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Jurewicz A.J.G. Burnett D.S. Wiens R.C. Friedmann T.A. Hays C.C. Hohlfelder R.J. Nishiizumi K. Stone J.A. Woolum D.S. Becker R. Butterworth A.L. Campbell A.J. Ebihara M. Franchi I.A. Heber V. Hohenberg C.M. Humayun M. McKeegan K.D. McNamara K. Meshik A. Pepin R.O. Schlutter D. Wieler R. 《Space Science Reviews》2003,105(3-4):535-560
Genesis (NASA Discovery Mission #5) is a sample return mission. Collectors comprised of ultra-high purity materials will be
exposed to the solar wind and then returned to Earth for laboratory analysis. There is a suite of fifteen types of ultra-pure
materials distributed among several locations. Most of the materials are mounted on deployable panels (‘collector arrays’),
with some as targets in the focal spot of an electrostatic mirror (the ‘concentrator’). Other materials are strategically
placed on the spacecraft as additional targets of opportunity to maximize the area for solar-wind collection.
Most of the collection area consists of hexagonal collectors in the arrays; approximately half are silicon, the rest are for
solar-wind components not retained and/or not easily measured in silicon. There are a variety of materials both in collector
arrays and elsewhere targeted for the analyses of specific solar-wind components.
Engineering and science factors drove the selection process. Engineering required testing of physical properties such as the
ability to withstand shaking on launch and thermal cycling during deployment. Science constraints included bulk purity, surface
and interface cleanliness, retentiveness with respect to individual solar-wind components, and availability.
A detailed report of material parameters planned as a resource for choosing materials for study will be published on a Genesis
website, and will be updated as additional information is obtained. Some material is already linked to the Genesis plasma
data website (genesis.lanl.gov). Genesis should provide a reservoir of materials for allocation to the scientific community
throughout the 21st Century.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Summary The observational features of the arc are fairly well established. At present, the thermal conduction model appears to explain the red arc features most consistently, but it must be noted that a soft electron flux would give very similar results. Ion temperature measurements in the vicinity of an arc, which should be forthcoming in the very near future, can establish conclusively whether transverse electric fields play any important role in the formation of the arcs. Accepting the assumption that the arcs are the result of energy flowing down from the plasmasphere, the major remaining question is: where does the energy come from and how does it get into the plasmasphere? The various proposed mechanisms discussed in the previous chapter appear feasible, but much work needs to be done before this problem is completely resolved.On leave from the Department of Electrical Engineering, The University of Michigan, Ann Arbor.The National Center for Atmospheric Research is sponsored by the National Science Foundation. 相似文献
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T.L. Killeen P.B. Hays N.W. Spencer L.E. Wharton 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(10):133-136
Remote sensing measurements of the meridional thermospheric neutral wind using the Fabry-Perot Interferometer on Dynamics Explorer have been combined within-situ measurements of the zonal component using the Wind and Temperature Spectrometer on the same spacecraft. The two data sets with appropriate spatial phasing and averaging determine the vector wind along the track of the polar orbiting spacecraft. A study of fifty-eight passes over the Southern (sunlit) pole has enabled the average Universal Time dependence of the wind field to be determined for essentially a single solar local time cut. The results show the presence of a “back-ground” wind field driven by solar EUV heating upon which is superposed a circulating wind field driven by high latitude momentum and energy sources. 相似文献
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There is as yet no widely accepted theory of spacepower, although links to the development of seapower theory are generally acknowledged. An ongoing NDU study is building a framework to explicate the fundamental aspects of spacepower and its relation to the pursuit of a variety of objectives. Two distinct “ages” of the current space era can be discerned, the first based on Cold War competition and the need for prestige, the second based on the requirement for information in a globalized world. The most important features of future space activity are likely to be economic development, and national and international security. Developing a spacepower theory will provide an opportunity to maximize the benefits of space for global society. 相似文献
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