• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.997-1010
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• 2021

This study collected and analyzed flight data of SpaceX's Falcon 9 launch vehicle. All missions were classified by orbital types, such as Polar, SSO, ISS, LEO and GTO missions. In characteristic maneuvers of main engine cutoff, boostback, reentry and landing burn at each stage of 1st stage launch vehicle, changes of the physical parameters like speed, altitude, dynamic pressure and acceleration were investigated. The guidelines derived from detailed maneuver analysis were suggested, which can be used as design and evaluation references for developing reusable launch vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.2
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• pp.133-140
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• 2015

In this paper, a roll angle estimation method of a rolling airframe using a low grade GPS and a roll rate gyro is proposed. The strength of the received signal of the GPS antenna attached on the rolling airframe is maximized when the GPS satellite is placed on the plane determined by the x-axis of the rolling airframe and the GPS antenna axis. Under the assumption that the x-axis of the rolling airframe is coincident with its velocity vector, the roll angle of the rolling airframe is calculated from the relative position vector of the satellite to the GPS when the GPS signal strength becomes maximum. The Kalman filter combined with a roll rate gyro is introduced to increase the determination accuracy of the roll angle. The performance of the proposed method is verified via 6-DOF simulations.

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.1
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• pp.44-54
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• 2006

초음속 또는 극초음속 비행체용 추진기관은 산화재 공급방식에 따라 공기흡입형과 로켓 그리고 이들을 혼합한 형태인 복합사이클 추진기관으로 구분할 수 있다. 그러나 재사용이 가능하다는 측면에서 미래의 추진기관들은 공기흡입형과 복합사이클 추진기관들이 주류를 이룰 것으로 예상된다. 본 논문에서는 차세대 초고속 추진기관으로 유력시 되고 있는 공기흡입형 추진기관들 중에서 램/스크램 제트 추진기관들을 중심으로 세계적인 개발동향과 기술개념을 기술하였으며 이 두 가지 추진기관들을 바탕으로 구성된 복합사이클 추진기관들에 대한 개념들을 소개하였다. 항공우주선진국들을 중심으로 차세대 고속비행체 및 고속추진기관의 실용화 개발 움직임들이 구체화 되고 있는 가운데 최근 들어 비록 미약하지만 한국항공우주연구원을 비롯한 몇 개의 기관 및 대학에서 램제트/스크램제트 추진기관에 대한 핵심 요소기술 연구들이 진행되고 있는 것은 그나마 다행이라 할 수 있으며 본 논문이 차세대 초고속 추진기관에 대한 이해를 돕는데 도움이 되기를 기대한다.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.43-55
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• 2009

Advanced countries in aerospace have been struggle to realize the hypersonic air-breathing system since originating the concept of the hypersonic air-breathing propulsion system during the first half of the twentieth century. At last, NASA's X-43A Hyper-X did successful Mach 10 flight in November 2004. Each countries are running the program to applicate this hypersonic air-breathing propulsion system to SSTO(Single Stage to Orbit) or TSTO(Two Stage to Orbit) vehicle or hypersonic missile system at present. In this paper, we wrote the history and current issues of the hypersonic air-breathing propulsion system and hypersonic flight with the hypersonic air-breathing propulsion system.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.97-102
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• 2004

Propulsion System provides the required velocity change impulse for orbit transfer from parking orbit to mission orbit and three-axis vehicle attitude control impulse. KOMPSAT-2 propulsion system(PS) is an all-welded, monopropellant hydrazine system. The PS consists of the subassemblies and components such as Thrusters, Propellant Tank, Pressure Transducer, Propellant Filter, Latching Isolation Valves, Fill/Drain Valves, interconnecting propellant line assembly, and thermal hardwares for operation-environment control of the PS. This paper summarizes a development process of the liquid propulsion system from the design engineering up to the test and evaluation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.681-688
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• 2021

This paper considers the trajectory and impact point dispersion analysis of the test launch vehicle (TLV). The analysis, which performed before and after its flight test on November 28, 2018, is described and verified by comparing with the flight test results. The six degree-offreedom (DOF) simulation is used to compute the dispersion of the trajectory, attitude, and impact point, where the launch vehicle performance variations and wind effects during the atmospheric phase are included. The impact area to guarantee the flight safety is determined using the results of the dispersion analysis. The flight test results confirm that the safe flight of TLV is performed within the predicted dispersion boundary.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.1
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• pp.147-154
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• 2002

This paper describes the devlopment and implementation for the KOMPSAT-1 scheduling & automatic command plan generator(KSCG). Some problems in mission planning and command planning had occurred using the mission & command planning s/w in MAPS(Missin Analysis and Planning Subsystem) during the LEOP(Launch & Early Orbit Phase) & early normal mission phase due to lots of manual input process and non-automatic process. Therefore, the more mission operations for KOMPSAT-1. In order to prevent the development of new one(KSCG) which should reduce the manual process and generate automatically the command plan has been needed. As a result, the mission operations of KOMPSAT-1 has greatly became stable and more effient.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.17-27
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• 2022

A certain level of stability margin airworthiness criteria should be met to secure robustness against uncertainties between the real plant and the model in a flight control system design. The U.S. Department of Defense (DoD) specification of MIL-F-9490D and airworthiness certification standard of MIL-HDBK-516B uses gain and phase margin criteria of flight control system. However, the same stability margin criteria is applied at all development phases without considering the design maturity of each development phase of the aircraft. Ultimately, a problem arises when the aircraft operation envelope is excessively restricted. This paper proposes the relation of handling qualities and stability margin, and presents re-established stability margin criteria as a development phases and verification methods. The results of the research study are considered to contribute to the verification of the stability margin criteria more flexibly and effectively by applying the method to not only the currently manned developing aircrafts but also the unmanned vehicle to be developed in the future.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.105-123
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• 2007

The launching of the Taepo-dong 1 on 31 August 1998 by the North Korea was the first case where the diplomatic protests was made against the flight, the purpose of which, the launching State claimed, consisted in space exploration and use. It is the principle regarding the freedom of space exploration and use, as included in the international treaty, that is relevant in applying the various rules and in defining the legal status of the flight. Its legal status, however, was not actually taken into account, as political negotiations leading to the test moratorium has been successful until present day in freezing the political crisis. This implies that the rules of the law lack the validity and logic sufficient in dictating the conduct of the States. This case shows that, in effect, it is not the rule but the politics that is to govern the status of the flight.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.87-104
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• 2007

The launching of the Taepo-dong 1 on 31 August 1998 by the North Korea was the first case where the diplomatic protests was made against the flight, the purpose of which, the launching State claimed, consisted in space exploration and use. It is the principle regarding the freedom of space exploration and use, as included in the international treaty, that is relevant in applying the various rules and in defining the legal status of the flight. Its legal status, however, was not actually taken into account, as political negotiations leading to the test moratorium has been successful until present day in freezing the political crisis. This implies that the rules of the law lack the validity and logic sufficient in dictating the conduct of the States. This case shows that, in effect, it is not the rule but the politics that is to govern the status of the flight.