美国地球观测任务新一轮投资的10年计划

2007年新年伊始,美国科学院向众议院提交了题为“利用太空的地球科学与应用:下一个10年及以后的发展势在必行”的报告,这是美国地球科学任务     

A mission template for exploration and damage mitigation of potential hazard of Near Earth Asteroids

The Apophis Exploratory and Mitigation Platform (AEMP) concept was developed as a prototype mission to explore and potentially deflect the Near Earth Asteroid (NEA) 99942 Apophis. Deflection of the asteroid from the potential 2036 impact will be achieved using a gravity tractor technique, while a permanent deflection, eliminating future threats, will be imparted using a novel albedo manipulation technique. This mission will serve as an archetypal template for future missions to small NEAs and could be adapted to mitigate the threat of collision with other potential Earth-crossing objects.     

Research priorities and plans for the International Space Station-results of the 'REMAP' Task Force

Recent events in the International Space Station (ISS) Program have resulted in the necessity to re-examine the research priorities and research plans for future years. Due to both technical and fiscal resource constraints expected on the International Space Station, it is imperative that research priorities be carefully reviewed and clearly articulated. In consultation with OSTP and the Office of Management and budget (OMB), NASA's Office of Biological and Physical Research (OBPR) assembled an ad-hoc external advisory committee, the Biological and Physical Research Maximization and Prioritization (REMAP) Task Force. This paper describes the outcome of the Task Force and how it is being used to define a roadmap for near and long-term Biological and Physical Research objectives that supports NASA's Vision and Mission. Additionally, the paper discusses further prioritizations that were necessitated by budget and ISS resource constraints in order to maximize utilization of the International Space Station. Finally, a process has been developed to integrate the requirements for this prioritized research with other agency requirements to develop an integrated ISS assembly and utilization plan that maximizes scientific output.     

近空间飞行器成为各国近期研究的热点(上)

近空间（Nearspace）通常是指20～lOOkm的高空，其下面的空域（20km以下）是传统航空器的主要运行空间，其上面的空域（100km以上）是航天器的运行空间。近空间飞行器是指运行在近空间范围的飞行器。由于技术和认识上的原因，近空间的战略价值直到最近才引起各国的重视。因此。近空间飞行器成为各国近期研究的热点。美国、俄罗斯、欧洲、韩国、英国、     

近空间飞行器成为各国近期研究的热点(下)

2.美国空军2005年攀登者裸机飞行试验未能达到预期目的。     

Earth as an extrasolar planet: Earth model validation using EPOXI earth observations

The EPOXI Discovery Mission of Opportunity reused the Deep Impact flyby spacecraft to obtain spatially and temporally resolved visible photometric and moderate resolution near-infrared (NIR) spectroscopic observations of Earth. These remote observations provide a rigorous validation of whole-disk Earth model simulations used to better understand remotely detectable extrasolar planet characteristics. We have used these data to upgrade, correct, and validate the NASA Astrobiology Institute's Virtual Planetary Laboratory three-dimensional line-by-line, multiple-scattering spectral Earth model. This comprehensive model now includes specular reflectance from the ocean and explicitly includes atmospheric effects such as Rayleigh scattering, gas absorption, and temperature structure. We have used this model to generate spatially and temporally resolved synthetic spectra and images of Earth for the dates of EPOXI observation. Model parameters were varied to yield an optimum fit to the data. We found that a minimum spatial resolution of ～100 pixels on the visible disk, and four categories of water clouds, which were defined by using observed cloud positions and optical thicknesses, were needed to yield acceptable fits. The validated model provides a simultaneous fit to Earth's lightcurve, absolute brightness, and spectral data, with a root-mean-square (RMS) error of typically less than 3% for the multiwavelength lightcurves and residuals of ～10% for the absolute brightness throughout the visible and NIR spectral range. We have extended our validation into the mid-infrared by comparing the model to high spectral resolution observations of Earth from the Atmospheric Infrared Sounder, obtaining a fit with residuals of ～7% and brightness temperature errors of less than 1?K in the atmospheric window. For the purpose of understanding the observable characteristics of the distant Earth at arbitrary viewing geometry and observing cadence, our validated forward model can be used to simulate Earth's time-dependent brightness and spectral properties for wavelengths from the far ultraviolet to the far infrared. Key Words: Astrobiology-Extrasolar terrestrial planets-Habitability-Planetary science-Radiative transfer. Astrobiology 11, 393-408.     

Earth observations: the view from the ground

A ground-level view of Earth observations reveals that emerging ground segments are of at least two major categories: those that are satellite-driven and which have top-down organizations and those that are data-driven and organized from the bottom up. Or put differently, the former are generally data users. A ground-level perspective also suggests that continually rising scientific and economic value of data and decreasing national budgets require balancing satellite investment with effective ground segment evolution to provide demonstrable reasons to continue funding both satellites and ground activities.     

