• Journal of Astronomy and Space Sciences
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• v.32 no.2
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• pp.121-125
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• 2015

At the suggestion of the NASA Meteoroid Environment Office (NASA/MEO), which promotes lunar impact monitoring worldwide during NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) mission period (launched Sept. 2013), we set up a video observation system for lunar impact flashes using a 16-inch educational telescope at Chungnam National University. From Oct. 2013 through Apr. 2014, we recorded 80 hours of video observation of the unilluminated part of the crescent moon in the evening hours. We found a plausible candidate impact flash on Feb. 3, 2014 at selenographic longitude $2.1^{\circ}$ and latitude $25.4^{\circ}$. The flash lasted for 0.2 s and the light curve was asymmetric with a slow decrease after a peak brightness of $8.7{\pm}0.3mag$. Based on a star-like distribution of pixel brightness and asymmetric light curve, we conclude that the observed flash was due to a meteoroid impact on the lunar surface. Since unequivocal detection of an impact flash requires simultaneous observation from at least two sites, we strongly recommend that other institutes and universities in Korea set up similar inexpensive monitoring systems involving educational or amateur telescopes, and that they collaborate in the near future.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.39.4-40
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• 2017

According to the Korean government's Long-term Space Development Plan 2040, "Creative space science research" is included in a statement to investigate the origin and evolution of the universe by conducting a series of Korean space telescope missions: launch of space telescopes on a small satellite and an international collaboration explorer by 2020, a mid-size domestic space telescope by 2030, and a large size Korea leading international space telescope by 2040. We studied the feasibility of the future Korean Space Telescope (KST) for a mid-size domestic satellite platform. In order to pursue the uniqueness of the science program, we consider a wide range of observing wavelength (0.2um ~ 2.0um) with a spectral resolution of R~6 in the NUV and optical bands, and R~30 for NIR, utilizing an off-axis TMS(Three Mirror System) optics with a wide field of view ($2{\times}4$ degrees) which is optimized for ultra-low surface brightness sources. The main science goals of the mission include investigations of the galaxy formation, cosmic web, and the cosmic background radiation in the NUV-NIR regions. In this paper, we present the science cases and several technical challenges to be resolved along with the future milestones for the success of the KST mission.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.47.1-47.1
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• 2018

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 have successfully developed by KASI. The capability of both imaging and spectroscopy is a unique function of the NISS. At first, it have realized the low-resolution spectroscopy (R~20) with a wide field of view of $2{\times}2deg$. in a wide near-infrared range from 0.95 to $2.5{\mu}m$. The major scientific mission is to study the cosmic star formation history in local and distant universe. It will also demonstrate the space technologies related to the infrared spectro-photometry in space. Now, the NISS is ready to launch in late 2018. After the launch, the NISS will be operated during 2 years. As an extension of the NISS, the SPEHREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) is the NASA MIDEX (Medium-class Explorer) mission proposed together with KASI (PI Institute: Caltech). It will perform the first all-sky infrared spectro-photometric survey to probe the origin of our Universe, to explore the origin and evolution of galaxies, and to explore whether planets around other stars could harbor life. Compared to the NISS, the SPHEREx is designed to have much more wide FoV of $3.5{\times}11.3deg$. as well as wide spectral range from 0.75 to $5.0{\mu}m$. After passing the first selection process, the SPHEREx is under the Phase-A study. The final selection will be made in the end of 2018. Here, we report the status of the NISS and SPHEREx missions.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.57.2-57.2
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• 2019

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 was successfully launched on last December and is now under the operation phase. The capability of both imaging and spectroscopy is a unique function of the NISS. It has realized the imaging spectroscopy (R~20) with a wide field of view of $2{\times}2deg$. in a wide near-infrared range from 0.95 to $2.5{\mu}m$. The major scientific mission is to study the cosmic star formation history in the local and distant universe. It also demonstrated the space technologies related to the infrared spectro-photometry in space. The NISS is performing the imaging spectroscopic survey for local star-forming galaxies, clusters of galaxies, star-forming regions, ecliptic deep fields and so on. As an extension of the NISS, the SPEHREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) was selected as the NASA MIDEX (Medium-class Explorer) mission (PI Institute: Caltech). As an international partner, KASI will participate in the development and the science for SPHEREx. It will perform the first all-sky infrared spectro-photometric survey to probe the origin of our Universe, to explore the origin and evolution of galaxies, and to explore whether planets around other stars could harbor life. Compared to the NISS, the SPHEREx is designed to have a much wider FoV of $3.5{\times}11.3deg$. as well as wider spectral range from 0.75 to $5.0{\mu}m$. Here, we introduce the status of the two space missions.

