The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
P Constantinou - One of the best experts on this subject based on the ideXlab platform.
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determination of the coordination area for mobile earth Stations operating with geostationary Space Stations in the frequency bands shared with the terrestrial services
Vehicular Technology Conference, 2005Co-Authors: M Koletta, V Milas, P ConstantinouAbstract:This paper examines the development of the coordination contour for mobile (except aeronautical mobile) earth Stations operating in frequency bands shared with the terrestrial services. The method used today by the national administrations for developing the coordination contour around these Stations is vague and leads to unnecessarily large coordination areas. A new method of calculating the coordination contour is proposed for this type of Stations. Its application to realistic scenarios leads to interesting results.
Ernst Messerschmid - One of the best experts on this subject based on the ideXlab platform.
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analysis of parking orbits and transfer trajectories for mission design of cis lunar Space Stations
Acta Astronautica, 2004Co-Authors: Kian Yazdi, Ernst MesserschmidAbstract:Abstract Future human Space exploration activities will very likely incorporate Space Stations and platforms located in the Earth–Moon system, in particular in lunar orbit or in the Lagrange points. It is reasonable to start assembly and mission logistics from today's frequently used near-Earth orbits, such as the ISS orbit, in order to utilize common launcher systems and other infrastructure elements. This contribution deals with the conceptual design of cis-lunar Space missions and presents results based on analytic analysis as well as numerical trajectory computation taking gravitational perturbations of multiple celestial bodies into account. While analytic methods generate data suitable for initial estimates and general assessments on delta-v and transfer time for rather fast trajectories, the selected approach also covers long transfer time missions and allows direct and easy access to other relevant mission parameters. The report gives an overview of the perturbation shares in various orbits and trajectories in Earth vicinity and along in and outbound lunar transfers. Then, it addresses the long-term evolution of selected Earth-bound orbits that are likely to be used as staging or parking locations (on the way to and from the Moon). A summary of results is included on how these orbits are being altered by perturbations over time and consequential impacts on mission parameters like delta-v, transfer time and periods for preferable in- and outbound transfer window periods.
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Space Stations
1999Co-Authors: Ernst Messerschmid, Reinhold BertrandAbstract:The design of Space Stations like the recently launched ISS is a highly complex and interdisciplinary task. This book describes component technologies, system integration, and the potential usage of Space Stations in general and of the ISS in particular. It so adresses students and engineers in Space technology. Ernst Messerschmid holds the chair of Space systems at the University of Stuttgart and was one of the first German astronauts
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Space Stations systems and utilization
1999Co-Authors: Ernst Messerschmid, Reinhold BertrandAbstract:1 Introduction.- 2 History and Current Development.- 3 Orbital Environment.- 4 Environmental Control and Life Support System.- 5 Power and Thermal Control System.- 6 Attitude and Orbit Control System.- 7 Utilization.- 8 Microgravity.- 9 System Engineering.- 10 Synergisms.- 11 Human Factors.- 12 Logistics, Communications and Operation.- 13 The International Space Station.- References.- Fundamental Constants.
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nonsteady behaviour of solar dynamic power systems with stirling cycle for Space Stations
Aerospace Science and Technology, 1999Co-Authors: Ch Audy, M Fischer, Ernst MesserschmidAbstract:Abstract In the first part of this paper, a solar dynamic power system with a Stirling engine for Space station application is described. Its unsteady behaviour is theoretically modelled and numerically simulated for four representative orbit configurations. The results are compared to that of a solar dynamic power module with a Brayton gas turbine. In the second part, it is shown that the complex nonsteady behaviour of solar dynamic power modules with either the Brayton cycle or Stirling cycle can be analysed in a simplified way with sufficient accuracy for practical purposes on the basis of parametrizations and simple energy balances.
Aritra Chandra - One of the best experts on this subject based on the ideXlab platform.
