Impacts and evolution: future prospects

The discipline of astrobiology includes the dynamics of biological evolution. One of the major ways that the cosmos influences life is through the catastrophic environmental disruptions caused when comets and asteroids collide with a planet. We now recognize that such impacts have caused mass extinctions and played a major role in determining the evolution of life on Earth. The time-averaged impact flux as a function of projectile energy can be derived from lunar cratering statistics as well as the current population of near Earth asteroids (NEAs). Effects of impacts of various energies can be modeled, using data from historic impacts [such as the Cretaceous-Tertiary (KT) impactor 65 million years ago] and the observed 1994 bombardment of Jupiter by fragments of Comet Shoemaker-Levy 9. It is of particular interest to find from such models that the terrestrial environment is highly vulnerable to perturbation from impacts, so that even such a small event as the KT impact (by a projectile 10-15 km in diameter) can lead to a mass extinction. Similar considerations allow us to model the effects of still smaller (and much more likely) impacts, down to the size of the asteroid that exploded over Tunguska in 1908 (energy approximately 10 megatons). Combining the impact flux with estimates of environmental and ecological effects reveals that the greatest contemporary hazard is associated with impactors near 1 million megatons in energy (approximately 2 km in diameter for an asteroid). The current impact hazard is significant relative to other natural hazards, and arguments can be developed to illuminate a variety of public policy issues. The first priority in any plan for defense against impactors is to survey the population of Earth-crossing NEAs and project their orbits forward in time. This is the purpose of the Spaceguard Survey, which has already found more than half of the NEAs >1 km in diameter. If there is an NEA on a collision course with Earth, it can be discovered and the impact predicted with decades or more of warning. It is then possible to consider how to deflect or disrupt the NEA. Unlike other natural hazards, the impact risk can be largely eliminated, given sufficient advanced knowledge to take action against the threatening projectile.     

Contemporary Czech space policy and its future prospects

Czechoslovakia was the third nation to have a citizen in space when Vladimir Remek flew in 1978. It was present at the formulation of international space law principles and ran some space-related projects within Intercosmos. The Czech Republic reassumed this tradition after Czechoslovakia was dissolved in 1993. There are no special funds to support space R&D. Hence, participants must compete for R&D resources with companies from other areas of industry. This improves their competitiveness. Czech society is broadly interested in space-related activities. The graduate system structure reflects this. Not only can one study space-related courses at technical universities but international space law is an obligatory part of international public law courses in the Czech Republic. Strong support for space activities is mirrored in the institutional fragmentation of this sphere. Competences in space applications are distributed among some 20 institutions and organizations. This status harms the Czech potential in space activities and R&D. The Czech Republic became a member of ESA in 2008 but Czech companies have not taken advantage of the full potential of membership. Participation in international projects is very important for a small post-communist economy because economic growth is based on convergence towards developed countries, which may dissipate after 2020. Now is the right time to strengthen the primary research that will establish a strong foundation for innovation-based economic growth.     

Return to the Moon: A sustainable strategy

On 14 January 2004 President George Bush announced his vision for space exploration, to include a human return to the Moon. He argued that, with a moderate increase in NASA's annual expenditure, such a return was possible. This paper is an exploration of how the President's space initiative can be realised on an international co-operative basis along similar lines to those already existing with the international space station (ISS). By abandoning the concept of a lunar landing as the major goal of a lunar programme, the initiative is made feasible. The three-stage plan here presented meshes with the currently evolving plans for the US space initiative to provide a realistic, affordable and sustainable strategy for manned lunar exploration. It represents a significant opportunity for the USA to unite and lead the world on this grand, civilisation defining adventure.     

通向月球之路

通向月球的路是漫长的。从现在起,有针对性地对空间探测理论与技术进行研究是非必需的。本文对月球探测轨道作一介绍,利用借力飞行和WSB转移,减少轨道机动所需的△V,从而减少发射费用,这对支持长期的持续的空间探测是非常必要的。离子推进推力器是空间探测用推进器的理想选择,应继续进行研究,并进行飞行试验验证。     

The men who sold the Moon: science fiction or legal nonsense?

Previously the exclusive domain of science-fiction novels, the sale of extraterrestrial real estate has nowadays become a favourite feature of tabloid reports. This article critically analyses and dismantles with legal arguments the issue of the sale of extraterrestrial land, after having outlined some of the trivial claims of ownership of celestial bodies. From Dennis Hope's lunar claim to the alleged Martian trespass by NASA's Pathfinder, the only consequence these claims have on the legal plane is to highlight the need for better regulation of extraterrestrial landed property rights.     

双星探月，美欲重返月球

北京时间2009年6月19日凌晨5点,NASA发射两颗卫星探月。这是美国“重返月球”计划的第一步。美国是最先探索月球的国家之一。从卫星“绕月”到“阿波罗”飞船首次登月,再到如今“重返月球”计划中建立永久性月球基地,美国的月球探索已进入更深屡次。月球,田其独特的空间位置,被美国视为太空探索的重要跳板。     

美探测器成功撞击月球

NASA的“月坑观测与探测卫星”（LCROSS）探测器及随行的“半人马座”火箭上面级10月9日成功地对月球表面进行了两次撞击。NASA称．科学家们将对探测器上的仪器所采集的数据进行分析．以判断是否有水存在。撞击目标是月球南极一座终年不见阳光的月坑．称为卡比厄斯。     

Estimation of radiation risk for astronauts on the Moon

The problem of estimating the risk of radiation for humans on the Moon is discussed, taking into account the probabilistic nature of occurrence of solar particle events. Calculations of the expected values of tissue-averaged equivalent dose rates, which are created by galactic and solar cosmic-ray particle fluxes on the lunar surface behind shielding, are made for different durations of lunar missions.     

