Meditations on the new space vision: the Moon as a stepping stone to Mars

The Vision for Space Exploration invokes activities on the Moon in preparation for exploration of Mars and also directs International Space Station (ISS) research toward the same goal. Lunar missions will emphasize development of capability and concomitant reduction of risk for future exploration of Mars. Earlier papers identified three critical issues related to the so-called NASA Mars Design Reference Mission (MDRM) to be addressed in the lunar context: (a) safety, health, and performance of the human crew; (b) various modalities of mission operations ranging surface activities to logistics, planning, and navigation; and (c) reliability and maintainability of systems in the planetary environment. In simple terms, lunar expeditions build a résumé that demonstrates the ability to design, construct, and operate an enterprise such as the MDRM with an expectation of mission success. We can evolve from Apollo-like missions to ones that resemble the complexity and duration of the MDRM. Investment in lunar resource utilization technologies falls naturally into the Vision. NASA must construct an exit strategy from the Moon in the third decade. With a mandate for continuing exploration, it cannot assume responsibility for long-term operation of lunar assets. Therefore, NASA must enter into a partnership with some other entity--governmental, international, or commercial--that can responsibly carry on lunar development past the exploration phase.     

A socio-economic evaluation of the lunar environment and resources: II. Energy for the selenosphere

This first of several study papers, based on a fundamental paper presented in 1972, provides an independent conceptual analysis and evaluation of the lunar environment as industrial base and habitat. A selenosphere system strategy is outlined. The underlying concept is that of one or several lunar industrial zones for resource extraction and on-surface processing, integrated with a circumlunar zero-g processing capability, serving markets in geolunar space. A classification of lunar elements by utilization category is presented. Lunar oxygen is a prime candidate for being an initial economic “drawing card”, because of its value for fast transportation in geolunar space, requiring significantly fewer ships for equal transfer capability per unit time than electric transports which, however, have value, especially between geosynchronous and lunar orbit. The reduced development difficulties of controlled fusion outside the atmosphere and its advantages for extracting oxygen and other elements in quantity are summarized. Examples of lunar cycle management as fundamental exoindustrial requirement for economic resource enhancement are presented. The principal initial socio-economic value of lunar industry lies in the use of lunar resources for exoindustrial products and operations designed to accelerate, intensify and diversify Earth-related benefits. In the longer run, lunar settlements are a highly suitable proving ground for studying and testing the complex matrix of technological, biological, cultural, social and psychological aspects that must be understood and manageable before large settlements beyond Earth can have a realistic basis for viability. The lunar environment is more suitable for experimentation and comparatively more “forgiving” in case of failures than is orbital space.     

Stepping stones to the future: Achieving a sustainable lunar outpost

The current emphasis in the US and internationally on lunar robotic missions is generally viewed as a precursor to possible future human missions to the Moon. As initially framed, the implementation of high level policies such as the US Vision for Space Exploration (VSE) might have been limited to either human lunar sortie missions, or to the testing at the Moon of concepts-of-operations and systems for eventual human missions to Mars [White House, Vision for Space Exploration, Washington, DC, 14 January, 2004. [1]]. However, recently announced (December 2006) US goals go much further: these plans now place at the center of future US—and perhaps international—human spaceflight activities a long-term commitment to an outpost on the Moon.Based on available documents, a human lunar outpost could be emplaced as early as the 2020–2025 timeframe, and would involve numerous novel systems, new technologies and unique operations requirements. As such, substantial investments in research and development (R&D) will be necessary prior to, during, and following the deployment of such an outpost. It seems possible that such an outpost will be an international endeavor, not just the undertaking of a single country—and the US has actively courted partners in the VSE. However, critical questions remain concerning an international lunar outpost. What might such an outpost accomplish? To what extent will “sustainability” be built into the outpost? And, most importantly, what will be the outpost's life cycle cost (LCC)?This paper will explore these issues with a view toward informing key policy and program decisions that must be made during the next several years. The paper will (1) describe a high-level analytical model of a modest lunar outpost, (2) examine (using this model) the parametric characteristics of the outpost in terms of the three critical questions indicated above, and (3) present rough estimates of the relationships of outpost goals and “sustainability” to LCC. The paper will also consider possible outpost requirements for near-term investments in enabling research in light of experiences in past advanced technology programs.     

