共查询到17条相似文献,搜索用时 15 毫秒
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从商业航天应用的需求出发,围绕商业航天"低成本、低风险"的要求,结合航天任务本身"高技术、高风险、高投入"的特点,分析了近地轨道中不同高度、倾角下的辐射环境,给出了LEO轨道空间辐射环境需求。基于商业航天应用特点和辐射可靠性要求,建立了卫星元器件抗辐射保证的技术流程,提出了近地轨道卫星元器件抗总剂量效应、抗单粒子效应和抗位移效应的辐射指标要求。结合不同工艺结构器件辐射敏感性特征,给出了空间不同辐射效应评估的关重点及内容要求。针对卫星核心部位的关键元器件,给出了辐射风险分析和相应的抗辐射保证措施。通过某卫星型号的抗辐射保证实践,验证了该保证流程和评估技术要求。最后给出了商业卫星辐射指标以及抗辐射保证建议。 相似文献
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太阳同步轨道空间粒子辐射剂量探测与研究 总被引:2,自引:0,他引:2
利用“实践六号”A星3台辐射剂量仪2004年9月至2007年1月的在轨探测数据,对太阳活动低年,该卫星所处太阳同步轨道不同方向、不同屏蔽厚度下的辐射剂量水平及辐射剂量增长变化特性进行了分析和讨论。结果表明:空间环境扰动会导致日辐射剂量率较之空间环境宁静期有1个数量级的增长,这种增长一般滞后于空间环境扰动事件1~2天,持续时间为十几天至数十天;太阳活动低年,平均日辐射剂量率小于5rad天,与地球辐射带模型计算结果大致相当。这些结果对卫星的在轨安全保障和抗辐射加固设计都具有重要意义。 相似文献
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对地球同步轨道空间辐射环境监测及应用进行了研究。给出了持续开展的国外GOES系列卫星和国内FY-2系列卫星的地球同步轨道空间粒子辐射探测介绍,以及AE8和AP8、AE9和AP9、POLE、FLUMIC等用于地球同步轨道带电粒子辐射环境评估的经验模型发展。我国自主高能带电粒子辐射监测自20世纪90年代中后期开始,FY-2系列卫星上的带电粒子探测仪器经过了两代卫星的技术巩固和第三代卫星的创新发展,实现了更精细的能道划分并拓宽了对带电粒子辐射能谱的探测。介绍了用FY-2系列卫星获得的不同扰动状态下高能电子能谱特性,兆电子伏特级高能电子快速、缓慢增强事件,以及与GOES-13,15卫星联合应用分析高能电子不同地方时动态与太阳质子事件动态演化结果。用FY-2系列卫星获得的观测数据能准确、灵敏反映轨道空间高能带电粒子的动态变化;与GOES系列卫星的同期观测结果比较既反映出相对平静时的趋于一致性,又反映了强扰动下的显著短时局地差异,这为开展该轨道粒子辐射实测数据多星联合分析,发展磁层对扰动响应更全面、更复杂的图像,为带电粒子起源、重新分布、损失机制等深入研究提供了可能。在最新的第一代静止气象卫星FY-4卫星上,带电粒子探测仪器兼顾了能谱和方向的设计,既具备FY-2系列卫星平台高能电子、质子全能谱的探测,又增加了高能电子的多方向探测。目前除GOES系列卫星以外,仅有我国地球同步轨道系列卫星可提供持续的轨道空间粒子辐射环境长期实测记录,数据的长时间积累和信息丰富将促进地球同步轨道空间粒子辐射经验模型向更精细化的方向发展,并推动我国空间粒子辐射环境理论和自主建模研究,更好地服务于我国空间天气监测预警业务。 相似文献
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研究低轨月球卫星在月球非球形摄动和地球第三体引力摄动作用下轨道高度变化问题.首先依据Kaula准则比较分析目前国际上公认的最精确的两个重力场模型GLGM-2和LP165P,提出了在一定阶次截断重力场模型的问题,然后通过仿真不同阶次重力场模型作用下轨道高度为50km的圆形极轨道环月卫星轨道特征的变化,验证了 50km以上高度卫星非球形摄动分析时可以将重力场模型截断至一定阶次的结论,并利用截断至70阶次的重力场模型仿真得到了50km和200km圆轨道卫星无控条件下正常运行的时间.最后在仿真地球引力对200km圆轨道卫星高度影响的基础E仿真其在月球非球形和地球引力摄动作用下轨道要素变化,对低轨环月卫星轨道保持控制提供依据. 相似文献
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空间单粒子翻转(SEU)对于在轨卫星寿命和可靠性有着较大的影响,然而,针对低轨互联网卫星1000~1200 km的典型极地轨道空间SEU,目前缺少在轨试验验证结果。文章对某型号的两颗卫星在轨7个月以来的SEU事件记录数据进行处理和分析,给出互联网卫星1050~1425 km不同轨道高度上的SEU事件发生的频度、区域及概率,结合在轨运行情况提出互联网卫星在轨单粒子翻转的软硬件防护设计措施。数据表明,在当前低轨互联网卫星的典型轨道高度上,对于抗单粒子翻转阈值为0.7 MeV·cm2/mg的低阈值SRAM器件,在轨SEU事件大部分发生在SAA区域,发生概率约为7.63×10-7 bit-1·d-1。结合卫星在轨空间防护设计经验,通过加强元器件选用控制、软硬件冗余设计、关键器件限流等措施,可以有效提高低轨互联网卫星的在轨可靠性。 相似文献
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M. I. Panasyuk M. V. Podzolko A. S. Kovtyukh I. A. Brilkov N. A. Vlasova V. V. Kalegaev V. I. Osedlo V. I. Tulupov I. V. Yashin 《Cosmic Research》2017,55(2):79-87
The Earth’s radiation belts discovered at the end of the 1950s have great scientific and practical interest. Their main characteristics in magnetically quiet periods are well known. However, the dynamics of the Earth’s radiation belts during magnetic storms and substorms, particularly the dynamics of relativistic electrons of the outer belt, when Earth’s radiation belt particle fluxes undergo significant time variations, is studied insufficiently. At present, principally new experiments have been performed and planned with the intention to better study the dynamics of the Earth’s radiation belts and to operationally control the space-energy distributions of the Earth’s radiation belt particle fluxes. In this paper, for spacecraft designed to measure the fluxes of electrons and protons of the Earth’s radiation belts at altitudes of 0.5–10000 km, the optimal versions for detector orientation and orbital parameters have been considered and selected. 相似文献
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影响GEO卫星长寿命高可靠的空间环境因素及其评估、验证和保障技术研究 总被引:1,自引:1,他引:0
