• Title/Summary/Keyword: STSAT-3

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Ground Station Design for STSAT-3

  • Kim, Kyung-Hee;Bang, Hyo-Choong;Chae, Jang-Soo;Park, Hong-Young;Lee, Sang-Hyun
    • International Journal of Aeronautical and Space Sciences
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    • v.12 no.3
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    • pp.283-287
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    • 2011
  • Science and Technology Satellite-3 (STSAT-3) is a 150 kg class micro satellite based with the national space program. The STSAT-3 system consists of a space segment, ground segment, launch service segment, and various external interfaces including additional ground stations to support launch and early operation phases. The major ground segment is the ground station at the Satellite Technology Research Center, Korea Advanced Institute of Science and Technology site. The ground station provides the capability to monitor and control STSAT-3, conduct STSAT-3 mission planning, and receive, process, and distribute STSAT-3 payload data to satisfy the overall missions of STSAT-3. The ground station consists of the mission control element and the data receiving element. This ground station is designed with the concept of low cost and high efficiency. In this paper, the requirements and design of the ground station that has been developed are examined.

Analysis and Comparison of Error Detection and Correction Codes for the Memory of STSAT-3 OBC and Mass Data Storage Unit (과학기술위성 3호 탑재 컴퓨터와 대용량 메모리에 적용될 오류 복구 코드의 비교 및 분석)

  • Kim, Byung-Jun;Seo, In-Ho;Kwak, Seong-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.2
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    • pp.417-422
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    • 2010
  • When memory devices are exposed to space environments, they suffer various effects such as SEU(Single Event Upset). Memory systems for space applications are generally equipped with error detection and correction(EDAC) logics against SEUs. In this paper, several error detection and correction codes - RS(10,8) code, (7,4) Hamming code and (16,8) code - are analyzed and compared with each other. Each code is implemented using VHDL and its performances(encoding/decoding speed, required memory size) are compared. Also the failure probability equation of each EDAC code is derived, and the probability value is analyzed for various occurrence rates of SEUs which the STSAT-3 possibly suffers. Finally, the EDAC algorithm for STSAT-3 is determined based on the comparison results.

STSAT-3 Operations Concept (과학기술위성 3호 운영개념)

  • Lee, Seung-Hun;Park, Jong-Oh;Rhee, Seung-Wu;Jung, Tae-Jin;Lee, Dae-Hee;Lee, Joon-Ho
    • Aerospace Engineering and Technology
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    • v.10 no.2
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    • pp.29-36
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    • 2011
  • The Science and Technology Satellite-3 (STSAT-3) is based on the KITSAT-1, 2, 3 and STSAT-1, 2 which were Korea micro-satellites for the mission of space and earth science. The objectives of the STSAT-3 are to support earth and space sciences in parallel with the demonstration of spacecraft technology. The STSAT-3 carries an infrared (IR) camera for space & earth observation and an imaging spectrometer for earth observation. The IR payload instrument of the STSAT-3, Multi-purpose Infrared Imaging System (MIRIS), will observe the Galactic plane and North/South Ecliptic poles to research the origin of universe. The secondary payload instrument, Compact Imaging Spectrometer (COMIS), images the Earth's surface. The data acquired from COMIS are expected to be used for various application fields such as monitoring of disaster management, water quality studies, and farmland assessment. In this paper we present the operations concept of STSAT-3 which will be launched into a sun-synchronous orbit at a nominal altitude of 600km in late 2012.

Design and Implementation of Engineering Qualification Model of S-Band Transmitter for STSAT-3 (과학기술위성 3호 S-대역 송신기 인증모델 설계 및 제작)

  • Oh, Seung-Han;Seo, Gyu-Jae;Oh, Dae-Soo;Lee, Jung-Soo;Oh, Chi-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.1
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    • pp.80-86
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    • 2010
  • This paper describes the development result of S-band Transmitter of STSAT-3 by satellite research center(SaTReC), KAIST. STSAT-3 has two kinds of communication channels, S- band for Telemetry & Command and X-band for mission payload. S-band Transmiiter(STX) consist of modulator, frequency synthesizer, power amp and DC/DC converter. The modulation scheme of STX is FSK(Frequency Shift Keying). The interface between spacecraft OBC and STX is RS-422. The STX is based on modular design. The RF output power of STX is 1.5W(31.7dBm) and BER of STX is under 1E-5. The Test of STX is completed successfully such as functional Test and environmental(vibration, thermal vacuum) Test.

