The availability of potable water, both in terms of quality and quantity is essential for the International Space Station (ISS) crew. Potable water is produced on ground and is transported to the ISS. During each launching/transportation campaign, water quality complies either to Russian or US standards. The disinfection agent is silver for the Russian type of water and iodine for the US type of water. So far, fluctuation of silver has been confirmed throughout the campaigns by performing silver analyses during several stages from the beginning to the end of each campaign. In all cases the recorded silver concentration was within the acceptable concentration range. However, important health issues arise concerning the safe and durable storage of potable water supplies in future (long term) missions.
The aim of this project is to evaluate the physical- (electro) chemical phenomena responsible for the observed silver fluctuations. Eight wetted materials are examined as basic suspects. The phenomena under investigation include galvanic corrosion, precipitation, adsorption/desorption on the surface of the wetted materials.