• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제35권4호
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• pp.363-368
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• 2007

Lithium-ion batteries providing high gravimetric energy density are rapidly replacing Ni-Cd and Ni-H2 in aerospace applications. The main advantage is the weight reduction of the battery system. Weight is a major concern in aerospace applications. Also, lithium-ion offer low thermal dissipation, high energy efficiency, and low cell cost. The Onboard battery module for KSLV-I(Korea Space Launch Vehicle) contains 80 Sony US18650 cells configured as 10 strings in parallel, with each string containing 8 series connected cells. This allows to meet voltage and capacity requirements specified for the mission. In this paper design description and specifications of lithium-ion battery developed are presented. Qualification test flow is also shown to make sure the performance in the predicted space environment. Electrical performance was simulated by dedicated program, and verified with electronic load. Lastly, the capacity was proven on real equipment load assembly.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제40권5호
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• pp.439-445
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• 2012

The COMS(Communication, Ocean, and Meteorological Satellite) is subjected to shock loads when the stage or fairing of a launch vehicle is separated and the satellite is separated from the launch vehicle during the launch vehicle flight. And, after the satellite is separated from the launcher, the COMS is subjected to shock loads when the solar array is deployed, Ka-Band communication antenna is deployed, and meteorological imager radiator cover is released. In order to validate the satellite safety against these shock loads on ground, shock tests were performed. In this paper, the shock tests performed in the course of the COMS development are described, and the method to assess the test result is presented with an example of Geostationary Ocean Color Imager(GOCI). In Ariane-5 launch vehicle, the clampband release shock for satellite separation is lower than the fairing or stage separation. In this paper, the extrapolation method to take into account the maximum shock load from the launch vehicle by using the satellite separation shock test result is also introduced.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제33권9호
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• pp.27-33
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• 2005

This research presents the influence of the base region modeling on the aerodynamic characteristics of a launch vehicle using CFD. The vicinity of a launch vehicle is divided into four zones, and four computational cases are made using these four zones. The aerodynamic coefficients are predicted for the angle-of-attack of 6 degrees and Mach numbers ranging from 0.4 to 2.86. It was found that modeling of the base region should not be neglected for the prediction of the aerodynamic characteristics of a launch vehicle in subsonic and transonic regions. It was also found that the modeling of the sting support used in the wind tunnel test is necessary to get a better agreement with the experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.175-178
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• 2011

A performance characteristics and application status of liquid-monopropellants used for 3-axis control thrusters are surveyed, in this paper. Hydrogen peroxide was widely used as monopropellant until mid-1960s, but it is rapidly replaced with hydrazine which has better performance of specific impulse, storability, and so on. Hydrazine is mostly employed as a liquid-monopropellant of satellite, interplanetary spacecraft, and space launch vehicle owing to its moderate performance features.

• Aerospace Engineering and Technology
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• 제9권1호
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• pp.151-157
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• 2010

The tracking radars in NARO space center are precious, long-range tracking systems for tracking the launch vehicle (KSLV-1) and transmitting TSPI (Time, Space and Position Information) data to MCC (Mission Control Center). Because TSPI data from tracking radars to MCC are important information for the launch mission and flight safety control, TSPI data are required to be more accurate. In this paper, we analyzed theoretically the required specification of the random noise error in tracking radar and verified the real random noise error. In this analysis, we evaluated the TSPI data of several flight tests performed in NARO space center.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제37권2호
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• pp.156-165
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• 2009

Threat due to malfunction of space launch vehicles is significant since it is bigger and flights longer range than military missiles or scientific rockets. It is necessary to implement a flight safety system to minimize the possible hazard. Design objective of the tracking filter for the flight safety system is different from conventional tracking filters since estimation reliability is more emphasized than estimation accuracy. In this paper, a fusion tracking filter was implemented for processing multi-sensor data from a space launch vehicle. The filter performance is evaluated by analyzing the error of the estimated position and instantaneous impact point. Also a fault detection algorithm is implemented to guarantee fusion filter's reliability under any sensor failure and verified to maintain stability successfully.

• Aerospace Engineering and Technology
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• 제11권1호
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• pp.135-144
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• 2012

The NARO is South Korea's first carrier launch vehicle, which made its flights from NARO Space Center on 25 August 2009 and 10 June 2010. LV PACS(Preparation Automated Control System) is a electrical ground support system to monitor and control the integrated launch vehicle during the launch preparation and operation in Launch Complex. As a subsystem of LV PACS, LV PACS-II was developed for launch preparation and operation of the NARO upper stage, and all the functions and requirements were verified successfully through NARO flight tests. In this paper the core technology and characteristics applied to LV PACS-II are described.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제39권6호
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• pp.576-584
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• 2011

In order to develop a launch vehicle successfully, it is important to estimate development costs accurately but it is also important to plan the annual budget. In this paper, the statistical method was utilized for cost spreading. For cost spread modeling, the suitability of the model by analyzing several statistical models was evaluated and consequently, the beta-distribution model has been selected. In this study, the validity of the annual estimation cost model was verified through the comparison of the actual development cost distribution and the estimating cost distribution of Space Shuttle Main Engine. In addition, this paper estimated the annual budget required for the development of the KSLV-II using currently allocated cost for successful development. It is anticipated that the present cost spread model can be applied to not only launch vehicle development but also other large complex system development.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제40권4호
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• pp.364-374
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• 2012

The purpose of this study is to perform the reliability-corrected development cost estimation of the launch vehicle at the conceptual design phase. In order to estimate the launch vehicle development cost, the estimation method based on the independent variable such as the rocket performance and dry mass has been mainly implemented up to now. This approach has made the approximate cost estimation possible, however, the cost variation according to the reliability requirement could not be reflected. In this paper, the cost estimation methodology that introduces the reliability factor in addition to the performance and mass in the TRANSCOST model is presented in order to improve the limitation of current cost estimation method. The development cost of KSLV(Korea Space Launch Vehicle)-II is estimated on the basis of this newly implemented concept with reliability as an added parameter.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제37권3호
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• pp.314-327
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• 2009

Weather launch criteria of launch at Oenarodo Space Center is important for the successful launch operation. In particular, most of the launch failure occurs during the period of separation from the launch pad, thus meteorological condition is critical at this phase. In earlier days, the weather launch criteria adopted wind and forecast data for the launch operation. Nevertheless, the control of position and stability require other meteorological components such as vertical wind shear, lightning, temperature and visibility, because the launch vehicle is moving mostly vertically. We analyze these meteorological components by using the observed data at KMA at neighboring Oenarodo to determine the weather launch criteria. These criteria need further refinements through long-term observation.