月球重力场环境对月球卫星轨道影响分析

文章分析了月球复杂的重力场环境对月球卫星轨道运行的影响。通过月球卫星冻结轨道与地球卫星冻结轨道的对比分析,结果表明月球重力场存在较大异常,并由此引起月球卫星轨道发生较大漂移。另外,月球冻结轨道在带谐项影响下还存在中等周期的漂移,仅简单考虑带谐项系数无法求得完美的月球冻结系数。由于月球重力场异常对绕月卫星的影响与地球轨道卫星情况相比存在很大差异,因此月球轨道卫星的长期运行与控制策略的设计必须充分考虑此影响。     

月面巡视探测器地面试验方法与技术综述

“嫦娥三号”任务的圆满完成标志着我国已经突破了软着陆、巡视勘察、月夜生存等一系列深空探测关键技术。由于任务目标以及月面环境的复杂性,对巡视器的地面试验验证工作提出了很高的要求。在研制过程中,不但开展了常规航天器必做的试验项目,还开展了大量的专项试验,充分的地面试验对确保任务的成功发挥了重要作用。文章对“嫦娥三号”巡视器的地面验证需求、验证试验要求、验证试验实施情况进行了分析和总结,主要包括低重力模拟、月表地形地貌模拟、工程模拟月壤的制备与整备、光照环境模拟、月尘模拟等方面,对深空探测器试验方法与技术的发展方向提出了建议。     

Lunar exploration and development--a sustainable model

A long-term goal of space exploration is the development of a lunar settlement that will not only be largely self-sufficient but also contribute to the economy of the Earth-Moon system. Proposals for lunar mining and materials processing developments, as well as tourism-based applications, have appeared in the literature for many years. However, so great are the technical and financial difficulties associated with sustained lunar development that, more than 30 years after the end of the Apollo programme, there have been no practical advances towards this goal. While this may soon be remedied by a series of proposed unmanned orbiters, landers and rovers, the philosophy of lunar exploration and development remains the same as it has for decades: conquer, exploit, and ignore the consequences. By contrasting the well-recognised problems of Earth orbital debris and the barely recognised issue of intentional spacecraft impacts on the lunar surface, this paper illustrates the need for a new model for lunar exploration and development. This new paradigm would assign a value to the lunar environment and provide a balance between protection and exploitation, creating, in effect, a philosophy of sustainable development for the Moon. It is suggested that this new philosophy should be an integral part of any future strategy for lunar colonisation.     

应用计算几何的月面太阳辐照度仿真模型

月面太阳辐照度对月面环境分析、月面巡视器设计具有重要意义。文章提出了一种应用计算几何的月面任意位置太阳辐照度仿真模型。首先,计算太阳、地球等天体相对月面点的位置;然后,将各天体投影至以月面点为球心的天球球面,并通过裁剪运算和二维布尔运算得到太阳未被遮挡的形状;最后,利用太阳可见面积对理想太阳辐照度模型进行修正,得到通用的模型。为验证提出模型的有效性,将仿真结果与STK软件进行比较。结果表明,文章中的模型综合考虑了地球、月面等多种因素对太阳辐射的耦合影响,其与STK软件获得的结果相比,更符合真实的太阳光照状态。     

Strategies of developing advanced lunar power systems

Electric and thermal power have to be available at the base site on the lunar surface before the first lunar crew arrives. Unlimited solar energy is available during the lunar day, but this must be stored for use during the lunar night unless nuclear energy systems are available. State-of-the-art candidate systems are reviewed and the production of solar cells on the moon is discussed. Various options for developing a lunar power plant are proposed. These must be simulated and optimized in a real lifecycle systems scenario to provide operations and cost data essential for choosing a strategy.     

Strategies of developing advanced lunar power systems

Electric and thermal power have to be available at the base site on the lunar surface before the first lunar crew arrives. Unlimited solar energy is available during the lunar day, but this must be stored for use during the lunar night unless nuclear energy systems are available. State-of-the-art candidate systems are reviewed and the production of solar cells on the moon is discussed. Various options for developing a lunar power plant are proposed. These must be simulated and optimized in a real life-cycle systems scenario to provide operations and cost data essential for choosing a strategy.     

