• Journal of Astronomy and Space Sciences
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• v.29 no.1
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• pp.23-31
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• 2012

Thermal analysis and control design are prerequisite essential to design the satellite. In the space environment, it makes satellite survive from extreme hot and cold conditions. In recent years CubeSat mission is developed for many kinds of purpose. Triplet Ionospheric Observatory (TRIO)-CubeSat for Ion, Neutral, Electron, MAgnetic fields (CINEMA) is required to weigh less than 3 kg and operate on minimal 3 W power. In this paper we describe the thermal analysis and control design for TRIO-CINEMA mission. For this thermal analysis, we made a thermal model of the CubeSat with finite element method and NX6.0 TMG software is used to simulate this analysis model. Based on this result, passive thermal control method has been applied to thermal design of CINEMA. In order to get the better conduction between solar panel and chassis, we choose aluminum 6061-T6 for the material property of standoff. We can increase the average temperature of top and bottom solar panels from $-70^{\circ}C$ to $-40^{\circ}C $ and decrease the average temperature of the magnetometer from $+93^{\circ}C$ to $-4^{\circ}C$ using black paint on the surface of the chassis, inside of top & bottom solar panels, and magnetometer.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.795-801
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• 2014

STEP Cube Lab. classified as a pico-satellite has been being developed by SSTL(Space Technology Synthesis Laboratory) in Chosun University. Its main mission objective is to perform the on-orbit verification of core space technologies, which will be the potential candidates for future space missions. In this paper, to guarantee successful mission operation of the cube satellite under extremely severe space thermal environment condition, the system level thermal design and analysis has been performed. The effectiveness of the design has been verified through on-orbit thermal analysis of cube satellite.

• Journal of computational fluids engineering
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• v.15 no.1
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• pp.24-30
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• 2010

A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. The results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature and shutter wheel motor gradient are found slightly out their specification, therefore further detailed analyses should be continued on these elements.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.227-236
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• 2018

The focus control mechanism of the multi-purpose camera can be required for the better quality image acquisition. A good image acquisition through the hardware system including the optics and image sensor, has to be processed before the post correction for improvement of image quality. In the case of the high-resolution satellite camera, the focus control is not a necessity, unlike a normal camera due to a fixed optical system, but may be required due to various reasons. Although there is a basic focus control method using a motor for satellite electronic optical camera, a focus control method using thermal control can be a good alternative because of its various advantages in design, installation, operation, contamination, high reliability and etc. In this paper, we describe the design method and implementation results for the focus control mechanism using the temperature sensor and heater installed in the telescope structure. In the proposed focus control method, the measured temperature information is converted into temperature data by the Kalman filter and the converted temperature data are used in PI controller for the thermal focus control.

• Corrosion Science and Technology
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• v.18 no.5
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• pp.182-189
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• 2019

A thin spray coating of inorganic black lithium polysilicate (IBLP) on black anodized AZ31B magnesium alloy was fabricated for better corrosion resistance and thermo-optical properties for thermal control of spacecraft components. The morphology of the specimens with and without IBLP-based spray coating was characterized by SEM-EDS techniques. Impedance and potentiodynamic measurements on the specimens revealed better corrosion resistance for the specimen with a thin coating of lithium polysilicate. This was primarily due to the presence of lithium polysilicate inside the micro-cracks of the black anodized specimen, restricting the diffusion paths for corrosive media. Environmental tests, namely, humidity, thermal cycling, thermo vacuum performance, were used to evaluate the space-worthiness of the coating. The thermo-optical properties of the coating were measured before and after each environmental test to ascertain its stability. The specimen with an IBLP-based spray coating showed enhanced thermo-optical properties, greater than ~0.90. Hence, the proposed coating demonstrated better handling, better corrosion resistance, and space-worthiness during the pre-launch phase owing to its improved thermo-optical properties.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.798-804
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• 2009

A high-resolution electro-optical camera system, EOS-C, is under development in Satrec Initiative. This system is the mission payload of a 400-kg Earth observation satellite. We designed this system to give improved opto-mechanical and thermal performance compared with a similar camera system to be flown on the DubaiSat-1 system. The thermal control subsystem (TCS) of the EOS-C system uses heaters to meet the opto-mechanical requirements during in-orbit operation and it uses different thermal coating materials and multi-layer insulation (MLI) blankets to minimize the heater power consumption. We performed its thermal analysis for the mission orbit using a thermal analysis model and the result shows that its TCS satisfies the design requirements.

• Journal of the Korean Magnetics Society
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• v.16 no.3
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• pp.182-185
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• 2006

In this work, we have constructed 3-axis flux-gate magnetometer for the attitude control of satellite. The constructed magnetometer shows uncertainty of ${\pm}1%$, noise level of $0.2nT/\sqrt{Hz}$ at 1 Hz under 1W power consumption. Environment test for satellite component, acceleration test and thermal cycle test were carried out. For the acceleration test, magnetometer was vibrated frequency ranging from 10 Hz to 1 kHz at 15 g (g : gravitational acceleration at earth), and for thermal cycle test, 4 times of thermal cycle were carried out temperature ranging from $-55^{\circ}C\;to\;+80^{\circ}C$ under vacuum of $1x10^{-6}Torr$.

• Journal of Astronomy and Space Sciences
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• v.30 no.4
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• pp.335-344
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• 2013

TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA) is a CubeSat with 3.14 kg in weight and 3-U ($10{\times}10{\times}30$ cm) in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultra-high vacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.30-42
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• 2000

On-orbit thermal environment test of KOMPSAT was performed in early 1999. An analysis of the test data are addressed in this paper. For the thermal-environmental simulation of spacecraft bus, an artificial heating through the radiator zones and onto some critical heat-dissipating electronic boxes was made by Absorbed-heat Flux Method. Test data obtained in terms of temperature history were reduced into flight heater duty cycles and converted into the total electrical power required for spacecraft thermal control. Verification result of flight heaters dedicated to the bus thermal control is presented. Additionally, an exhaustive heating-control process for maintaining the spacecraft thermally safe and for realistic simulation of the orbital-thermal environment during the test are graphically shown. Qualitative suggestions to post-test model correlation are given in consequency of the analysis.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.64-73
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• 2007

A Large thermal vacuum chamber (LTVC) for space environment simulation on large satellites was successfully developed and constructed by KARI (Korea Aerospace Research Institute) in Korea with a local company. This chamber has an effective diameter of 8 meters and depth of 10 meters, and is composed of vacuum system, thermal control system, and anti-vibration system. Temperature below $-190^{\circ}C$ is maintained over the thermal shroud wrapping a satellite under $3.7{\times}10^{-5}Pa$ ($5{\times}10^{-7}torr$) vacuum level, and optical test can be done in this chamber by seismic mass with $10^{-5}g_{rms}$ or lower vibration level. In addition, the shroud temperature can be increased up to $123^{\circ}C$ using halogen lamps. Chamber control program based on PLC (Programmable Logic Controller) could control this large thermal vacuum chamber automatically.