橋本 樹明

Lunar Imaging Camera (LIC) is a small, compact and lightweight monochromatic imager designed and developed for LUNAR-A, Japanese lunar mission. The scientific objectives of the camera address impact cratering, tectonic processes, volcanic features, and optical properties of the regolith surface.The image sensor is a linear CCD and is aligned with the spin axis of the spacecraft, which orbits the Moon at altitudes of 200-300 km. The two-dimensional image is taken using the spin motion of the spacecraft. The total field of view (FOV) of the camera is 360°(around the spin axis)×14.6°(along the CCD-array). LIC obtains an image in one spin. The angular resolution of the camera is about 20 arcsec/pixel at a spin rate of 3 rpm. The spatial resolution is about 25 m/pixels at the surface when the altitude is 250 km. The spin axis of the LUNAR-A approximately points toward the Sun, therefore, LIC can take images of the lunar surface with highly oblique illumination conditions near the terminator. A series of pre-flight tests of LIC was performed. In those tests, the hardware performance and the functions of LIC were verified and the data for radiometric and geometric corrections were obtained. This paper outlines the scientific objective, characteristics of LIC, the procedure and the results of the pre-flight tests and the operation plan of LIC.

MUSES-C engineering spacecraft for asteroid sample and return technologies was successfully launched on May 9th, in 2003 and was renamed as Hayabusa in orbit. The spacecraft is now in the cruising phase toward the asteroid 1998SF36. This report presents the outline of Hayabusa spacecraft. This report also describes AOCS(Attitude and Orbit Control System), which is focused on the cruising phase functions, autonomous star identification, Ion engine gimbal control, back-up attitude control mode, etc. The performance evaluated in orbit is also shown in this report.

科学衛星ミッションは宇宙研究・観測を目的にしており、宇宙科学研究所の理学・工学両グループおよび外部の共同研究者の緊密な協力の下に進められる。理学グループがその企画をし、工学グループが担当する衛星製作やロケット打上げにも深く関与していくので、典型的ボトムアップ型プロジェクトと言える。本稿では工学実験衛星(MUSES)のミッションも含めて、宇宙科学研究所で進められるミッションを例にして、歴史の概観、ミッション内容さらには研究・開発の仕方について述べる。特にミッションを支える工学技術については、個々のミッションに対応して新しく採用したものと共に、共通的なものを重点的に説明する。