Variable wing configuration assessment for hypersonic transportation system

A preliminary study investigating the possible variable wing options for the reusable booster of SpaceLiner is described here. This investigation is motivated by a critical condition that arises during the first part of the booster descent, which must be avoided. Based on the previous SpaceLiner 7-3 configuration some modifications on the wing geometry are performed, with the main objective of reducing the wing span. Three wing types are studied here: a fixed wing, a variable sweep wing and a foldable wing. In the study’s first step the geometry of the wing is designed for each of the wing type considered. Mass, centre of gravity and aerodynamic data sets are evaluated with the main purpose of maximizing the aerodynamic performances and keeping the mass as low as possible. Particular attention is paid on the subsonic part of the descent, when the booster is supposed to be in-air captured by a towing aircraft. Some simplified and preliminary calculations are done to estimate the flight performances during this part of the mission. Moreover, an analysis on the existence of a trimmed condition for the entire Mach range is carried on. The most promising configuration among those studied is selected for further investigations. The second part of the study includes the simulation of the ascent and the descent trajectory. The TSTO mission is taken as a reference for this study. Once the descent trajectory is computed, the Thermal Protection System is designed. Two different set of materials are considered for the TPS: one is composed by non-metallic materials only, while the other is made of bot metallic and non-metallic materials. The optimization of the ascent trajectory is then performed and the mission payload mass is evaluated. Finally, the new booster configuration is analysed with Missile Datcom and the results are compared to the aerodynamic data that have been calculated previously with the DLR’s tools. A preliminary design of the vertical fins is also carried out.