共查询到20条相似文献,搜索用时 31 毫秒
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C.W. Carlson D.W. Curtis G. Paschmann W. Michel 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(7):67-70
A new instrument which can rapidly measure plasma particle distribution functions has been developed based upon recent innovations in electrostatic analyzer design and position sensitive particle detection. The new analyzer uses a quadrispherical geometry, but has a completely uniform 360° fan-shaped field of view. The polar angular distribution of entering particles is spatially imaged onto a position sensitive detector at the annular exit aperture after a deflection through 90°. Several methods of position sensitive detection have been successfully used in conjunction with this analyzer. The simplest is individual channel multipliers spaced around the annular exit. Microchannel plate electron multipliers permit greater position resolution to be obtained, and a detector using microchannel plates followed by a resistive anode image converter obtains angular resolution of about one degree -- , 360 individual angle pixels. Instruments of this type were flown on a sounding rocket in early 1982 and will be included on the Giotto comet mission and the AMPTE ion release module (IRM). 相似文献
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H.E. Hinteregger 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(12):39-52
The development of significantly improved representations of solar EUV inputs for computer-aided investigations of the terrestrial thermosphere and ionosphere has become attractive particularly for the present solar cycle which has been covered by reasonably complete and continuous EUV observations from the AE-E Satellite. These representations try to satisfy some rather incongruous , regarding (a) the strong wavelength-dependence in the atmospheric cross sections of the various types of EUV photon interactions, (b) the great differences in the relative amplitudes of the various types of variations in the full-disk fluxes of emissions at different wavelengths, and (c) the persisting desire to use only a as actual input variables for computational models supposed to cover the entire EUV wavelength range (remembering the great success of empirical thermospheric models using only two indices). These general physical and specific aeronomical demands indeed outline a very difficult task. The present study, based mainly on AE-E satellite observations during 1976–1979, represents an exploratory step, only clarifying some important developmental aspects, without recommending any specific formulations for immediately practicable adoption in aeronomical modelling at this time. 相似文献
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A.C. Levasseur-Regourd D.W. Schuerman R.H. Zerull R.H. Giese 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(8):113-120
Remote optical observations of comets provide information only along the whole line of sight and require some assumptions to be interpreted. Due to the advent of cometary space missions, a two-step strategy has been defined to derive without any assumption spatial distribution and physical properties of dust by in-situ optical observations. First, an , suitable for a fast fly-by, should provide passive in-situ measurements in the direction of the approaching (or receding) comet near encounter; by suitably differencing such observations, the brightness and polarization per can be recovered along the trajectory of the spacecraft. Secondly, a , suitable for a rendez-vous mission, should permit the determination of the scattering properties of . Both experiments also provide a connecting link between non-optical in-situ measurements (from mass spectrometers or impact detectors) and remote optical observations. 相似文献
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Leon Golub 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(8):75-82
We describe the progress which has been made in constructing a new type of X-ray telescope, which operates at normal incidence in the soft X-ray region by the use of multilayer coatings. The principles involved in state-of-the-art multilayer technology and some recent high-resolution imaging results are discussed. A rocket payload incorporating a multilayer X-ray mirror is presently being constructed. It is of Ritchey-Chretien design and the expected spatial resolution is . The scientific program for solar coronal studies and future instrumental developments are also discussed. 相似文献
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Paul D. Feldman 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(9):177-184
Since its launch in 1978 the () satellite observatory has been used to record ultraviolet spectra of nearly two dozen comets. These observations have been applied principally to studies of the composition, chemistry and evolution of the gaseous coma and more recently, with the substantially increased data base, to comparative analyses. The observations of Comets Bowell (1982 I) and Cernis (1983?) at a heliocentric distance of ≈ 3.4 AU show these two comets to be virtually identical and pose problems for water ice vaporization models. The most significant recent result from was the discovery of S2 in the Earth-approaching comet IRAS-Araki-Alcock (1983d) and the use of the S2 emission as a monitor of short-term variations in cometary activity. In early 1984, periodic comet Encke was observed for the second time by , this time post-perihelion. 相似文献