文章叙述了空间环境与卫星长寿命高可靠的关系,着重分析了影响GEO卫星长寿命高可靠的各种空间环境效应,如:地磁亚暴电子造成的卫星表面带电及诱导的二次放电、辐射带高能电子引起卫星内带电、太阳耀斑质子和银河宇宙射线造成的单粒子效应、空间带电粒子和太阳电磁辐照造成的辐照总剂量效应以及空间环境下敏感表面的污染效应等.文章最后给出GEO卫星空间环境效应的评估、验证和保障技术研究的必要性及其主要研究方向. 相似文献
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The paper provides a survey of novel mission concepts for continuous, hemispheric polar observation and direct-link polar telecommunications. It is well known that these services cannot be provided by traditional platforms: geostationary satellites do not cover high-latitude regions, while low- and medium-orbit Sun-synchronous spacecraft only cover a narrow swath of the Earth at each passage. Concepts that are proposed in the literature are described, including the pole-sitter concept (in which a spacecraft is stationary above the pole), spacecraft in artificial equilibrium points in the Sun–Earth system and non-Keplerian polar Molniya orbits. Additionally, novel displaced eight-shaped orbits at Lagrangian points are presented. For many of these concepts, a continuous acceleration is required and propulsion systems include solar electric propulsion, solar sail and a hybridisation of the two. Advantages and drawbacks of each mission concept are assessed, and a comparison in terms of high-latitude coverage and distance, spacecraft mass, payload and lifetime is presented. Finally, the paper will describe a number of potential applications enabled by these concepts, focusing on polar Earth observation and telecommunications. 相似文献
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V.M. Petrov 《Acta Astronautica》2011,68(9-10):1424-1429
Radiation hazard caused by exposure during a spaceflight is characterized by radiobiological consequences at all levels of organism. These consequences have a stochastic nature. Even deterministic effects are basically random quantity having all attributes of such mathematical values. The radiation risk is defined in this case as an additional probability of health damage or as a death probability in extreme case. For the manned spaceflight additional peculiarity of a human’s exposure is added. A natural space radiation environment has a stochastic character because solar particle events and crew of a spacecraft can be exposed to dose from background level up to lethal one.The report presents a procedure of radiation risk assessment for quantitative expression of radiation hazard level during a flight and using this value for developing protection recommendations. It is emphasized that the risk value is connected specifically with the time interval of possible hazard’s existent. The form of risk representation must be chosen depending on a time scale of radiobiological processes induced by the exposure (expressing in fact the radiation hazard model). Surviving function specified for the crewmember mortality rate changed by the professional exposure must be used for risk calculation. Solar particle events determine a stochastic character of radiation environment in space that must be taken into account for a risk assessment. The reliability of radiation risk assessment can be used for this goal. 相似文献