Introduction to Japanese exploration study to the moon

The Japan Aerospace Exploration Agency (JAXA) views the lunar lander SELENE-2 as the successor to the SELENE mission. In this presentation, the mission objectives of SELENE-2 are shown together with the present design status of the spacecraft. JAXA launched the Kaguya (SELENE) lunar orbiter in September 2007, and the spacecraft observed the Moon and a couple of small satellites using 15 instruments. As the next step in lunar exploration, the lunar lander SELENE-2 is being considered. SELENE-2 will land on the lunar surface and perform in-situ scientific observations, environmental investigations, and research for future lunar utilization including human activity. At the same time, it will demonstrate key technologies for lunar and planetary exploration such as precise and safe landing, surface mobility, and overnight survival. The lander will carry laser altimeters, image sensors, and landing radars for precise and safe landing. Landing legs and a precisely controlled propulsion system will also be developed. A rover is being designed to be able to travel over a wide area and observe featured terrain using scientific instruments. Since some of the instruments require long-term observation on the lunar surface, technology for night survival over more than 2 weeks needs to be considered. The SELENE-2 technologies are expected to be one of the stepping stones towards future Japanese human activities on the moon and to expand the possibilities for deep space science.     

A gateway for human exploration of space? The weak stability boundary

NASA's plans for future human exploration of the Solar System describe only missions to Mars. Before such missions can be initiated, much study remains to be done in technology development, mission operations and human performance. While, for example, technology validation and operational experience could be gained in the context of lunar exploration missions, a NASA lunar program is seen as a competitor to a Mars mission rather than a step towards it. The recently characterized weak stability boundary in the Earth–Moon gravitational field may provide an operational approach to all types of planetary exploration, and infrastructure developed for a gateway to the Solar System may be a programmatic solution for exploration that avoids the fractious bickering between Mars and Moon advocates. This viewpoint proposes utilizing the concept of Greater Earth to educate policy makers, opinion makers and the public about these subtle attributes of our space neighborhood.     

Towards a lunar base programme

When the requisite technology exists, the US political process will inevitably include lunar surface activities as a major space objective. This article examines a manned lunar base in terms of three distinct functions: the scientific investigation of the Moon and its environment; development of the capability to use lunar resources for beneficial purposes throughout the Earth-Moon systems; and conduct of R&D leading to a self-sufficient and self-supporting manned lunar base. Three scenarios are outlined with respect to each possible function.     

Further analyses of the slide lander and of drop delivery systems for improved lunar surface access

The paper discusses two methods for lunar surface access. One method is characterized by very little propellant consumption for landing (lunar slide lander, LSL); the other (drop delivery method, DDM) avoids release of propellant gases at the lunar surface. The LSL is of particular promise and importance. Its analysis and development introduces a new field of cosmic dynamics—harenodynamics, the science and technology of interaction of surfaces with dust and sand at near-orbital speeds down to low velocities. Although the data base is small so far and needs to be enlarged, analyses of the LSL so far indicate promise as to feasibility. Its realization will revolutionize present conventional concepts of lunar development. The DDM offers cost-effective alternatives to conventional lunar landing by retrothrust, but on a more selective basis, because propellant-savings are secondary to avoiding gas releases into the lunar high-vacuum environment. It was found that stationary energy absorption systems (EAS) are required, because vehicle-attached absorption systems are entirely inadequate. This requires large structures which can be built on the lunar surface only after a somewhat higher degree of industrial capability has been established. However, they can be built entirely of lunar materials. Altogether, the LSL is the more significant of the two both in terms of economy and of operational scope.     

