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91.
Cosmic-ray isotope observations from NASAs Advanced Composition Explorer (ACE) mission have been used to investigate the composition of cosmic-ray source material. Source abundances relative to 56Fe are reported for eleven isotopes of Ca, Fe, Co, and Ni, including the very rare isotopes 48Ca and 64Ni. Although the source abundances range over a factor 104, most of the ratios to 56Fe are consistent with solar-system values to within 20%. However, there are some notable differences, the most significant being an excess of (70±30)% relative to the solar system for the cosmic-ray source ratio 58Fe/56Fe. The possible association of such an excess with a contribution to the cosmic-ray source from Wolf–Rayet star ejecta is discussed.  相似文献   
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93.
This Note emphasizes the need, in a space station, of an emergency room, especially equipped with regard to clean air and competent paramedical personnel. The establishment of some degree of artificial gravity is desirable.  相似文献   
94.
Conscious space orientation depends on afferent information from different sense organs including the labyrinth, the eyes, tactile cues from the skin, joint receptors, muscle spindles, tendon organs and possibly viscera. An important role is played by impulses from the cervical position receptors in interaction with concomitant information from the otolith system. In order to isolate the effect of cervical position receptors from that of the otolith system, space experiments in orbital weightlessness and in parabolic aircraft flight were performed. It was found that stimulation of the neck receptors in weightlessness markedly influences the perception of the subjective vertical and horizontal and in addition has a weak effect on ocular torsion.  相似文献   
95.
The growth of low- and medium-Earth orbit mobile satellite communications poses a threat to radio astronomers which could be mitigated by the establishment of international radio quiet zones (IRQZs), where communications traffic is managed (not eliminated) to allow radio astronomy to continue. Using the prototype of national such zones in the USA, this article explains how the system would work and discusses the international legal parameters that would bound it, drawing on current aerospace, outer space and high seas legislation. Precedents for an IRQZ—Exclusive Economic Zones, denuclearised zones and the Antarctic regime—are also examined.  相似文献   
96.
Europe has at last started to integrate the assets of its broad set of actors into a comprehensive European Space Strategy. But will this first approach be ambitious enough to strengthen Europe as a global actor? In this contribution, the individuals responsible for strategy in the French and German space agencies seek an answer to this question. They do so by reviewing the historical background to European space efforts, and its role in shaping present-day activities; setting forth a vision of how Europe should proceed in space, and measuring current progress in drafting a European space strategy against this vision.  相似文献   
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98.
Venus and Mars likely had liquid water bodies on their surface early in the Solar System history. The surfaces of Venus and Mars are presently not a suitable habitat for life, but reservoirs of liquid water remain in the atmosphere of Venus and the subsurface of Mars, and with it also the possibility of microbial life. Microbial organisms may have adapted to live in these ecological niches by the evolutionary force of directional selection. Missions to our neighboring planets should therefore be planned to explore these potentially life-containing refuges and return samples for analysis. Sample return missions should also include ice samples from Mercury and the Moon, which may contain information about the biogenic material that catalyzed the early evolution of life on Earth (or elsewhere). To obtain such information, science-driven exploration is necessary through varying degrees of mission operation autonomy. A hierarchical mission design is envisioned that includes spaceborne (orbital), atmosphere (airborne), surface (mobile such as rover and stationary such as lander or sensor), and subsurface (e.g., ground-penetrating radar, drilling, etc.) agents working in concert to allow for sufficient mission safety and redundancy, to perform extensive and challenging reconnaissance, and to lead to a thorough search for evidence of life and habitability.  相似文献   
99.
Athough a poor nation with limited resources, India has spent large amounts of money on sophisticated space programme. It is pursuing a policy of using high technology to solve the country's social and economic problems, and at the same time to strengthen its international position. Satellite-aided communications, educational programmes, meteorology and resources survey and management are thus priority areas. This article examines the history and achievements of India's space programme, and considers the constraints faced and budget and staffing plans. Foreign policy and national security aspects are covered in detail, including the question of whether India's peaceful space policy can be put to military use.  相似文献   
100.
With ongoing progress in space technology, questions of its potential for the modification of weather and climate phenomena (often summarized by the term ‘geoengineering’) ranging from small-scale severe weather events to mitigation of effects caused by global climate change and ozone depletion have become popular. This paper reviews the current state of scientifically based studies in this context and attempts to provide a basis for an assessment of geoengineering efforts with respect to technological, economic and fundamental scientific aspects. The overview indicates that the current state of knowledge about climate variability as a consequence of natural and anthropogenic influences is sufficient to classify geoengineering solutions as highly risky and their consequences as extremely difficult to predict. Even on smaller scales and with less complexity of interacting processes, only very limited boundary conditions, i.e. a narrow range of atmospheric variability and land surface topography favouring the intended alteration, seem to justify weather modification. Moreover, as for systems reaching scales of large organized storms and hurricanes, required energy and control resources are well beyond existing capabilities. Consequently, the use of space technology for provision of better information on environmental change and integration of remote sensing data into weather and climate models forecasts is supported.  相似文献   
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