• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.537-558
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• 2005

This paper addresses the results of HAUSAT-2 radiation environment and effect analyses, including TID and SEE analyses. Trapped proton and electron, solar proton, galactic cosmic ray models were considered for HAUSAT-2 TID radiation environment analysis. TID was analyzed through total dose-depth curve and the radiation tolerance of TID for HAUSAT-2 components was verified by using DMBP method and sectoring analysis. HAUSAT-2 LET spectrum for heavy ion and proton were also analyzed for SEE investigation. SEE(SEU, SEL) analyses were accomplished for MPC860T2B microprocessor and K6X8008T2B memory. It was estimated that several SEUs may occur without SEL during the HAUSAT-2 mission life(2 years). Software Hamming Code EDAC has been implemented to detect and correct the SEU. In this study, all radiation analyses were conducted by using SPENVIS software.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.94-104
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• 1996

The satellite experiences the launch environment such as vibration, acceleration, shock induced by rocket and the orbit environment such as high vacuum, no gravity, high temperature and cryogenic. Therefore, the satellite should be designed and manufactured to endure such environments. Also, special care must be taken on the assembly of parts and subsystem. Finally, we describe the environment test of microsatellite to ensure the reliable operation during launch period as well as in-orbit operation.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.163-173
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• 2001

In this paper, space radiation environment and single event effect(SEE) have been analyzed for the KOMPSAT-2 operational orbit. As spacecraft external and internal space environment, trapped proton, SEP(solar energetic particle) and GCR(galactic cosmic ray) high energy Protons and heavy ions spectrums are analyzed. Finally, SEU and SEL rate prediction has been performed for the Intel 80386 microprocessor CPU that is planned to be used in the KOMPSAT-2. As the estimation results, under nominal operational condition, it is predicted that trapped proton and high energetic proton induced SBU effect will not occur. But, it is predicted that heavy ion induced SEU can occur several times during KOMPSAT-2 3-year mission operation. KOMPSAT-2 has been implementing system level design to mitigate SEU occurrence using processor CPU error detection function of the on-board flight software.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1399-1404
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• 2012

Because satellites operate in space, it is impossible to repair them when they malfunction. Therefore, to ensure the normal function of the payload used in the satellites, accurate assembly and installation of parts are crucial. To prevent abnormal functioning in the extreme environments during launch and in space, it is essential to test changes at the parts and system levels by performing alignment measurement before and after the launch environment test and the space environment test. Recently, noncontact three-dimensional precision machinery for medium- and large-sized parts has been developed. One of these is the theodolite measurement system, which is widely used in the aerospace industry. This study measures the angle of the dual thruster module that is used to control the attitude of KOMPSAT by using a theodolite, and alignment measurement and a reliability analysis are performed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.5
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• pp.428-437
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• 2008

e-AIRS, an abbreviation of ‘e-Aerospace Integrated Research System’, is a virtual organization designed to support the aerospace engineering processes in the e-Science environment. As the first step toward a virtual aerospace engineering organization, the e-AIRS intends to give a full support to aerodynamic research processes. Currently, the e-AIRS can handle both the computational and experimental aerodynamic researches on the e-Science infrastructure. In detail, users can conduct the full CFD(Computational Fluid Dynamics) research processes, request wind tunnel experiments, perform the comparative analysis between computational and experimental resultants and finally collaborate with other researchers using the web portal. The current paper will describe those functions and the internal architecture of the e-AIRS system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.795-801
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• 2014

STEP Cube Lab. classified as a pico-satellite has been being developed by SSTL(Space Technology Synthesis Laboratory) in Chosun University. Its main mission objective is to perform the on-orbit verification of core space technologies, which will be the potential candidates for future space missions. In this paper, to guarantee successful mission operation of the cube satellite under extremely severe space thermal environment condition, the system level thermal design and analysis has been performed. The effectiveness of the design has been verified through on-orbit thermal analysis of cube satellite.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1209-1216
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• 2009

This paper presents the pose estimation of a small UAV utilizing visual information from low cost cameras installed indoor. To overcome the limitation of the outside flight experiment, the indoor flight test environment based on multi-camera systems is proposed. Computer vision algorithms for the proposed system include camera calibration, color marker detection, and pose estimation. The well-known extended Kalman filter is used to obtain an accurate position and pose estimation for the small UAV. This paper finishes with several experiment results illustrating the performance and properties of the proposed vision-based indoor flight test environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.6
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• pp.545-550
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• 2009

Generally, the smoothing pre-filter of sensor's raw measurement(accelerometer and gyroscope) is used for INS's fast alignment. When the pre-filter is abruptly removed at Navigation-mode entry in vibration environment, INS's initial attitude error can be largely generated. So that we propose initial attitude error reducing methods(monotone increasing of cutoff-frequency, real-time attitude estimation), these are proved by simulation.

• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.83-89
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• 1999

The Earth is exposed to constant outflow of the solar wind from the outer layers of the Sun, and violent transient events taking place from active regions increase the energy flux of both radiation and particles leaving the Sun. Thus the space surrounding the Earth is a highly dynamic environment that responds sensitively to changes in radiation, particles and magnetic field arriving from the Sun. Nowadays, it becomes increasingly important to understand how the physical system of Earth-space works and how the space around the Earth connects to interplanetary space. In the present paper we describe how explosive solar events, such as CME(Coronal Mass Ejection) and flares affect the Earth-space environment and how the space weather reacts to them. Practical consequences are presented to demonstrate why a broader view of Earth's environment is greatly needed to cope with modern day's inhabitation problem in a rapidly developing space age.

• Journal of Advanced Navigation Technology
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• v.25 no.4
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• pp.267-272
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• 2021

The end of the ROK-U.S. missile guidelines opened up the possibility of developing space launch vehicles for various platforms based on air and sea. In particular, the air-based space launch vehicle is an essential space power projection capability compared to the ground-based space launch vehicle in consideration of the geographical location of the Korean Peninsula, such as the deployment of various satellite orbits and the timely launch of satellite. In addition, compared to the ground-based launch vehicle, the cost reduction effect is large, and it has the merit of energy gain because it can be launched with the advantage of the aircraft's altitude and speed. Therefore, in this paper, the necessity of air-based space launch vehicle in the strategic environment of the Korean Peninsula is clearly presented, and through technology trend analysis of various air launch vehicle, the three methods are proposed to have the most efficient air-based space launch vehicle capability in the Korean situation.