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Prof. Dr. Hyun-Ung Oh
Department of Smart Vehicle System Engineering, CHOSUN University, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Korea

Basic Info


Research Keywords & Expertise

0 Satellite and payload thermo-mechanical system
0 Cube satellite system and relevant technologies
0 Vibration control for space applications
0 Smart materials and structures for space applications
0 Spaceborne mechanism

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Journal article
Published: 26 July 2021 in Aerospace
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Whole-spacecraft launch-vibration isolation systems are attractive for achieving the goal of better, faster, cheaper, and lighter small satellites by reducing the design-load and vibration-test specifications for on-board components. In this study, a three-axis passive launch-vibration isolation system, based on superelastic shape memory alloy (SMA) technology, was developed to significantly attenuate the dynamic launch loads transmitted to a small satellite. This provides a superior damping characteristic, achieved by superelastic SMA blades stiffened by multilayered thin plates with viscous lamina adhesive layers of acrylic tape. The basic characteristics of the proposed isolation system with various numbers of viscoelastic multilayers were obtained through a static load test. In addition, the effectiveness of the design was validated through a launch environment simulating sine and random vibration tests.

ACS Style

Yeon-Hyeok Park; Seong-Cheol Kwon; Kyung-Rae Koo; Hyun-Ung Oh. High Damping Passive Launch Vibration Isolation System Using Superelastic SMA with Multilayered Viscous Lamina. Aerospace 2021, 8, 201 .

AMA Style

Yeon-Hyeok Park, Seong-Cheol Kwon, Kyung-Rae Koo, Hyun-Ung Oh. High Damping Passive Launch Vibration Isolation System Using Superelastic SMA with Multilayered Viscous Lamina. Aerospace. 2021; 8 (8):201.

Chicago/Turabian Style

Yeon-Hyeok Park; Seong-Cheol Kwon; Kyung-Rae Koo; Hyun-Ung Oh. 2021. "High Damping Passive Launch Vibration Isolation System Using Superelastic SMA with Multilayered Viscous Lamina." Aerospace 8, no. 8: 201.

Journal article
Published: 26 July 2021 in Aerospace
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In a previous study, a high-damping printed circuit board (PCB) implemented by multilayered viscoelastic acrylic tapes was investigated to increase the fatigue life of solder joints of electronic packages by vibration attenuation in a random vibration environment. However, the main drawback of this concept is its inability to mount electronic parts on the PCB surface area occupied by interlaminated layers. For the efficient spatial accommodation of electronics, this paper proposes a new version of a high-damping PCB with multilayered viscoelastic tapes interlaminated on a thin metal stiffener spaced from a PCB. Compared to the previous study, this concept ensures efficient utilization of the PCB area for mounting electronic parts as well as the vibration attenuation capability. Free vibration tests were performed at various temperatures to obtain the basic characteristics of the proposed PCB. The effectiveness of the proposed PCB was verified by random vibration fatigue tests of sample PCBs with various numbers of viscoelastic layers to compare the fatigue life of electronic packages.

ACS Style

Tae-Yong Park; Seok-Jin Shin; Hyun-Ung Oh. New Version of High-Damping PCB with Multi-Layered Viscous Lamina. Aerospace 2021, 8, 202 .

AMA Style

Tae-Yong Park, Seok-Jin Shin, Hyun-Ung Oh. New Version of High-Damping PCB with Multi-Layered Viscous Lamina. Aerospace. 2021; 8 (8):202.

Chicago/Turabian Style

Tae-Yong Park; Seok-Jin Shin; Hyun-Ung Oh. 2021. "New Version of High-Damping PCB with Multi-Layered Viscous Lamina." Aerospace 8, no. 8: 202.

Journal article
Published: 16 July 2021 in Aerospace
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In this study, we present the Diverse Holding and Release Mechanism Can Satellite (DHRM CanSat) platform developed by the Space Technology Synthesis Laboratory (STSL) at Chosun University, South Korea. This platform focuses on several types of holding and release mechanisms (HRMs) for application in deployable appendages of nanosatellites. The objectives of the DHRM CanSat mission are to demonstrate the design effectiveness and functionality of the three newly proposed HRMs based on the burn wire triggering method, i.e., the pogo pin-type HRM, separation nut-type HRM, and Velcro tape-type HRM, which were implemented on deployable dummy solar panels of the CanSat. The proposed mechanisms have many advantages, including a high holding capability, simultaneous constraints in multi-plane directions, and simplicity of handling. Additionally, each mechanism has distinctive features, such as spring-loaded pins to initiate deployment, a plate with a thread as a nut for a high holding capability, and a hook and loop fastener for easy access to subsystems of the satellite without releasing the holding constraint. The design effectiveness and functional performance of the proposed mechanisms were demonstrated through an actual flight test of the DHRM CanSat launched by a model rocket.