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performance of vertical multi junction solar cell for long distance wireless power transfer using high intensity laser beam
Ubiquitous Computing, 2017Co-Authors: Pradeep Kumar Sharma, Shaswata Banerjee, Subhodeep Bose, Biswajit Jana, Omkar Goswami, Ankan Bhunia, Pritam Modak, Arindam Shyam, Rajdip Mitra, Aritra ChandraAbstract:Wireless Power Transfer to long distance objects has been a much awaited task for researchers and scientists but old technologies like magnetic resonance coupling method were failed to provide any satisfactory result for long distance power transfer though it was good for small or very near distance power transfer. Far distant moving objects like Space Stations, lunar modules, rovers, unmanned aerial vehicles or drones largely suffer from lack of power providing mechanism resulting in short flight time of these vehicles. Major limitation is poor endurance for helicopters and quad-copters due to their very less efficient design and nature of vertical take-off and landing in comparison to those vehicle having fixed wings. Unlimited flight endurance can be achieved by using laser power beaming to recharge any target having optical tracking system done by beam riding method. Here wireless power transmission using a high intensity laser beaming (HILB) system by illuminating vertical multi-junction solar cell (VMJSC) has been discussed and its performance is studied and analyzed. Many of the HILB systems have been used to examine the performance of VMJSC under different types of conditions. Here many of the methods like optimal receiver geometry, parallel cell back-feeding, laser wavelength, thermal effects and non-uniform illumination at high intensities are studied and analyzed. Suggestions are made to further improve the system and to achieve sufficient power densities. Study shows that VMJSC mechanism can be used for high intensity laser beaming to power transfer without being damaged and retaining its efficiency.
M Koletta - One of the best experts on this subject based on the ideXlab platform.
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determination of the coordination area for mobile earth Stations operating with geostationary Space Stations in the frequency bands shared with the terrestrial services
Vehicular Technology Conference, 2005Co-Authors: M Koletta, V Milas, P ConstantinouAbstract:This paper examines the development of the coordination contour for mobile (except aeronautical mobile) earth Stations operating in frequency bands shared with the terrestrial services. The method used today by the national administrations for developing the coordination contour around these Stations is vague and leads to unnecessarily large coordination areas. A new method of calculating the coordination contour is proposed for this type of Stations. Its application to realistic scenarios leads to interesting results.
Reinhold Bertrand - One of the best experts on this subject based on the ideXlab platform.
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Conceptual design and flight simulation of Space Stations
Aerospace Science and Technology, 2001Co-Authors: Reinhold BertrandAbstract:Abstract This paper focuses on the conceptual design and flight simulation of Space Stations. Its goal is to discern the factors which influence the configurational design of a Space station system. This is done in order to define an adequate methodology with an adapted set of computer tools for early conceptual design of Space Stations. First we review the history of Space station design in order to show what factors drove conceptual Space station designs in the past. After that, a methodological design approach for Space Stations is introduced with special emphasis on design rules applicable to the development of the configuration of a Space station. Finally, the design example of a minimum Space station with growth potential demonstrates the way in which methods and tools established in this study can be applied to a conceptual design problem.
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Space Stations
1999Co-Authors: Ernst Messerschmid, Reinhold BertrandAbstract:The design of Space Stations like the recently launched ISS is a highly complex and interdisciplinary task. This book describes component technologies, system integration, and the potential usage of Space Stations in general and of the ISS in particular. It so adresses students and engineers in Space technology. Ernst Messerschmid holds the chair of Space systems at the University of Stuttgart and was one of the first German astronauts
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Space Stations systems and utilization
1999Co-Authors: Ernst Messerschmid, Reinhold BertrandAbstract:1 Introduction.- 2 History and Current Development.- 3 Orbital Environment.- 4 Environmental Control and Life Support System.- 5 Power and Thermal Control System.- 6 Attitude and Orbit Control System.- 7 Utilization.- 8 Microgravity.- 9 System Engineering.- 10 Synergisms.- 11 Human Factors.- 12 Logistics, Communications and Operation.- 13 The International Space Station.- References.- Fundamental Constants.
