A multidisciplinary team involving researchers from the IAS, the CIMAP, the IPNO, the GANIL, and Rio de Janeiro's PUC Catholic University has characterized in the laboratory the effects of heavy cosmic rays on the structure and sputtering of water ice in interstellar and planetary environments. These experiments are used to study phase changes induced by swift heavy ions, similar to the Galactic cosmic rays. They complement and extend the knowledge already obtained at lower energies. In addition to the ice phase change, these studies reveal the importance of water ice molecules released in the gas phase by swift heavy Galactic ions, or sputtering of interstellar ices present in dense and cold interstellar clouds.