ACS Style

Shankar Bhattarai; Ji-Seong Go; Hyun-Ung Oh. Experimental CanSat Platform for Functional Verification of Burn Wire Triggering-Based Holding and Release Mechanisms. Aerospace 2021, 8, 192 .

AMA Style

Shankar Bhattarai, Ji-Seong Go, Hyun-Ung Oh. Experimental CanSat Platform for Functional Verification of Burn Wire Triggering-Based Holding and Release Mechanisms. Aerospace. 2021; 8 (7):192.

Chicago/Turabian Style

Shankar Bhattarai; Ji-Seong Go; Hyun-Ung Oh. 2021. "Experimental CanSat Platform for Functional Verification of Burn Wire Triggering-Based Holding and Release Mechanisms." Aerospace 8, no. 7: 192.

Journal article
Published: 06 July 2021 in International Journal of Aeronautical and Space Sciences
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ACS Style

Bong-Geon Chae; Hyun-Ung Oh. Development of Power Plant Trio CanSat Platform Powered by Solar, Wind and Piezo Energy Harvesting Systems. International Journal of Aeronautical and Space Sciences 2021, 1 .

AMA Style

Bong-Geon Chae, Hyun-Ung Oh. Development of Power Plant Trio CanSat Platform Powered by Solar, Wind and Piezo Energy Harvesting Systems. International Journal of Aeronautical and Space Sciences. 2021; ():1.

Chicago/Turabian Style

Bong-Geon Chae; Hyun-Ung Oh. 2021. "Development of Power Plant Trio CanSat Platform Powered by Solar, Wind and Piezo Energy Harvesting Systems." International Journal of Aeronautical and Space Sciences , no. : 1.

Journal article
Published: 26 May 2021 in Aerospace
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The Small SAR Technology Experimental Project (S-STEP) mission aims to develop a new (space-based 80 kg-class active X-band synthetic aperture radar (SAR)) satellite with a main imaging mode of 1 m resolution stripmap. In the S-STEP mission, to achieve the design goal of developing faster, cheaper, better, and lighter small SAR satellite systems, innovative thermo-mechanical design approaches have been proposed and investigated. The major design approaches are the bus-payload integrated flat plate-type structure, multifunctional transmit/receive (TR) module, and dedicated vibration-free orbit deployer (VFOD) with the function of whole spacecraft vibration isolation. To validate the feasibility of the innovative mechanical design of S-STEP, a structural analysis considering launch and on-orbit environments is performed. In addition, development test results are presented to confirm the effectiveness of the proposed design approach for VFOD.

ACS Style

Seong-Cheol Kwon; Ji-Hae Son; Sung-Chan Song; Jin-Han Park; Kyung-Rae Koo; Hyun-Ung Oh. Innovative Mechanical Design Strategy for Actualizing 80 kg-Class X-Band Active SAR Small Satellite of S-STEP. Aerospace 2021, 8, 149 .

AMA Style

Seong-Cheol Kwon, Ji-Hae Son, Sung-Chan Song, Jin-Han Park, Kyung-Rae Koo, Hyun-Ung Oh. Innovative Mechanical Design Strategy for Actualizing 80 kg-Class X-Band Active SAR Small Satellite of S-STEP. Aerospace. 2021; 8 (6):149.

Chicago/Turabian Style

Seong-Cheol Kwon; Ji-Hae Son; Sung-Chan Song; Jin-Han Park; Kyung-Rae Koo; Hyun-Ung Oh. 2021. "Innovative Mechanical Design Strategy for Actualizing 80 kg-Class X-Band Active SAR Small Satellite of S-STEP." Aerospace 8, no. 6: 149.