100 kWe月面核电站方案研究

随着太空探索活动的深入开展,在月球表面建立有人基地成为必然选择。与常规化学能或太阳能相比,月面核电源具有诸多优点,是月球基地的最佳能源选择之一。本文提出了电功率100 kWe的核反应堆电源系统方案,给出了该方案的关键系统参数。针对反应堆模块,展开方案选型、参数优化、常规物理参数分析、初步热工分析和特种临界安全分析等工作。计算结果显示:燃料包壳温度小于使用限值,掉落事故工况下有效增值因数均小于0.98。该设计方案满足各项技术指标和设计准则。     

再入航天器陶瓷拐角环防热计算与结构适用性分析

文章基于近地轨道及探月返回再入热环境,应用超高温陶瓷到再入航天器的典型防热结构,计算分析了再入过程中的防热结构温度场。利用温度场计算结果,再结合超高温陶瓷抗烧蚀性能以及结构设计与工艺性分析,就超高温陶瓷作为再入航天器防热结构的适用性进行了深入探讨。结果表明,由于超高温陶瓷的优良耐高温及耐烧蚀性能,在近地轨道及探月返回再入航天器防热结构上具有良好的应用前景。     

月面和近月空间环境及其影响

月球探测器所经历的月面和近月空间环境主要包括：月面低重力、月面温度、近月空间辐射、月壤、月尘、月面地形地貌、月面静电等。文章在对月面和近月空间环境研究的基础上,结合国外月球探测器在月球环境方面的研究成果,分析了我国月球探测器所经历的月面和近月空间环境特点及其影响效应,并提出相应的改进措施或必要的试验验证,可为月球探测器的研制提供参考。     

A socio-economic evaluation of the lunar environment and resources—III: Selenospheric economics and cislunar/terrestrial market analysis

Geosocio-economically useful lunar development requires adoption of a development strategy designed to balance investments and returns as attractively as possible. This paper deals with a systematic approach to developing early and profitable returns through an appropriate investment strategy and through cislunar and terrestrial market research. In addition, long-term aspects are outlined, including the production of helium-3 for terrestrial fusion power plants and of water from fusion products and lunar oxygen.     

着陆冲击仿真月壤本构模型及有限元建模

为建立合理的月壤有限元模型用于着陆器着陆冲击动力学仿真分析,在对已知月壤的相关力学特性参数和试验数据进行分析推理的基础上,推断出月壤屈服面在低围压条件下可能会呈现出剪切膨胀特性,而在高围压条件下则可能会呈现出塑性压缩和应变硬化特性,因此定性地选择帽盖德鲁克-普拉格（Cap Drucker-Prager,CDP）模型作为月壤本构模型。模型的参数通过月壤或模拟月壤的试验数据定量地标定。对着陆器地面着陆冲击试验进行有限元建模和仿真分析,仿真结果表明：模型参数的标定方法是合理可行的;CDP模型可以准确模拟月壤在着陆冲击载荷下的动力学响应,可用于着陆冲击动力学仿真月壤有限元建模。对月壤模型参数进行了参数分析,并评估了月壤模型参数对着陆器着陆冲击性能的影响。     

月亮女神探月计划及对我国月球与深空探测的思考

日本月亮女神月球探测器在顺利完成各项探测任务后,于北京时间2009年6月11日受控落月.该探月计划在一箭三星组网探测月球背面重力场、有效载荷创新设计、科研活动组织、成果产出、公众参与和科普宣传等方面有许多亮点,对我国探月工程有重要参考价值.文章综合回顾、分析和评述了月亮女神探月计划的任务、探测器、轨道与飞控、重要事件等...     

开发月球车用的月表环境的地面模拟方法研究

当前中国正在进行自己的探月工程,预计将会发射月球车登陆月球表面.在研制月球探测器过程中,为了在地面验证月球车的可靠性和各项功能(如着陆冲击、自主巡航和遥控),必须建立相应的地面试验中心.根据目前对月球表面环境的认识和现有的仿真技术,文章提出了实现月表综合环境模拟的试验设施的设想.由于月球表面环境非常恶劣并且月表的地形也非常复杂,文章提出了一种组合式月表环境模拟器的设想.主要部分是模拟各种月貌特征(如陨石坑、斜坡、沟壑等)的可移动单元.每个单元是一个用模拟月壤制作的小沙盘,其化学成分、组成颗粒分布和力学性能和已经获取的真实月壤样品相似.根据不同的试验要求,选择相应的单元按照一定的规律组合成为试验场.这样在有限的场地面积内可以按需实现对月表不同地域的地貌特征模拟.同时,可以选择少量单元的组合构成更小规模的试验场,以方便与其它环境模拟器(如落塔,热/真空容器等)联合,实现模拟月表的综合环境.