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1.
Spacelab permits investigation in new seicntific disciplines like material processing, life sciences, chemistry, etc. The large mass and volume capabilities of Spacelab offer better possibilities for some areas of traditional space sciences like infrared astronomy, multi-spectral solar observations and large instruments for astronomical observations.Since free-flyers will require normally a new spacecraft development for each mission, the reusability of space qualified components and experiments will be a significant cost reduction factor over a long period. In the early phase of Spacelab utilisation, however, the scaling factor introduced by Spacelab utilisation, however, the scaling factor introduced by Spacelab results in higher payload development costs than originally appreciated.The costs of Spacelab utilisation are computed and compared with those of conventional free-flying satellites. The mission implementation costs and experiment development costs are shown for both cases. The Spacelab mission implementation costs are subdivided into NASA charges for the Standard Shuttle Mission, NASA charges to fly and operate Spacelab, the European costs of Spacelab payload integration and experiment development costs. In order to evaluate and compare mission implementation costs, the simple parameters are adopted of the cost per kg of experiments and the data collection-transmission capability of Shuttle/Spacelab and ESRO/ESA satellites. The mission implementation costs turn out to be very favourable for Spacelab. The experiment development costs, which are not included in the mission implementation costs, are compared for several free flyers with the corresponding development costs for several experiments of the first Spacelab payload. The comparison shows that the cost per kg of Spacelab experiment development is about five times less than of satellite experiments.  相似文献   

2.
This article reviews the three major policy issues likely to arise from an SSP system: environmental safety, frequency allocation and prevention of interference with other frequency-using activities. Supporters of SSP must make sure that their case is heard clearly at the ITU, but they must also do more to promote public awareness of the technology's potential benefits in order to counter inappropriate use of the Precautionary Principle by anti-technology groups. The strengthening of standard-setting groups world-wide will also assist this process.  相似文献   

3.
The paper describes the basic definition and application of 'Cost Engineering' which means to design a vehicle system for minimum development cost and/or for minimum operations cost. This is important now and for the future since space transportation has become primarily a commercial business in contrast to the past where it has been mainly a subject of military power and national prestige. Several examples are presented for minimum-cost space launch vehicle configurations, such as increasing vehicle size and/or the use of less efficient rocket engines in order to reduce development and operations cost. Further a cost comparison is presented on single-stage (SSTO)-vehicles vs. two-stage launchers which shows that SSTOs have lower development and operations cost although they are larger, respectively have a higher lift-off mass than two-stage vehicles with the same performance. The design of a space tourism-dedicated launch vehicle is an extreme challenge for a cost-engineered vehicle design in order to achieve cost per seat not higher than $50,000. Finally an outlook is presented on the different options for manned Earth-to-Moon transportation modes and vehicles – another most important application of 'cost engineering', taking into account the large cost of such a future venture.  相似文献   

4.
This report summarizes the findings of a report entitled Can Power from Space Compete? produced for NASA by Resources for the Future (RFF). In considering how well satellite solar power (SSP) is likely to compete in the market for electricity from the present to 2020, it finds that neither perceived shortages of fossil fuel nor climate change factors are likely to be major issues in this time frame. Moreover, the high costs of SSP and possible concerns over public health and national security will continue to constrain its development. This does not mean, however, that R&D into the subject should cease; it may well have a future in the short term when applied to non-terrestrial systems. The full report is available at http://www.rff.org.  相似文献   

5.
The history of the deployment of nuclear reactors in Earth orbits is reviewed with emphases on lessons learned and the operation and safety experiences. The former Soviet Union's “BUK” power systems, with SiGe thermoelectric conversion and fast neutron energy spectrum reactors, powered a total of 31 Radar Ocean Reconnaissance Satellites (RORSATs) from 1970 to 1988 in 260 km orbit. Two of the former Soviet Union's TOPAZ reactors, with in-core thermionic conversion and epithermal neutron energy spectrum, powered two Cosmos missions launched in 1987 in ~800 km orbit. The US’ SNAP-10A system, with SiGe energy conversion and a thermal neutron energy spectrum reactor, was launched in 1965 in 1300 km orbit. The three reactor systems used liquid NaK-78 coolant, stainless steel structure and highly enriched uranium fuel (90–96 wt%) and operated at a reactor exit temperature of 833–973 K. The BUK reactors used U-Mo fuel rods, TOPAZ used UO2 fuel rods and four ZrH moderator disks, and the SNAP-10A used moderated U-ZrH fuel rods. These low power space reactor systems were designed for short missions (~0.5 kWe and ~1 year for SNAP-10A, <3.0 kWe and <6 months for BUK, and ~5.5 kWe and up to 1 year for TOPAZ). The deactivated BUK reactors at the end of mission, which varied in duration from a few hours to ~4.5 months, were boosted into ~800 km storage orbit with a decay life of more than 600 year. The ejection of the last 16 BUK reactor fuel cores caused significant contamination of Earth orbits with NaK droplets that varied in sizes from a few microns to 5 cm. Power systems to enhance or enable future interplanetary exploration, in-situ resources utilization on Mars and the Moon, and civilian missions in 1000–3000 km orbits would generate significantly more power of 10's to 100's kWe for 5–10 years, or even longer. A number of design options to enhance the operation reliability and safety of these high power space reactor power systems are presented and discussed.  相似文献   