Journal article
Published: 10 May 2021 in Smart Materials and Structures
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We propose and demonstrate a novel method to enhance vibration harvesting based on surge-induced synchronized switch harvesting on inductor (S3HI). S3HI allows harvesting of a large amount of energy even from low-amplitude vibrations by inducing a surge voltage during the voltage inversion of a synchronized switch harvesting on inductor (SSHI). The surge voltage and the voltage amplification from the conventional voltage inversion improve energy harvesting. S3HI modifies SSHI by both rewiring the circuit without adding components and using a novel switching pattern for voltage inversion, thus maintaining the simplicity of SSHI. We propose a novel switching strategy and circuit topology and analyze six methods that constitute the S3HI family, which includes traditional S3HI and high-frequency S3HI. We demonstrate that the six methods suitably harvest energy even from low-amplitude vibrations. Nevertheless, the harvestable energy per vibration cycle depends on the switching pattern and storage-capacitor voltage. The use of the proposed switching strategy, which allows energy harvesting before energy-dissipative voltage inversion, substantially increases the harvestable energy per vibration cycle. In the typical case considered in this study, the said increase is on the order of 11%–31% and 15%–450% compared to the traditional and existing high-frequency S3HI methods, respectively, depending on the storage-capacitor voltage. Additionally, the proposed circuit can be used as a traditional circuit. It could be considered a promising alternative to S3HI methods owing to its potential auto-reboot capability, which is not found in traditional S3HI circuit.

ACS Style

Junjiro Onoda; Kenji Minesugi; Seong-Cheol Kwon; Hyun-Ung Oh. Enhancement of surge-induced synchronized switch harvesting on inductor strategy. Smart Materials and Structures 2021, 30, 065014 .

AMA Style

Junjiro Onoda, Kenji Minesugi, Seong-Cheol Kwon, Hyun-Ung Oh. Enhancement of surge-induced synchronized switch harvesting on inductor strategy. Smart Materials and Structures. 2021; 30 (6):065014.

Chicago/Turabian Style

Junjiro Onoda; Kenji Minesugi; Seong-Cheol Kwon; Hyun-Ung Oh. 2021. "Enhancement of surge-induced synchronized switch harvesting on inductor strategy." Smart Materials and Structures 30, no. 6: 065014.

Journal article
Published: 05 March 2021 in Aerospace
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The structural safety of solar cells mounted on deployable solar panels in the launch vibration environment is a significant aspect of a successful CubeSat mission. This paper presents a novel highly damped deployable solar panel module that is effective in ensuring structural protection of solar cells under the launch environment by rapidly suppressing the vibrations transmitting through the solar panel by constrained layer damping achieved using printed circuit board (PCB)-based multilayered thin stiffeners with double-sided viscoelastic tapes. A high-damping solar panel demonstration model with a three-pogo pin-based burn wire release mechanism was fabricated and tested for application in the 6U CubeSat “STEP Cube Lab-II” developed by Chosun University, South Korea. The reliable release function and radiation hardness assurance of the mechanism in an in-orbit environment were confirmed by performing solar panel deployment tests and radiation tests, respectively. The design effectiveness and structural safety of the proposed solar panel module were validated by launch vibration and in-orbit environment tests at the qualification level.

ACS Style

Shankar Bhattarai; Ji-Seong Go; Hongrae Kim; Hyun-Ung Oh. Development of a Novel Deployable Solar Panel and Mechanism for 6U CubeSat of STEP Cube Lab-II. Aerospace 2021, 8, 64 .

AMA Style

Shankar Bhattarai, Ji-Seong Go, Hongrae Kim, Hyun-Ung Oh. Development of a Novel Deployable Solar Panel and Mechanism for 6U CubeSat of STEP Cube Lab-II. Aerospace. 2021; 8 (3):64.

Chicago/Turabian Style

Shankar Bhattarai; Ji-Seong Go; Hongrae Kim; Hyun-Ung Oh. 2021. "Development of a Novel Deployable Solar Panel and Mechanism for 6U CubeSat of STEP Cube Lab-II." Aerospace 8, no. 3: 64.

Journal article
Published: 08 January 2021 in International Journal of Fatigue
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In this study, a novel printed circuit board (PCB) strain-based structural design methodology for spaceborne electronics was proposed to compensate for the drawbacks of the conventional Steinberg’s theory. In addition, finite element modeling technique based on strain-based theory, which provides a reliable and rapid solution to structural design of electronics, was investigated. The effectiveness of the proposed methodology was validated through fatigue life tests of sample electronic packages mounted on PCBs with various boundary conditions. These results indicated that the proposed methodology enables more reliable evaluation on the mechanical safety of solder joints as compared with the Steinberg’s theory.

ACS Style

Tae-Yong Park; Hyun-Ung Oh. New PCB strain-based structural design methodology for reliable and rapid evaluation of spaceborne electronics under random vibration. International Journal of Fatigue 2021, 146, 106147 .

