• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.355-357
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• 2017

For future space IR missions, such as SPICA, it is crucial to establish an experimental method for evaluating the performance of mid-IR detectors. In particular, the wavelength dependence of the sensitivity is important but difficult to be measured properly. We are now preparing a testing system for mid-IR Si:As/Si:Sb detectors on SPICA. We have designed a cryogenic optical system in which IR signal light from a pinhole is collimated, passed through an optical filter, and focused onto a detector. With this system, we can measure the photoresponse of the detector for various IR light using optical filters with different wavelength properties. We have fabricated aluminum mirrors which are adopted to minimize thermal distortion effects and evaluated the surface figure errors. The total wavefront error of the optical system is $1.3{\mu}m$ RMS, which is small enough for the target wavelengths ($20-37{\mu}m$) of SPICA. The point spread function measured at a room temperature is consistent with that predicted by the simulation. We report the optical performance of the system at cryogenic temperatures.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.331-335
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• 2017

We present project updates of the next-generation infrared space mission SPICA (Space Infrared Telescope for Cosmology and Astrophysics) as of November 2015. SPICA is optimized for mid- and far-infrared astronomy with unprecedented sensitivity, which will be achieved with a cryogenically cooled (below 8 K), large (2.5 m) telescope. SPICA is expected to address a number of key questions in various fields of astrophysics, ranging from studies of the star-formation history in the universe to the formation and evolution of planetary systems. The international collaboration framework of SPICA has been revisited. SPICA under the new framework passed the Mission Definition Review by JAXA in 2015. A proposal under the new framework to ESA is being prepared. The target launch year in the new framework is 2027/28.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.11-13
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• 2005

The Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded that many collective observations gave a aspect of a global warming and other changes in the climate system. Future earth observation using satellite data should monitor global climate change, and should contribute to social benefits. Especially, human activities has given the big impacts to earth environment This is a very complex affair, and nature itself also impacts the clouds, namely the seasonal variations. JAXA (former NASDA) has the plan of the Global Change Observation Mission (GCOM) for monitoring of global environmental change. SGLI (Second Generation GLI) onboard GCOM-C (Climate) satellite, which is one of this mission, is an optical sensor from Near-UV to TIR. This sensor is the GLI follow-on sensor, which has the various new characteristics. Polarized/multi-directional channels and 250m resolution channels are the unique characteristics on this sensor. This sensor can be contributed to clarification of coastal change in sea surface. This paper shows the introduction of the unique aspects and characteristics of the next generation satellite sensor, SGLIIGCOM-C, and shows the preliminary research for this sensor.

• 한국항공우주법학회:학술대회논문집
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• 2008.05a
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• pp.273-294
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• 2008

Korea now has a rapidly expanding space programme with exploration aspirations. The government is giving priority to the aerospace industry and, to put it on a better footing, enacted an Aerospace Industry Development Promotion Act in 1987, a Space Development Promotion Act in 2005 and a New Space Compensation for Damage Act in 2007. I would like to describe briefly the legislative history, main contents and comment for these three space acts including especially launch licensing, registration of space objects, use of satellite information, astronaut rescue, liability for compensation, third party liability insurance and establishment of committee and plans to assist the Korean space effort. Furthermore author proposed to legislate a draft for the establishment of a new Korean National Space Development Agency (KNSDA: tentative title) to create a similar body to Japan Aerospace Exploration Agency (JAXA), British National Space Centre (BNSC) of UK, French Centre National d'Etudes Spatiales (CNES), German Aerospace Center (DLR), Swedish Space Corporation, China Aerospace Science and Industry Corporation, Indian Space Research Organization (ISRO) as well as the Korean Space Agency (KSA: Tentative title) to create a similar body to Canadian Space Agency, European Space Agency, Russian Space Agency, Italian Space Agency, Israel Space Agency, Indian Department of Space, National Aeronautics and Space Administration (NASA) of USA, China National Space Administration in order to develope efficiently space industry. A call is made for Asian countries to unite and further their space development through a regional space agency.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.64.1-64.1
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• 2012

Cosmic Infrared Background Experiment (CIBER)는 적외선 카메라 및 분광기를 NASA Sounding Rocket에 탑재, 발사하여 적외선우주배경복사를 관측하는 과제이다. CIBER1은 2006년 NASA의 공식 과제로 승인되어, 미국의 Caltech, 한국의 KASI, 일본의 ISAS/JAXA가 국제협력으로 진행되었으며, 2009년 2월 25일, 2010년 7월 10일, 그리고 2012년 2월 25일에 미국 화이트샌드 미사일 기지에서 NASA 사운딩 로켓에 의해 성공적으로 발사되어 우주관측에 성공하였다. CIBER2는 CIBER1 보다 약 10 배 이상의 성능을 가지는 적외선카메라로써 한국의 KASI는 CIBER2 개발에서 광학계 및 광기계부 개발, 전자부 개발에 참여하고 있다. CIBER2는 2012년에 개발을 시작하여 2013년과 2014년에 각각 발사될 예정이다.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.49.3-50
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• 2017

