Hypersonic Point-to-Point Travel for the Common Man

Abstract

Objects travelling at hypersonic speeds typically experience significant mechanical loads, particularly during acceleration/deceleration. Excluding both technical and economic limitations, sub-orbital point-to-point travel is inevitably restricted to a group of individuals that are trained and whose health is certified prior to travel. This work seeks to explore the possibility of identifying, for a chosen route and reference vehicle, a set of parameters such that an individual could participate in hypersonic travel without health screenings or prior training. An open-loop guidance system is used with idealised navigation and control systems. The guidance method is based on node control with the assumption of instant implementation of commanded states. After an initial design space exploration is performed with various evolutionary algorithms, the Multi-objective Evolutionary Algorithm based on Decomposition with differential evolution (MOEA/D) (DE) is selected for further use, along with a preferred set of objective functions and a decision vector length. The subsequent optimisation strategy is separated into a coupled and decoupled phase approach, where the coupled approach combines the vehicle’s ascent and descent optimisations, while the decoupled approach performs a descent phase optimisation and attempts to link an ascent phase to the optimised descent phase. Decoupling, as performed, did not allow for the identification of a linkable trajectory. An optimal trajectory was identified with the coupled approach that required a significant amount of additional propellant and dry mass, yet maximum g₀-loads approached the constraint of an increase of 1 g₀. Recommendations are given to further the study.