AMA Style

Tae-Yong Park, Hyun-Ung Oh. New PCB strain-based structural design methodology for reliable and rapid evaluation of spaceborne electronics under random vibration. International Journal of Fatigue. 2021; 146 ():106147.

Chicago/Turabian Style

Tae-Yong Park; Hyun-Ung Oh. 2021. "New PCB strain-based structural design methodology for reliable and rapid evaluation of spaceborne electronics under random vibration." International Journal of Fatigue 146, no. : 106147.

Research article
Published: 14 December 2020 in International Journal of Aerospace Engineering
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In this present work, a highly damped deployable solar panel module was developed for application in the 3 U CubeSat. The solar panel proposed herein is effective in guaranteeing the structural safety of solar cells under a launch environment owing to the superior damping characteristics achieved using multilayered stiffeners with viscoelastic acrylic tapes. A holding and release action of the solar panel was achieved by a new version of spring-loaded pogo pin-based burn wire triggering mechanism. A demonstration model of high-damping solar panel assembly was fabricated and tested to validate the effectiveness of the design. The holding and release mechanism achieved using a pogo pin was functionally tested through solar panel deployment tests under ambient room temperature and a thermal vacuum environment. The design effectiveness and structural safety of the solar panel module were validated through qualification-level launch and in-orbit environment tests.

ACS Style

Shankar Bhattarai; Ji-Seong Go; Hongrae Kim; Hyun-Ung Oh. Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism. International Journal of Aerospace Engineering 2020, 2020, 1 -14.

AMA Style

Shankar Bhattarai, Ji-Seong Go, Hongrae Kim, Hyun-Ung Oh. Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism. International Journal of Aerospace Engineering. 2020; 2020 ():1-14.

Chicago/Turabian Style

Shankar Bhattarai; Ji-Seong Go; Hongrae Kim; Hyun-Ung Oh. 2020. "Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism." International Journal of Aerospace Engineering 2020, no. : 1-14.

Journal article
Published: 20 October 2020 in Engineering Fracture Mechanics
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Wedge locks have been widely used for effective spatial accommodation and easier integration of electronics. However, an increase in the dynamic displacement of the printed circuit board (PCB) with the increase in the board size is unavoidable because the wedge lock provides mechanical fixation only along the edge of the board. This is one of the technical issues in assuring the fatigue life of electronic packages under a severe vibration environment. However, application of a stiffener for the reduction of board displacement leads to an increase in the mass and volume of the electronics. In this study, for implementing lightweight and compact electronics, we proposed a high-damping PCB for effective vibration attenuation caused by high damping characteristics implemented by multi-layered viscoelastic acrylic tapes. The basic characteristics of the proposed PCB were obtained through free-vibration tests under various temperature conditions. Additionally, random vibration tests of PCB specimens with various layers of viscoelastic tapes were performed, and the fatigue life of electronic packages was compared to that of the specimen without tapes.

ACS Style

Tae-Yong Park; Seok-Jin Shin; Sung-Woo Park; Soo-Jin Kang; Hyun-Ung Oh. High-damping PCB implemented by multi-layered viscoelastic acrylic tapes for use of wedge lock applications. Engineering Fracture Mechanics 2020, 241, 107370 .

AMA Style

Tae-Yong Park, Seok-Jin Shin, Sung-Woo Park, Soo-Jin Kang, Hyun-Ung Oh. High-damping PCB implemented by multi-layered viscoelastic acrylic tapes for use of wedge lock applications. Engineering Fracture Mechanics. 2020; 241 ():107370.

Chicago/Turabian Style

Tae-Yong Park; Seok-Jin Shin; Sung-Woo Park; Soo-Jin Kang; Hyun-Ung Oh. 2020. "High-damping PCB implemented by multi-layered viscoelastic acrylic tapes for use of wedge lock applications." Engineering Fracture Mechanics 241, no. : 107370.

Research article
Published: 11 August 2020 in International Journal of Aerospace Engineering
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Ensuring the structural safety of a deployable solar panel under a severe launch vibration environment is one of the important factors for a successful CubeSat mission. A CubeSat’s deployable solar panel proposed in this study is effective to guarantee the structural safety of solar cells by attenuating launch loads owing to the superior damping characteristic achieved by a multilayered stiffener with viscoelastic acrylic tapes. The demonstration model of 3 U CubeSat’s deployable solar panel was fabricated and tested to validate the effectiveness of the proposed design. The basic dynamic characteristics of the solar panel were measured through free-vibration tests according to the various layers of the stiffener. Moreover, the characteristics of the deployed solar panel were measured and investigated under various temperatures to predict its capability under in-orbit operation. The effectiveness of the proposed design for launch vibration attenuation was demonstrated through qualification level sine and random vibration tests.

