TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN
Online ISSN : 1347-3840
ISSN-L : 1347-3840
7 巻
選択された号の論文の5件中1~5を表示しています
  • Mohammed K. IBRAHIM, Tetsuya NAKAMURA, Keiichi KITAMURA, Koichi MORI, ...
    原稿種別: Technical Paper
    専門分野: Aerodynamics
    2009 年 7 巻 p. 1-10
    発行日: 2009年
    公開日: 2009/01/29
    ジャーナル フリー
    A numerical investigation was carried out for a blunt body with a circular sonic air jet normally injected into a hypersonic flow from the body surface, where the angle of attack was changed up to 40◦. Computed results were compared with the experimental data collected using the shock tunnel of Nagoya University. The aerodynamic interaction due to the jet creates complicated flow fields, which are rather difficult to analyze alone experimentally. The computed results show good agreement with the experimental data with regard to surface pressure distribution and schlieren visualization. It was found that at rather low angles of attack, two vortices, i.e., a separation vortex and a horseshoe vortex, are formed inside the separated boundary layer upstream of the jet. The location of these vortices corresponds to low-pressure regions in the pressure distribution. On the other hand, at a rather high angle of attack, the interaction produces a complex flow field, where vortices have little influence on the pressure distribution. Finally the jet interaction was found to enhance the jet reaction forces by about 35% - 45 % on the body surface, the value of which is close to the experimental data.
  • Yukishige NOZAKI, Hirokazu MASUI, Kazuhiro TOYODA, Mengu CHO, Hirokazu ...
    原稿種別: Technical Paper
    専門分野: Space System and Technology
    2009 年 7 巻 p. 11-17
    発行日: 2009年
    公開日: 2009/03/19
    ジャーナル フリー
    High-efficiency triple-junction (TJ) solar cells with monolithic diodes (MD) are being used for recent spacecraft solar arrays. Because the cell-to-cell inter-connector is usually connected on the MD pad, studying the effects of electrostatic discharge (ESD) on MD is necessary. Laboratory testing of two types of MD functions revealed that the weaker design was damaged by an energy discharge of 0.8J. With an external circuit simulating flight solar array, however, discharge as large as 9.3J didn't destroy the solar cell. Based on the test results, it was concluded that MD solar cells have sufficient resistance against ESD in orbit.
  • Hirohisa KOJIMA, Naoki MATSUDA, Kohei TAKADA
    原稿種別: Technical Paper
    専門分野: Astronautics
    2009 年 7 巻 p. 19-24
    発行日: 2009年
    公開日: 2009/06/06
    ジャーナル フリー
    In this paper, an adaptive skewing pyramid-type control moment gyro (AS-CMG) is proposed, in which the skew angle is treated as an available parameter to obtain larger torques. This proposed AS-CMG can be categorized as either a single-gimbal CMG or a double-gimbal CMG, but not both. The AS-CMG is superior to the DGCMG due to its lightweight structure, and is superior to the conventional pyramid CMG with respect to maximum torque generated along the desired direction. The effectiveness of the proposed AS-CMG for fast attitude maneuvering, as compared to the conventional pyramid-type CMG with fixed skew angles, is demonstrated by numerical simulations.
  • Takanao SAIKI, Koji NAKAYA, Takayuki YAMAMOTO, Yuichi TSUDA, Osamu MOR ...
    原稿種別: Technical Paper
    専門分野: Space System and Technology
    2009 年 7 巻 p. 25-32
    発行日: 2009年
    公開日: 2009/08/12
    ジャーナル フリー
    電子付録
    The instruments and actuators in the attitude control system of small spacecraft are restricted in weight and space, and need to be reduced in weight and size. The rhumb line control strategy is one of the most popular schemes in reorientation of spin-stabilized spacecraft, since it requires only a spin sun sensor and a single axis reaction control system. By being combined with active nutation control, rhumb line control can reorient the spin axis of the spacecraft to any direction. To verify the control strategy, we manufactured an attitude controller and demonstration experiments were conducted using a motion table at ISAS/JAXA. This paper reviews the configuration of the controller and the outlines of the experiments, and evaluates the control performance. The same type of controller was installed in the Solar Sail Subpayload Satellite (SSSAT) launched in September 2006. An attitude control experiment in orbit was not conducted because of trouble with the satellite, but new control logic for the SSSAT was implemented for the attitude controller. This paper also reviews the control logic of the SSSAT.
  • Yasuhiro KAWAKATSU, Masanao ABE, Jun'ichiro KAWAGUCHI
    原稿種別: Technical Paper
    専門分野: Astronautics
    2009 年 7 巻 p. 33-41
    発行日: 2009年
    公開日: 2009/12/26
    ジャーナル フリー
    Reported in this paper are the results of a mission analysis conducted for an asteroid exploration mission. Following the results obtained from HAYABUSA, a Japanese asteroid explorer, the Japan Aerospace Exploration Agency has started studying the possibility of the next asteroid exploration mission. The mission studied gives priority to the “early” retrieval of a sample from an asteroid with a primitive composition. Therefore, the design of the spacecraft follows that of the HAYABUSA, basically as it is, and the spacecraft is planned to be launched early in the next decade. The objective of the mission analysis is to design a mission sequence which has a launch window early in the next decade, is feasible utilizing a HAYABUSA-type spacecraft, and whose target asteroid complies with the scientific objectives. The results include the selection of the target asteroid, the design of the nominal mission sequence, and the alternative sequence to overcome the drawbacks of the nominal sequence.
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