• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.842-847
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• 2010

Thermal analysis for the simulation of satellite component level thermal vacuum test processes was carried out by considering thermal vacuum test environment condition, thermal vacuum chamber configuration, and satellite's inner thermal environment. The transient analysis results can be obtained for the temperatures of component and thermal vacuum chamber assemblies. The thermal analysis model was verified with the component thermal environmental test results by using enhanced thermal vacuum chamber.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.739-748
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• 2021

This paper discusses the prediction and validation of design loads of satellite components using modal mass acceleration curve (Modal MAC). To calculate the acceleration upper bound of the satellite components subjected to the launch environment by the Modal MAC, the parameters of SpaceX Falcon 9 launch vehicle were used, and the acceleration upper bound curve in the modal domain was derived. After that, the maximum acceleration loads applied to the satellite components were predicted by combining Modal MAC with the spacecraft interface loads of the satellite/launch vehicle and modal information of the satellite. In addition, the accuracy of the Modal MAC was validated through comparison with the results of the coupled loads analysis using a simple satellite and launch vehicle model.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.57-62
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• 2010

SAR payload of LEO satellite will consume about 150A current. This high current makes the voltage drop between battery, satellite main bus and payload interface, which cannot guarantee the input voltage level of the satellite electrical unit and payload. So, it is necessary to predict the main bus and payload input voltage level when the payload works. In this paper, the worst case analysis of the harness and contact resistance was executed and predicted the voltage drop when the payload works.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.319-326
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• 2002

Laboratory tests have been carried out for investigation of the spectroscopic characteristics at visible wavelength of 12 common satellite materials used in satellite bus and payload. The obtained spectral data show that the materials can be classified and identified since their spectral features and albedos distinctly differ among them. It is suggested that the result of the laboratory tests for the satellite materials can be used for the predictions of material types, material composition ratios, sizes, and masses in comparison with the spectral data obtained from observations of new satellites or space debris.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.105-105
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• 2003

인공위성의 개발과정에서 비행모델을 만들기 전 EM (Engineering Model) 들로 구성하는 Electrical Test Bed (ETB) 를 개발하여 위성의 하니스를 포함함 각 서브시스템 전장품들의 성능을 점검하게 되고, ETB 시험기간 동안 발생된 문제점 들은 비행모델 설계와 제작에 반영하게 된다. 다목적실용위성 2호에 대한 ETB를 개발하여 각종 위성 전장품에 대한 성능과 부분품들간의 인터페이스 신호들의 점검을 성공적으로 완료하였으며, 시험기간 동안 발생된 각종 문제점들은 비행모델 설계와 제작에 이미 반영하였다. 본 논문에서는 다목적실용위성 2호 비행모델에 대한 시험을 위하여 각 서브시스템 즉, 원격측 정명령계, 전력계, 자세제어계의 전장품과 탑재소프트웨어 그리고 각종 시뮬레이터들의 구성과 전기/전자적인 기능시험을 위한 시험항목 및 방법에 대해 고찰하고자 한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.5
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• pp.466-473
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• 2011

The purpose of satellite thermal control design is to maintain all the elements of a spacecraft system within their temperature limits for all mission phases. The thermal analysis model for Low Earth Orbit satellite payload level simulation is established by considering thermal vacuum test environment condition, thermal vacuum chamber configuration, and satellite's payload inner thermal environment. The established thermal analysis model is used to determine thermal vacuum test conditions and test case requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.105-111
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• 2003

A measurement of spacecraft alignment is an important process of spacecraft assembly, integration and test. Because, it is necessary that a operator of a ground station controls the precise positions of on-orbit spacecraft by using the alignment data of attitude orbit control sensors(AOCS) on spacecraft. And, an accuracy of spacecraft alignment requirement is about $0.1^{\circ}{\sim}0.7^{\circ}$. A spacecraft alignment is measured by autocollimation of theodolite. This paper describes the measurement principle and method of spacecraft alignment. The result shows that all the AOCS on the spacecraft are aligned within the tolerance required through the alignment measurement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1399-1404
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• 2012

Because satellites operate in space, it is impossible to repair them when they malfunction. Therefore, to ensure the normal function of the payload used in the satellites, accurate assembly and installation of parts are crucial. To prevent abnormal functioning in the extreme environments during launch and in space, it is essential to test changes at the parts and system levels by performing alignment measurement before and after the launch environment test and the space environment test. Recently, noncontact three-dimensional precision machinery for medium- and large-sized parts has been developed. One of these is the theodolite measurement system, which is widely used in the aerospace industry. This study measures the angle of the dual thruster module that is used to control the attitude of KOMPSAT by using a theodolite, and alignment measurement and a reliability analysis are performed.

• Journal of Aerospace System Engineering
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• v.13 no.2
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• pp.66-72
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• 2019

The observation satellites which uses high heat-dissipating equipment such as synthetic aperture radar (SAR) satellites require a radiator to transmit heat from the equipment into outer space. However, during cold conditions it requires a heater to maintain the temperature of equipment within the allowable minimum limit when it is not in operation. In this study, we proposed a variable conductivity radiator that changes its thermal conductivity value through movement of the liquid metal between two reservoirs based on the temperature condition. This reduces the power consumption of the heater by limiting heat transfer path to the radiator in cold condition, while effectively transferring heat to the radiator during hot condition. The feasibility of the proposed radiator was validated through comparison of the thermal control performance with the conventional fixed conductivity radiator via a thermal analysis.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.1-7
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• 2022

Recently, satellites equipped with high-performance electronics have required higher power consumption because of the advancement of satellite missions. For this reason, the size of the solar panel is gradually increasing to meet the required power budget. Increasing the size and weight of the solar panel is one of the factors that induce the elastic vibration of the flexible solar panel during the highly agile maneuvering of the satellite or the mode of vibration coupling to the satellite or the mode of vibration coupling to the micro-jitter from the on-board appendages. Previously, an additional damper system was applied to reduce the elastic vibration of the solar panel, but the increase in size and mass of system was inevitable. In this study, to overcome the abovementioned limitations, we proposed a high -damping yoke structure consisting of a superplastic SMA(Shape Memory Alloy) laminating a thin FR4 layer with viscoelastic tape on both sides. Therefore, this advantage contributes to system simplicity by reducing vibrations with small volume and mass without additional system. The effectiveness of the proposed superelastic SMA multilayer solar panel yoke was validated through free vibration testing and temperature testing using a solar panel dummy.