ACS Style

Shankar Bhattarai; Hongrae Kim; Hyun-Ung Oh. CubeSat’s Deployable Solar Panel with Viscoelastic Multilayered Stiffener for Launch Vibration Attenuation. International Journal of Aerospace Engineering 2020, 2020, 1 -10.

AMA Style

Shankar Bhattarai, Hongrae Kim, Hyun-Ung Oh. CubeSat’s Deployable Solar Panel with Viscoelastic Multilayered Stiffener for Launch Vibration Attenuation. International Journal of Aerospace Engineering. 2020; 2020 ():1-10.

Chicago/Turabian Style

Shankar Bhattarai; Hongrae Kim; Hyun-Ung Oh. 2020. "CubeSat’s Deployable Solar Panel with Viscoelastic Multilayered Stiffener for Launch Vibration Attenuation." International Journal of Aerospace Engineering 2020, no. : 1-10.

Research article
Published: 04 August 2020 in International Journal of Aerospace Engineering
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A spaceborne cryogenic cooler induces undesirable microvibration disturbances during its on-orbit operation, which is one of the main sources that degrades the image quality of submeter-level high-resolution observation satellites. Several types of vibration isolation systems based on passive approaches have been developed for reducing the microvibration of the cooler. A coil-spring-type passive vibration isolation system developed in a previous study has shown excellent performance in both launch vibration and on-orbit microvibration isolation. To improve the capability of the conventional cooler isolator, including the position sensitivity and launch vibration reduction, we propose a new version of a dual coil-spring-type passive vibration isolator system. The effectiveness of the newly proposed design was validated through a microjitter measurement test, position sensitivity test, and qualification-level launch vibration test of the isolator.

ACS Style

Yeon-Hyeok Park; Mun-Shin Jo; Eung-Shik Lee; Hyun-Ung Oh. Performance Enhancement of Spaceborne Cooler Passive Launch and On-Orbit Vibration Isolation System. International Journal of Aerospace Engineering 2020, 2020, 1 -14.

AMA Style

Yeon-Hyeok Park, Mun-Shin Jo, Eung-Shik Lee, Hyun-Ung Oh. Performance Enhancement of Spaceborne Cooler Passive Launch and On-Orbit Vibration Isolation System. International Journal of Aerospace Engineering. 2020; 2020 ():1-14.

Chicago/Turabian Style

Yeon-Hyeok Park; Mun-Shin Jo; Eung-Shik Lee; Hyun-Ung Oh. 2020. "Performance Enhancement of Spaceborne Cooler Passive Launch and On-Orbit Vibration Isolation System." International Journal of Aerospace Engineering 2020, no. : 1-14.

Original paper
Published: 14 July 2020 in International Journal of Aeronautical and Space Sciences
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To ensure high-resolution image acquisition for a spaceborne parabolic synthetic aperture radar (SAR) antenna, an appropriate thermal design is important to minimize the thermal distortion of the antenna reflector in severe on-orbit thermal environments. This paper describes the results of a preliminary thermal design and the analysis of a carbon fiber reinforced plastic skin-based unfurlable parabolic reflector for use in a spaceborne SAR antenna. The effectiveness of passive thermal designs for an antenna reflector using different thermal coatings was investigated with on-orbit thermal analyses according to the various antenna look angles to derive the most suitable design for minimizing the thermal gradient of the reflector. This contributes to minimize loss in antenna gain to ensure the SAR performance. In addition, the influence of the solar panel on the thermal gradient of the reflector was also analyzed because it is also important in affecting the thermal distortion.

ACS Style

Tae-Yong Park; Se-Young Kim; Dong-Woo Yi; Hwa-Young Jung; Jae-Eun Lee; Ji-Hyeon Yun; Hyun-Ung Oh. Thermal Design and Analysis of Unfurlable CFRP Skin-Based Parabolic Reflector for Spaceborne SAR Antenna. International Journal of Aeronautical and Space Sciences 2020, 22, 433 -444.