6.
介绍航天行业标准《航天电子电气产品手工焊接工艺技术要求》的修订内容及修订原因与依据,并对标准的实施提出建议。  相似文献   

7.
From the start of the 20th century, a strong tradition of collaboration has developed in the physical sciences. World War II and the following period changed this situation with a quickening of the pace of application. Thus, while basic research continues to benefit from collaboration among scientists worldwide, the increasingly complex background in which science evolves, through higher implementation costs and more difficult approval processes, renders collaboration among nations ever more pressing. Space science, with its comparatively high access cost but large fundamental importance, substantial public appeal and outstanding ability to motivate young people, shares this need. This article focuses on a recent ESSC-ESF study undertaken to improve the effectiveness of such cooperative efforts. Related findings and recommendations are presented along with a proposed operational structure for their implementation.  相似文献   

8.
This paper describes and analyses the economics of a power relay system that takes advantage of recent technological advances to implement a system that is economically viable. A series of power relay systems are described which transport power ranging from 1250 to 5000 MW and distribute it to receiving sites at transcontinental distances. It is shown that, when offering electricity at prices competitive to those prevalent in developed cities in the USA, that a low IRR is inevitable, and economic feasibility of a business is unlikely. However, when the target market is Japan, where the prevalent electricity prices are much higher an IRR exceeding 65% is readily attainable. This is extremely attractive to potential investors, making capitalization of a venture likely. The paper shows that the capital investment required for the system can be less than $1 per installed watt, contributing less than 0.02 $ to the cost of energy provision. Since selling prices in feasible regions range from 0.18 to over 0.30 $, these costs are but a small fraction of the operating expenses. Thus a very large IRR is possible for such a business.  相似文献   

9.
Roger X. Lenard   《Space Policy》2001,17(4):285-289
The development and exploitation of nuclear power and propulsion represent certain didactic imperatives for human civilization. Among these are economic, epistemological, moral and commercial propositions. Developing space nuclear power and propulsion represents one future; the choice of not to pursue the course barring some breakthrough in physics represents a dramatically different future. The author argues that the time is now fortuitous for deployment and operation of nuclear propulsion and power, primarily nuclear electric propulsion, at significant levels, employing figures of merit that transcend simple cost models used to justify nuclear power sources in the past. The proposition is examined, in the light of US and UN restrictions, to ascertain how best to proceed. The author argues that viewpoints of certain vocal albeit uninformed public interest groups are typically self-serving and generally categorically incorrect; it can be asserted that these same groups do not truly represent the public interest at all. It is, therefore, necessary to present an even-handed assessment of both sides of the argument to determine the virtues and liabilities of embarking on such a developmental path. Given the imperatives mentioned, the author argues that nuclear power and propulsion for space systems is a societal necessity.  相似文献   

10.
Because the need for energy is global, and many energy networks are already interdependent, because no one country has sufficient technological capability or sufficient funds to provide a space solar powered solution on its own, and because any such solution will require international regulation, international coordination will be vital to any attempt to produce energy for Earth from space. This will be made easier by the fact that work on the subject has already been widely publicized and distributed and cooperative efforts have already been made. Various coordinating approaches are described and the need to forge partnerships between government, industry and academia — with greater involvement of all non-space groups concerned with energy — is emphasized. A “terracing approach” to the actual implementation of SPS is suggested and outlined.  相似文献   

