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A compact cluster of two 80-mm-wide emitters has been designed, built and tested. The field emission thruster using this cluster is able to produce thrust in excess of 5 mN at high mass efficiency. 相似文献
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A laboratory model of field emission ion thruster has been used to demonstrate the clustering capability of field emission ion sources.The single emitters sustained preliminary tests aimed to increase elementary trust. Clustering had shown the additivity of elementary sources characteristics and the lack of interference between ion beamlets. 相似文献
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Myrtille Laas-Bourez Sébastien Wailliez Florent Deleflie Alain Klotz Dominique Albanese Nathalie Saba 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The MéO (for Métrologie Optique) telescope is the Satellite and Lunar Laser Ranging (SLR) dedicated telescope of Observatoire de la Côte d’Azur (France) located at plateau de Calern. The telescope uses an altazimuth mount. The motorization of the mount has a capability of 6 deg/s allowing the follow up of Low Earth Orbits (LEO) satellites, as well as Medium Earth Orbits (MEO) and geostationary (GEO) satellites, and the Moon. The telescope has a primary mirror of 1.54 m. It uses a Nasmyth focus equipped with an EMCCD camera. The telescope field of view, defined by the equivalent focal length and the size of the camera, is currently 3.4 arcmin × 3.4 arcmin. 相似文献
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Philippe Caisso Alain Souchier Christophe Rothmund Patrick Alliot Christophe Bonhomme Walter Zinner Randy Parsley Todd Neill Scott Forde Robert Starke William Wang Mamoru Takahashi Masahiro Atsumi Dominique Valentian 《Acta Astronautica》2009,65(11-12):1723-1737
Liquid-propellant rocket engines are widely used all over the world, thanks to their high performances, in particular high thrust-to-weight ratio. The present paper presents a general panorama of liquid propulsion as a contribution of the IAF Advanced Propulsion Prospective Group.After a brief history of its past development in the different parts of the world, the current status of liquid propulsion, the currently observed trends, the possible areas of future improvement and a summarized road map of future developments are presented. The road map includes a summary of the liquid propulsion status presented in the “Year in review 2007” of Aerospace America.Although liquid propulsion is often seen as a mature technology with few areas of potential improvement, the requirements of an active commercial market and a renewed interest for space exploration has led to the development of a family of new engines, with more design margins, simpler to use and to produce associated with a wide variety of thrust and life requirements. 相似文献
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Sergey A. Bulat Irina A. Alekhina Dominique Marie Jean Martins Jean Robert Petit 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
The objective was to estimate the genuine microbial content of ice samples from refrozen water (accretion ice) from the subglacial Lake Vostok (Antarctica) buried beneath the 4-km thick East Antarctic ice sheet. The samples were extracted by heavy deep ice drilling from 3659 m below the surface. High pressure, a low carbon and chemical content, isolation, complete darkness and the probable excess of oxygen in water for millions of years characterize this extreme environment. A decontamination protocol was first applied to samples selected for the absence of cracks to remove the outer part contaminated by handling and drilling fluid. Preliminary indications showed the accretion ice samples to be almost gas free with a low impurity content. Flow cytometry showed the very low unevenly distributed biomass while repeated microscopic observations were unsuccessful. 相似文献
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Vladimir Pletser Pierre Emmanuel Paulis Edwin Loosveldt Dominique Gering Mireille Body Robert Schewijck 《Acta Astronautica》2005,57(12):910-919
Since 1984, the European Space Agency (ESA) has organized 30 aircraft parabolic flight campaigns in the frame of its Microgravity Programme to perform short duration scientific and technological experiments. On each campaign, ESA invites journalists to report to the general public on the research work conducted in weightlessness. A new initiative was launched in 2000 with the introduction of pedagogical experiments aiming at educating youngsters and the general public on weightlessness effects. In November 2000, four secondary school teachers detached to the Euro Space Center (ESC) participated in the 29th ESA campaign. The ESC in Belgium provides recreational and educational activities for the general public and organizes space classes targeted at primary and secondary school pupils. The four teachers performed simple experiments with gyroscopes, yo-yos, magnetic balls, pendulum and food to explain their different behaviour in weightlessness, to show characteristics and possibilities of the microgravity environment and the difficulties that astronauts encounter in their daily life in orbit. 相似文献