• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.131-136
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• 2018

Research on space development and satellites is being actively pursued. An interesting field is the study of reliable low-cost space launch vehicles. Since chemical fuel-based launching systems are expensive and take a lot of time and cost to maintain, the EML system, which is an electromagnetic force launching apparatus, is attracting attention. The EML system converts electrical energy stored in a capacitor into magnetic energy, and converts magnetic energy into mechanical kinetic energy, thereby accelerating the projectile. Although studies are actively conducted in the field, it is difficult to solve the equation because the impedance and speedance change with time and the nonlinearity is strong. Many researchers have solved this equation in a variety of methods. In this paper, the velocity analysis of the projectile was carried out by FEM (finite element method) using the commercial electromagnetic analysis program MAXWELL.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.439-445
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• 2008

In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and Geostationary Earth Orbit (GEO) launch vehicles in the frequency range [1MHz-47MHz] is described. The considered launch vehicles are arian V, sea Launch, land Launch, atlas III&V, delta IV, proton M/breeze M, soyuz, HII-A and Angara. The launch vehicle Radiated Emission (RE) specifications have been compared to COMS satellite Radiated Susceptibility (RS) limits. The COMS RS limits are the RS qualification levels of COMS units during launch. As a result, The radiated emission levels of arian V, sea launch, atlas III&V, delta IV, proton M/breeze M, HII-A and angara are compliant with COMS RS limits. The negative margins appear between land launch or soyuz launch vehicle RE and COMS RS. Then, if the land launch or soyuz is chosen by the customer, The tests should be performed at satellite level in order to demonstrate the compatibility with respect to launch vehicles specifications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.329-337
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• 2007

This paper deals with electromagnetic tests of the GPS receiver system that should be developed to satisfy emission and susceptibility requirements for a satellite launch vehicle. Performance of the GPS receiver system against electromagnetic environment that is improved through several tests satisfies all requirements about electromagnetic tests. The outline of the electromagnetic tests and emission test results of CE102, CE106 and RE102 on MIL-STD-461E are described in Part I.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.338-346
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• 2007

This paper deals with electromagnetic tests of the GPS receiver system that should be developed to satisfy emission and susceptibility requirements for a satellite launch vehicle. The performance of the GPS receiver system against electromagnetic environment that is improved through several tests satisfies all requirements about electromagnetic tests. The susceptibility test results of CS101, CS114, CS115, CS116 and RS103 on MIL-STD-461E are described in Part II.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.774-778
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• 2010

In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and the Geostationary Earth Orbit (GEO) launch vehicles in the frequency range is described. The considered launch vehicles are Arian Ⅴ, Sea Launch, Land Launch, Atlas III&Ⅴ, Delta IV, Proton M/breeze M, Soyuz, H II-Aa. The launch vehicle Radiated Susceptibility (RS) specifications have been compared to COMS satellite Radiated Emission (RE) limits. The COMS Radiated Emission (RE) level is determined by calculating the radiated field equal to the quadratic sum of radiated emissions of each equipment switched "ON" during launch. As a result, The RS requirements of Arian V, Atlas III&V and Delta IV lauchers are compliant with COMS RE limits. The negative margins appear between the others launch vehicle RS (Sea Launch, Land Launch, Proton M/Breeze M, Soyuz and H II-A) and COMS RE. Then, if the launchers that have negative margin were chosen by the customer, The EMC tests should be performed at satellite level in order to demonstrate the compatibility with respect to launch vehicles requirements.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.33-40
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• 2009

In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and Geostationary Earth Orbit (GEO) launch vehicles in the frequency range [1MHz-47MHz] is described. The launch vehicle Radiated Emission (RE) specifications have been compared to COMS satellite Radiated Susceptibility (RS) limits. The COMS RS limits are the RS qualification levels of COMS units during launch. The negative margins appear between land launch or soyuz launch vehicle RE and COMS RS. Then, if the land launch or soyuz is chosen by the customer, The tests should be performed at satellite level in order to demonstrate the compatibility with respect to launch vehicles specifications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.929-937
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• 2008

A GPS receiver system utilized on satellite launch vehicles should operate normally under harsh environments as well as high-dynamic conditions. The GPS receiver system to use for range safety of KSLV(Korea Space Launch Vehicle)-I that is the first satellite launch vehicle developed by KARI(Korea Aerospace Research Institute) has been confirmed to survive under the environment of the launcher through extensive terrestrial tests including humidity, high and low temperatures, vacuum, sinusoidal and random vibrations, shocks, acceleration, EMI/EMC(Electromagnetic Interference/ Electromagnetic Compatibility), etc. Several performance tests have been also carried out in order to evaluate tracking capability and accuracy of the GPS receiver under high-dynamic conditions using a GPS signal simulator. Some lessons-learned during development of the GPS receiver system and its special characteristics compared with COTS(Commercial-Off-The-Shelf) GPS receiver systems are described in this paper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.118-123
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• 2018

Coil guns are known worldwide as inexpensive space launch vehicles. The principle of Fleming's right-hand rule allows the coil gun to accelerate the projectile by applying enormous voltage to the solenoid coil. This study was performed to improve the speed of the coil gun using MATLAB, a commercially available numerical program for high launching force of electromagnetic projectiles. To maximize the speed of the projectile, the largest coil of American wire gauge was used, and the number of windings in the radial and axial directions of the solenoid coil was optimized. Optimal length of the projectile was obtained by calculating the optimal aspect ratio between the axial length of the solenoid coil and the length of the projectile.

• Journal of Magnetics
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• v.20 no.3
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• pp.322-329
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• 2015

This paper presents a new overlapped coilgun configuration to launch medium weight projectiles. The proposed configuration consists of a two-stage coilgun with overlapped coil covers with spacing between them. The theoretical operation of a multi-stage coilgun is introduced, and a transient simulation was conducted for projectile motion through the launcher by using a commercial transient finite element software, ANSOFT MAXWELL. The excitation circuit design for each coilgun is reported, and the results indicate that the overlapped configuration increased the exit velocity relative to a non-overlapped configuration. Different configurations in terms of the optimum length and switching time were attempted for the proposed structure, and all of these cases exhibited an increase in the exit velocity. The exit velocity tends to increase by 27.2% relative to that of a non-overlapped coilgun of the same length.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.108-117
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• 2003