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171.
Paul B. Larsen 《Space Policy》2000,16(2)
This paper discusses a range of legal issues that need to be considered in planning for a space solar power system. Because objects placed in space are inherently international, the paper primarily looks at international law that affects launching, construction, operation, property rights, the environment, communication and liability. International coordination early in the planning process is urged to make space solar powers systems a reality more speedily. 相似文献
172.
Smart Sensor Web (SSW) is a recent DUSD (S&T) initiative inspired by extraordinary technological advances in sensors and microelectronics and by the emergence of the Internet as a real time communication tool. The overall vision for SSW is an intelligent, Web-centric distribution and fusion of sensor information that provides greatly enhanced situational awareness, on demand, to warfighters at lower echelons. Emphasis is on multi-sensor fusion of large arrays of local sensors, joined with other assets, to provide real-time imagery, weather, targeting information, mission planning, and simulations for military operations on land, sea, and air. This paper gives an overview of this new initiative, highlights some of the technology challenges in sensor/information Fusion, and presents a program approach for near-term demonstrations and long-term solutions, involving the DoD, National Labs, commercial industry, and academia 相似文献
173.
174.
The LISA Pathfinder Mission 总被引:1,自引:0,他引:1
LISA Pathfinder, formerly known as SMART-2, is the second of the European Space Agency’s Small Missions for Advance Research and Technology, and is designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission, by testing the core assumption of gravitational wave detection and general relativity: that free particles follow geodesics. The new technologies to be demonstrated in a space environment include: inertial sensors, high precision laser interferometry to free floating mirrors, and micro-Newton proportional thrusters. LISA Pathfinder will be launched on a dedicated launch vehicle in late 2011 into a low Earth orbit. By a transfer trajectory, the sciencecraft will enter its final orbit around the first Sun-Earth Lagrange point. First science results are expected approximately 3 months thereafter. Here, we give an overview of the mission including the technologies being demonstrated. 相似文献
175.
货舱和行李舱所受的磨损程度仅次于机轮和刹车装置。这是因为在货物装卸过程中,货舱及行李舱受到日复一日的损坏。货舱和行李舱也是腐蚀最多的部位,而且在飞机进行大修检查前是无法察觉的。 相似文献
176.
Paul Seidenman 《航空维修与工程》2009,(4)
在金融危机发生之前,航空战略咨询公司曾预计2009年国际直升机MRO市场的增长速度是3%,达到56亿美元.但考虑到目前的经济状况,2009年民用直升机的MRO市场会比2008年减少5%~10%.这主要是因为直升机的使用率在下降,以及金融危机爆发之前高企的油价所致.(本文所指的民用直升机还包括经过特殊改装后的军用和准军用直升机,但不包括武装直升机.) 相似文献
177.
Paul Withers 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
Recent measurements by Mars Global Surveyor and Mars Express have greatly increased the number of observations of the martian dayside ionosphere available for study. Together with earlier measurements from the Viking era, these datasets have been used to investigate variations in well-known properties of the martian dayside ionosphere and to discover new ionospheric features. The dayside ionosphere includes the main peak, called the M2 layer, and a lower layer, called the M1 layer. In the topside, above the M2 layer, electron densities exponentially decrease with increasing altitude. 相似文献
178.
(SIGMA: Project of a high resolution space observatory for gamma rays sources)—The SIGMA space observatory is designed to obtain images of the sky in the hard X-ray/low energy gamma-ray domain (30–2000 keV range), with an angular accuracy of a few are min, within a field of ~7° × 7°, and a sensitivity for point sources down to a level of a few 10?6 photons cm?2s?1keV?1 (exposure 24 hr). The instrument is designed using the principle of the coded aperture mask telescope with a position sensitive detector derived from the Anger gamma-camera which is used in nuclear medicine. The pseudo-images of the sky are accumulated on board and transmitted to the ground stations for decoding processing. The gross weight of the instrument is 750 kg and its overall dimensions are 3 m long and 1.2 m in diameter. 相似文献
179.
180.
Advanced materials for space applications 总被引:1,自引:0,他引:1
Since NASA was created in 1958, over 6400 patents have been issued to the agency—nearly one in a thousand of all patents ever issued in the United States. A large number of these inventions have focused on new materials that have made space travel and exploration of the moon, Mars, and the outer planets possible. In the last few years, the materials developed by NASA Langley Research Center embody breakthroughs in performance and properties that will enable great achievements in space. The examples discussed below offer significant advantages for use in small satellites, i.e., those with payloads under a metric ton. These include patented products such as LaRC SI, LaRC RP 46, LaRC RP 50, PETI-5, TEEK, PETI-330, LaRC CP, TOR-LM and LaRC LCR (patent pending). These and other new advances in nanotechnology engineering, self-assembling nanostructures and multifunctional aerospace materials are presented and discussed below, and applications with significant technological and commercial advantages are proposed. 相似文献