AMA Style

Tae-Yong Park, Se-Young Kim, Dong-Woo Yi, Hwa-Young Jung, Jae-Eun Lee, Ji-Hyeon Yun, Hyun-Ung Oh. Thermal Design and Analysis of Unfurlable CFRP Skin-Based Parabolic Reflector for Spaceborne SAR Antenna. International Journal of Aeronautical and Space Sciences. 2020; 22 (2):433-444.

Chicago/Turabian Style

Tae-Yong Park; Se-Young Kim; Dong-Woo Yi; Hwa-Young Jung; Jae-Eun Lee; Ji-Hyeon Yun; Hyun-Ung Oh. 2020. "Thermal Design and Analysis of Unfurlable CFRP Skin-Based Parabolic Reflector for Spaceborne SAR Antenna." International Journal of Aeronautical and Space Sciences 22, no. 2: 433-444.

Journal article
Published: 27 September 2019 in Cryogenics
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This paper proposes a blade-type passive vibration isolator, realized by multilayered thin metal plates with viscoelastic acrylic tapes, to attenuate the micro-jitter induced by a spaceborne cryogenic cooler. Structural safety of the cooler under severe launch loads is assured without implementing a launch-lock device. One advantage of the isolator is that the implementation of a 1G compensation device is unnecessary during on-ground micro-jitter measurement tests. Moreover, a stable jitter reduction performance could be obtained owing to the unsusceptible alignment sensitivity of the isolator. Free-vibration tests were performed for various temperature conditions to acquire the basic characteristics of the isolator. The effectiveness of the isolator design in launch environments was demonstrated through qualification-level sine vibration and random vibration tests. The micro-jitter isolation capability regarding the isolator alignment shift was confirmed through on-ground micro-jitter estimation test. Besides, the characteristic variations of the viscoelastic multilayered blade isolator in on-orbit thermal vacuum environments were investigated.

ACS Style

Seong-Cheol Kwon; Mun-Shin Jo; Dai-Ho Ko; Hyun-Ung Oh. Viscoelastic multilayered blade-type passive vibration isolation system for a spaceborne cryogenic cooler. Cryogenics 2019, 105, 102982 .

AMA Style

Seong-Cheol Kwon, Mun-Shin Jo, Dai-Ho Ko, Hyun-Ung Oh. Viscoelastic multilayered blade-type passive vibration isolation system for a spaceborne cryogenic cooler. Cryogenics. 2019; 105 ():102982.

Chicago/Turabian Style

Seong-Cheol Kwon; Mun-Shin Jo; Dai-Ho Ko; Hyun-Ung Oh. 2019. "Viscoelastic multilayered blade-type passive vibration isolation system for a spaceborne cryogenic cooler." Cryogenics 105, no. : 102982.

Research article
Published: 05 May 2019 in International Journal of Aerospace Engineering
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CubeSats are revolutionary to the space industry and are transforming space exploration which enables the next generation of scientists and engineers to complete all phases of space missions. Deployable solar panels have been widely used for the generation of enough power in CubeSats due to their limited volume area for solar cell integration. In general, the cable cutting release mechanism have been used in 1U-3U small satellites because of its simplicity and low cost. However, this mechanism has a low constraint force and is unable to apply constraints along the in-plane and out-of-plane directions. In this study, for the improvement of the conventional cable cutting mechanism, a spring-loaded pogo pin-based nichrome burn wire holding and release mechanism (HRM) was proposed and fabricated. The pogo pin constitutes an immensely attractive function for the holding and release mechanism of solar panels because it works as an electrical interface to provide power, a separation spring to initiate the reaction force to deploy the panels, and a status switch to determine deployments. In addition, the proposed mechanism guarantees the loading capability along the in-plane and out-of-plane directions of solar panels, the synchronous release of multiple panels, and a handling simplicity that differentiates it from the conventional mechanism. The design feasibility, structural safety, and reliability of the mechanism were verified through functionality tests and launch and on-orbit environmental tests. The proposed pogo pin-based holding and release mechanism would be equally applicable for other CubeSat deployable appendages.

ACS Style

Shankar Bhattarai; Hongrae Kim; Sung-Hoon Jung; Hyun-Ung Oh. Development of Pogo Pin-Based Holding and Release Mechanism for Deployable Solar Panel of CubeSat. International Journal of Aerospace Engineering 2019, 2019, 1 -13.

AMA Style

Shankar Bhattarai, Hongrae Kim, Sung-Hoon Jung, Hyun-Ung Oh. Development of Pogo Pin-Based Holding and Release Mechanism for Deployable Solar Panel of CubeSat. International Journal of Aerospace Engineering. 2019; 2019 ():1-13.

