Chemo-hydrodynamic instabilities appear when chemical reactions couple to hydrodynamic flows by inducing density, viscosity, permeability or surface tension gradients across reactive interfaces. The related patterns, which combine properties of both chemical and hydrodynamic systems, can be quite complex when several sources of instability interplay. Our overall goal is to obtain, by theoretical and experimental approaches, a fundamental classification of the generic chemo-hydrodynamic instability scenarios occurring around reaction fronts. In the framework of our “CHYPI” Topical Team sponsored by ESA, our objective is to disentangle in microgravity conditions the relative role of buoyancy, permeability and surface tension changes on reaction fronts.