Chandrayaan-1 mission to the Moon

Chandrayaan-1 is the first Indian planetary exploration mission that will perform remote sensing observation of the Moon to further our understanding about its origin and evolution. Hyper-spectral studies in the 0.4– region using three different imaging spectrometers, coupled with a low energy X-ray spectrometer, a sub-keV atom analyzer, a 3D terrain mapping camera and a laser ranging instrument will provide data on mineralogical and chemical composition and topography of the lunar surface at high spatial resolution. A low energy gamma ray spectrometer and a miniature imaging radar will investigate volatile transport on lunar surface and possible presence of water ice in the polar region. A radiation dose monitor will provide an estimation of energetic particle flux en route to the Moon as well as in lunar orbit. An impact probe carrying a mass spectrometer will also be a part of the spacecraft. The 1 ton class spacecraft will be launched by using a variant of flight proven indigenous Polar Satellite Launch Vehicle (PSLV-XL). The spacecraft will be finally placed in a 100 km circular polar orbit around the Moon with a planned mission life of two years.     

Conference round-up: Space,defence and trips to the Moon

What are the trends in missile defence, the perceptions of space and defence in society and the now emergent commercial human spaceflight industry? Europe seems stuck in a financial rut and unable to fashion a united approach, the USA and Russia have not acknowledged the need to understand the issues in a context broader than that of a bilateral debate over the intentions of Iran, and a growing number of companies is getting serious about taking paying customers into space. This report covers the Royal United Services Institute (RUSI) Missile Defence Conference 2012; the RUSI Defence, Industries and Society Conference 2012 and the third European Space Tourism Conference held at the Royal Aeronautical Society in July, all in London.     

嫦娥1号的奔月之路

从地球到月球不但距离遥远,将近40万公里,而且月球自身还在围绕地球进行公转,平均运动速度1.023公里/秒。因此,     

Chang'e 2's Journey to the Moon

<正>OCTOBER 1:INITIAL STAGE OF THE FLIGHT TO THE mOON At 18:59,October 1,2010,a LM-3C launch vehicle blasted off from the Xichang Satellite Launch Center (XSLC) and precisely placed China's second lunar probe Chang'e 2 into the Earth-moon transfer orbit. Chang'e 2 began its 112-hour journey to the moon and the second phase of China Lunar Exploration Program was formally started.     

嫦娥二号的奔月之旅

<正>10月1日:踏上奔月之旅10月1日18时59分,长征三号丙运载火箭从西昌卫星发射中心豪迈出征,将中国探月工程二期的先导星——嫦娥二号卫星准确送入地月转移轨道。嫦娥二号卫星踏上了     

The International Space Station: a pathway to the future

Nearly six years after the launch of the first International Space Station element, and four years after its initial occupation, the United States and our 6 international partners have made great strides in operating this impressive Earth orbiting research facility. This past year we have done so in the face of the adversity of operating without the benefit of the Space Shuttle. In his January 14, 2004, speech announcing a new vision for America's space program, President Bush affirmed the United States' commitment to completing construction of the International Space Station by 2010. The President also stated that we would focus our future research aboard the Station on the long-term effects of space travel on human biology. This research will help enable human crews to venture through the vast voids of space for months at a time. In addition, ISS affords a unique opportunity to serve as an engineering test bed for hardware and operations critical to the exploration tasks. NASA looks forward to working with our partners on International Space Station research that will help open up new pathways for future exploration and discovery beyond low Earth orbit. This paper provides an overview of the International Space Station Program focusing on a review of the events of the past year, as well as plans for next year and the future.     

月球探测技术--奔月变轨过程自旋稳定指向控制

根据月球探测器奔月变轨过程中自旋稳定各阶段的特点,提出了分阶段进行主动章动、进动控制的策略和方法。对影响自旋稳定指向精度的因素和控制方法进行了研究。数学仿真结果表明:起旋推力器推力偏差是引起章动的主要因素;质量不平衡和能量耗散引起的章动很小,初步设计时可略去不计。采用限制横向角速率以限制最大章动角的控制策略可快速消除章动,便于工程实现。     

Magnifying our world: Why we must extend civilization to the Moon

Since the completion of its original prehistoric migration some 10 000 years ago, humankind has had nowhere else on Earth to go. The Space Age has produced the wherewithal for a new off-Earth human migration to restart, with the Moon as the clear initial destination. As insurance against cataclysmic and human-induced natural disasters, as a means of creating new commercial industrial–financial opportunities at a time of fundamental change in the global economy, and as a way for the USA to regain some international political influence, it should pursue Moon settlement vigorously and soon. However, the developing US space exploration program being designed by NASA for such an undertaking is too narrowly confined to the pursuit of natural-science objectives. There must be fundamental involvement of the private sector and of a much wider range of professionals and federal departments therein.     

月球探测技术--轨道设计和计算

分析了月球探测器的受力情况及其对轨道运动的影响。经简化和假设后 ,给出了探月轨道设计常用的各种力学模型和计算公式 ,并对其应用作了评述。最后介绍了奔月过程中工程上使用的 3种典型方案和各自的优缺点。