• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.110-112
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• 2003

The researchers, who seek geological and environmental information, depend on the remote sensing and aerial photographic datum from various commercial satellites and aircraft. However, the adverse weather conditions and the expensive equipment can restrict that the researcher can collect their data anywhere and any time. To allow for better flexibility, we have developed a compact, a multispectral automatic Aerial photographic system. This system's Multi-spectral camera can catch the visible (RGB) and infrared (NIR) bands (3032${\ast}$2008 pixel) image. Our system consists of a thermal infrared camera and automatic balance control, and it managed and controlled by a palm-top computer. And it includes a camera gimbals system, GPS receiver, weather sensor and etc. As a result, we have successfully tested its ability to acquire aerial photography, weather data, as well as GPS data, making it a very flexible tool for environmental data monitoring.

• 한국전산유체공학회지
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• 제10권3호
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• pp.63-69
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• 2005

The COMS, the first meteorological geostationary satellite in Korea, is under development by KARI. The radiator size and the heater power for the thermal control of COMS are calculated using an analytic method. The total radiator area of $4.85\;m^2$ and the total heater power of 794.77 W are determined at a conceptual design of COMS. The commercial software, SINDA and TRASYS, are utilized in order to compare and verify the analytic results. The results of on-orbit numerical simulation of cold and hot cases show that the radiator size and heater power obtained from the analytic method are appropriate to maintain COMS equipments within required temperature ranges.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.364-367
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• 2004

This paper presents the flight software of KoDSat (KSLV-l Demonstration Satellite) which performs demonstrating the KSLV-l (Korea Space Launch Vehicle-l)'s satellite launch capability. The KoDSat Flight Software executes in a single-processor, multi-function flight computer on the spacecraft, the OBC (On Board Computer). The flight software running on the single processor is responsible for all real-time processing associated with: processor startup and hardware initialization, task scheduling, RS422 handling function, command and data handling including uplink command and down-link telemetry, attitude determination and control, battery state of charge monitoring and control, thermal control processing.

• 한국수산과학회지
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• 제56권5호
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• pp.660-666
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• 2023

This study aimed to examine the effect of external pop-up satellite archival tags (PSATs) attachment and water temperature on the oxygen consumption rate (OCR) of the olive flounder (mean body weight 2281.7 g). The OCRs of fish were measured under conditions of three different water temperature conditions (15, 20, and 25℃) and two different tagging methods [non-tagging, control; bio-logger external attachment with a miniature PSAT (dummy mrPAT), BEA] using a closed flow-through respirometer. The OCRs of fish linearly increased with the increase in water temperature in both the control and BEA (P<0.001); however, the OCRs of BEA were approximately 1.8-1.9 times lower than those of the control at each water temperature (P<0.001). The Q₁₀ values of the control and BEA were the highest in the water temperature range of 15 to 20℃, but sensitivity to water temperature changes was higher in BEA than in the control. The metabolic energy loss rate (MEL) of fish increased with increasing water temperature regardless of external tagging, but the MEL of the control was higher than that of BEA (P<0.001). These results demonstrate that OCR, thermal sensitivity, and energy expenditure are all affected in adult olive flounder with external PSAT attachment.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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• pp.25-29
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• 2007

마이크로 인공위성의 자세제어를 위한 마이크로 추진장치에 대한 연구는 대부분 기존의 추진장치를 소형화하는 방향으로 진행되고 있다. 본 연구에서는 이러한 미소추력 발생을 위한 노즐의 소형화로 인한 점성손실, 배압에 의한 손실 등을 대기압실험, 진공환경실험, CFD 해석을 통하여 검증하였다. 또한 마이크로 노즐에서의 유동 손실을 극복하기 위한 방법으로 열적발산원리에 대해 이론적 접근을 시도하였다. 마이크로 추진장치에 적용을 위한 열적발산원리는 움직이는 부품 없이 오직 온도 구배만으로 유동을 제어할 수 있기 때문에 추진장치의 소형화로 야기되는 손실을 극복할 수 있을 것으로 기대된다.

