• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.59-67
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• 2014

Acceptance level random vibration and life firing test for development model of 1 N-class monopropellant thruster have been performed. From the results of random vibration, the natural frequency of the dual thurst module composed of 1 N-class development model thrusters was higher than the part level requirement(>100 Hz) and the structural robustness was verified. Thrust decrease of steady sate was below 7% and thrust instability was within ${\pm}5%$ in the life firing test using over 20 kg propellant throughput. The computerized tomography for catalyst bed showed a less than 7% of catalyst loss and it revealed the design appropriateness of the current thruster development model.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.1-8
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• 2015

A ground hot-firing test(HFT) was accomplished to draw a correlation between the pressure oscillation intensity of combustion chamber and thrust response characteristics in a 70 N-class hydrazine thruster which has been developed recently. Monopropellant grade hydrazine was adopted as a propellant for the HFT, and combustion-chamber characteristic length, propellant injection pressure were applied as test parameters. It was confirmed that the decrease of thrust-chamber diameter and injection pressure augmented the pressure oscillation of stagnation chamber in the test condition specified, and the oscillation hampered the pulse response performance of test models.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.61-64
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• 2003

A comprehensive understanding is given for the hot-firing test results, which were obtained throughout the verification program of mono-propellant hydrazine thrusters producing 0.95 lbf (4.2 Newtons) of nominal steady-state thrust at an inlet pressure of 350 psia (2.41 ㎫). The scrutiny is made in terms of thrust and temperature behavior of steady state firing mode at the given propellant injection pressures of 400, 250, 100, and 50 psi. Engineering philosophy of data measurement and reduction is shortly mentioned, too.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.2
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• pp.32-38
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• 2004

A comprehensive understanding is given for the hot-firing test results, which were obtained throughout the verification program of mono-propellant hydrazine rocket engines (thrusters) producing 0.95 lbf (4.2 N) of nominal steady-state thrust at an inlet pressure of 350 psia (2.41 Mpa). A scrutiny for the engine performance is made in terms of thrust and temperature behavior of steady state firing mode at the given propellant injection pressures: Pinj = 400, 250, 100, and 50 psi. The thrust and specific impulse are compared with a reference performance of 1-lbf standard rocket engines and their normalization procedure is introduced. A practical engineering approach to the data measurement and reduction is addressed, too.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.753-756
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• 2017

With the advancement of technology, miniaturization, integration, and weight reduction have become possible, and the existing medium and large satellites have been replaced by small satellites, and the need for a micro thruster has emerged. Laser ablation micro-thruster is a new type thruster using laser ablation. It is emerging as a new candidate in micro-thrusters with wide thrust range and low single impulse thrust. The objective of present study is to introduces the structure, propellant, and research trends of the laser ablation micro-thruster.

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

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.29-37
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• 2018

This paper reports the preliminary firing test performed with an ADN-based monopropellant using a 5 N scale thruster. ADN-based propellant and catalyst was fabricated and catalytic combustion of propellant was characterized by DSC-TG analysis. Although an explosion in the catalyst bed was occurred, high temperature in the catalyst bed obtained and demonstrated catalytic combustion of the propellant. Preliminary test results motivates the research for catalysts with better thermal stability.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.581-584
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• 2010

Korea Aerospace Research Institute (KARI) started preliminary research about the propulsion system for lunar orbiter and moon lander this year in order to prepare korean moon exploration plan of 2020s. The final goal of this study is to develop a prototype propulsion system for lunar exploration and to perform ground landing test using this propulsion system. In this year, preliminary design of propulsion system and 200N class monopropellant thruster have been conducted. In this paper, the trade-off study result and the design concept of the propulsion system for Korean moon exploration will be introduced and preliminary design of propulsion system will be presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.196-200
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• 2005

A theoretical model for the calculation of chemical equilibrium composition of propellant combustion product is briefly presented for the performance analysis of monopropellant hydrazine rocket engine. Analysis result is compared to that of test and evaluation of 1-lbf class thruster and is scrutinized primarily from the view point of ammonia dissociation fraction. Chemical equilibrium composition and average molecular weight is additionally depicted according to the variation of propellant inlet pressures and the varying nozzle area ratio. The theoretical analysis is tried as a way of derivation of design parameters for mid- and large-thrust class of monopropellant rocket engines.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.292-295
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• 2004

Firing performance test of hydrazine decomposition catalyst which is used in mono-propellant thruster of satellite and launcher was peformed. Equipment for catalyst test was developed and with this equipment reaction delay time, catalyst activity, granule stability of the catalyst firing performance was measured and analyzed.