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