Dementyev A.N.,Central Research Institute of Machine Building |
Klyuev D.S.,Samara State University |
Shatrov S.A.,Progress Rocket Space Center
Doklady Physics | Year: 2016
The problem about the distribution of the surface current density in a narrow circular strip antenna as an infinitely thin perfectly conducting ribbon folded in a circle and positioned on the surface of a dielectric cylinder is reduced to a one-dimensional integral equation (IE). A method for solving the obtained IE is proposed. Complex distributions of the azimuthal component of the surface current density over the circular conductor are presented for different values of the dielectric permittivity of the cylinder. © 2016, Pleiades Publishing, Ltd.
Anton B.,Central Research Institute of Machine Building
Proceedings of the International Astronautical Congress, IAC | Year: 2013
Future space programs for the study and development of outer space are impossible without increasing the energy potential of space complexes. It is related as with the service systems of the spacecraft, as well as with the scientific equipment. The tasks covered by these space crafts, may be both applied and fundamental. It could be remote sensing devices, communications and intelligence space crafts, space vehicles for Moon and outer space exploration. In this regard, there is a problem to release a large amount of heat to the surroundings. The only type of heat transfer in space is radiation, so it is advisable to raise the temperature of the emitting surface and to translate low potential heat into high. Such transformation is possible by the refrigerating machine. The paper will consider the possibility of cooling the space craft equipment module. This will require compensate for the200 kW of heat from devices, the work of most of which is not possible at temperatures above 40-50°C. The main advantage of the refrigeration plant over the cooler-radiator is its weight and size. Copyright © 2013 by the International Astronautical Federation.
Revnivykh S.,Central Research Institute of Machine Building
23rd International Technical Meeting of the Satellite Division of the Institute of Navigation 2010, ION GNSS 2010 | Year: 2010
• GLONASS Program is the high priority of the Russian Government policy • GLONASS open service is free for all users • GLONASS Program is in a progress, objective to be achieved by 2011 • GLONASS improvement is a major objective: - Performance to be comparable with GPS by the end of 2011 - Full constellation (24 sats) by the end of 2010 • GLONASS will continue - Keep the GLONASS traditional frequency bands - Transmit existing FDMA signals - Introduce new CDMA signals • New GLONASS Program is under development - State commitments for major performance - GLONASS sustainment, development, use • International cooperation - make GLONASS as one of key elements of the international GNSS for worldwide use © 2010. All rights reserved.
Revnivykh S.,Central Research Institute of Machine Building
24th International Technical Meeting of the Satellite Division of the Institute of Navigation 2011, ION GNSS 2011 | Year: 2011
• GLONASS Program is the high priority of the Russian Government policy • GLONASS open service is free for all users • Present GLONASS Program is completing, objective to be achieved by 2011 - Performance to be comparable with GPS by the end of 2011 - Full constellation (24 sats) by the end of 2011 • GLONASS will continue - Keep the GLONASS traditional frequency bands - Transmit existing FDMA signals - Introduce new CDMA signals • New GLONASS Program (2012-2020) is under development to be approved by the end of 2011 - State commitments for major performance - GLONASS sustainment, development, use • International cooperation - make GLONASS as one of key elements of the international GNSS infrastructure for worldwide user benefits.
Boissier J.,Institut Universitaire de France |
Bockelee-Morvan D.,University of Paris Descartes |
Rodionov A.V.,Central Research Institute of Machine Building |
Crifo J.-F.,French National Center for Scientific Research
Astronomy and Astrophysics | Year: 2010
Context. Millimetre line observations of comet C/1995 O1 (Hale-Bopp) close to perihelion, completed using the IRAM Plateau de Bure Interferometer, have detected temporal variations in the CO J(2-1) 230 GHz line shape, and in the position of its maximum emission brightness within the field-of-view, whose heuristic analysis has suggested the presence in the coma of a slowly rotating spiral-shaped enhancement of the CO density. Aims. Here, we reanalyse these data using a physically consistent model of the coma. Methods. We consider a large, rotating, icy nucleus with an arbitrarily aspherical shape and an adhoc rotation mode, and compute its tridimensional, time-dependent ("3D+t") mixed CO + H2O coma, using a previously developed tridimensional hydrodynamical code (HDC). The line emission of CO is then computed using a molecular excitation and radiation transfer code (ERC). In the present, pioneering phase, the HDC and ERC both contain crude, and not thoroughly mutually consistent approximations. Several alternative CO surface flux distributions are considered, and the resulting CO 230 GHz line spectra and brightness maps are compared with observations. Results. We find that when an uniform surface flux of CO is assumed, the spiral structures created by the nucleus asphericity in the CO coma are too faint to account for the observational data, whereas we confirm earlier conclusions based on a heuristic approach that the assumption of an area of suitable dimensions and localization with increased CO flux leads to results in agreement with a large subset of (but not all) the data. This suggests that the true CO coma production map may be more complex than the presently assumed rather simple-minded one. Refined and mutually consistent HDC and ERC are needed for a more satisfactory interpretation of the present and any similar future data. © ESO, 2010.