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1.
We compare a variety of mission scenarios to assess the strengths and weaknesses of options for Mars exploration. The mission design space is modeled along two dimensions: trajectory architectures and propulsion system technologies. We examine direct, semi-direct, stop-over, semi-cycler, and cycler architectures, and we include electric propulsion, nuclear thermal rockets, methane and oxygen production on Mars, Mars water excavation, aerocapture, and reusable propulsion systems in our technology assessment. The mission sensitivity to crew size, vehicle masses, and crew travel time is also examined. Many different combinations of technologies and architectures are applied to the same Mars mission to determine which combinations provide the greatest potential reduction in the injected mass to LEO. We approximate the technology readiness level of a mission to rank development risk, but omit development cost and time calculations in our assessment. It is found that Earth–Mars semi-cyclers and cyclers require the least injected mass to LEO of any architecture and that the discovery of accessible water on Mars has the most dramatic effect on the evolution of Mars exploration. 相似文献
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介绍了目前国外提出的一种三元结构的火星采样返回任务方案,整个方案分3次发射,分别发射漫游车、着陆器和轨道器,每次发射间隔为4年,最终目的是将火星样品带回地球。该方案的优势在于,通过3次发射分别完成漫游车巡视勘察、着陆器现场探测、轨道器数据中继和在轨探测,最终综合完成火星采样返回,能够极大地缓解项目进度和资金压力,充分利用每次发射窗口分步骤完成探测任务。文章重点对方案涉及的关键技术进行了分析,包括样品获取与封装、行星保护、精准着陆、漫游车的危险规避能力和移动性、火星上升器、交会与样品捕获、地球再入器技术等;对方案的前景和优势进行了探讨,并给出几点启示,如精准着陆或成为今后行星探测着陆方式的新趋势,火星采样返回任务将是人类火星探测的里程碑,今后的深空探测任务趋向国际合作模式等。 相似文献
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针对火星返回上升器由于环境等因素造成的推力器故障导致的姿态控制系统失稳而难以安全返回的严重问题,提出基于模型预测的动态容错控制再分配方法。根据推力器动态特性建立上升器推力分配模型,对模型参数误差进行实时估计从而修正分配模型,根据模型预测自适应推力再分配方法实施容错控制。同时,将推力器输出限制作为优化求解器的约束,并将推力器故障模型作为优化求解的约束域,实现最小化分配误差和最小化燃料消耗意义下的最优推力再分配。计算机仿真表明了该方法的可行性和实用性,获得了满意的结果,它能使推力器输出推力误差降低60%以上,姿态控制系统能在故障状态下3~5 s快速镇定。 相似文献
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《Space Policy》2014,30(3):163-169
The planning of human spaceflight programmes is an exercise in careful rationing of a scarce and expensive resource. Current NASA plans are to develop the new capability for human-rated launch into space to replace the Space Transportation System (STS), more commonly known as the Space Shuttle, combined with a heavy lift capability, and followed by an eventual Mars mission. As an intermediate step towards Mars, NASA proposes to venture beyond Low Earth Orbit to cis-lunar space to visit a small asteroid which will be captured and moved to lunar orbit by a separate robotic mission. The rationale for this and how to garner support from the scientific community for such an asteroid mission are discussed. Key points that emerge are that a programme usually has greater legitimacy when it emerges from public debate, mostly via a Presidential Commission, a report by the National Research Council or a Decadal Review of science goals etc. Also, human spaceflight missions need to have support from a wide range of interested communities. Accordingly, an outline scientific case for a human visit to an asteroid is made. Further, it is argued here that the scientific interest in an asteroid mission needs to be included early in the planning stages, so that the appropriate capabilities (here the need for drilling cores and carrying equipment to, and returning samples from, the asteroid) can be included. 相似文献
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Some major risks-of-failure issues for the future manned missions to Mars are discussed, with an objective to address criteria for making such missions possible, successful, safe and cost-effective. The following astronautical and instrumentation-and-equipment-reliability related aspects of the missions are considered: redundancies and backup strategies; costs; assessed probability of failure as a suitable reliability criterion for the instrumentation (equipment); probabilistic assessment of the likelihood of the mission success and safety. It is concluded that parametric risk modeling is a must for a risk-driven decision-making process. 相似文献
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冻结轨道是一种稳定的轨道,地球、火星、月球的卫星因引力场的南北不对称,都存在冻结轨道.由于主星体引力场的不同,它们卫星的冻结轨道也有不同的特性.地球卫星的冻结执道的偏心率非常小,对卫星遥感非常有利,国内外已有相当多的近地遥感卫星采用这种轨道.月球卫星的冻结轨道偏心率随轨道倾角的不同有很大的变化,对月球卫星冻结轨道的研究... 相似文献
8.
