than 10 mg, in lunar samples. It is shown that four parts of the Luna-20 lunar highland sample differ in their chemical composition.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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