The Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moons Explorer (JUICE): Mission, science, and instrumentation of its receiver modules

The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan’s contribution

Easy Aligned Telescope for CubeSat

Recently there is high demand on earth observation with Cubesat. Usually the researcher only uses general COTS on board camera with Cubesat on its purpose. However, if the researcher needs more resolution or different wavelength, it needs custom designed telescope for it, but telescope needs high accurate optics components and its aligned accuracy. Creating a specially designed optical telescope not only costs enormously, but also takes time from design to manufacture. Furthermore, if the processing accuracy in optical processing and the accuracy in the degree of adjustment in the assembly adjustment stage are ensured, higher-precision design, processing, and assembly adjustment are required. When using Cubesat, considering how to shorten the time from kick-off to launch, and considering the short lifetime due to low orbit, it is important to build a system that can acquire fast, cheap, but high-definition images. In this study, we aimed to achieve higher resolution even with a limited optical element configuration by combining the optical design of the reflection system and the refraction system. Furthermore, by simplifying the assembling adjustment process as much as possible, a low cost and quick manufacturing was sought