• Journal of Aerospace System Engineering
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• v.18 no.3
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• pp.27-33
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• 2024

According to the success of the Nuri Space Launch Vehicle (KSLV-II) and the development goal of the next generation space launch vehicle (KSLV-III), it is expected that the domestic geostationary satellite capability will be increased from (1 to 3.7) ton. Also, it is predicted that substantial ability of about 1 ton can be provided for the space exploration of the Moon, Mars, asteroids, etc. The Goheung space launch site is optimized for sun-synchronous small satellites, and due to the essential precondition that the launch trajectory does not impinge another country's sovereign airspace, it is not satisfactory as a geostationary satellite launching site. Its latitude also requires more energy to shape the rotating orbital plane from the initial injection status. This results in a decreasing factor of economic feasibility, including the operating complexity. Therefore, in parallel with the development of a next generation space launch vehicle, the practical process for acquisition of oversea land or sea space launch site near the Earth's equator and research for the optimization of orbiting methods of geostationary satellite injection must be continued.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.46.3-47
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• 2020

Variations in the brightness of asteroids are caused by their spins, irregular shapes and companions. Thus, in principle, the spin state and shape model of a single object or, a combined model of spins, shapes and mutual orbit of a multiple components can be constructed from the analysis of light curves obtained from the time-series photometry. Using ground- and space-based facilities, a number of time-series photometric observations of asteroids have been conducted to find the possible causes of their light variations. Nonetheless, only about 2% of the known asteroids have been confirmed for their rotation periods. Therefore, a follow-on systematic photometric survey of asteroids is essential. We started an asteroid light curve survey for this purpose using Korea Microlensing Telescope Network (KMTNet) during 199 nights between the second half of 2019 and the first half of 2020. We monitored within a 2° × 14° region of the sky per each night with 25 min cadences. In order to observe as many asteroids as possible with a single exposure, we mostly focus on the ecliptic plane. In our survey, 25,925 asteroids were observed and about 8,000 of them were confirmed for their rotation periods. In addition, using KMTNet's 24-hour continuous monitoring, we collected many composite light curves of slow rotating asteroids that were rarely obtained with previous observations. In this presentation, we will introduce the typical light curves of asteroids obtained from our survey and present a statistical analysis of spin states and shapes of the asteroids from this study.