Some results so far achieved in the framework of the HELIOS (Highly rEliable LInks during sOlar conjunctionS) Project, founded by the European Space Agency (ESA), are presented. The purpose of the project is the definition of a TT&C communication subsystem architecture (including both ground and space segments, as well as operational methods) being robust to impairments due to superior solar conjunction, especially when the Sun-Earth-Probe angle is below 5 degrees.