Steven D. Howe 《Space Policy》2001,17(4):275-283
The potential benefits to humankind of space exploration are tremendous. Space is not only the final frontier but is also the next marketplace. The orbital space above Earth offers tremendous opportunities for both strategic assets and commercial development. The critical obstacle retarding the use of the space around the Earth is the lack of low cost access to orbit. Further out, the next giant leap for mankind will be the human exploration of Mars. Almost certainly within the next 30 years, a human crew will brave the isolation, the radiation, and the lack of gravity to walk on and explore the Red planet. Both of these missions will change the outlook and perspective of every human being on the planet. However, these missions are expensive and extremely difficult. Chemical propulsion has demonstrated an inability to achieve orbit cheaply and is a very high-risk option to accomplish the Mars mission. An alternative solution is to develop a high performance propulsion system. Nuclear propulsion has the potential to be such a system. The question will be whether humanity is willing to take on the challenge. 相似文献
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The human exploration of multiple deep space destinations (e.g. Cis-Lunar, NEAs), in view of the final challenge of sending astronauts to Mars, represents a current and consistent study domain especially in terms of its possible scenarios and mission architectures assessments, as proved by the numerous on-going activities about this topic and moreover by the global exploration roadmap. After exploring and analysing different possible solutions to identify the most flexible path, a detailed characterisation of several Design Reference Missions (DRMs) represents a necessity in order to evaluate the feasibility and affordability of deep space exploration missions, specifically in terms of enabling technological capabilities.The study presented in this paper was aimed at defining an evolutionary scenario for deep space exploration in the next 30 years with the final goal of sending astronauts on the surface of Mars by the end of 2030 decade. Different destinations were considered as targets to build the human exploration scenario, with particular attention to Earth–Moon Lagrangian points, NEA and Moon. For all the destinations selected as part of the exploration scenario, the assessment and characterisation of the relative Design Reference Missions were performed. Specifically they were defined in terms of strategies, architectures and mission elements. All the analyses were based on a pure technical approach with the objective of evaluating the feasibility of a long term strategy for capabilities achievement and technological development to enable future space exploration.This paper describes the process that was followed within the study, focusing on the adopted methodology, and reports the major obtained results, in terms of scenario and mission analysis. 相似文献
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Conceptual study of Mars Aeroflyby Sample Collection (MASC) is conducted as a part of the next Mars exploration mission currently entertained in Japan Aerospace Exploration Agency. In the mission scenario, an atmospheric entry vehicle is flown into the Martian atmosphere, collects the Martian dust particles as well as atmospheric gases during the guided hypersonic flight, exits the Martian atmosphere, and is inserted into a parking orbit from which a return system departs for the earth to deliver the dust and gas samples. In order to accomplish a controlled flight and a successful orbit insertion, aeroassist orbit transfer technologies are introduced into the guidance and control system. System analysis is conducted to assess the feasibility and to make a conceptual design, finding that the MASC system is feasible at the minimum system mass of 600 kg approximately. The aerogel, which is one of the candidates for the dust sample collector, is assessed by arcjet heating tests to examine its behavior when exposed to high-temperature gases, as well as by particle impingement tests to evaluate its dust capturing capability. 相似文献
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Ehlmann BL Chowdhury J Marzullo TC Collins RE Litzenberger J Ibsen S Krauser WR DeKock B Hannon M Kinnevan J Shepard R Grant FD 《Acta Astronautica》2005,56(9-12):851-858
