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751.
The systems of gyrodynes installed on a spacecraft body on the one-axis controlled platform are considered. An algorithm to determine the special states and the special surfaces corresponding to them in the region of variation of the total angular momentum is obtained, as well as an algorithm to study the permeability of special surfaces. The results of calculation of the special surfaces for two types of gyro systems are presented. 相似文献
752.
Gonzalez S.A. Valla M.I. Muravchik C.H. 《IEEE transactions on aerospace and electronic systems》2004,40(3):919-928
A clamped-mode resonant converter (CMRC) is proposed to be used as a transmitter which broadcasts correction signals in a differential Global Positioning System (DGPS). The digital information of the DGPS modulates the carrier with different modulation methods minimum shift keying (MSK) (recommended for the marine radiobeacon band), stepped binary phase shift keying (S-BPSK) and BPSK. The first two methods allow keeping the converter's operation in soft switching mode. Extensive trials under impedance mismatch and modulation conditions confirm that the soft switching mode is preserved. 相似文献
753.
In-orbit demonstration of rendezvous laser radar for unmanned autonomous rendezvous docking 总被引:1,自引:0,他引:1
Mokuno M. Kawano I. Suzuki T. 《IEEE transactions on aerospace and electronic systems》2004,40(2):617-626
The National Space Development Agency of Japan (NASDA) performed unmanned autonomous rendezvous docking (RVD) experiments using the Engineering Test Satellite VII (ETS-VII) in 1998 and 1999. In these experiments, a rendezvous laser radar (RVR) was used as the primary navigation sensor during the final approach phase (relative distances from 500 m to 2 m). The RVR functioned properly, and its characteristics, which are measurement accuracy, optical propagation, and acquisition/tracking, satisfied the requirements. The experimental results show that RVR is effective for autonomous rendezvous docking. 相似文献
754.
Variations in fluxes of quasi-trapped energetic protons were studied on the basis of the data of the CORONAS-I satellite. These variations are characterized by an increase in the proton fluxes with E P ≥ 1 MeV both in the vicinity of the geomagnetic equator and in the high-latitude region of the magnetosphere. The analysis of structural features of the proton distributions in the regions at L ~ 1–1.1; 3 < L < 4; and L > 4, was performed and made it possible to detect reliably the type of the proton flux increase in this region. The mechanisms of particle scattering leading to the precipitation of energetic protons under conditions of various types of geomagnetic disturbances are considered. 相似文献
755.
A Kondyurin B Lauke I Kondyurina E Orba 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,34(7):1585-1591
The large-size frame of space ship and space station can be created with the use of the technology of the polymerization of fiber-filled composites and a liquid reactionable matrix applied in free space or on the other space body when the space ship or space station will be used during a long period of time. For the polymerization of the station frame the fabric impregnated with a long-life polymer matrix (prepreg) is prepared in terrestrial conditions and, after folding, can be shipped in a compact container to orbit and kept folded on board the station. In due time the prepreg is carried out into free space and unfolded. Then a reaction of matrix polymerization starts. After reaction of polymerization the durable frame is ready for exploitation. After that, the frame can be filled out with air, the apparatus and life support systems. The technology can be used for creation of biological frame as element of self regulating ecological system, and for creation of technological frame which can be used for a production of new materials on Earth orbit in microgravity conditions and on other space bodies (Mars, Moon, asteroids) for unique high price mineral extraction. Based on such technology a future space base on Earth orbit with volume of 10(6) m3 and a crew of 100 astronauts is considered. 相似文献
756.
O M Nedukha I V Vasyltsov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,27(5):977-981
Formation and structure of potato minitubers grown aseptically for 30 days on a horizontal clinostat and in stationary control have been studied by light and electron microscopy. It was demonstrated that the number of plants that formed minitubers, their size and fresh weight, was higher when clino-rotated than in the stationary control. It was revealed that the amount of amyloplasts in parenchyma cell sections was doubled in minitubers formed under clino-rotation. Other factors (shape of minitubers and size of reserve parenchyma cells) did not differ from the stationary control. The changes in amyloplast ultrastructure suggest accelerated cell maturity of potato reserve parenchyma in extended clino-rotation. 相似文献
757.
The career of Luis Walter Alvarez is sketched, focusing on one of three important radar developments for which he was responsible, namely, the ground-controlled approach. The process of implementing the concept is described 相似文献
758.
759.
N. V. Emelyanov J. -E. Arlot M. I. Varfolomeev S. N. Vashkov’yak A. A. Kanter S. M. Kudryavtsev L. P. Nasonova V. S. Ural’skaya 《Cosmic Research》2006,44(2):128-136
A knowledge base for natural satellites of planets is created. On the basis of observations, new numerical models of motion are constructed for all 96 outer satellites of Jupiter, Saturn, Uranus, and Neptune. A special database is compiled from all available observational data for natural satellites of planets, as well as a bibliographical database and information system of physical and orbital parameters of planets and satellites. The tools for calculations of ephemerides of all natural satellites (except for the Moon) of planets are developed. They represent the final result of studies and actually incorporate the entire knowledge about dynamics of the satellites of planets. Also developed are special ephemerides in order to observe singular phenomena in the apparent motion of the satellites of planets. A computer environment and the Internet allowed us to concentrate all above-listed options in a single toolkit easily available to any user in the world. 相似文献
760.