• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.7-10
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• 2006

In order to inject satellites into a target orbit, launch vehicles should have a precise attitude and control system capable of controlling three axises of pitch, yaw and roll. For launch vehicles, there are two types of attitude control system currently in popular use; the first one is a cold gas method, and the other is a liquid propulsion system using a single and dual property propellant. The purpose of this paper is to analyze the characteristics of thrust control system using said propellant, thereby providing for a rationale for its application to the upper stages of launch vehicles, in terms of the simplicity of the system, economics of structure and operation.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.93-98
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• 2012

To solve the combustion instability, especially chuffing phenomena, happened during development process of a drive-away motor that was required for cold launch system of missile, various technical approaches have been performed through ground firing tests. The ignition energy or its supply system, generally closely related with the chuffing phenomena, does not affect suppression of the chuffing, but the increase of characteristic length($L^*$) as well as the addition of 2% ZrC as a damping material is effective to suppress the chuffing. Therefore we could have a typical experience on the combustion instability in double base propellant.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.8
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• pp.686-694
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• 2016

During the Cold War, all space developments were focused on the performance only. However economy becomes more important for space development after the Cold War. There is a growing interest in reusable launch vehicle to secure the economic feasibility. In this paper, technology development prospects and direction of reusable launch vehicles and future propulsion systems of various countries are presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.369-374
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• 2011

To solve the combustion instability, especially chuffing phenomena, happened during development process of the drive-away motor that was required for cold launch system of missile, we tried various technical approaches and performed ground firing tests. The supplying content or method of ignition energy, generally that is deeply related with the chuffing phenomena, does not affect suppression of the chuffing, but the addition of 2% ZrC as a damping material is effective to suppress the chuffing. Therefore we could newly experience a special solution of the combustion instability in double base propellant.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1067-1072
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• 2011

If the flow of booster gas which is exhausted to the rear part of a canister is properly restricted in the canister of a hot-launch system, the resultant pressure built up in the canister provides additional force to accelerate the missile to a required launch velocity. These thrust augmentation performances can be controlled through the configuration design of baseplate orifices. In this paper, the simple technique to analyze the thrust augmentation performances of baseplate orifices is suggested and the thrust augmentation characteristics by its various configurations are compared. According to the initial displacement of a missile, the inner pressure of a canister is measured from scaled cold flow tests, and the discharge coefficient of baseplate orifices is calculated. Then the thrust augmentation in a canister is simulated by applying these discharge characteristics to the AMESIM software for launch dynamics.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.75-82
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• 1999

Theoretical analysis and performance test of Jet vane type Thrust Vector Control(TVC) were conducted using supersonic cold-flow system. The use of TVC Systems an in particular jet vanes, are currently being researched for use in air launch, ship launch, underwater launch and high altitude maneuvering of tactical missiles and rockets. The necessity to generate control forces to rapidly change the course of the missile is frequently required when traditional, exterior aerodynamic surfaces are unable to produce these forces, when the flow over the control surface is insufficient. This situation can occur at launch, or high angles of attack of the control surfaces. Jet vanes peformed well at all altitudes and environmental conditions, and jet vanes are extremely effective at deflection angles up to as high as $30^{\circ}$, make them ideal for the launch and maneuver applications. In this study, performance test of supersonic cold-flow system and visualization of supersonic jet was conducted, and shape and deflection angle effect of two types of jet vanes are investigated.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.3
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• pp.19-27
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• 2010

KSLV(Korea Space Launch Vehicle)-I is designed as a launch vehicle to enter a 100 kg-class satellite to the LEO(Low-Earth Orbit). Attitude angles of the upper-stage, including roll, pitch and yaw are controlled by cold gas thruster system using nitrogen gas. The thruster for the KSLV-I is the main pneumatic valve in the RCS(Reaction Control System). In this paper, the design, function tests, and environment tests of the thruster for KSLV-I are described. The developed thrusters are experimentally evaluated and successfully passed the required qualification and acceptance tests.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.4
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• pp.303-312
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• 2010

This paper introduces the upper stage attitude control system of KSLV-I, which is the first space launch vehicle in Korea. The KSLV-I upper stage attitude control system consists of two electro-hydraulic actuators and a reaction control system using cold nitrogen gas. A proportional, derivative, and integral controller is designed for the electro-hydraulic thrust vectoring system, and Schmidt trigger ON/OFF controllers are designed for the reaction control system. Each attitude controller is designed to have enough stability margins. The stability and performance of KSLV-I upper stage attitude control system is verified via hardware in the loop tests. Hardware in the loop tests are accomplished for perturbed flight conditions as well as nominal flight condition. The test results show that the attitude control loop of KSLV-I upper stage is very stable and the attitude controllers perform well for all flight conditions. Attitude controllers designed in this paper have been successfully applied to the first flight of KSLV-I on August 25, 2009. The flight test results show that all attitude controllers of the KSLV-I upper stage performed well and satisfied the accuracy specifications even during abnormal flight conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.96-99
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• 2012

The test facility for confirming performance of a propulsion system is essential infra-structure to develop launch vehicle system. Using the PSTC, cold flow and combustion tests are performed to the propulsion system of individual stage in launcher. Moreover the ground test for the total launching process is conducted. In order to construct the PSTC, we not only have surveyed technology of internal and external countries, but also actively use the case in terms of the system. The test facility consists of feeding system, test stand, control and measurement, and flame deflector.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.122-126
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• 2009

KSLV(Korea Space Launch Vehicle)-I is designed as a launch vehicle to enter a 100 kg-class satellite to the LEO(Low-Earth Orbit). Attitude angles of the upper-stage, including roll, pitch and yaw are controlled by cold gas thruster system using nitrogen gas. To verify the flow rate of the gas charging system and to prepare a nitrogen gas charging scenario, the development of a gas charging simulator for RCS(Reaction Control System) is required. This paper describes the orifice design, development, and test of the gas charging simulator for RCS of KSLV-I.