Methodology and tool to support the conceptual design of a reusable TSTO HTHL vehicle and cost assessment

A great deal of well-established and cutting-edge practices and reliable tools have been developed over the last decades to support hypersonic aircraft conceptual and preliminary design. Among these, the Hypersonic Convergence sizing approach for transonic to hypersonic vehicle applications first developed at formerly McDonnell Aircraft Company between 1970 and 1990, represents one of the most common in the field. An innovative approach to a such consolidated sizing methodology with relevant modifications is presented as main topic of this thesis. In particular, the integration of the Multiple Matching Chart Analysis tool, implemented in the last years by the Aerospace Engineering Department of Politecnico di Torino, to the classical procedure widely described in literature enables an important refinement of the design point searching algorithm, when the objective is to size SSTO (Single-Stage-To-Orbit) or TSTO (Two-Stage-To-Orbit) HTHL (Horizontal Take-off and Landing) vehicles. The modularity, through the utilization of multiple functions, and a more user-friendly customization of the tool with respect to previous works are two of the main achievements illustrated in the thesis. Moreover, considerable insight about potential improvements of the methodology as well as new and derived formulas concerning the Kuchemann correlation for subsonic carriers, the concept of effective efficiency in Breguet's formula and the correction of the mass ratio for first stages subjected to separation events are the major aim of this work. A statistical analysis about both existing and aborted TSTO HTHL projects and concepts is preliminarly conducted to depict the framework and the field of applicability of the methodology. Eventually, the results of the validation of the updated methodology and tool and a preliminary cost assessment based on the economical TransCost Model are reported, using as case study the SANGER II vehicle configuration, a TSTO HTHL design concept elaborated in Germany during the 80s.