• 한국항공우주학회지
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• 제43권10호
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• pp.875-887
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• 2015

최적 배치 설계는 다양한 산업분야에서 활용되고 있다. 우주분야인 위성 플랫폼에서도 제한된 공간 내에서 기계적, 열적, 전기적 인터페이스를 고려한 구성품 배치가 가능하도록 최적 배치 설계가 요구된다. 최적 배치 설계를 통해 합리적인 수준에서 최소화된 위성 플랫폼의 관성모멘트는 위성의 효율적인 자세제어 및 신속한 기동을 가능하게 하며, 위성의 임무성능을 향상시키는데 도움을 준다. 이를 위해 본 논문에서는 육면체 구조의 위성 플랫폼을 기반으로 내부 구성품들이 서로 간섭이 없는 상태에서 위성의 관성모멘트와 구성품 간 발열로 인한 영향을 최소로 하는 3D 최적 배치 설계를 제안한다. 본 연구에서는 3D 최적 배치 설계를 위해 새로운 유전 알고리즘을 제안한다.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.526-534
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• 2016

A MEMS solid propellant thruster array shall be operated within an allowable range of operating temperatures to avoid ignition failure by incomplete combustion due to a time delay in ignition. The structural safety of the MEMS thruster array under severe on-orbit thermal conditions can also be guaranteed by a suitable thermal control. In this study, we propose a thermal control strategy to perform on-orbit verification of a MEMS thruster module, which is expected to be the primary payload of the STEP Cube Lab mission. The strategy involves, the use of micro-igniters as heaters and temperature sensors for active thermal control because an additional heater cannot be implemented in the current design. In addition, we made efforts to reduce the launch loads transmitted to the MEMS thruster module at the system level structural design. The effectiveness of the proposed thermo-mechanical design strategy has been demonstrated by numerical analysis.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.229-234
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• 2002

Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

• 한국항공우주학회지
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• 제40권3호
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• pp.237-242
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• 2012

극저온이 요구되는 우주용 탑재장비의 냉각을 위해 일반적으로 Pulse Tube-type 압축기가 적용되고 있으며, 궤도상에서 압축기의 냉각성능, 임무수명 및 비대칭 온도분포에 의한 미소진동발생 방지를 위해 압축기를 허용온도 범위로 유지하는 열제어가 필요하다. 압축기는 궤도 운용 시 미소진동을 발생하여 관측성능이 요구되는 탑재체의 지향성능을 저하시키는 원인으로 작용한다. 본 논문에서는 압축기의 미소진동 방지를 목적으로 적용된 진동절연기의 성능유지 및 압축기의 허용온도범위 유지를 위한 열제어 성능을 동시에 만족하는 우주용 압축기 조립체의 열설계를 제안하였으며, 설계의 유효성을 해석적으로 입증하였다.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1377-1384
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• 2003

An analysis has been performed for active thermal control of the KOMPSAT monopropellant rocket engine assembly, i.e., dual thruster module(DTM). The main efforts of this work have been directed at determining proper heater sizes for propellant valves and catalyst beds necessary to maintain their temperatures within specified temperature ranges under KOMPSAT environment and operational conditions. The TAS incorporated with TRASYS thermal radiation analyzer was used to establish a complete heat transfer model which allows to predict the DTM temperature as a function of time. The thermal analysis has been performed in transient mode to verify the appropriate power for catalyst bed heaters necessary to increase catalyst bed temperature to the required value within a specified period of time. Similar analysis has been executed to validate the heater power for the thermostatically controlled primary and redundant heater circuits used to prevent hydrazine freezing, i.e., single fault. Moreover the effect of the radiative property of thermal control coating of heat shield was examined. Thruster firing condition was also simulated for the heat soakback condition. As a consequence, all thermal analysis results for DTM satisfactorily met the thermal requirements for the KOMPSAT DTM under the worst case average voltage, i.e. 25 volt.