• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.12
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• pp.877-888
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• 2022

Recently, as the CAPSTONE, a precursor mission for Lunar Gateway, was launched on a small launch vehicle for the purpose of demonstrating communications and navigation technology in the NRHO, large attention was brought to this event that enabled high-impact deep space mission using dedicated small launch vehicle and small spacecraft. In this study, we introduced the concept of a dual launch operation and examined the capability of the new concept in the exploration of the Moon, Mars and asteroid. It turned out a single launch is sufficient for the lunar low orbit mission up to around 247 kg, and the dual launch option can transport 215 kg and 183 kg to nearby destinations as such as Mars and astroid Apophis respectively.

• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.40-40
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• 2006

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.80-89
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• 2010

Transponder is the significant equipment for the telemetry and telecommand operation between the ground station and the satellite. Recently, various transponder technology like Compact Standard Transponder(CST), Small User Transponder(SUT) for data relay satellite, Dual Mode TT&C Transponder(DMT) for large user, and Deep Space Transponder(DST) for deep space mission have been developed according to the communication method and user requirements. Especially, the transponder based on the digital technology comes into the spotlight in the satellite communication field. This paper describes the various analog transponder technology and the state-of-art digital transponder technology grafted onto the existing analog transponder technology.

• Satellite Communications and Space Industry
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• v.2 no.2
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• pp.125-130
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• 1994

지난 4월 25일 종합과학기술심의회에서 국책사업으로 "다목적 실용위성 개발사업"의 기본계획, 개발체계, 정부부처간 역할분담 등 세부계획이 심의.의결을 거쳐 확정되었다. 이 사업은 오는 97년까지 정부지원 1천4백15억원 민간출연 2백35억원을 포함 총 1천6백50억원을 투입하여 해양탐사.환경관측.과학실험 등에 활용할 수 있는 지구저궤도용 다목적 실용위성을 개발 발사하는 것을 목표로 추진되고 있다. 다목적 실용위성 개발사업은 추진 체계 및 일정이 최종 확정됨에 따라 항공우주연구소를 사업총괄 주관기관으로 오는 9월부터 본격적으로 착수될 전망이다. 인공위성연구센터가 우리별 1호와 2호를 성공적으로 발사하여 우리나라 위성분야의 새로운 장을 열어 놓은데 이어 다목적 실용위성 개발사업이 구체화 됨에 따라 사업의 총괄 주관기관으로 선정된 항공우주연구소를 탐방하여 홍재학소장과 대담을 통하여 구체적인 사업추진 계획과 전망을 조명함은 물론 우주 첨단과학 기술의 산실인 항공우주연구소의 활동상황과 앞으로의 포부를 들어 보았다.

• Bulletin of the Korean Space Science Society
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• 1998.10a
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• pp.40.2-40
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• 1998

• Aerospace Industry
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• v.67
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• pp.10-13
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• 1999

지난 4월 22일 총리주재로 개최된 항공우주산업개발정책심의회에서 "항공우주산업개발기본계획"을 승인하였다. 동 계획은 우리나라 항공우주산업을 21세기 전략사업으로 육성하기 위해 기틀을 마련한 것으로 올 상반기중 세부시행계획을 수립할 예정이다. 본지에서는 동 계획의 요약본을 게재하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.69-75
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• 2011

As part of its space development program, Korea has a plan for the launch of a lunar orbiter and a lunar lander. To enable the transmission of lunar information based on multimedia, it is necessary to construct a communication system that is capable of transmitting large-volume telemetry data. The CCSDS standard recommends the deferred NAK mode as ARQ scheme for reliable long-distance deep-space communication systems. In this paper, we implement a space communication system simulator in the deferred NAK mode using models of the lunar orbiter, the earth station, and the space environment. The simulator employs modulation techniques and turbo coding schemes for transmitting large-volume telemetry data. We analyze the transmission performance of telemetry data through the simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.746-756
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• 2017

An algorithm is developed to generate measurement data of deep space network for Korea Pathfinder Lunar Orbiter (KPLO) mission. The algorithm can provide corrected measurement data for the Orbit Determination (OD) module in deep space. This study describes how to generate the computed data such as range, Doppler, azimuth angle and elevation angle. The geometric data were obtained by General Mission Analysis Tool (GMAT) simulation and the corrected data were calculated with measurement models. Therefore, the result of total delay includes effects of tropospheric delay, ionospheric delay, charged particle delay, antenna offset delay, and tropospheric refraction delay. The computed measurement data were validated by comparison with the results from Orbit Determination ToolBoX (ODTBX).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.63-68
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• 2011

Many countries all over the world have been doing lunar exploration projects. Korea has also been doing basic research on lunar exploration. The development of communication systems for lunar exploration projects is one of the most important aspects of performing a successful lunar mission. In this paper, we design a DSP (Digital Signal Processor) prototype based on the requirement analysis of a communication link for lunar exploration and implement its core module considering the international standards for deep space communications to perform a basic research on baseband processor development. It is verified by comparing the bit error rate of the DSP prototype with that of a computer simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.3
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• pp.218-227
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• 2016

Korean government plans to launch a lunar orbiter and a lander to the Moon by 2020. Before launch these two proves, an experimental lunar orbiter will be launched by 2018 to obtain key space technologies for the lunar exploration. Several payloads equipped in experimental lunar orbiter will monitor the surface of the Moon and will gather science data. Lunar orbiter sends telemetry and receives tele-command from ground using S-band while science data is sent to ground stations using X-band when the visibility is available. Korean deep space network will be mainly used for S and X-band communication with lunar orbiter. Deep Space Network or Universal Space Network can also be used for the S-band during trans-lunar phase when korean deep space network is not available and will be used for the S-band in normal mission orbit as a backup. This paper analyzes a visibility condition based on the combination of various ground antennas and its mask angles according to mission scenario to predict the number of contacts per day and to build an operational scenario for the lunar orbiter.