The EFESOS project aims to develop and evaluate a cutting-edge ASIC technology for space applications. More specifically, departing from the characterization of the commercial technology, a radiation-hardened-by-design digital library and a set of complex analog IP cores (ADC, DAC, SERDES and PLL) will be implemented using the 22FDX process from Global Foundries, available at their production facility in Dresden (Germany). A complete electrical, environmental (radiation) and reliability validation of the technology will be performed, and the resulting fully-European design flow will be evaluated according to the ESCC standards with a representative sample chip. The 22FDX is a 22nm Fully-Depleted SOI technology providing up to 40% die scaling relative to the standard 28nm node, nearly 70% lower power than 28nm and similar power efficiency to FinFET technology. EFESOS responds to the increasing demand of the European space industry of more integrated ASICs at higher performance, and greatly contributes to the strategic goal of achieving non-dependence on critical technologies. The project will provide Europe with a technical capability beyond the current state-of-the-art, thus becoming a global reference in space microelectronics.