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Communications and weather satellites in geosynchronous (GEO, altitude: 35,793 km.) and geostationary orbits (GSO) are revolutionizing our ability to almost instantly communicate with each other, capture high resolution global imagery for weather forecasting and obtain a multitude of other geophysical data for environmental protection purposes. The rapid increase in the number of satellites at GEO is partly due to the exponential expansion of the internet, its commercial potential and the need to deliver a large amount of digital information in near real time. With the large number of satellites operating at GEO and particularly at GSO, there is a need to think of viable approaches to retrieve, rejuvenate and perhaps repair these satellites. The first step in this process is a detailed understanding of the ionizing radiation environment at GEO. Currently, the most widely used trapped particle radiation environment definition near Earth is based on the NASA’s static AP8/AE8 models which define the trapped proton and electron intensities. These models are based on a large number of satellite measurements carried out in the 1960s and 1970s. In this paper, the AP8/AE8 models as well as a heavy ion galactic cosmic ray (GCR) model are used to define the radiation environments for protons, electrons and heavy ions at low Earth orbit (LEO), medium Earth orbit (MEO) and GEO. LEO and MEO dosimetric calculations are included in the analysis since any launch platform capable of delivering a payload to GEO will accumulate exposure during its transit through LEO and MEO. The computational approach (particle transport) taken in this paper is to use the static LEO, MEO, GEO and geomagnetically attenuated GCR environments as input to the NASA Langley Research Center (LaRC) developed deterministic particle transport codes high charge and energy transport (HZETRN) and coupled electron photon transport (CEPTRN). This is done through exposure prediction within a spherical shell, a legacy Apollo era command service module (CSM) configuration, and a large modular structure represented by a specific configuration of the international Space Station (ISS-11A, circa 2005). Based on the results of the simulations, conclusions are drawn on the exposure levels accumulated by these geometries throughout a mission to GEO. 相似文献
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In order to explore the Moon and Mars it is necessary to investigate the hazards due to the space environment and especially ionizing radiation. According to previous papers, much information has been presented in radiation analysis inside the Earth's magnetosphere, but much of this work was not directly relevant to the interplanetary medium. This work intends to explore the effect of radiation on humans inside structures such as the ISS and provide a detailed analysis of galactic cosmic rays (GCRs) and solar proton events (SPEs) using SPENVIS (Space Environment Effects and Information System) and CREME96 data files for particle flux outside the Earth's magnetosphere. The simulation was conducted using GRAS, a European Space Agency (ESA) software based on GEANT4. Dose and equivalent dose have been calculated as well as secondary particle effects and GCR energy spectrum. The calculated total dose effects and equivalent dose indicate the risk and effects that space radiation could have on the crew, these values are calculated using two different types of structures, the ISS and the TransHab modules. Final results indicate the amounts of radiation expected to be absorbed by the astronauts during long duration interplanetary flights; this denotes importance of radiation shielding and the use of proper materials to reduce the effects. 相似文献
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