In recent years, the Space Industry has been focusing on reusable launch vehicles demonstrating their feasibility and emphasizing their advantages in terms of costs and sustainability. Although United States is leading the development of this kind of launchers, Europe is beginning to invest and research in this sector, in order to increase its capacity to access the space autonomously. In 2022 Politecnico di Torino research team, under the supervision of the European Space Agency, launched the “iDREAM” project with the objective of developing a comprehensive methodology for the conceptual design of space systems, with a particular focus on expendable Micro-Launchers and Human Landing System.