• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.103-107
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• 2005

There is an X-band transmission system in KOMPSAT-2 in order to downlink the acquired image data in high speed. KOMPSAT-2 employs a steerable high gain X-band antenna for that purpose. During the ground test, the X-band RF radiation is so strong that it has to be controlled for safety, while spacecraft needs to keep flight configuration. Also in a launch site of which all test facilities are the subjects of strict radiation control, the antenna system should be tested again without any change in the configuration. To limit the actual radiation of RF power, an antenna hat was manufactured and thoroughly tested to demonstrate the spacecraft safety when using it.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.135-138
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• 2011

As a basic research for the development of Korean lunar lander, propulsion system development for ground test is in progress. Thrust for descent is 200 N class. Design target is 220 N in vacuum thrust at 100 g/s flow rate, 200 psi chamber pressure. For ground test, thrust measurement system using LM guide was developed and test was performed. The result shows 160 N thrust in atmosphere condition at 210 psi chamber pressure.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.503-506
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• 2011

항공기 착륙장치 피로 수명평가에는 안전 수명방법이 사용된다. 안전 수명방법은 항공기 전 수명기간을 모사하는 피로하중 스펙트럼 조건에서 균열 또는 유해한 변형과 같은 구조적 결함이 발생하지 않도록 설계/입증하는 것을 말한다. 설계 단계에서는 해석적 방법을 통해 착륙 및 지상운용하중을 구하고, 이를 착륙장치 피로해석에 적용하여 피로수명을 확인한다. 착륙장치는 수명 기간 중 일반적으로 High Cycle 피로를 겪게 되므로, 피로해석 시 응력 기반의 접근 방법이 적용된다. 시험평가 단계에서는 일반적으로 4배의 운용수명에 해당하는 피로하중 스펙트럼에 대해 시험을 수행하여, 착륙장치의 안전 수명을 최종 입증하게 된다. 이와 같이 항공기 착륙장치 피로 수명평가를 위해서는 착륙 및 지상운용 하중해석에서부터 피로해석, 피로시험에 이르기까지 전 과정이 유기적으로 결합되어 이루어져야 한다. 본 연구에서는 항공기 착륙장치 피로시험에 필요한 세부과정과 관련 기술을 실제 적용 사례와 함께 기술하였다.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.180-187
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• 2007

Korea Aerospace Research Institute(KARI) is developing Korea Space Launch Vehicle(KSLV). KSLV-I is composed of liquid propulsion system for the first stage and apogee kick motor as the second stage. Kick motor has a high expansion ratio nozzle and its starting altitude is 300km high. To verify the performance of kick motor, high altitude test facility (HATF) to simulate its operating condition is necessary. This paper contains preliminary design for construction of HATF.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.185-191
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• 2012

This paper developed Helicopter Chassis Dynamometer System(HCDS) to perform the bench test of the scaled rotor blade and to design a scaled model helicopter flight test bed and accomplished the scaled helicopter ground test. The scaled helicopter should be checked the relation of thrust and power input to maintain regular RPM by collective pitch angle versus throttle input. It showed hovering performance results of IGE with OGE, the max. F.M. was 0.76 without ground effect. The results of the chassis dynamometer test of scaled helicopter will usefully apply to design the scaled helicopter and evaluate the rotor blade performance.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.46.4-47
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• 2009

인공위성은 지상에서 설계 제작된 후에 발사체에 탑재되어 궤도에 진입되어 위성에 부여된 고유임무를 수행하게 된다. 위성체가 임무를 수행하는 우주공간은 고진공 환경과 태양 복사열에 의한 고온 환경 및 극저온이 반복되는 가혹한 환경으로 특징지어진다. 때때로 위성체는 이러한 가혹한 우주환경의 영향으로 인해 주요 부품의 기능장애가 초래되기도 하며 이는 결국 임무의 실패로 이어지도 한다. 따라서 고진공과 극저온 환경으로 일컬어지는 우주환경을 지상에서 모사하여 위성체의 안정성 및 신뢰성을 시험하기 위해서 열진공 시험장비를 이용한 열진공시험을 수행한다. 한국항공우주연구원에서는 인공위성의 탑재체인 광학카메라의 국산화 개발을 위하여 우주공간의 고진공과 극저온 상태를 모사할 수 있는 $\varphi4m\timesL10m$ 규모의 광학탑재체 전용 열진공챔버를 국산화 제작하였다. 관측 위성용 광학카메라는 초고정밀 장비로서, 이를 테스트하기 위한 광학탑재체용 진공챔버는 특히 진동환경에 매우 민감한 하여 10-7 grms 이하의 진동레벨을 허용하고 있다. 그러나 진공용기는 지진 및 외부 환경으로부터의 시스템외부진동과 진공펌프 및 기타 장비들로부터의 내부 진동환경에 항상 노출되어 있으며, 가진 주파수가 구조물 자체의 고유진동수와 일치될 경우 공진이 발생하여 시스템에 큰 영향을 미칠 수 있으므로, 외부 진동 및 챔버 자체 진동이 광학계에 전달되지 않도록 진동차단장치가 필요하다. 이 논문에서는 광학탑재체 궤도환경시험용 챔버에 대한 진동차단장치의 개발 및 활용 예를 논의하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1021-1025
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• 2017

Numerical heat/flow analysis was performed on a liquid rocket engine head with the cooling water manifold to ensure the durability of a ground test facility for heat exchanger. Through these studies, the shapes of the injector and the flow path were determined and applied to the head of the engine under development. Firing tests were conducted to verify the designed coolant manifold and no thermal damage was found on the engine-head-face. Comparing the combustion test results with the numerical analysis, the outlet temperature of coolant showed a difference of about $15^{\circ}C$. This trend is reasonable considering existence of LOX manifold, thermal barrier coating, and the actual location of flame.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.187-192
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• 2009

Telecommand & telemetry control equipment is needed for the testing of the transponders during the development of satellite. This equipment must have a loopback function to perform the self testing without satellite. The fabrication of the designed system is easier and cheaper than the conventional testing system using direct modulation method. The measured results of fabricated equipment are satisfied with required specifications. A overall path loss of uplink and downlink is 47.8 dB and 42.6 dB, respectively. Also, IMD3 of uplink has measured 60.68 dBc at an output of -50 dBm.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.40-47
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• 2019

This paper proposes the environment construction and test method of system integration laboratory (SIL) and system integration test (SIT) for verification of interface between onboard equipment and ground control equipment of unmanned aerial systems (UAS). This research also describes the interface environment between subsystems built in SIL and verification methods for the systems' operation logic through simulated flights. Similarly, the paper handles the ground integration test process of UAS in the real testing environments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.329-334
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• 2021

Korean Air has set the goal of the first stage of the development of unmanned helicopters to perform in hovering flight by remote control. In order to achieve the development goal, Korean Air carried out system integration, ground test, and safety wire test in sequence after carrying out programmed depot maintenance and aircraft modification of manned aircraft, and verified the controllability and flight safety of the unmanned helicopter system step by step. In particular, it was confirmed that the safety wire test technique used in the final stage of verification was an effective method to verify flight safety and controllability for a fully unmanned helicopter system.