Abstract (Session-1): 
The Ganymede Laser Altimeter (GALA) is one of the payloads
 for ESA's Jupiter Icy Moons Explorer (JUICE) to be launched in 2022.
 Major objectives of GALA are to provide global, regional and local
 topographic data of Jupiter's largest satellite Ganymede and 
to measure its tidal amplitudes. The latter are crucial for the
 detection and characterization of a subsurface ocean on Ganymede. 
GALA will further support geological studies, e.g. to identify and
 characterize tectonic and cryo-volcanic regions impact basins and
 craters on Ganymede. By pulse-shape analysis GALA will provide
 surface roughness and the satllite's albedo at the laser
 wavelngth of 1064 nm. The scientific objectives and GALA's performance
 for characterizing the icy surfaces of Ganymede, Europa and 
Callisto will be summarized in this talk.