Registration of space objects: ESA member states’ practice

The registration of space objects is indispensable for the orderly administration of outer space. Most states recognize this and comply with the instruments—the Registration Convention and the UN General Assembly Resolution—set up to permit registration, but they display different approaches to and interpretations of the concept of registration. This article examines the registration practices of various European Space Agency (ESA) member states and of ESA itself. It finds that, despite varied policies, the system seems to be working well. However, there has been a worrying rise in non-registrations over the past few years, perhaps linked to the growth in the number of, especially commercial, entities engaging in space activities.     

Space in the UK: something to celebrate?

This article discusses current UK space activities that were debated during the ‘policy’ day of a 3-day ‘Festival of Space’ held at Surrey University in July 2003. While the emphasis is on using space to fulfil the needs of society, it is apparent that crafting a coherent strategy that would provide the political support needed to do this—in Europe as well as in the UK—remains difficult.     

Tropical Earth Resources Satellite: is the investment warranted?

All existing and planned Earth observation satellites have near-polar orbits (hence global coverage), but the Tropical Earth Resources Satellite (TERS) will have a true equatorial orbit at 1681 km. The TERS, conceived for the equatorial countries and Indonesia in particular, complements the existing and planned remote sensing satellites and will enable the monitoring of critical processes, such as food production, conservation of the national environment and land usage. The swath-width of the high resolution multispectral instrument can be pointed anywhere between latitude 10°N and 10°S, offering the tropical countries an opportunity to observe any part of their territory four times a day during daylight. A forward looking cloud sensor detects which areas are free of clouds and the pushbroom optical instrument will be pointed to specific clear areas. It is expected that the benefits of the monitoring capability warrant the investment in TERS.     

The extraterrestrial Earth: Antarctica as analogue for space exploration

The polar regions have often been suggested as surrogates for the exploration and colonization of space. In particular, Antarctica's greater isolation makes it a useful analogue. Its features—abiotic, acultural, alien to human habitation—all echo the regions of interest to contemporary exploration, notably the solar system and the deep oceans. But more than a century of Antarctic experience also suggests that exploration will likely resemble the Renaissance's Great Voyages and their outposts rather than become portals for wholesale colonization. These sites will traffic mostly in information—the spices and luxury goods of interest to their sustaining societies.     

Asymmetry in Active SETI: A case for transmissions from Earth

The Search for Extraterrestrial Intelligence (SETI) typically presupposes contact with extraterrestrial civilizations much longer lived than humanity. Many have argued that given humanity's “youth,” the burden of transmitting should be placed on the extraterrestrial civilizations, which presumably possess more advanced technologies. These assumptions have contributed to the current emphasis on Passive SETI. Complementing this existing stress on Passive SETI with an additional commitment to Active SETI, in which humankind transmits messages to other civilizations, would have several advantages, including (1) addressing the reality that regardless of whether older civilizations should be transmitting, they may not be transmitting; (2) placing the burden of decoding and interpreting messages on advanced extraterrestrials, which may facilitate mutual comprehension; and (3) signaling a move toward an intergenerational model of science with a long-term vision for benefiting other civilizations as well as future generations of humans. Technological requirements for Active SETI are considered, and a case is made for Active SETI as a means for experimentally testing variants of the Zoo Hypothesis. Recommendations are provided for sustaining Passive and Active SETI and the communities that conduct these searches.     

The Global Earth Observation System of Systems: Science Serving Society

Over the next decade, a Global Earth Observation System of Systems (GEOSS) will revolutionize our understanding of the Earth and how it works, producing societal benefits through more coordinated observations, better data management, increased data sharing and timely applications. The political momentum behind the establishment of GEOSS is described and examples of its benefits—drought prediction, disease monitoring, accuracy of weather and energy needs forecasting, disaster mitigation—are provided. While challenges exist, particularly in the area of making data accessible, steps are being taken to meet them, e.g. through the new GEO-Netcast concept. Interagency collaboration within countries is as important as international cooperation; the efforts of the US Group on Earth Observations in this regard are discussed. Maintaining the strong political support here and in all participating countries will be key to the success of GEOSS.     

人民是抗“疫”致胜的决定力量

疫情防控是一场人民战役,取得战“疫”的最后胜利,必须团结和带领人民群众,紧紧依靠人民群众.这就要求我们要坚定人民必胜信念,坚持人民中心立场,注重舆论宣传教育,坚持科学防疫,增强人民抗“疫”的信心、提振人民抗“疫”士气、增强人民抗“疫”自觉,提高人民抗“疫”能力,尽快打赢疫情防控阻击战.     

The Earth Observation Summit: heralding a new era for international cooperation

The world's first political summit on Earth observation was attended by senior policy makers and expert organizations from a range of scientific disciplines. Its aim was to improve global cooperation in Earth observation and increase its use as a decision-making tool for sustainable development and resource conservation. This article presents a brief survey of the progress made in Earth observation since its birth, along with the specific events driving the convening of the summit. The summit produced a declaration outlining four key areas requiring support, and an ad hoc group was established to produce a 10-year plan and drive implementation of policy.