Evaluating launcher options for Europe in a world of Starship

As soon as the SpaceX Starship & SuperHeavy launcher configuration is operationally available it likely will cause a fundamental shift to space transportation. In a first step, the paper provides a thorough technical analysis of Starship's estimated capabilities in its early operational phase, based on independent modeling with openly available data. The main part of the paper is dedicated to the technical evaluation of European options for serving a roughly similar payload class above 20 Mg up to approaching 100 Mg in single launch to LEO. A launcher system analysis looks into Ariane 6 evolution options and explores the technical limits based on the assumption of expendable stages. A significantly better performance perspective can be achieved through a completely new architecture. In case of these new architecture launchers, all first stages are reusable and exclusively liquid cryogenic propellants are chosen. Fully reusable configurations have been addressed in the small ESA-funded PROTEIN-study for which some complementary concepts are summarized. The different launcher options show a broad range in payload performance. As these diverse vehicles come with significantly different cost, the NRC and RC are modeled for reasonable European heavy-lift transportation scenarios. The paper concludes with a comparative evaluation of main technical characteristics of the launch vehicle options and an indication of promising development roadmaps. • Independent performance cross-check of SpaceX Starship and Raptor engine. • System analysis of European heavy-lift options from Ariane 6 to future TSTO. • Identification of dominant cost trends in heavy-lift launch concepts. • Strategic 25-year implementation roadmap for European heavy-lift launchers.