Mars is a compelling astrobiological target, and a human mission would provide an opportunity to collect immense amounts of scientific data. Exploration alone, however, cannot justify the increased risk. Instead, three factors drive a human mission: economics, education, and exploration. A human mission has a unique potential to inspire the next generation of young people to enter critically needed science and engineering disciplines. A mission is economically feasible, and the research and development program put in place for a human mission would propel growth in related high-technology industries. The main hurdles are human physiological responses to 1–2 years of radiation and microgravity exposure. However, enabling technologies are sufficiently mature in these areas that they can be developed within a few decade timescale. Hence, the decision of whether or not to undertake a human mission to Mars is a political decision, and thus, educational and economic benefits are the crucial factors. 相似文献
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The Japan Aerospace Exploration Agency is currently developing the second asteroid sample return mission, designated as Hayabusa 2. Following the successful return of Hayabusa from the asteroid “Itokawa”, Hayabusa 2 is designed as a round-trip mission to the asteroid “1999 JU3”. The 1999 JU3 is a C-type asteroid, which is believed to contain organic matter and hydrated minerals. Thus, it is expected that successful sample collection will provide additional knowledge on the origin and evolution of the planets and, in particular, the origin of water and organic matter. The current mission scenario will enable the spacecraft to reach 1999 JU3 in the middle of 2018 and perform an asteroid proximity operation for 1.5 years. Three touch downs for sampling and one 2-m-class crater generation by means of a high-speed impact operation are planned during the asteroid proximity operation. The samples are to be brought back to the Earth by a re-entry capsule. The present paper describes the system design of Hayabusa 2, some key technical challenges of the mission, and the development status. 相似文献
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美国火星表面探测使命述评(下) 总被引:2,自引:2,他引:2
从1975年8月发射(1976年7月着陆火星)的海盗-1探测器以来,美国已成功执行了6次火星表面探测使命,即海盗-1与海盗-2轨道器/着陆器,"火星探路者"(MPF)着陆器/巡游车,"勇气"与"机遇"火星探测巡游车(MER),以及"凤凰"着陆器;而推迟到2011年发射的火星科学实验室(MSL)将火星着陆技术与表面巡游车技术推向一个新的高度。从"海盗"着陆器到MSL"好奇心"巡游车、美国历经三种火星着陆系统与三代火星表面巡游车技术的发展。三种着陆系统为着陆腿着陆系统("海盗"与"凤凰"),气囊着陆系统(MPF与MER),以及空中吊机着陆系统(MSL)。三代巡游车为MPF"旅居者"巡游车、MER"勇气"与"机遇"巡游车,以及MSL"好奇心"巡游车。现在,美国在火星进入、降落与着陆(EDL)运作与表面避障移动方面,已达到技术成熟与先进的水平,满足安全着陆与表面移动探测的要求。文章阐述美国上述七项火星表面探测使命的立项背景、科学目标与有效载荷、飞行系统组成,以及飞行运作程序;分析美国火星着陆技术与表面巡游车技术的发展。 相似文献
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火星探测的主要科学问题 总被引:5,自引:5,他引:5
在太阳系的行星中,火星与地球之间存在最多的相似之处,因此,火星是一颗承载人类最多梦想的星球。火星有水和生命存在的问题,激发了人类火星探索的好奇心,成为人类持续探测火星的推动力。火星的起源和演化与太阳系形成过程的关系,火星与类地行星的共性和特性,是当代行星科学研究的重要内容。为了人类社会的可持续发展,火星可否改造成为适宜人类居住的绿色星球——这些是人类在火星探测中必须面对的重大科学问题。只有这些重大科学问题被一一解答,我们才能清晰地去思考地球和人类自身的未来! 相似文献
17.
美国火星表面探测使命述评(上) 总被引:3,自引:1,他引:3
从1975年发射(1976年着陆火星)的海盗-1探测器以来,美国已成功执行了6次火星表面探测使命,即海盗-1与海盗-2轨道器/着陆器,"火星探路者"(MPF)着陆器/巡游车,"勇气"与"机遇"火星探测巡游车(MER),以及"凤凰"着陆器;而推迟到2011年发射的"好奇心"火星科学实验室(MSL)将火星着陆技术与表面巡游车技术推向一个新的高度。从"海盗"着陆器到"好奇心"巡游车、美国历经三种火星着陆系统与三代火星表面巡游车技术的发展。三种着陆系统为着陆腿着陆系统("海盗"与"凤凰"),气囊着陆系统(MPF与MER),以及空中吊机着陆系统(MSL)。三代巡游车为MPF"旅居者"巡游车、MER"勇气"与"机遇"巡游车,以及MSL"好奇心"巡游车。现在,美国在火星进入、降落与着陆(EDL)运作与表面避障移动方面,已达到技术成熟与先进的水平,满足安全着陆与表面移动探测的要求。文章阐述美国上述七项火星表面探测使命的立项背景、科学目标与有效载荷、飞行系统组成,以及飞行运作程序;分析美国火星着陆技术与表面巡游车技术的发展。 相似文献
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《Space Policy》2014,30(3):149-155
The Global Exploration Roadmap reflects the collaborative effort of twelve space agencies to define a long-term human space exploration strategy which provides substantial benefits for improving the quality of life on Earth and is implementable and sustainable. Such a strategy is a necessary precondition to the government investments required to enable the challenging and rewarding missions that extend human presence into the solar system. The article introduces the international strategy and elaborates on NASA's leadership role in shaping that strategy. The publication of the roadmap, a reflection of the space landscape and multilateral agency-level dialog over the last four years, allows NASA to demonstrate its commitment to leading a long-term space exploration endeavor that delivers benefits, maintains strategic human spaceflight capabilities and expands human presence in space, with human missions to the surface of Mars as a driving goal. The road mapping process has clearly demonstrated the complementary interests of the participants and the potential benefits that can be gained through cooperation among nations to achieve a common goal. The present US human spaceflight policy is examined and it is shown that the establishment of a sustainable global space exploration strategy is fully consistent with that policy. 相似文献
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月球取样返回器回收半实物仿真系统是通过模拟返回器取压孔附近压力环境,将回收程控装置硬件实物接入仿真系统并构成实时仿真回路的半实物仿真平台。文章介绍了月球取样返回器回收半实物仿真系统的研制意义,对系统总体结构和设计方案、网络环境、运行流程和新的设计特点进行概括,在面向对象的基础上建立了分阶段的月球取样返回器降落伞回收系统整个工作过程的动力学模型,利用空投试验测量数据对模型的仿真精度进行验证分析,并对半实物仿真系统的实时性和压力模拟精度进行了分析。结果表明,半实物仿真系统的各项技术参数均达到设计指标,可为中国探月工程三期中月球取样返回器回收分系统的可靠性评估提供重要的技术支持。 相似文献