• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.83-88
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• 2003

Satellite mounted on the launch vehicles experiences several environmental heating, such as direct solar flux, Earth IR, Albedo, and free molecular heating during faring jettison-separation launch stage. So, the most outer payload box of satellite is under the worst hot condition. The thermal governing equation is reduced into 1st order ordinary differential equation and analytic solution is acquired if payload box is assumed as a single lumped mass. Applying the analytic solution, we can predict the temperature increase of payload box experienced the worst hot condition, easily.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.5
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• pp.413-421
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• 2015

Since the first Cubesat was launched in 2003, there have been more than 230 Cubesats launched so far. Due to their small size and lightweight, Cubesats were launched by utilizing the empty space of regular launch vehicle. However, this launch method has a weakness that has been easily affecting by the schedule of major payloads. As a new solution to this problem, it has been proposed that a robot arm installed on ISS would be used to launch Cubesats. The orbits of Cubesat deployed from the ISS in various angles and directions are analyzed in this paper. We also analyze the possibility of collision between the Cubesat and ISS within the operational orbit of the CubeSat and eventually calculate the optimal angle of a robot arm, which maximizes the lifetime of Cubesat and minimizes the risk of collision between the Cubesat and ISS.

• 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.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.134-140
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• 2007

Since the successful launch of Sputnik 1, a rocket engine was evolved rapidly. The first artificial satellite Sputnik has only 182 lb mass with a size of a basket ball, a modern artificial satellite is over 10 tons. As the size and the mass of an artificial satellite increases, the stronger launch vehicles are required. However, the story is different in the field of the rocket engine development. In the early to mid age of the space race, rocket engine study was focused on the stronger and bigger engine development, but from the 80's the tide has changed. A rocket engine must be strong and also economic. This trend was accelerated from when a rocket launch was used commercially. In this study, a capability of the launch vehicle and engine was investigated to provide a reference for a liquid rocket engine development plan.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.7
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• pp.737-745
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• 2010

This paper describes the operation results of the GPS receiver system for KSLV (Korea Space Launch Vehicle)-I on the launch site at Naro Space Center that is the first spaceport of South Korea located at Goheung. All equipments of KSLV-I including the GPS receiver system should be monitored and controlled through hard-wired interface during KSLV-I is on standby at the launch pad. The GPS receiver for KSLV-I is connected to triple almost omni-directional patch antennas mounted on the cylindrical surface of KSLV-I that should be erected vertically on the launch pad until lift-off. Signal interference and multipath effects observed in the GPS receiver on the launch site are analyzed in this paper based on the GPS signals received from each GPS antenna.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.42-49
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• 2004

Analytical solutions are developed to predict temperature of a satellite box during launch stage under the assumption of worst hot condition. The considered time period is from fairing jettison to separation of satellite during launch stage. After fairing jettison, a box mounted on outer surface of satellite are exposed to space environments such as direct solar flux, Earth IR, Albedo, and free molecular heating. The thermal governing equation is simplified to 1st order ordinary differential equation such that analytic solutions are acquired after the box is assumed as a single lumped mass. The analytical solutions are also available for mass varying box. Finally, the practical application is performed for the case of STSAT-1 launch scenario.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.102-107
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• 2006

In this study, the dynamic environment of satellite consists of excessive vibration at low frequency and irregular acceleration transferred by launch vehicle structure. Excessive vibration at low frequency is generally approximated by a sinusoidal wave from 100Hz to 200Hz and primarily used to preliminary design The random vibration is created by structural vibration due to the combustion of launch vehicle, separation stage and external aerodynamic noise. these are transferred to the adapter structure between satellite and launch vehicle through the structure of launch vehicle. random vibration is being specified for acceptance tests, screening tests, and qualification tests, because it has been shown that random vibration more closely represents the true environments in which the electronic equipment must operate.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.46-46
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• 2004

한국항공우주산업(주) 우주개발연구센타에서는 고흥의 외나로도 우주센터에서 국내 최초로 발사되는 소형위성 발사체인 KSLV-1(Korea Space Launch Vehicle-1)의 성능검증을 위해 탑재되는 발사체 성능 검증위성(Korea Demonstration Satellite)을 개발하고 있다. 탑재소프트웨어는 검증위성의 임무를 수행하기 위하여 요구되는 데이터를 처리하고, 위성을 제어하는 역할을 수행한다. 이에 따라 검증위성의 탑재소프트웨어의 주요 기능은 발사체 환경 측정 및 비디오 영상 자료의 획득, GPS로부터 위성체 궤도자료의 저장, 밧데리 충방전 제어, 태양 지향 및 지상과의 통신 등을 고려한 자세제어이다. (중략)

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.69-74
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• 2010

As a part of development process of the COMS, an acoustic vibration test was performed in order to verify that the COMS is safe from the acoustic loads coming from the Ariane-5ECA launch vehicle when it is launched. In this paper, the acoustic vibration test preparation which was performed during the development of the COMS is explained, and through the evaluation of the test results, it was verified whether the COMS is safe from the acoustic load that the COMS will experience during the launch. Through detail evaluation of the acoustic loads on the solar array, Ka band communication payload antenna and feed, GOCI(Geo-Stationary Ocean Color Imager), MI(Meteorological Imager), it was confirmed that the COMS is safe from the acoustic loads from launch vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.774-787
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• 2011

This paper deals with quantitative analysis about the characteristics of GNSS(Global Navigation Satellite System) signals contaminated with multipath signals and day-to-day repeatability of the navigation solution and SNR(Signal to Noise Ratio) caused by multipath signals using the collected data from GPS receiver installed on KSLV-I which was on standby on the launch pad at Naro Space Center. Since the GPS antennas, surrounding environments and GPS satellite orbits were very slightly changed with respect to the day, the repeating pattern of the solution and SNR caused by the multipath signals was verified from the collected data. Analytic result of the multipath effects and day-to-day repeatability of the navigation solution and SNR observed at the launch pad would be used for obtaining more stable performance of the GPS receiver when the satellite launch vehicles are on standby.