Robust trajectory optimisation of a TSTO spaceplane using uncertainty-based atmospheric models

This paper presents a multi-objective trajectory optimisation under uncertainty for the ascent of a two-stage, semi-reusable space launch system. Using Orbital Access’ Orbital 500- R launcher as a test case, robust multi-disciplinary design optimisation is used to analyse the trade-offs with both the vehicle and system design, and operation. An area of focus is on the predicted performance and its impact on the design and planned mission scenarios. The atmospheric model uncertainties are quantified for the atmospheric surrogate model and integrated into the optimal control solver MODHOC, extended by the addition of an unscented transformation to handle the uncertainties. A multi-objective optimisation under uncertainty is run, examining the Pareto-optimal sets for the ascent trajectory and vehicle design