Reusable Launch Vehicles (RLVs) are not only key for an economically and ecologically sustainable space access but also represent a paramount innovation towards the increasing demand for smaller satellites and mega-
constellations. In order to ensure Europe's independent space access capabilities, ASCenSIon (Advancing Space Access Capabilities - Reusability and Multiple Satellite Injection) is born as an innovative training network with fifteen Early Stage Researchers, ten beneficiaries, and fourteen partner organisations across Europe. This paper provides an overview of the mission, ranging from the ascent to the re-entry of the reusable stages and including the multi-orbit injection and the safe disposal. A special focus is put on the activities developed within ASCenSIon regarding Mission Analysis (MA), Guidance Navigation and Control (GNC) and Aerothermodynamics (ATD). The foreseen methods, approaches and goals of the project are presented. These topics require innovation within and a high level of collaboration due to their interconnection. The pre-flight design capability drives the necessity of a MA and GNC missionisation tool coupled with ATD software to test/explore re-entry solutions. Such a reliable and efficient tool will require the development of GNC algorithms for the re-entry of the launcher. Additionally, specific challenges of trajectory optimization for RLVs are addressed, such as integrated multi-disciplinary vehicle design and trajectory analysis, fast and reliable on-board methods. The results of this study are subsequently used to develop the controlled strategy. Moreover, to perform the novel multi-orbit multi-payload injection. This activity is followed by the development of, a GNC architecture capable of optimally steering the vehicle towards a targeted landing site under precision and soft-landing constraints. In addition, ATD affects the mission profile at multiple phases and needs to be considered at each design step. Due to complexity and limited computational resources during the preliminary design phase, surrogate models with low response times are required to predict wall heat fluxes along the considered trajectories based on the pressure topology. The complete profile is wrapped up with the Post Mission Disposal strategies to be used by the launchers in order to ensure the compliance with the space debris
mitigation guidelines, as well as preliminary reliability aspects of these strategies. The paper provides a preliminary analysis of the discussed topics and their interconnections within the work-frame of ASCenSIon paving the way towards the development of novel cutting-edge technologies for RLVs
