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25 August 1988, Volume 8 Issue 04 Previous Issue    Next Issue

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NOT ALL REUSABLES ARE ECONOMICAL Wang Xiji (CAST) 1988, 8 (04):  .  Abstract ( 1773 )   Save This paper presents a comprehensive view about the problem of realizing economical transportation by using reusable space vehicles, and points out that the development of the reusable hardwares of the spacecraft must adopt a prudent Policy at present conditions. Related Articles | Metrics

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COMPUTATION OF RADIATION CHARACTERISTICS OF NARROW FLARE ANGLE CORRUGATED HORN Xu Guohua Qi Yihong Wang Wutu (Northwest Telecommunication Engineering Institute) Guo Jiajian Hu Ruifen (Xian Institute of Radio Technology) 1988, 8 (04):  .  Abstract ( 1936 )   Save Computation method of near and far field radiating characteristics of narrow flare angle corrugated horn about its radiation center is given in this paper. The computer aided analysis diagram is listed and the satisfactory results are obtained. Related Articles | Metrics

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CORRELATOR WITH TWO PHASE LOCK LOOPS AND DETECTION METHOD FOR SETTING FLOAT THRESHOLD Tang Sheng yuan (Xian INST.of Radio Engineering) 1988, 8 (04):  .  Abstract ( 1586 )   Save A correlator and a detection method are presented. The detection method is modified from "Appollo" ranging system and suitable specifically for tone-code mixed ranging system. In the "Appollo" system the maximum likelihood detection was used, while in the present detection method setting of detection threshold is float.In comparison with"Appollo"system it has obvio us advantages: cor-relation loss decreases by 6dB and configuration is very simple. These feat-ures have been proved in use. Related Articles | Metrics

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THE EFFECTS OF ATMOSPHERIC DENSITY VARIANCE ON RETURN TRAJECTORY PARAMETERS OF SATELLITE Du Wenwen (Beijing INST.of Electromachinery) 1988, 8 (04):  .  Abstract ( 1911 )   Save In this paper, a statistical model of random atmospheric density as a function of latitude, altitude and time (month), below an altitude of 90km and along the return trajectory of satellite, has been developed.The sample of random atmospheric density generated by the model has been used in Monte Carlo trajectory simulating. By statistical analysis of samples of return trajectory parameters obtained in trajectory simulation, the effects of random atmospheric density variance on return trajectory parameters has been learned. Also, this paper deals with the "method of influence coefficients" used in evaluating approximately the effects of random atmospheric density variance on return trajectory parameters. Related Articles | Metrics

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THE FAST LAPLACE INVERSE TRASFORMS Huang Liede 1988, 8 (04):  .  Abstract ( 1732 )   Save In numerical calculations of fracture problems in space shuttle, vre often have to find the numerical inversion of Laplace transformations. In this paper, 1, a fast numerical inversion method for Laplace transform using a Fourier series expansion is given. 2,A fast numerical inversion method for Laplace transform using delta function expansion is given.3,A numerical inversion method for Laplace transform using the shifted Legendre polynomial expansion is given. Related Articles | Metrics

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ADVANCED PROPULSION SYSTEM OF SPACE STATION Lin Laixing (Beijing Institute of Control Engineering) 1988, 8 (04):  .  Abstract ( 2044 )   Save In this paper propulsion systems for space station control is discussed.It is concluded that propellant consumption will be a major cost factor. Electric propulsion system offers specific impulse at least an order of magnitude higher than those of chemical thrusters, so propellant masses can be reduced by the same factor. Electic propujsion systems will be used for high impulse tasks such as drag compensation and orbit transfer. Related Articles | Metrics

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USE OF SYSTOLIC TIME INTERVAL IN ASSESSMENT CARDIAC CONTRACTION FUNCTION IN NOMAL SUBJECTS Shen Xianyun, Yan Xiaoxia et al (Institute of Aerospace Medico-Engineering, Beijing) 1988, 8 (04):  .  Abstract ( 1851 )   Save Systolic time intervals(SIT) after 3 min. exercise were compared among three kinds of subjects with different cardiac contraction function. The results showed that the isovolumetric contraction period(IC), ejection index (LVET/R-R) and mechanical contraction index (MT/R-R) are useful indices for assessment of cardiac function. According to the three indices the selecting standard of astronauts was established and it's experimental evidence and application were discussed Related Articles | Metrics

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INTERNATIONAL METEOROLOGICAL SATELLITES DEVELOPMENT AND ITS TREND Wang Qinmo (Satellite Meteorological Center, SMA) 1988, 8 (04):  .  Abstract ( 1866 )   Save This paper summarizes the advances in development of meteorological satellites in the past 27 years, and discusses the prospects in the future 13 years, thus it can be seen that the development of meteorological satellites has the following characteristics: multi-band, multi-level, multi-country and comprehensive, international, normalized. This ensures continuity, reliability, and commonness for data from satellites. Related Articles | Metrics

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DESIGN OF EARTH RESOURCES TECHNOLOGY SATELLITE ORBIT Luo Kezhuang (Space Science and Application Research Centre of Chinese Academy of Sciences) 1988, 8 (04):  .  Abstract ( 1793 )   Save The paper offers the computation method of Earth Resources Technology Satellite orbit meeting the requirements. And the paper gives a simple formula which can make the ground tracks of the orbit repeat and recover the whole globe. Related Articles | Metrics

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CALCULATION OF SATELLITE MAGNETIC DIPOLE MOMENT BY MEASURING QUASI-DIPOLE FIELD INTENSITY Jin Zhiyu (Beijing Inst.of Electromachinery) 1988, 8 (04):  .  Abstract ( 1795 )   Save On the basis of the harmonic description of a satellite magnetic field, a mathematical model is described. According to the model, we can calculate the magnetic dipole moment of a satellite by measuring guasi-dipole field intensity. And an example of the dipole moment calculation is given in this paper. Related Articles | Metrics