• Title/Summary/Keyword: STSAT-3

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The design and performance analysis of RS(255,223) code for X-band downlink of STSAT-3 (과학기술위성3호의 X-대역 하향링크를 위한 RS(255,223) 코드 설계 및 성능 분석)

  • Seo, In-Ho;Kim, Byung-Jun;Lee, Jong-Ju;Kwak, Seong-Woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.2
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    • pp.195-199
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    • 2010
  • (255,223) RS(Reed-Solomon) code which is the CCSDS(Consultative Committee for Space Data Systems) standard was used in the STSAT-3 to correct errors during the downlink of payload data. The RS encoder developed by VHDL was implemented in MMU(Mass Memory Unit). Moreover, the RS decoder developed by C-language was implemented in the DRS(Data Receiving System) of ground station. In this paper, we reported the design and analysis results of RS(255,223) for STSAT-3. The BER(Bit Error Rate) performance from MMU to DRS was confirmed through the downlink test at 16 Mbps. Also, the error correction performance and capability of RS(255,223) was tested by the manual attenuation of the RF(Radio Frequency) signal in the X-band transmitter resulting in putting some errors in the communication line.

Tolerance Analysis of Compact Imaging Spectrometer (COMIS) for a microsatellite STSAT3

  • Kim, Eun-Sil;Lee, Jun-Ho
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.27.2-27.2
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    • 2008
  • The STSAT-3 satellite was initiated in October 2006 and will be launched into a lower sun-synchronous earth orbit (~700km) in 2010. COMIS takes hyperspectral images of 30m/60m ground sampling distance over a 30km swath width. The payload will be used for environmental monitoring, such as in-land water quality monitoring of Paldang Lake located next to Seoul, the capital of South Korea. An extensive sensitivity and error budget analysis of COMIS optical system have been performed. As way of estimating aggregate effects of all tolerances, a Monte Carlo simulation is used.

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Inertia Estimation of Spacecraft Based on Modified Law of Conservation of Angular Momentum

  • Kim, Dong-Hoon;Choi, Dae-Gyun;Oh, Hwa-Suk
    • Journal of Astronomy and Space Sciences
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    • v.27 no.4
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    • pp.353-357
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    • 2010
  • In general, the information of inertia properties is required to control a spacecraft. The inertia properties are changed by some activities such as consumption of propellant, deployment of solar panel, sloshing, etc. Extensive estimation methods have been investigated to obtain the precise inertia properties. The gyro-based attitude data including noise and bias needs to be compensated for improvement of attitude control accuracy. A modified estimation method based on the law of conservation of angular momentum is suggested to avoid inconvenience like filtering process for noise-effect compensation. The conventional method is modified and beforehand estimated moment of inertia is applied to improve estimation efficiency of product of inertia. The performance of the suggested method has been verified for the case of STSAT-3, Korea Science Technology Satellite.

Dynamic Response Assessment of Space Use Telescope (우주용 광학구조체의 진동응답 평가)

  • Cho, Hee Keun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.1
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    • pp.87-93
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    • 2015
  • The dynamic responses of a telescope loaded on an STSAT-3 satellite were analyzed, and environmental tests were conducted to verify the reliability of the design. The space use telescope COMIS (compact imaging spectrometer) is a major payload of the STSAT-3 launched on November 21, 2013. Vibration responses such as the acceleration, displacement, and velocity with respect to random vibration and shock impulse inputs were obtained based on theoretical fundamentals in conjunction with finite element analysis. The main focus of this study was on developing technology for accurate and/or favorable modeling and analysis of the structure and fitting the results to that of experiments. Cutting-edge technology for manipulating the vibrations of a space use telescope is suggested.

Design Considerations of a Lithium Ion Battery Management System (BMS) for the STSAT-3 Satellite

  • Park, Kyung-Hwa;Kim, Chol-Ho;Cho, Hee-Keun;Seo, Joung-Ki
    • Journal of Power Electronics
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    • v.10 no.2
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    • pp.210-217
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    • 2010
  • This paper introduces a lithium ion battery management system (BMS) for the STSAT-3 satellite. The specifications of a lithium ion battery unit are proposed to supply power to the satellite and the overall electrical and mechanical designs for a lithium ion battery management system are presented. The structural simulation results will be shown to confirm the behavior of both the BMS and the cells.

Optical Design of A Compact Imaging Spectrometer for STSAT3

  • Lee, Jun-Ho;Jang, Tae-Seong;Yang, Ho-Soon;Rhee, Seung-Wu
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.262-268
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    • 2008
  • A compact imaging spectrometer (COMIS) for use in the STSAT3 microsatellite is currently under development. It is scheduled to be launched into a low Sun-synchronous Earth orbit (${\sim}700km$) by the end of 2010. COMIS was inspired by the success of CHRIS, which is a small hyperspectral imager developed for the ESA microsatellite PROBA. COMIS is designed to achieve nearly equivalent imaging capabilities of CHRIS in a smaller (65 mm diameter and 4.3 kg mass) and mechanically superior (in terms of alignment and robustness) package. Its main operational goal will be the imaging of Earth's surface and atmosphere with ground sampling distances of ${\sim}30m$ at the $18{\sim}62$ spectral bands ($4.0{\sim}1.05{\mu}m$). This imaging will be used for environmental monitoring, such as the in-land water quality monitoring of Paldang Lake, which is located next to Seoul, South Korea. The optics of COMIS consists of two parts: imaging telescope and dispersing relay optics. The imaging telescope, which operates at an f-ratio of 4.6, forms an image (of Earth's surface or atmosphere) onto an intermediate image plane. The dispersion relay optics disperses the image and relay it onto a CCD plane. All COMIS lenses and mirrors are spherical and are made from used silica exclusively. In addition, the optics is designed such that the optical axis of the dispersed image is parallel to the optical axis of the telescope. Previous efforts focused on manufacturing ease, alignment, assembly, testing, and improved robustness in space environments.

Error Correction Code and SEU Test Analysis of Mass Memory for STSAT-3 (과학기술위성 3호 대용량 메모리에 대한 오류복구 코드 및 SEU 시험 결과 분석)

  • Seo, In-Ho;Ryu, Kwang-Sun;Oh, Dae-Soo;Kim, Byung-Jun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.1
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    • pp.87-93
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    • 2010
  • RS(10,8) Code by 4-bit symbol was developed to protect the mass memory of STSAT-3 from SEU in orbit. Therefore, one symbol can be corrected for 32-bit data with 8-bit parity configuration. Moreover, scrubbing period and SEU occurrence rate was calculated based on the KITSAT-3 result. A prediction of SEU rates was performed based on the ground experiment results with a proton accelerator in the KIRAMS(Korea Institute of Radiological Medical Sciences).