• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.7
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• pp.529-536
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• 2020

Reaction Control System of the third stage of the Korean Space Launch Vehicle II conducts roll control and 3 axis control throughout third stage engine start, satellite separation, and collision and contamination avoidance maneuver. Reaction control system consumes its propellant in each thruster operation. Hence, loading of proper amount of the propellant is important for mission success. It is needed to have a rough estimation method of propellant consumption during the flight. In this paper, we developed a energy equation using pressure and temperature data which are acquired in the on-board reaction control system. We constructed a test system which is similar with the on-board reaction control system to verify the energy equation. Test results using deionized water were compared with estimated propellant consumption. We also conducted an error analysis of the energy equation. We also presented the propellant consumption result of a system level operation test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.526-529
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• 2009

In this study, we analyze the characteristic of burning classified by a propellant according to a flux of an oxidizer to analyze propellant regression distance in accordance with a thrust control and burning time of hybrid rocket using hybrid combustor of Lab-Scale. To control a flux of an oxidizer, we design flow control system to regulate the mount of opening and shutting of a needle valve by a driving of stepping motor by a combination the needle valve with stepping motor. We derive the relationships between mass flow rate and regression rate according to a propellant through the oxidizer flux change. While doing the thrust control, we estimate regression distance through the oxidizer flux in accordance with thrust and confirm the creditability through the actual thrust control burning experimentation.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.353-357
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• 2010

In general, the information of inertia properties is required to control a spacecraft. The inertia properties are changed by some activities such as consumption of propellant, deployment of solar panel, sloshing, etc. Extensive estimation methods have been investigated to obtain the precise inertia properties. The gyro-based attitude data including noise and bias needs to be compensated for improvement of attitude control accuracy. A modified estimation method based on the law of conservation of angular momentum is suggested to avoid inconvenience like filtering process for noise-effect compensation. The conventional method is modified and beforehand estimated moment of inertia is applied to improve estimation efficiency of product of inertia. The performance of the suggested method has been verified for the case of STSAT-3, Korea Science Technology Satellite.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.1-6
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• 2012

The accurate information of mass properties is required for the precise control of the spacecraft. The mass properties, mass and inertia, are changeable by some reasons such as consumption of propellant, deployment of solar panel, sloshing, environmental effect, etc. The gyro-based attitude data including noise and bias reduces the control accuracy so it needs to be compensated for improvement. This paper introduces a real-time inertia estimation method for the attitude determination of STSAT-3, Korea Science Technology Satellite. In this method we first filter the gyro noise with the Extended Kalman Filter(EKF), and then estimate the moment of inertia by using the filtered data from the EKF based on the Recursive Least Square(RLS).