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VINCI:用于阿里安5上面级的一种新型低温发动机 总被引:1,自引:0,他引:1
VINCI发动机是新一代低温上面级发动机,它将从2005-2006年起,为阿里安5火箭提供动力。基于对未来市场所需同步轨道载荷质量的展望,1998年欧空局作出决定,启动阿里安5上面级新型低温发动机的研制计划,以适应飞行器重量增加和轨道服务多样化的趋势。地球同步轨道,或适用于星座卫星的中轨道等非传统发射任务的市场份额将逐步增加。高比冲、加大推力、再起动能力,是新型VINCI发动机要实现的关键技术目标。另外,在工程时间和资源有限的情况下,研制风险的最小化,实现预期的低重复成本,也是俩个挑战性目标。两者的目的均在于保证运载器的竞争力。在过去的头两年中,设计与研制计划中的一些具有里程碑意义的目标,已经实现了。 相似文献
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《中国航天(英文版)》2017,(1)
Upper stage is an indispensable vehicle in the space transportation system.For its role in multi-satellite transportation area in China,the development of the Yuanzheng 3 upper stage was approved.The article introduces in detail the Yuanzheng 3 upper stage development requirements,task definition and systems as well as main features and performance including payload capacity and insertion accuracy for typical orbits,interfaces with satellites.The article also presents the development cycle of Yuanzheng 3 upper stage,which is divided into 3 stages including concept demonstration stage,prototype stage and flight proof stage.The Yuanzheng 3 upper stage,which will make its maiden flight in 2018,is capable of restarting more than 20 times,and operating for more than 48 hours.It is equivalent to mainstream upper stages in the world in terms of performance,such as restart times,in-orbit operation time,independent digital control system,and adaptable behavior for various tasks.Technologies tackled and accumulated in the development of the Yuanzheng 3 upper stage will lay a solid foundation for the development of future space transportation vehicles. 相似文献
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When Ariane 5 ECA development has been decided by Europe to increase Ariane 5 performance, the rule of 25 years in GTO orbit for the upper stage has been anticipated. This was 14 years ago and this rule was known to be satisfied with a perigee lower than 250 km. Even when lowering slightly Ariane 5 ECA performance, this maximum perigee altitude has been held and the whole Launch System has been developed under CNES responsibility with this GTO perigee. In the meantime, more precise calculations demonstrated that such a GTO perigee was giving for the ESCA a mean lifetime higher than 25 years. So studies are in progress inside CNES to decrease the perigee and re-enter inside the 25 years lifetime domain. This paper presents a CNES study to reduce the orbital lifetime of Ariane 5's upper stage that last in GTO after each commercial mission. Usually the aimed orbit has a perigee altitude of 250 km, an apogee altitude near to the geostationary position and an inclination between 2° and 7°. These conditions make stage's mean lifetime superior to 90 years. The CNES study is to expose the possibility to decrease this lifetime by reducing the perigee altitude of the final upper stage orbit through a passivation process optimised to produce orbit modification. It is shown that taking into account material and functional stage constraints the optimised passivation process is able to decrease the perigee by a few tenths of kilometres. 相似文献
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船只目标检测识别技术是现阶段遥感图像研究领域的一个重要发展方向。随着国产高分辨率卫星的快速发展,高分遥感卫星陆续发射,基于光学遥感图像的船只检测识别技术会逐步成为研究热门。主要介绍了近年来基于光学图片的船只检测识别技术发展、以及当前技术存在的问题。当前基于深度学习的船只目标检测识别技术取得了较好的检测效果,成为主流研究方向,但在光学遥感图像船只检测领域基于深度学习的方法有一些基本问题限制了检测效果,对这些问题进行了归纳总结,并对未来光学遥感图像船只检测技术的发展进行了展望。 相似文献
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随着地面移动通信系统的建设发展和移动互联网业务的爆发式增长,多样化的移动通信需求和应用场景不断涌现,传统的“人与人”之间的通信正在扩展向“人与物”、“物与物”的通信。物联网(internet of things, IoT)技术近年飞速发展,并已投入广泛建设和应用。卫星因其广域覆盖和抗毁性,比较适应于大区域数据采集和物联业务。近年来随着卫星通信技术能力的提升和产业链条的优化,商业航天蓬勃发展,天地一体成为趋势。天基物联网、天地融合物联网成为新的关注点。国际上近年来涌现出数十个天基物联网系统,部分已投入工程建设和应用,已在天基物联网的系统架构和体制设计上取得进展。针对卫星物联网技术发展和建设应用开展调研,对Orbcomm、Kepler、SpaceMobile、ELO等低轨星座物联网系统的建设规划、能力定位、系统架构、星座方案、通信技术、频率资源、市场应用等方面进行了全面分析,并对天基物联网星座系统的发展趋势和关键问题进行总结。 相似文献
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未来空间技术发展展望 总被引:1,自引:1,他引:1
经过近50年的发展,我国空间技术取得了举世瞩目的成就,在新的历史时期,世界航天将跨入一个新的发展高潮,我国经济社会的发展对航天事业提出了更高的要求。文章提出了我国未来航天器发展体系,介绍了未来5年我国空间技术发展的重点任务,分析了专业技术发展方向,提出了创新发展的对策建议。 相似文献
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Kyril Serafimov 《Space Policy》1985,1(4):369-378
This article analyses the patterns and trends of small countries' participation in various forms of international space cooperation. The background to formulating a national space programme is discussed, together with considerations in linking national needs, stage of development, resources and capacity with those of the international community. The need for a selective national strategy on space activities is demonstrated: efforts must be concentrated around a few reasonably selected goals, provisions for acquiring information must be maintained, and the space programme must prepare the country for rapid development in all other fields of space research and applications, if world trends require. A brief examination of Bulgaria's space activity is made. A series of advanced space investigations have been undertaken in that country, and space technology transfer and spin-offs have resulted, with valuable benefits for the society and the economy. 相似文献
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《中国航天(英文版)》2016,(2)
At an accelerating development pace, Micro-Nano Satellite technology has become one of the most active research topics in the current aerospace field. Its applications have been extended from engineering education and technology demonstration into various other fields, such as communication, remote sensing, navigation and scientific experiments just to name a few. In this paper issues raised on Micro/Nano-Satellites in recent news are reviewed and the opportunities and challenges confronting Micro/Nano-Satellites are analyzed. Then the Micro/nano-Satellites of National University of Defense Technology(NUDT) are briefly introduced. Finally, some suggestions on the development of Micro/Nano-Satellites in the future are proposed. 相似文献