• Asia Marketing Journal
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• v.15 no.4
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• pp.1-32
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• 2014

The purpose of this paper is to investigate upon a diversification strategy through market creation of CJ Group, which has contributed in positioning of the firm as one of the leading conglomerates in South Korea. With such objective, the background of CJ Group, followed by its business diversification strategies were explored, with reference to several case studies. The history of CJ Group began with establishment of CheilJedang Industrial Corporation in 1953, as the first domestic sugar producer and exporter of South Korea. The corporation gradually expanded its business ever since at both national and global level, to include the fields of food production, pharmaceutical, biotechnology, and life chemicals. Later, CheilJedang (CJ) Group was established as an affiliate of CheilJedang Industrial Corporation. With such independence, extension of business has been witnessed across the industries of media, entertainment, finance, information technology and distribution. Thus, the current CJ Group pursues to define itself as a progressive global living culture company with four major business categories from food and food service, biotechnology, entertainment and media, and logistics. Despite its success in today's market, CJ Group underwent hardships in its business diversification in 1990s due to indiscreet management, along with the Asian financial crisis. Here, many firms overcame the financial difficulties by taking advantage of the exchange rate for overseas expansion. Though, CJ Group tried to differentiate itself by focusing on the domestic market by creating something out of nothing. Hence, CJ Group takes a unique position among many cases of business diversification and their categorization. In an effort to identify and classify the types of growth experienced by the top 30 companies in South Korea, the firms were categorized into four groups according to their diversification strategies adapted after the Asian financial crisis. Based on the mode and time of entry, corporations were identified either as the 'Explorer', 'Invader', 'Venture Capitalist', or 'Assimilator'. Here, the majority of the firms showed the qualities of Invader, entering mature markets through large-scaled mergers and acquisitions. However, CJ Group was the only firm that was categorized as an Explorer, for its focus on the newly emerging service sector in culture-contents industry. This diversification strategy through market creation is worth examining, due to its contribution in generating simultaneous growth between the market and the company itself. Diverse brands of CJ Group have been referred to as case studies in this regard, from 'Hatban', 'Cine de Chef', 'VIPS' to 'CJ GLS'. These four businesses, each to represent processed food, film, restaurant service, and logistics industries respectively, show CJ Group's effectiveness in creating a whole new category of goods and services that are innovative. In fact, such businesses not only contributed in advancement of consumers' wellbeing, but toward generating additional value and employment. It is true that the diversification strategy of CJ Group requires long-term capital investment with high risk, compared to the other strategies mentioned in the paper. However, this model does create high employment and additional values that are positive to both the society and the firm itself. Therefore, the paper comes to a conclusion that the diversification strategy through market creation conveys the most positive impact relative to the others.

• Journal of Astronomy and Space Sciences
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• v.26 no.2
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• pp.171-186
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• 2009

Various Earth-Moon transfer trajectories are designed and analyzed to prepare the future Korea's Lunar missions. Minimum fuel trajectory solutions are obtained for the departure year of 2017, 2020, 2022, and every required mission phases are analyzed from Earth departure to the final lunar mission orbit. N-body equations of motion are formulated which include the gravitational effect of the Sun, Earth and Moon. In addition, accelerations due to geopotential harmonics, Lunar J2 and solar radiation pressures are considered. Impulsive high thrust is assumed as the main thrusting method of spacecraft with launcher capability of KSLV-2 which is planned to be developed. For the method of injecting a spacecraft into a trans Lunar trajectory, both direct shooting from circular parking orbit and shooting from the multiple elliptical intermediate orbits are adapted, and their design results are compared and analyzed. In addition, spacecraft's visibility from Deajeon ground station are constrained to see how they affect the magnitude of TLI(Trans Lunar Injection) maneuver. The results presented in this paper includes launch opportunities, required optimal maneuver characteristics for each mission phase as well as the trajectory characteristics and numerous related parameters. It is confirmed that the final mass of Korean lunar explorer strongly depends onto the initial parking orbit's altitude and launcher's capability, rather than mission start time.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.203-216
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• 2011