Engineering Qualification Model Development of S-band Receiver for STSAT-3 (과학기술위성 3호 S 대역 수신기 기술인증모델 개발)

  • Lee, Jung-Su;Oh, Seung-Han;Seo, Gyu-Jae;Oh, Chi-Wook;Myung, Noh-Hoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.6
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    • pp.609-614
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    • 2009
  • The TT&C communication subsystem of STSAT-3 is consisted of communication link to send telemetry data of spacecraft to the ground station and receive command data from ground station. The S-band receiver is used to receive command data from ground station, Engineering Qualification Model of S-band receiver has been designed and manufactured. The Designed S-band Receiver uses a single conversion for a simple frequency conversion, including a DC-DC Converter and EMI Filter. Also, Digital demodulation part designed using FPGA and RS-422 data interface. The performance of S-band Receiver in functional and space environments test satisfies the requirements of STSAT-3.

Analysis of STSAT-3 Jitter due to the Reaction Wheel Disturbance (반작용 휠의 외란에 의한 STSAT-3 지터 분석)

  • Kim, Dong-Hoon;Cheon, Dong-Ik;Oh, Hwa-Suk;Lee, Sangchul;Bang, Hyochoong;Rhee, Seung-Wu
    • Journal of Aerospace System Engineering
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    • v.1 no.3
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    • pp.32-36
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    • 2007
  • When the reaction wheel rotates, the disturbance occurs mainly due to the mass imbalance. It is necessary to predict the effect of disturbance on the attitude stability of the satellite. The disturbance forces and torques are identified and the attitude jitter of the satellite is analyzed depending on the configuration of the wheels. On the analysis the equation of the satellite motion is combined with the translational and rotational dynamics of the wheels. The accuracy of analysis is verified by simulation of STSAT-3 satellite.

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A Study on Real-Time Inertia Estimation Method for STSAT-3 (과학기술위성 3호 실시간 관성모멘트 추정 기법 연구)

  • Kim, Kwangjin;Lee, Sangchul;Oh, Hwa-Suk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.20 no.4
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    • pp.1-6
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    • 2012
  • The accurate information of mass properties is required for the precise control of the spacecraft. The mass properties, mass and inertia, are changeable by some reasons such as consumption of propellant, deployment of solar panel, sloshing, environmental effect, etc. The gyro-based attitude data including noise and bias reduces the control accuracy so it needs to be compensated for improvement. This paper introduces a real-time inertia estimation method for the attitude determination of STSAT-3, Korea Science Technology Satellite. In this method we first filter the gyro noise with the Extended Kalman Filter(EKF), and then estimate the moment of inertia by using the filtered data from the EKF based on the Recursive Least Square(RLS).

Design, Implementation and Test of Flight Model of S-Band Transmitter for STSAT-3 (과학기술위성 3호 S-대역 송신기 비행모델 설계, 제작 및 시험)

  • Oh, Seung-Han;Seo, Gyu-Jae;Lee, Jung-Soo;Oh, Chi-Wook;Park, Hong-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.6
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    • pp.553-558
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    • 2011
  • This paper describes the development and test result of S-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels, S-band for Telemetry & Command and X-band for mission data. S-band Transmitter(STX) functionally made of modulator, frequency synthesizer, power amp and DC/DC converter. The transmission data is modulated by FSK(Frequency Shift Keying) and the interface between spacecraft sub-module and STX is RS-422 standard method. The FM STX is based on modular design. The RF output power of STX is 1.5W(31.7dBm) and BER of STX is under $1{\times}10^{-5}$ which meets the specification respectively. The FM STX is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

Design, Implementation and Test of Flight Model of X-Band Transmitter for STSAT-3 (과학기술위성 3호 X-대역 송신기 비행모델 설계, 제작 및 시험)

  • Seo, Gyu-Jae;Lee, Jung-Soo;Oh, Chi-Wook;Oh, Seung-Han;Chae, Jang-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.5
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    • pp.461-466
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    • 2012
  • This paper describes the development and test result of X-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels. S-band frequency is used for Telemetry & Command, and X-band frequency is used for mission data. Payload observations data in Mass Memory Unit (MMU) is modulated by QPSK modulator in X-band Transmitter, and then QPSK modulation signal is transmitted to antenna through transfer switch. In this Paper, we described the results of modulation, low-pass filter design, power amp development, and switch test. The FM XTU is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

SEU Mitigation Strategy and Analysis on the Mass Memory of the STSAT-3 (과학기술위성 3호 대용량 메모리에서의 SEU 극복 및 확률 해석)

  • Kwak, Seong-Woo
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.4
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    • pp.35-41
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    • 2008
  • When memory devices are exposed to a space environment. they suffer various effects such as SEU(Single Event Upset). For these reasons, memory systems for space applications are generally equipped with error detection and correction(EDAC) logics against SEUs. In this paper, the error detection and correction strategy in the Mass Memory Unit(MMU) of the STSAT-3 is discussed. The probability equation of un-recoverable SEUs in the mass memory system is derived when the whole memory is encoded and decoded by the RS(10,8) Reed-Solomon code. Also the probability value is analyzed for various occurrence rates of SEUs which the STSAT-3 possibly suffers. The analyzed results can be used to determine the period of scrubbing the whole memory, which is one of the important parameters in the design of the MMU.