• Journal of Space Technology and Applications
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• v.3 no.1
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• pp.72-85
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• 2023

Most Nanosatellites are launched in nanosatellite deployers. Nanosatellites in the deployer are turned off during launch, and they start boot sequence after deploying at their mission orbit. For this reason, nanosatellites must have deployment switch. Most of the nanosatellite deployment switch has two part, first is electric switch to boot the satellite system and second is mechanical assembly to push the switch. In most cases, electric switches are installed in the satellite main body, and the switch operations are translated via the mechanical assembly. These implementations are mechanically complicated and hard to guarantee the appropriate operation without the problems due to friction between pusher and satellite structure. This paper proposes the another implementation method of deployment switch for nanosatellites by installing the electric switch outside the main body without any kind of mechanical parts.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.133-136
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• 2006

Unlike large satellites, small satellites, such as nanosatellite and microsatellite, provide a limited interior space for components mounting. In order to mitigate this issue, the compact Bus Electronic Unit (BEU) that integrates satellite electronic modules, combining most of bus subsystems and payloads electronic modules into one unit, has been developed for HAUSAT-2 nanosatellite. This paper addresses the design and environmental test result analyses of BEU.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.353-362
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• 2007

Unlike large satellites, small satellites, such as nanosatellite and microsatellite, can provide a limited interior space for components mounting. In order to mitigate this issue, the compact Bus Electronic Unit(BEU) that integrates satellite electronic modules, combining most of bus subsystems and payload electronic modules into one unit, has been developed for HAUSAT-2 nanosatellite. This paper addresses the design and environmental test result analyses of BEU. The vibration and thermal vacuum tests were conducted at qualification level for the verification of design margin of newly developed BEU. The performance of individual electronic subsystem modules has been verified through performance tests before and after the qualification tests. It was confirmed that the natural frequency of BEU satisfies the design stiffness requirement without structural damage in the vibration test. Thermal analysis results were also almost consistent with test results through modified thermal analysis modeling.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.556-558
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• 2022

This paper proposes a CanSat system with a vehicle tracking function based on Jetson Nano, a high-performance small computer capable of operating artificial intelligence algorithms. The CanSat system consists of a CanSat and a ground station. The CanSat falls in the atmosphere and transmits the data obtained through the installed sensors to the ground station using wireless communication. The existing CanSat is limited to the mission of simply transmitting the collected information to the ground station, and there is a limit to efficiently performing the mission due to the limited fall time and bandwidth limitation of wireless communication. The Jetson Nano based CanSat proposed in this paper uses a pre-trained neural network model to detect the location of a vehicle in each image taken from the air in real time, and then uses a 2-axis motor to move the camera to track the vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.423-433
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• 2022

This paper introduces the case studies of launch environmental test for cube nanosatellites and lessons learned of the design and integration from those. Generally, nanosatellites are launched and deployed in space while being contained in nanosatellite deployers, mechanical loads of launch are transferred through the deployer. This characteristic make nanosatellites under larger loads and higher possibilities of mechanical failure. This study represents guidelines of the design and the integration of the nanosatellites by showing the cases of launch environmental test of nanosatellite system. Moreover, it is suggested that the modern nanosatellite deployer with the capability of fixing the internal nanosatellite be preferable to conventional deployer by comparing the test results with those deployers.

• Journal of Space Technology and Applications
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• v.3 no.2
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• pp.144-153
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• 2023

The existing military satellite communication system was based on geostationary satellites equipped with special communication payloads against enemy's jamming and signal reception. With the advent of new weapon systems such as unmanned systems, the need for low-orbit satellite-based communication system is increasing. This paper introduces various waveform technologies suitable for cube satellite-based communication system and the operational concept of a future military nanosatellite communication system.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.22.4-22.4
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• 2011

위성항법시스템에서 위성 신호의 이상 발생 시 신속하게 위성시계의 고장 유무를 판단할 수 있도록 실시간 위성 시계 이상감지 시스템을 구축하였다. 위성 시계는 시스템 성능에 직접적인 영향을 미치는 핵심 요소로서 고장이나 이상 발생 시 측정치에 매우 큰 영향을 미칠 수 있다. 특정 위성 시계에 고장이나 이상이 발생한 경우 사용자들이 해당 위성의 측정치를 사용하지 않도록 가능한 빨리 이를 감지하고 공지할 수 있어야 한다. 현재 GPS의 경우 시스템 자체만으로는 위성 상태 정보가 적절한 시간 내에 제공되지 못하므로, 사용자가 직접 위성 신호의 사용 유무를 판단할 수 있는 위성 상태 감시 기능이 필요하다. 이 논문에서는 위성 시계 이상 발생 시 이를 실시간으로 감지할 수 있도록 한국항공우주연구에서 구축한 실시간 위성 시계 이상 감지 시스템에 대해 소개하고자 한다. 시스템 구현을 위해 적용한 방법은 크게 세 단계로 나뉠 수 있다. 첫 번째, 실시간으로 수신한 GPS 이중 주파수 측정치로부터 반송파 스무딩 필터를 적용하여 위성 시계 바이어스를 추정한다. 두 번째, 위성 위치 및 시계 정보의 실시간 적용을 위해 항법력보다 성능이 뛰어난 IGS Ultra-rapid 예측 정보를 활용한다. 마지막으로 위성시계 바이어스 추정치와 예측치를 비교하여 시계 이상 유무를 판별한다. 실제 위성 시계 이상이 발생한 위성의 측정치를 적용하여 시스템에 대한 검증시험을 수행하였고, 10 나노 초 수준의 위성 시계도약 현상이 발생한 위성의 감지를 통해 시스템의 성능을 확인하였다. 이는 항공항법분야와 같이 고성능의 위치 정보를 요구하는 응용분야에 신뢰성 있는 위성 정보 제공을 위해 활용될 수 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.11
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• pp.919-931
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• 2021

In the recent New Space era, Nanosatellites are being used to carry out space business and practical missions by private space companies, government agencies and military reconnaissance organizations, away from satellite system education tools. In Korea, the development of nanosatellite satellites, which started with universities at the center, is gradually being attempted by various subjects, including private industries. However, it is not easy to find relevant information to share the experience and prepare for the space environment test, test results, and the various problems that may arise in the process, which can increase the chances of mission success for nanosatellites. In this paper, we expect that the subjects who want to develop the nanosatellite(SNIPE) will be used as useful references for reducing trial and error and increasing the possibility of mission success by organizing the 6U-class space environment test, test process, test results and problems.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.125-128
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• 2006

Communication Subsystem of HAUSAT-2 which is 25kg class nanosatellite is designed, manufactured and tested for its performance verification at the Space System Research Laboratory (SSRL). HAUSAT-2 Communication Subsystem provides communication link for commands receiving, mission and state of health data transmission with high reliability. This paper describes design, manufacturing, test results of Engineering Model of HAUSAT-2.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.83-91
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• 2005

Air-Launching is an effective method that can launch the 'Nanosat' with low launching cost. In this study, system and subsystem design of the air launching rocket for nanosats which perform a simple mission, have been performed. For this purpose, the WBS of the MIRINAEⅡ, and the subsystem schematics have been defined first. Based on these results, detailed configuration and DMU have been developed.