• Journal of the Korean Society of Propulsion Engineers
• /
• v.18 no.2
• /
• pp.80-85
• /
• 2014

Side jet thruster using nozzle closure separation device provides a solid rocket with a trajectory shift function. Side jet thruster consists of low combustion temperature propellant, neutral type propellant grain and nozzle closure separation device. If a trajectory shift is required, side jet thrust is generated on the rocket by separating some nozzle closures located in the opposite direction to thrust. After completing trajectory shift, the other nozzle closures located in the thrust direction are separated to cease side jet thrust. The operation process is verified through ground static test. The result in this study can be applied to changing rocket trajectory by controlling side jet thrust through nozzle closure separation.

• Aerospace Engineering and Technology
• /
• v.2 no.2
• /
• pp.96-104
• /
• 2003

Geostationary satellite propulsion system provides satellite with the velocity increment for attitude control operations and sationkeeping operations from satellite launch to de-orbit at the end of life. Today, various types of propulsion system and its thrusters are produced by worldwide manufactures. Therefore, geostationary satellite manufacturers give significant modification to the Mission Analysis Software whenever different type of propulsion system type is adopted. Mission Analysis Software is a tool for planning and verification of satellite mission. For the development of the Generalized Mission Analysis Software, many thrusters are carefully investigated and modeled.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2002.04a
• /
• pp.82-83
• /
• 2002

궤도상에 올려진 위성들은 인형의 궤도 운행을 하게 된다. 그러나 지구가 완전한 구형이 아니고 태양과 달의 인력이 작용하여 위성에 섭동이 발생하게 된다. 그리고 무중력 상태의 우주이므로 태양풍이나 미세 운석 그리고 위성체 내부의 가스 누출이나 내부의 토크 변화에 의해 위성 자세에 조금의 변동을 야기한다. 통신 위성의 경우 지상의 한 지점을 계속 향하고 있어야 하므로 정기적인 자세제어가 필요하다. 위성의 섭동에 의해 EWSK(East-West station keeping)나 NSSK(North-South station keeping)를 하기 위해 추력 모델은 단일 $\Delta$$\upsilon$기동이나 회전 세차 운동(spin precession maneuver)을 지원해야 한다. 위성은 주어진 임무를 수행하는데 필요한 $\Delta$$\upsilon$기동을 위해 적절한 성능의 추력기와 임무기간 동안 사용할 적절한 양의 추진제를 탑재하고 있다. 지상에서 필요한 임무를 수행하기 위해 위성에 지령을 하였을 때, 추력기가 정상작동을 하였는지 그리고 잔류 추진제가 어느 정도 인지를 정확히 알 수 있어야 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.363-367
• /
• 2005

Latching valves are operated like solenoid valves by open/close command and they maintain final open or close commend without electric power source, so they are widely used in propulsion system of satellite and launch vehicle requiring reliability and being subject of restriction of power. This paper present design and test procedure of latching valve using permanent magnet polarized solenoid, which is developed for 45N Hydrazine propulsion system, to estimate feasibility of design and manufacture of latching valve.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.10
• /
• pp.92-98
• /
• 2006

An 1 lbf of NASA standard monopropellant thruster, MRE-1, is used for KOMPSAT (Korea Multi-Purpose Satellite) which is launched in 2006 and provides reliable and cost-effective means for attitude and maneuvering control system. The monopropellant thruster obtains required thrust by thermal decomposition process of propellant through catalyst bed. During firing, the decomposition plays a role of a heat source that may occur an excessive radiation heat transfer to peripheral structures and electronics in relatively low temperature condition.Therefore, the radiation heat shield is needed to prevent the critical radiative heat exchange between thruster and satellite during firing. This paper summarizes an overall development process of radiation heat shield from the design engineering up to the manufacturing.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.16 no.6
• /
• pp.62-72
• /
• 2012

Divert and attitude control system(DACS) plays an important role for orbit transfer and attitude control, and therefore becomes important subject for recent space vehicle and Precision Guided Missile(PGM) development. To develop DACS system, main research areas include shape combination of pintle and nozzle to maximize thrust change, and reduction of aerodynamic pintle load to minimizle pintle driving force, and development of multi-axis control algorithm. In this paper, introduction, classification, and overseas/domestic research and development program, and prospects of DACS are reviewed and summarized.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.2 no.3
• /
• pp.80-89
• /
• 1998

Propulsion subsystem transfers KOMPSAT into mission orbit and controls its attitude. Design factor consists of structure safety, electrical circuit design, consumable power estimation of thermal hardwares, damping device design of fuel transient pressure, and system configuration design by considering plume effect from thruster firing. System level analysis should be performed for verification of system design under launch vehicle and orbital environment. Electrical functional test of thermal control hardware, proof pressure test, cleanliness verification test, and internal/external leakage test of fuel feeding system should be carried out for performance estimation of propulsion system. Design and assembly process of propulsion subsystem was depicted and reliability of system was verified by test analysis in this paper.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.1196-1199
• /
• 2017

A series-hybrid power system was designed for quad-tilt prop UAV and the characteristics was analysed. The power system consists of a 4.5kW rotary engine-generator and a li-battery as power sources, a power controller manages the overall power and supplies to the vehicle system. The output power of the engine is to be matched with the generator performance considering mechanical driving loss and generating efficiency, and also loss for charging and discharging of the battery energy. It is applied that the constant speed operation of the engine-generator to minimize overall fuel consumption by integrating the generating power and the battery energy, consequentially the battery capacity and characteristics could be important factors for improvement of the system efficiency.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.8
• /
• pp.85-90
• /
• 2003

To control spacecraft including satellite, we should understand precisely the performance of propulsion system and the program logic with appropriate format for satellite operations. In this study, the thruster performance functions was generated by using the best curve fitting for performance data from bi-propellant thrusters. Detailed thruster performance data are, in general, company proprietary information, therefore real firing tests were performed to understand the basic characteristics of the performance curve. Experimental rocket motor utilize liquid oxygen and kerosine as propellant and designed average thrust was 100 pound.

• Proceedings of the IEEK Conference
• /
• 2003.07c
• /
• pp.2541-2544
• /
• 2003

새로운 원리에 의한 원격 거리 및 각도측정 시스템［1］［2］(이하 TS, Total Station)을 개발하였다. 본 시스템은 마이크로 터널링 공법의 굴진기의 후미 또는 임의의 기준점에 원격으로 점멸할 수 있는 십자형의 발광체를 부착하고, 추진관에 고정시킨 상하좌우 각도측정 및 비접촉식 레이저 거리측정기가 부착된 무인 원격 제어장치에 의하여 십자형 발광체의 중심을 자동으로 검출한다. 또한. 회전각과 CCD 라인 스캔 센서의 조합에 의하여 각도를 정밀하게 원격 측정하게 된다. 한편 본 시스템을 이용하면 마이크로 터널링 공법에 의한 추진관내의 측정 가능한 범위를 연결하는 위치에 복수의 TS를 배치하여 서로의 위치를 자동으로 계측하고 그들 데이터를 컴퓨터에 의하여 계산함으로써, 맨홀의 임의의 기준점으로부터 굴진기의 현재 좌표를 신속하고 정확하게 계산할 수 있다.