• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.248-250
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• 2003

Thermal analysis is performed to protect the propulsion system of low-earth-orbit earth observation satellite from unwanted thermal disaster like propellant freezing. To implement thermal design adequately, heater powers for the propulsion system estimated through the thermal analysis are decided. Based on those values anticipated herein, the average power for propulsion system becomes 22.02 watts when the only one redundant catalyst bed heater is turned on. When for the preparation of thruster firing, 25.93 watts of the average power is required. All heaters selected for propulsion components operate to prevent propellant freezing meeting the thermal requirements for the propulsion system with the worst-case average voltage, i.e. 25 volts.

• International Journal of Aeronautical and Space Sciences
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• 제6권1호
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• pp.61-70
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• 2005

The currently developed propulsion system(PS) is composed of propellant tank, valves, thrusters, interconnecting line assembly and thermal hardwares to prevent propellant freezing in the space environment. Comprehensive engineering analyses in the structure, thermal, flow and plume fields are performed to evaluate main design parameters and to verify their suitabilities concurrently at the design phase. The integrated PS has undergone a series of acceptance tests to verify workmanship, performance, and functionality prior to spacecraft level integration. After all the processes of assembly, integration and test are completed, the PS is integrated with the satellite bus system successfully. At present, the severe environmental tests have been carried out to evaluate functionality performances of satellite bus system. This paper summarizes an overall development process of monopropellant propulsion system for the attitude and orbit control of LEO(Low Earth Orbit) observation satellite from the design engineering up to the integration and test.

• 한국항공우주학회지
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• 제37권7호
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• pp.709-716
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• 2009

위성 궤도 자세는 위성 열설계에 영향을 주는 중요한 요소로서, 궤도 운용 자세에 대한 열적 조건을 정확히 파악하는 것을 필요로 한다. 본 연구에서는 저궤도 위성의 yaw motion의 운영 자세에 따른 우주 열환경의 변화와 열설계의 열적 영향을 검토하였다. 본 위성은 고정형의 태양 전지판을 가지고 있기 때문에 태양광 구간 동안에 태양지향(sun-pointing)자세를 유지하고, 위성에 장착되는 별센서인 별추적기의 가시 방향이 심층 우주방향을 향하도록 하기 위하여 위성의 길이 방향을 축으로 일정한 각속도로 회전을 하는 yaw motion을 하도록 운용된다. 이것은 위성이 정밀한 자세 제어의 성능을 발휘할 수 있도록 별추적기가 별의 시야각을 확보하기 위한 것이다. 또한 위성 열설계 측면에서는 이러한 운용을 위한 자세 변화에 따른 열적 영향을 파악하는 것을 필요로 한다. 연구에서는 위성의 열모델에 이러한 궤도 운용 자세를 반영한 후의 궤도 열해석을 통하여 이를 알아보고자 한다.

• 한국전산유체공학회지
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• 제15권3호
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• pp.66-72
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• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat and utilize several heat pipe networks to control the temperatures of units and the main structures of satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary satellite design stage, so several thousands of nodes or more are utilized in order to perform detailed thermal analysis of panel. Generating a large number of panel nodes takes time and is tedious work because the nodes can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required to generate a detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of the panel thermal analysis program with its main modules and functions.

• 한국전산유체공학회지
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• 제19권4호
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• pp.37-44
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• 2014

A detailed satellite panel thermal model composed of more than thousands nodes can not be directly integrated into a spacecraft thermal model due to its node size and the limitation of commercial satellite thermal analysis programs. For the integration of the panel into the satellite thermal model, a reduced thermal model having proper accuracy is required. A thermal model reduction method was developed and validated by using a geostationary satellite panel. The temperature differences of main components between the detailed and the reduced thermal model were less than $1^{\circ}C$ in steady state analysis. Also, the dynamic responses of the detailed and the reduced thermal model show very similar trends. Thus, the developed reduction method can be applicable to actual satellite thermal design and analysis with resonable accuracy and convenience.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2007년도 한국우주과학회보 제16권2호
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• pp.89.2-89.2
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• 2007

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.416-421
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• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat dissipation of electronics units and utilize several heat pipe networks to control the temperatures of units and the satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary design stage so several thousands of nodes of more are utilized in order to perform thermal analysis of panel. Generating a large number of nodes(meshes) of the panel takes time and is tedious work because the mesh can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required in order to generate detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of panel thermal analysis program with ist main modules and its main functions.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.199-202
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean observation and meteorological observation. Conventional thermal control design, using MLI (Multi Layer Insulation), OSR (Optical Solar Reflector), heater and heat pipe, is utilized. Ka-band components are installed on South wall, while other equipment for sensors are installed on the opposite side, North wall. High dissipating communication units are located on external (surface) heat pipe and are covered by internal insulation blankets to decouple them from the rest of the satellite. External satellite walls are covered by MLI or OSR for insulation from space and for rejection internal heat to space. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. Single solar array wing is adopted in order to secure clear field of view of radiant cooler of IR meteorological sensor. This paper presents principles of thermal control design for the COMS.

• 한국항공우주학회지
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• 제37권9호
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• pp.916-922
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• 2009

우주공간에서 임무를 수행하는 인공위성의 열설계는 열모델을 활용한 열해석 결과를 바탕으로 수행되므로, 열모델의 정확성은 매우 중요하며 이것은 보정과정을 통하여 향상된다. 열모델의 보정은 인공위성이 열진공 챔버에 장착된 형상을 모사하는 모델링에서 시작하여 실제형상과 열모델간의 일치성에 대한 검증, 거시적 변수에서부터 미시적 변수에 이르기까지 열모델 변수에 대한 조정 등을 거쳐 주어진 성공 조건을 만족할 때까지 열모델을 지속적으로 수정하는 과정으로 이루어진다. 본 연구에서는 열모델 보정의 성공 기준을 수립하고 인공위성 열-구조 모델 열진공 시험결과를 활용한 열모델 보정을 수행하여 보정 기준을 충족시켰다. 본 연구에서 보정이 완료된 열모델은 저궤도 인공위성 상세 열설계에 적용될 수 있었다.

• 항공우주시스템공학회지
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• 제7권3호
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• pp.26-32
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• 2013

Passive attitude stabilization method has been widely usde for attitude determination and control of cube satellite due to its advantage of system simplicity. The permanent magnet installed on the cube satellite passively controls the attitude of the satellite such that the satellite is aligned with the earth magnetic field. In this paper, on-orbit thermal behavior of the cube satellite with the permanent magnet attitude stabilization method has been investigated through on-orbit thermal analysis. THe orbit profile obtained from the aforementioned attitude control method has been reflected in the analysis. The analysis results indicate that the thermal design proposed in this study is effective for satisfying the temperature requirements of the commericial mission equipments.