Chicago/Turabian Style

Shankar Bhattarai; Hongrae Kim; Sung-Hoon Jung; Hyun-Ung Oh. 2019. "Development of Pogo Pin-Based Holding and Release Mechanism for Deployable Solar Panel of CubeSat." International Journal of Aerospace Engineering 2019, no. : 1-13.

Research article
Published: 30 April 2019 in International Journal of Aerospace Engineering
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In the present work, a deployable solar panel based on a burn wire triggering holding and release mechanism was developed for use of 6 U CubeSat. The holding and release mechanism was designed based on a nichrome burn wire cutting method widely used for CubeSat applications. However, it provides a high loading capability, reliable wire cutting, multiplane constraints, and handling simplicity during the tightening process of wire. A demonstration model of a printed circuit board-based solar panel stiffened by a high-pressure fiberglass-laminated G10 material was fabricated and tested to validate the effectiveness of the design and functionality of the mechanism under various test conditions. The structural safety of the solar panel combined with the mechanism in a launch vibration environment was verified through sine and random vibration tests at qualification level.

ACS Style

Tae-Yong Park; Bong-Geon Chae; Hyun-Ung Oh. Development of 6 U CubeSat’s Deployable Solar Panel with Burn Wire Triggering Holding and Release Mechanism. International Journal of Aerospace Engineering 2019, 2019, 1 -13.

AMA Style

Tae-Yong Park, Bong-Geon Chae, Hyun-Ung Oh. Development of 6 U CubeSat’s Deployable Solar Panel with Burn Wire Triggering Holding and Release Mechanism. International Journal of Aerospace Engineering. 2019; 2019 ():1-13.

Chicago/Turabian Style

Tae-Yong Park; Bong-Geon Chae; Hyun-Ung Oh. 2019. "Development of 6 U CubeSat’s Deployable Solar Panel with Burn Wire Triggering Holding and Release Mechanism." International Journal of Aerospace Engineering 2019, no. : 1-13.

Journal article
Published: 16 November 2018 in Journal of Heat Transfer
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The feasibility of using a liquid metal with a high thermal conductivity as a functional fluid for realizing a variable conductance radiator (VCR) for space applications was proposed and investigated. The variable thermal conductivity of the radiator can be achieved by moving the liquid metal using a magneto-hydraulic pump between the two reservoirs in accordance with the temperature requirements of the on-board equipment. The liquid metal radiator proposed in this study is much more effective for saving heater power under cold condition while effectively dissipating heat to deep space under hot condition. The thermal behavior of the liquid metal radiator was demonstrated using the ambient thermal tests under cooling and insulation modes of the radiator. The performance of the proposed VCR was evaluated by comparing it with that of the conventional radiator whose conductivity value is fixed. The proposed radiator using the liquid metal was more effective than conventional radiator for suppressing the rate of increase of temperature for the heat dissipation unit in the cooling mode and for saving additional heater power by removing the liquid metal in the insulation mode.

ACS Style

Taegyu Kim; Hyun-Ung Oh. Experimental Investigation of the Feasibility of Using a Liquid Metal as a Variable Conductance Radiator for Space Applications. Journal of Heat Transfer 2018, 141, 012002 .

AMA Style

Taegyu Kim, Hyun-Ung Oh. Experimental Investigation of the Feasibility of Using a Liquid Metal as a Variable Conductance Radiator for Space Applications. Journal of Heat Transfer. 2018; 141 (1):012002.

Chicago/Turabian Style

Taegyu Kim; Hyun-Ung Oh. 2018. "Experimental Investigation of the Feasibility of Using a Liquid Metal as a Variable Conductance Radiator for Space Applications." Journal of Heat Transfer 141, no. 1: 012002.

Research article
Published: 30 October 2018 in International Journal of Aerospace Engineering
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A lunar lander is exposed to extreme lunar thermal environments with a nighttime of 14.75 earth days. Thus, a proper thermal design is an important task to guarantee a successful lunar mission. This paper describes a preliminary thermal design and analysis results of a lunar lander to ensure its survivability during lunar night. The effectiveness of the thermal designs of a lunar lander with various thermal hardwares was numerically investigated according to the landing candidate areas to determine which design is the most feasible for night survival. In addition, we analyzed the mechanical safety of the solder joint of electronic components in accordance with the operating temperature range, because it is an important factor for reducing the system power budget during night survival.

