• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.116-121
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• 2011

The tracking radar systems in NARO space center are used in order to acquire the TSPI (Time, Space, and Position Information) data of the launch vehicle. The tracking radar produce the measurements of tracked targets in the radar-centered coordinate system. When the tracking radar is in the Cartesian/Polar tracking mode, the state vector data is sent in radar-centered Cartesian/Polar coordinate system to RCC. RCC also send the slaving data in Test Range coordinate system to the tracking radar. So, the tracking radars have to transform the slaving data in Test Range coordinate system into in radar-centered coordinate system. In this study, we described the coordinate transformation between radar-centered coordinate system and Test Range coordinated system.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.279-280
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• 2017

본 논문에서는 대용량 데이터를 실시간으로 제어할 수 있는 Middleware 기반의 실시간 제어 시스템을 분석하고 유도무기 발사통제 시스템에 적용하는 방안에 대하여 설명한다. 기존의 발사통제 시스템과 비교하여 제안된 시스템이 제어가능 Task 개수, 제어 속도 및 실시간 제어 측면에서 우수한 특성을 제공할 수 있음을 보여준다. 이것은 실시간 대용량 제어 데이터를 필요로 하는 함정 전투체계, 무장, 항공기 항전 시스템 등의 실시간 제어 분야에서 활용될 수 있을 것이다.

• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.997-1010
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• 2021

This study collected and analyzed flight data of SpaceX's Falcon 9 launch vehicle. All missions were classified by orbital types, such as Polar, SSO, ISS, LEO and GTO missions. In characteristic maneuvers of main engine cutoff, boostback, reentry and landing burn at each stage of 1st stage launch vehicle, changes of the physical parameters like speed, altitude, dynamic pressure and acceleration were investigated. The guidelines derived from detailed maneuver analysis were suggested, which can be used as design and evaluation references for developing reusable launch vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.101-108
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• 2005

The GPS(Global Positioning System) receiver for satellite launch vehicles which will be mounted on a launch vehicle can be applied to the flight safety system with its accurately calculated position and velocity data during vehicle's flight. This paper analyzes the performance of the GPS receiver such as SNR(Signal to Noise Ratio), fix mode, position and velocity error, number of visible and tracking satellites, and PDOP(Position Dilution of Precision) under temperature variation which is changed from -34$^{\circ}C$ to +71$^{\circ}C$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.155-166
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• 2021

In this paper, design study of a small two-stage launch vehicle is undertaken for the dedicated launch of the Compact Advanced Satellite 500 (CAS500)-class satellite into the Low Earth Orbit (LEO) by modifying the second and third stages of the Korean Space Launch Vehicle II (KSLV-II). Since the KSLV-II has three stages, velocity increment is newly distributed for the two-stage small launch vehicle. For this end, the staging design is carried out for the design parameters such as stage mass ratios, structural coefficients and engine options for each stage followed by trajectory analysis. Investigation of the results provides the combination of design parameters for the small launch vehicle for the dedicated launch of 500 kg-class satellite into LEO.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.402-404
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• 2006

Electro-magnetic launcher(EML)는 전자기력을 이용하여 발사체를 추진시키는 장치이며 그 종류에는 레일건과 코일건이 있다 본 논문에서는 소형, 경량의 발사체를 추진, 가속시키기 위한 솔레노이드형 EML을 설계, 제작하여 시험 발사하고 그 특성을 분석하였다. 개발된 EML은 소형이기 때문에 launcher의 직경이 작아 자기장을 한 지점으로 집중시키는 장치가 필요없고, 전기에너지를 줄이기 위한 별도의 시스템이 필요하지 않으며, 솔레노이드의 형태와 발사체의 위치, 스위칭 시간에 의해 발사체의 추진력과 속도를 조절할 수 있는 장점이 있었다.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.169-177
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• 2012

This paper considers the explicit guidance algorithm to determine the closed-loop guidance law applicable to upper stages of a given space launch vehicle. It has the advantage of very simple forms derived from the flat earth assumption, which is appropriate for its on-board application. However the simple time-to-go prediction equation produces the degraded guidance performance of the launcher because of its inaccuracy. To overcome the problem, the elaborate prediction equations, which have been employed in Saturn and H-II, are attempted here. Finally, the simulation results show that the simple guidance approach requires the more accurate time-to-go prediction and gravity integrals for its broad application.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.89-97
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• 2011

This paper considers improved IGM (Iterative Guidance Mode), one of the explicit guidance algorithms, to determine the guidance algorithm for upper stages of a space launch vehicle. IGM, which has been employed successfully for the Saturn to put its payload into the parking orbit and lunar transfer orbit, is applied here for guidance of the launcher during the second and third stages. The orbit injection accuracy is evaluated through the 3-DOF computer simulations and an accurate prediction method, which can eliminate the prediction error of the downrange position at the orbit injection, is also proposed here.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.574-575
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• 2012