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11.
Ana I. Gómez de Castro Paola Sestito Néstor Sánchez Fátima López-Martínez Juan Seijas Maite Gómez Pablo Rodríguez José Quintana Marcos Ubierna Jacinto Muñoz 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
The Imaging and Slitless Spectroscopy Instrument (ISSIS) will be flown as part of the science instrumentation in the World Space Observatory-Ultraviolet (WSO-UV). ISSIS will be the first UV imager to operate in a high Earth orbit from a 2 m class space telescope. In this contribution, the science driving the ISSIS design and the main characteristics of this instrument are presented. 相似文献
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Jos Monserrat Filho 《Space Policy》2002,18(3)
As orbits are becoming overcrowded the need for a space traffic management system to track space objects, prevent collisions and interference and deal with debris is pressing. Serious political and economic barriers to its creation include the tendency for countries to seek unilateral solutions to safeguard individual nations and moves towards the weaponization of outer space. However, only a cooperative global body will be able to manage space efficiently and fairly. This viewpoint discusses the (lack of) institutions and instruments already in place to manage space and outlines the type of institutional arrangements that might work, suggesting ICAO as a possible model. 相似文献
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JoséMonserrat Filho 《Space Policy》1997,13(2):153-170
This paper aims to examine some of the most important juridical issues raised during the short, but rich, history of Brazilian-Chinese space cooperation. It tries to assess the effectiveness of the agreements signed by these countries on space matters.At the same time, it seeks to present the political and legal concepts which founded the main phases of this history. 相似文献
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E A Blakely I K Daftari W J Meecham L C Alonso J M Collier S M Kroll E L Gillette A C Lee J T Lett A B Cox J R Castro D H Char 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1994,14(10):501-505
Retrospective and ongoing analyses of clinical records from 347 primary intraocular melanoma patients treated with helium ions at LBL will allow examination of the exposure-response data for human cataract; which is a complication of the therapy from incidental exposure of the lens. Direct particle beam traversal of at least a portion of the lens usually is unavoidable in treatment of posterior intraocular tumors. The precise treatment planned for each patient permits quantitative assessment of the lenticular dose and its radiation quality. We are reporting our preliminary results on the development of helium-ion-induced lens opacifications and cataracts in 54 of these patients who had 10% or less of their lens in the treatment field. We believe these studies will be relevant to estimating the human risk for cataract in space flight. 相似文献
16.
Strategies for in-orbit calibration of drag-free control systems 总被引:3,自引:0,他引:3
Michel Silas Guilherme Waldemar Castro Leite Filho Stephan Theil 《Aerospace Science and Technology》2008,12(5):365-375
Drag-Free Satellites (DFS) are a class of scientific satellite missions designed for research on fundamental physics as well as geodesy. They consist, basically, of a small inner satellite (test mass) located in a cavity inside a larger satellite, the normal one. The Drag-Free Attitude Control System (DFACS) is the most complex technology on-board these satellites. This key technology allows the residual accelerations on experiments on board the satellites to be significantly reduced. In order to achieve this very low disturbance environment (for some missions <10−14 g) the drag-free control system has to be optimized. This optimization process is required because of uncertainties in system parameters that demand a robustness of the control system. This paper will present approaches for in-orbit calibration of drag-free control systems. The discussion includes modeling, with scale factors and cross couplings, possible excitation signals, comparison of different parameter identification/estimation methods as well as simulation results. 相似文献