• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.5
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• pp.507-517
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• 2010

The KOREAN AIR - R&D Center has developed a solar array for STSAT-2 Flight Model, SaTReC-KAIST, using a fully localized technology and has verified the performance through a launch vibration test, orbit environment test and electrical performance test. The solar array will be launched at NARO Space Center by KSLV-I which is the first Korean launch vehicle, in May 2010. In this paper, a current-voltage curve that shows the power characteristics of solar arrays was derived by applying elements that affects the power performance of STSAT-2's solar arrays to the solar cell equivalent models. The result was compared to LAPSS test results, and accuracy of the solar cell equivalent model and the power performance simulation has been analyzed.

• 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.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.31.4-32
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• 2008

The microwave instruments are used many areas of the space remote sensing and space science applications. The imaging radar of synthetic aperture radar (SAR) is well known microwave radar sensor for earth surface and ocean research. Unlike radar, microwave radiometer is passive instrument and it measures the emission energy of target, i.e. brightness temperature BT, from earth surface and atmosphere. From measured BT, the geophysical data like cloud liquid water, water vapor, sea surface temperature, surface permittivity can be retrieved. In this paper, the radiometer characteristics, system configuration and principle of BT measurement are described. Also the radiometer instruments TRMM, GPM, SMOS for earth climate, and ocean salinity research are introduce. As first korean microwave payload on STSAT-2, the DREAM (Dual-channels Radiometer for Earth and Atmosphere Monitoring) is described the mission, system configuration and operation plan for life time of two years. The main issues of DREAM unlike other spaceborne radiometers, will be addressed. The calibration is the one of main issues of DREAM mission and how it contribute on the space borne radiometer. In conclusion, the radiometer instrument to space science application will be considered.

• 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.

• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.96-100
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• 2006

We develop the Dual Head Star Tracker (DHST) to obtain the attitude information of science and Technology Satellite2 (STSAT-2). Because most of star sensor has only one head camera, star recognition is impossible when camera point to sun or earth. We therefore considered the DHST which can obtain star images from two spots simultaneously. That is, even though we fail a star recognition from an image obtained by one camera, it is possible to recognize stars from an image obtained by the other camera. In this paper, we introduce engineer model (EM) of the DHST and propose a star recognition and a star track algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.460-465
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• 2007

This paper deals with the Fine Digital Sun Sensor (FDSS) for Science & Technology Satellite 2(STSAT-2). The FDSS was firstly developed by using CMOS-Image sensor(CIS) in South Korea. This paper will describe the configuration of the FDSS, the design of the optical part, the analysis result of the optical characteristics of the sunlight, and the calibration result measured by solar simulator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.1
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• pp.95-102
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• 2006

The PPT being currently developed for the flight model represents a significant leap in techniques and technology compared to the previous flight ones. The electrical energy to be charged in the pulsed plasma thruster (PPT) is a very important aspect to provide an uniform impulse bit ,, and a specific impulse ,, for satellite attitude control. In this paper, we propose a nonlinear control technique and a stability analysis based on the Lyapunov function for the pulsed plasma thruster. Specifically, the proposed control law guarantees to charge and discharge the electrical energy generated from the power processing unit (PPU) within the specified time.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.205.2-205.2
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• 2012

MIRIS (Multipurpose Infra-Red Imaging System), the main payload of STSAT-3 (Science and Technology Satellite-3), is the first Korean Infrared Space Telescope developed by KASI (Korea Astronomy and Space Science Institute). The FM (fight model) of MIRIS has been recently completed, and various performance tests have been made to measure system parameters such as readout noise, system gain, linearity, and dark current. The MIRIS FM has been integrated to the satellite system for the environment tests scheduled in September 2012. The MIRIS is expected to be launched in November 2012.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.104-104
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• 2004