4 research outputs found
Robust trajectory optimisation of a TSTO spaceplane using uncertainty-based aerodynamic models
Get PDFThis 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
Robust multi-objective optimisation of a descent guidance strategy for a TSTO spaceplane
Get PDFThis paper presents a novel method for multi-objective optimisation under uncertainty developed to study a range of mission trade-offs, and the impact of uncertainties on the evaluation of launch system mission designs. A memetic multi-objective optimisation algorithm, MODHOC, which combines the Direct Finite Elements transcription method with Multi Agent Collaborative Search, is extended to account for model uncertainties. An Unscented Transformation is used to capture the first two statistical moments of the quantities of interest. A quantification model of the uncertainty was developed for the atmospheric model parameters. An optimisation under uncertainty was run for the design of descent trajectories for the Orbital-500R, a commercial semi-reusable, two-stage launch system under development by Orbital Access Lt