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G.V. Mayer 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(11):175-180
After a general definition of data- and instrument autonomy and an introduction to the End-to-End Data System concept the future guidelines for “Packet Telemetry and -Telecommand” are overviewed. These and other guidelines have been initiated by a NASA/ESA working group and further developed by an international “onsultative ommittee for pace ata ystems” (CCSDS), coordinated with 6 space agencies. The status of these documents is reviewed, especially the document on Packet Telemetry, which has reached a mature stage. A pilot project, utonomous ayload ontrol (APC), for the study and the demonstration of these new procedures is introduced shortly. 相似文献
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P. Edenhofer 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(12):201-209
Doppler and ranging measurements using the radio signal of the GIOTTO spacecraft were taken before, during, and after the encounter with Comet Halley on March 1986. The spacecraft velocity was found to decrease by a total of 23.3 cm s?1 due to impacting gas and (primarily) dust in the cometary atmosphere. A preliminary dust production rate is found to be consistent with this deceleration. Power spectra of the carrier phase fluctuations reveal an increase in level and a flattening of the spectrum just prior to encounter, presumably associated with the enhanced dust impact rate. Finally, simulated Doppler time profiles are computed using the radial dependence of plasma density observed by the GIOTTO investigations. It is shown that the cometary electron content profile would have been clearly seen if a dual-frequency downlink radio configuration had been available at encounter. 相似文献
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R.C. Elphic J.G. Luhmann C.T. Russell L.H. Brace 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(9):53-58
Force-free magnetic structures with cylindrical geometry appear under a variety of conditions in nature. Filamentary helical magnetic structures are observed to be associated with prominences and flares in the solar atmosphere, and can arise in superconductors and laboratory plasmas. Another example of cylindrical quasi-force-free configurations appears to exist in the Venus ionosphere. Magnetic flux ropes with diameters of ~20 – 30 km have been observed by the Pioneer Venus Orbiter to be a nearly ubiquitous feature of the dayside Venus ionosphere. Models of flux ropes suggest that many of these structures tend to be quasi-force-free, i.e., ×~0, while others are correlated with pressure variations in the ambient thermal plasma, ×=-?(nkT). 相似文献
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A.A. Imshenetsky L.A. Kuzyurina V.M. Jakshina I.K. Dorofeyeva 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(14):173-177
The influence of lowered gravitation on biomass and CO2 production in , a xerophyte, and , an aqueous spirillum, in liquid nutrient medium on a horizontal clinostat at 0.1 has been studied. As controls we considered: 1) growth under stationary conditions of cultivation with test tubes oriented horizontally; 2) growth on a synchronously revolving centrifuge; and 3) growth on a swing with stirring. A horizontal clinostat at 0.1 g stimulates biomass production and CO2 release in as compared with the controls. growth is reduced as a result of clinostating. The best development and CO2 production are observed under stationary conditions. The results do not support the assumption that microorganisms living in water are more resistant to lowered gravitation than those living in soil. 相似文献
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C.R. Philbrick D.P. Sipler B.B. Balsley J.C. Ulwick 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(6):129-132
The ructure and tmospheric urbulence nvironment (STATE) experiment was conducted during the second week of June 1983 at Poker Flat Research Range, Alaska. The measurements focus on a study of the middle atmosphere dynamics by comparison between in-situ probe measurements and MST radar measurements. Rocket launchings were conducted at three periods which were selected by monitoring the doppler velocity spectra of the MST radar.The STATE program has included the efforts of several scientists in planning and carrying out the ground-based and rocket measurements. An overview of the program is given together with some preliminary results. The regions in intense backscatter signals detected by the MST radar are shown to correlate with large irregularities in the electron profiles measured. 相似文献
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E.B. Shulzhenko I.F. Vil-Vilyams V.E. Panfilov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(14):131-134
We present the results of manned studies in which test subjects were exposed to simulated zero (water immersion or head-down tilt at ?6°) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 Gz after exposure to zero , whether simulated by immersion or by head-down tilt. The paper discusses the functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero . 相似文献