To prepare for a future Korean lunar orbiter mission, semi-optimal lunar capture orbits using finite thrust are designed and analyzed. Finite burn delta-V losses during lunar capture sequence are also analyzed by comparing those with values derived with impulsive thrusts in previous research. To design a hypothetical lunar capture sequence, two different intermediate capture orbits having orbital periods of about 12 hours and 3.5 hours are assumed, and final mission operation orbit around the Moon is assumed to be 100 km altitude with 90 degree of inclination. For the performance of the on-board thruster, three different performances (150 N with $I_{sp}$ of 200 seconds, 300 N with $I_{sp}$ of 250 seconds, 450 N with $I_{sp}$ of 300 seconds) are assumed, to provide a broad range of estimates of delta-V losses. As expected, it is found that the finite burn-arc sweeps almost symmetric orbital portions with respect to the perilune vector to minimize the delta-Vs required to achieve the final orbit. In addition, a difference of up to about 2% delta-V can occur during the lunar capture sequences with the use of assumed engine configurations, compared to scenarios with impulsive thrust. However, these delta-V losses will differ for every assumed lunar explorer's on-board thrust capability. Therefore, at the early stage of mission planning, careful consideration must be made while estimating mission budgets, particularly if the preliminary mission studies were assumed using impulsive thrust. The results provided in this paper are expected to lead to further progress in the design field of Korea's lunar orbiter mission, particularly the lunar capture sequences using finite thrust.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.37.3-37.3
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• 2016

The SPEHREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) is one of the candidates for the Astrophysical Small Explore mission of the NASA proposed together with KASI (PI Institute: Caltech). It will perform an all-sky near-infrared spectral survey to probe the origin of the Universe and water in the planetary systems and to explore the evolution of galaxies. The SPHEREx is designed to cover wide field of view of $3.5{\times}7deg$. as well as wide spectral range from 0.7 to $4.8{\mu}m$ by using four linear variable filters. The SPHEREx is under the Phase-A study to finalize the conceptual design and test plan of the instrument. The international partner, KASI will contribute to the SPHEREx in the hardware as well as the major science cases. The final selection will be made in the early 2017. Here, we report the current status of the SPHEREx mission.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.3
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• pp.240-246
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• 2016

The hottest news and achievements of space science and research in recent years may be NASA Curiosity rover's exploration (2013) of Mars, China Chang'e 3's exploration (2013) of Moon, ESA Rosetta's exploration (2014) of Comet 67P/Churyumov-Gerasimenko, and NASA New Horizons' exploration (2015) of Pluto, which are very astonishing achievement since such a deep space journey was possible with current technology. In contrast the wonderful cruise and navigation technologies evolution of explorer in deep space, there are no remarkable changes in deep space data communication, it is still in conservative area, of which much changes are reluctantly accepted so far. But there are some movements of deep space exploration in order to allow ground brilliant technologies to deep space. One of those experiments is internet, whose main topic of this paper. In this paper, we will present the analysis of effectiveness of solar system internet to deep space exploration.

• Journal of Space Technology and Applications
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• v.1 no.3
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• pp.283-301
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• 2021

In order to satisfy the intellectual curiosity of mankind to explore the unknown, National Aeronautics and Space Administration (NASA) in the United States and European Space Agency (ESA) in Europe are embarking on various R&D under the motto of the grand dream of pioneering space into a safe and sustainable environment. In the 2020s and 30s, it is expected that advanced giant observation equipment will be in operation, such as the development of a 10-meter-class telescope in space. In Korea, following the development of the 0.15 m Near-Infrared Imaging Spectrometer (NISS), Korea Astronomy and Space Science Institute (KASI) is also participating a 0.2 m Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) as an international cooperation partner in small exploration telescope. However, domestic experience in the development and operation of the space telescopes is still insufficient, and there is no plan with long-term prospects for constructing telescopes. In order to answer questions about the unknown world that mankind has not experienced using our own equipment, planning and preparation for the construction of a space telescope through close cooperation among industry-university-institute-government is urgently needed. In this paper, the necessity, background, development goals, and expected effects of the development of the Korean Space Telescope are summarized conceptually, and a working group (WG) is also proposed. In the WG activities, Korea shall take the lead in establishing the Korean-style space telescope development plan, and will start a valuable step to establish the national direction in the field of space astronomy and related technologies. We hope that the WG will be another milestone in Korea's space development.