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Scientific and policy developments in the field of Near-Earth Objects (NEOs) since the UN NEO conference in 1995 are briefly outlined. Some areas of research and discovery have exhibited considerable progress while others have languished. In particular, facilities in the southern hemisphere for discovery and tracking of NEOs are inadequate. Suggestions are made both at the scientific and technical levels as well as at the policy level to provide coordinated and coherent progress in developing a long-term approach to NEO hazard mitigation. The next step should be the establishment of a panel of international scientific experts on the subject.  相似文献   

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The literature on the history of spaceflight has depicted the early 1950s Colliers articles mostly as a forerunner to the peaceful and scientific exploration of space. Yet the centerpiece of Wernher von Braun's plan was a manned space station that would serve as reconnaissance platform and orbiting battle station for achieving “space superiority” over the USSR. One its roles could be the launching of nuclear missiles. When challenged as to the station's defensibility, von Braun even posited pre-emptive atomic strikes from space as a response to the development of a hostile anti-satellite capability.  相似文献   

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Yuri V. Trifonov 《Acta Astronautica》1996,39(9-12):1021-1024
The preliminary estimations show that the contemporary level of electronic and information engineering makes it possible to create a small s/c of 150–200 kg mass capable to solve both the problems of Earth remote sensing and many other applied and scientific problems orbiting the planets at 500–1000 km. In accordance with the fundamental criterion for choosing parameters of small multipurpose spacecraft the small UNISAT s/c has been created on the basis of a unified space platform. The design provides for s/c energetic, thermal and space-saving parameters satisfying the conditions for accommodation of various-purpose payload and a possibility of using relatively inexpensive and light launchers like “Start-1” mobile launch complexes. Space platform mass is 100–120 kg; permissible payloads (PL) mass is 40–80 kg; maximal average power consumption of the payload is up to 60 W; three-axes orientation accuracy up to 0.001 deg./s; s/c lifetime is not less than 3–5 years.  相似文献   

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John G. Fox   《Space Policy》2001,17(1):592
There is still little theory on the strategic use of space. Some have proposed naval theorist A.T. Mahan as a guide but this viewpoint argues that, while the analogy with sea power makes sense, it is the naval theories of Sir Julian Corbett that are most apt. Parallels are drawn between the latter's emphasis on attacking commerce as the best means of crippling a seafaring state and the implications of the current US dependence on trade in information. Ways for the USA to mitigate its vulnerability in this area are suggested.  相似文献   

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The UK civil space strategy for the years 2008–2012 and beyond was published in February 2008. This paper describes the key features of the strategy and highlights those areas that are new or different from the aims set out in previous strategies. In particular, the strategy lays out a new five-part high-level vision for UK civil space.  相似文献   

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The orbiting solar telescope on Salyut-4 (F = 2,5 m, d = 250 mm) produces images of the Sun on the entrance slit of a stigmatic two-grating spectrograph (R1 = 1 m, N1 = 1200 lines/mm; R2 = 0.5 m, N2 = 2400 lines/mm, dispersion 16 Å/mm, spectral resolution 0,3 Å). The automatic system keeps the observed solar features on the slit of the spectrograph with an accuracy of 3–4 arc sec. The far UV-spectra (970–1400 Å) of solar flares, brightenings, flocculi and prominences were photographed and fresh coatings of mirrors were made during the flight.  相似文献   

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In recent years Micro Systems Technology (MST) was introduced to manufacture miniaturized components for satellite subsystems, like small sensors, valves, micromotors, antennas and many more. These components can be used to build a new class of satellites weighing considerably less than 10 kg, with the capabilities comparable to present microsatellites. With the possibility of cheap mass production of such nanosatellites new applications become possible. However, the construction of very small satellites is connected with problems concerning launch, orbit control and, deorbiting. Furthermore the reduction of size creates certain limits for power consumption, data rates and optical resolutions which have to be carefully considered.  相似文献   

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