• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.678-699
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• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.8
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• pp.695-701
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• 2016

Spacecraft propulsion system is a kind of rocket engine that has been developed from the end of 1950s for attitude control and orbit maintenance of satellite. Since the spacecraft propulsion system has to be used for a relatively long time, therefore, stability of propellant and life of thruster could be very important factor for propulsion system design. Recently, green propellant propulsion and all electrical propulsion system have became very important issue, and we also need a development according to well organized plan. In this paper, we will introduce the development status, key technologies and development prospect of spacecraft propulsion system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.207-210
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• 2011

Chollian bipropellant propulsion system is composed of one main engine for orbit transfer and fourteen thrusters for on-station operations. The design and analyses of the propulsion system were carried out in the framework of international collaboration. Following the system integration and testings required, the Chollian was transported to Kourou Space Center in French Guiana and launched successfully. After it separated from the launcher, the propulsion system was initialised automatically. Then three times of main engine firing were successfully performed, and the target obit insertion was accomplished.

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.169-175
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• 2007

The international cooperation project CIBER (Cosmic Infrared Background ExpeRiment) is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. Currently, all the subsystems have been built, and the integration, testing, and calibration of the CIBER system are on process for the scheduled launch in June 2008.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.867-869
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• 2004

A smart blade conception has been proposed by the authors. With stretching-twisting coupling effect, the blade is twisted by centrifugal load or ambient temperature change. In this paper, the blades, made by three kinds of anti-symmetric laminates, are investigated by rotational tests. The results show the angle of smart blade tips increases in proportion to the 2nd power of a rotating speed and is well in agreement with the numerical results by FEM.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.1
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• pp.58-71
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• 2009

The blast wave released during the initiation of energetic materials gives rise to pulse energy generation, characterized by a sudden increase of potential energy. A highly efficient energy source, sought from pulse-type lasers, may be utilized in various space propulsion and power applications. This paper introduces a scheme of utilizing the laser energy in 1) attitude control of a satellite requiring of a low thrust, 2) innovative laser-induced drug delivery, 3) implosion-based micro piston development, 4) deflecting and zapping of space debris for laser kill purpose, and 5) finally lunar detection using laser induced breakdown spectroscopy.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.307-310
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• 2008

In the framework of COMS(Communication, Ocean and Meteorological Satellite) programme, the first bipropellant propulsion system for GEO satellite has been developed successfully. So far Korea has its own experience of development of a monopropellant propulsion system for LEO satellites, i.e., KOMPSAT's. Other types of propulsion systems for a satellite, such as cold gas and electric propulsion etc., are being developed somewhere in Korea, however they are not commercialised yet, apart from those two systems aforementioned. This paper mainly focused on the design of the Chemical Propulsion System(CPS) for the COMS, joint scientific and communications satellite. It includes descriptions of the general system design and a summary of the supporting analysis performed to verify suitability for space flight. Essentially it provides an overview and guide to the various engineering rationale generated in support of the COMS CPS design activities. The manufacture and subsequent testing of COMS CPS are briefly discussed. Feasibility of COMS CPS to an interplanetary mission is proposed as well.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.10
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• pp.959-965
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• 2011

A modeling and power simulation of a small UAV's electric propulsion systems is described. Each power source is modeled and simulated in Matlab/Simulink and it is compared flight test data during 4 hr 30 min with simulation results about 200 W electric propulsion system using fuel cell and battery as a main power sources. In result, it is properly simulated performance and dynamic characteristic of each electric power source. Through this, it is revealed that the simulation is available as a means of predicting power characteristic variation for electric propulsion systems of different class.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.1-9
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• 2019

Recently, in the space market, there has been a rapid reduction of the launch price. The major reason is that a few commercial companies, especially SpaceX, began to enter into the space market about ten years ago, which has changed the space market from monopolization to competition, and accelerated the adoption of commercial efficiency in the technology and management. Also, the successful landing and recovery of a first stage in 2016 by SpaceX proved to be a prelude to opening a new era of reusable launch vehicles, and SpaceX declared the groundbreaking launch price through using the reusable launch vehicle. This study calculates the total launch cost required to put a certain satellite into the LEO, compares the launch cost in three cases with different payload weights, and reviews the impacts of the payload on the cost effectiveness of a reusable vehicle. The total launch cost is divided into 6 subsections cost, namely development cost, production cost, refurbishment cost, operation cost, fixed-cost of factory and launch site, and insurance cost. The cost estimation relationships used in the calculation are taken from the commonly proven cost models such as TRANSCOST.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.763-767
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• 2004

A possible and practical engine system research method is proposed. Varieties of objectives of the engine component and system technology developments are fulfilled by the small scale rig and engine demonstration. Some research applications of small jet engines in National Aerospace Laboratory of Japan (NAL) are presented together with historical overview.