ACS Style

Tae-Yong Park; Jang-Joon Lee; Jung-Hoon Kim; Hyun-Ung Oh. Preliminary Thermal Design and Analysis of Lunar Lander for Night Survival. International Journal of Aerospace Engineering 2018, 2018, 1 -13.

AMA Style

Tae-Yong Park, Jang-Joon Lee, Jung-Hoon Kim, Hyun-Ung Oh. Preliminary Thermal Design and Analysis of Lunar Lander for Night Survival. International Journal of Aerospace Engineering. 2018; 2018 ():1-13.

Chicago/Turabian Style

Tae-Yong Park; Jang-Joon Lee; Jung-Hoon Kim; Hyun-Ung Oh. 2018. "Preliminary Thermal Design and Analysis of Lunar Lander for Night Survival." International Journal of Aerospace Engineering 2018, no. : 1-13.

Research article
Published: 08 October 2018 in International Journal of Aerospace Engineering
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Thermal gap pads are widely used for effective heat transfer from high-heat-dissipating components to a heat sink. The initial contact pressure of thermal pads is an important parameter for enhancing the heat transfer capability of thermal design during the assembly process of the heat sink. However, this causes stress on the solder joint of the component as a result of the pad’s inherent resistance to deformation. In this study, we investigated the effect of thermal pad on the fatigue life of the solder joint of CCGA 624 package for space usage. A random vibration fatigue test for several specimen assembly sets with various pressurization levels of thermal gap pads was performed, and their fatigue lives were compared with that of the package without the initial pressure of thermal gap pads.

ACS Style

Tae-Yong Park; Su-Hyeon Jeon; Su-Jeong Kim; Sung-Hoon Jung; Hyun-Ung Oh. Experimental Validation of Fatigue Life of CCGA 624 Package with Initial Contact Pressure of Thermal Gap Pads under Random Vibration Excitation. International Journal of Aerospace Engineering 2018, 2018, 1 -12.

AMA Style

Tae-Yong Park, Su-Hyeon Jeon, Su-Jeong Kim, Sung-Hoon Jung, Hyun-Ung Oh. Experimental Validation of Fatigue Life of CCGA 624 Package with Initial Contact Pressure of Thermal Gap Pads under Random Vibration Excitation. International Journal of Aerospace Engineering. 2018; 2018 ():1-12.

Chicago/Turabian Style

Tae-Yong Park; Su-Hyeon Jeon; Su-Jeong Kim; Sung-Hoon Jung; Hyun-Ung Oh. 2018. "Experimental Validation of Fatigue Life of CCGA 624 Package with Initial Contact Pressure of Thermal Gap Pads under Random Vibration Excitation." International Journal of Aerospace Engineering 2018, no. : 1-12.

Research article
Published: 09 September 2018 in International Journal of Aerospace Engineering
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A spring-loaded pogo pin as a holding and release mechanism of solar panels for cube satellite applications is proposed which functions as an electrical interface, a separation spring, and a status switch. The proposed mechanism has many advantages, including an increased loading capability, negligible induced shock level, synchronous release of multiple panels, and handling simplicity during integration. A demonstration model of the mechanism was fabricated and functionally tested under various test conditions such as different input voltages, different numbers of tightened nylon wires, and different temperatures (ranging from −40°C to 70°C).

ACS Style

Tae-Yong Park; Su-Hyeon Kim; Hongrae Kim; Hyun-Ung Oh. Experimental Investigation on the Feasibility of Using Spring-Loaded Pogo Pin as a Holding and Release Mechanism for CubeSat’s Deployable Solar Panels. International Journal of Aerospace Engineering 2018, 2018, 1 -10.

AMA Style

Tae-Yong Park, Su-Hyeon Kim, Hongrae Kim, Hyun-Ung Oh. Experimental Investigation on the Feasibility of Using Spring-Loaded Pogo Pin as a Holding and Release Mechanism for CubeSat’s Deployable Solar Panels. International Journal of Aerospace Engineering. 2018; 2018 ():1-10.

Chicago/Turabian Style

Tae-Yong Park; Su-Hyeon Kim; Hongrae Kim; Hyun-Ung Oh. 2018. "Experimental Investigation on the Feasibility of Using Spring-Loaded Pogo Pin as a Holding and Release Mechanism for CubeSat’s Deployable Solar Panels." International Journal of Aerospace Engineering 2018, no. : 1-10.