11.
空间核动力技术概览与发展脉络初探   总被引:2,自引:0,他引:2  
在概略介绍现有技术方案基础上,初步探讨空间核动力技术的发展脉络,并分析其未来发展方向.基于固体核反应堆的空间核电源、核电推进及核热推进,是经过试验验证可行、具有一定技术基础并可预期实现空间应用的空间核动力技术.更先进的概念方案包括:基于气体核反应堆的核电源/核热推进、脉冲核爆推进、核裂变碎片推进等,它们的性能逐代跨越直至逼近理论极限.要充分利用核能的潜力,一方面需要提高单位质量核燃料的核能释放率,另一方面也需要减少核反应产物动能转换为无轨热运动的比率.核能潜力的充分利用需要以增加系统质量为代价.为满足未来宽广的空间任务需求,多物理机制驱动的大深度变工况一体化核能空间动力系统是未来必然发展趋势.  相似文献   

12.
Berg HE  Tesch PA 《Acta Astronautica》1998,42(1-8):219-230
We have developed a non-gravity dependent mechanical device, which provides resistance during coupled concentric and eccentric muscle actions, through the inertia of a spinning fly-wheel (Fly-Wheel Ergometry; FWE). Our research shows that lower-limb FWE exercise can produce forces and thus muscular stress comparable to what is typical of advanced resistance training using free weights. FWE also offers greater training stimuli during eccentric relative to concentric muscle actions, as evidenced by force and electromyographic (EMG) measurements. Muscle use of specific muscle groups, as assessed by the exercise-induced contrast shift of magnetic resonance images, is similar during lower-limb FWE and the barbell squat. Unlike free-weight exercise, FWE allows for maximal voluntary effort in each repetition of an exercise bout. Likewise, FWE exercise, not unassisted free-weight exercise, produces eccentric "overload". Collectively, the inherent features of this resistive exercise device and the results of the physiological evaluations we have performed, suggest that resistance exercise using FWE could be used as an effective exercise counter-measure in space. The flywheel principle can be employed to any exercise configuration and designed into a compact device allowing for exercises stressing those muscles and bone structures, which are thought to be most affected by long-duration spaceflight.  相似文献   

13.
14.
论述型号产品工艺文件标准化审查的范围、目标和一般程序.重点介绍型号产品工艺文件标准化的审查项目及内容要求,包括共性审查项目、工艺总方案、管理用工艺文件、主要工艺规程及更改单等,并阐明标准化审查应做好的几项管理工作.  相似文献   

15.
Commercialization of space activities requires a legal framework for private investors and entrepreneurs in order to promote and develop this sector of industry into a fully-fledged commercial enterprise. Apart from the already existing international public legal framework of space law, rules should be created to provide a level playing field for all interested parties. These rules should point to transparency of risks and liabilities and liberalization of the various space market segments. Another legal instrument will be that of dispute resolution among participants in the arena of space activities. For the more distant future the Moon Agreement should be reassessed in the light of resources exploration, management and exploitation against the background of private enterprise involvement.  相似文献   

16.
Anna Burzykowska   《Space Policy》2009,25(3):187-192
The number of states capable of building, launching and operating satellites has grown significantly over the years. This article discusses how going to space in an egalitarian fashion may influence the current state of affairs related to the militarization and weaponization of outer space, the security postures of the already established space powers, and the global balance of power in general. Potential changes in the relationship between old and new spacefarers may instigate an entire shift in the understanding of threats and opportunities for international cooperation in space.  相似文献   

17.
日本空间力量长期以来藏军于民,但却拥有宏大的工业基础和雄厚的技术支撑,空间“动员能力”很强.重点对日本空间力量部署和作战能力进行了研究,对空间力量发展规律提出看法,为应对日本国家安全战略转变提供了参考.  相似文献   

18.
Those in the space community interested in deploying space solar power (SSP) need to know whether it would make economic sense. This article aims to develop a conceptual model of the economic value of SSP as a source of power to in-space activities, such as spacecraft and space stations. We offer several estimates of the value based on interviews and published data, discuss technological innovations that may compete with or be complementary to SSP, and consider alternative institutional arrangements for government and the private sector to provide SSP.  相似文献   

19.
20.
If mankind is to explore the solar system beyond the confines of our Earth and Moon the problem of radiation protection must be addressed. Galactic cosmic rays and highly variable energetic solar particles are an ever-present hazard in interplanetary space.  相似文献   

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