There have been recent studies which revealed a tendency that thermal inertia decreases with the size of asteroidal bodies, and suggestions that thermal inertias of cometary bodies should be much smaller than those asteroidal counterparts, regardless of comets' nuclear sizes, which hints a way to differentiate cometary candidates from asteroids using thermal inertia information. We thus selected two comet-like objects from AKARI satellite of JAXA, namely, 107P/ (4015) Wilson-Harrington and P/2006 HR30 (Siding Spring), and applied simple thermophysical model to test the idea. Both targets did not show any comet-like activity during the observations. From the model, we found Wilson-Harrington to have size of 3.7-4.4 km, geometric albedo 0.040-0.055 and thermal inertia of 100-250 J m-2 K-1 s-0.5, which coincide with previous works, and HR30 to have size of 24-27 km, geomoetric albedo of 0.035-0.045 with thermal inertia of 250-1000 J m-2 K-1 s-0.5. HR30 is found to have the rotation pole near the ecliptic plane (the latitude between -20 and +60 deg). Based on the results, we conjecture that comet-like objects are not clearly distinguishable from asteroidal counterpart using thermal inertia.

• Advanced Composite Materials
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• v.18 no.2
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• pp.121-134
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• 2009

The present study investigated, both experimentally and numerically, the improvement of low-velocity impact damage resistance of carbon fiber reinforced plastic (CFRP) laminates due to through-the-thickness stitching. First, we conducted drop-weight impact tests for stitched and unstitched laminates. The results of damage inspection confirmed that stitching did improve the impact damage resistance, and revealed that the improvement effect became greater as the impact energy increased. Moreover, the stitching affected the through-the-thickness damage distribution. Next, we performed FEM analysis and calculated the energy release rate of the delamination crack using the virtual crack closure technique (VCCT). The numerical results revealed that the stitching affected the through-the-thickness damage distribution because the stitch threads had a marked effect on decreasing both the modes I and II energy release rate around the bottom of the laminate. Comparison of the results for models that contained delaminations of various sizes revealed that the energy release rate became lower as delamination size increased; therefore the stitching improved the impact resistance more effectively when the impact energy was higher.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.57.1-57.1
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• 2010

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) is a next generation infrared space telescope being prepared by JAXA, ESA and other international collaborators. We propose to develop FPC (Focal Plane Camera) consisting of two near-infrared cameras: FPC-G (I band) for focal plane guidance and FPC-S (0.7 - 5 um) for a back-up of FPC-G and a NIR instrument for scientific observations. In this talk, we introduce the requirement and the design concept of the FPC as well as the development strategy of the project.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.87.2-87.2
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• 2010

Near-Earth asteroid-comet transition object 4015 Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. 4015 W-H was discovered showing cometary activity by Albert G. Wilson and Robert G. Harrington at Palomar Observatory in 1949. After recovered in 1979, 4015 W-H has been observed at every apparition, it always was seen as a point source. We made time series observations for 4015 W-H using the 1.8m telescope with 2K CCD at Bohyunsan Observatory, on the nights of 2009 November 17-19. The geocentric distance of 4015 H-W was about 0.38 AU at that time. No trace of cometary activity is seen from our images. From the light curve analysis, we find a double-peaked rotational period of 2.2 hours with amplitude of 0.4 magnitude. Our result is much shorter than previous measurements of 3.6 hours (Harris & Young 1983) and 6.1 hours (Osip et al 1995). We will discuss possible origin of the period variations.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.247-270
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• 2007

Space development and utilization must be conducted within a framework of "peaceful uses" principle under Space Treaty. Japan ratified the treaty in 1967, and interpreted "peaceful uses" as "non-military uses" then. A ghost of "peaceful uses" principle has been hung over Japan up to the moment. Japan's space development and utilization has been conducted with genuine academic interest, and therefore Japan did not introduce space infrastructures to national security policy and did not facilitate growth of space industry. When the Cold War ended, Northeast Asian security environment makes Japan difficult to maintain an interpretation as "non-military uses". Besides the change of external security environment, the domestic industry situation and a series of rocket launching failure needed reexamination of Japan's space policy. Japan is gradually changing its space policy, and introducing space infrastructure in a national security policy under a "generalization" theory that gave a broad interpretation of "peaceful uses" principle. Council for Science and Technology Policy (CSTP) adopted a basic strategy of Japan's space policy in 2004. Since then, a long-term report of Japan Aerospace Exploration Agency (JAXA), an investigation report of Society of Japanese Aerospace Companies (SJAC) and a proposal of Japan Business Federation (JSF) were followed. Japan will promote space development and utilization in national security policy with a "strictly defensive defense" strategy and "non-aggressive uses"principle for protection of life and property of Japanese people and stabilization of East Asian countries.