The GENESIS project will gauge the environmental sustainability of electric aircraft (A/C) in a life-cycle-based, foresight perspective to support the development of a technology roadmap for transitioning towards sustainable and competitive electric A/C systems. The focus is on regional class, 50 pax aircraft to identify, design and assess prospectively the best energy storage and transmission topology. Different alternatives within battery, fuel cell, hybrid and conventional powertrain technologies are evaluated and compared over different time horizons. To meet these objectives and scoping, GENESIS relies on a strong consortium of 10 partners – 5 world-leading research partners, 4 R&D-active SMEs and 1 large company – gathering excellence and complementary competences that cover all key aspects of the project. GENESIS will design electric (all-electric and hybrid) aircraft and elicit specific requirements, which will feed into technology foresight analyses. These will allow highlighting technological limits and potential solutions within each component of the aircraft system life cycle, which includes the life cycle of the aircraft itself as well as the life cycle of the fuels and that of the on-ground infrastructures. The analyses will enable the development of time- and technology-specific life cycle inventories, used as basis for a full-fledged prospective life cycle assessment. Combining the resulting environmental performances with those from an economic analysis and a technical analysis, comprehensive scenario comparisons between the different powertrain alternatives will be made, enabling GENESIS to identify relevant solutions and ultimately derive a detailed sustainability-based Technology Roadmap. GENESIS is anticipated to have large impact on all aeronautics stakeholders as its outputs will provide the means to steer research and boost industrial innovation and competitiveness in the EU while moving towards environmentally sustainable aviation.