Optimization methodology for the climb trajectory of a ssto lifting-body reusable launcher

A simulation and optimization methodology, created by the authors to optimize the trajectories of an airbreathings paceplanea nd already tested and validated, has been improved and applied to a new concepto f Single-Stage-to-Orbit(SSTO)l ifting-body spaceplanein order to search for optimal climb trajectoriesfo r a typical missionp rofile. After a brief discussion on preliminary assumptionsc oncerningt he available dam set, we first present the analysis procedure and the calculation method which allowed us to simulate the climb trajectoryo f a SST0 spaceplanme odel,a blet o connect the Earth-launch pad to the International Space Station (ISS). The optimization technique, belonging to the class of direct optimization methods and dealing with a wide number of independent parametersi,s then describedi n detail and specific results ensuring a better payload / lift-off weight ratio are widely shown. Shapea nds ize of the vehiclea s well as integrated propulsion system and weight distribution are derived from a complete data set originating Tom an aerospace company, while the aerodynamic performancehsa veb eend irectly generatedvi a a CFD Navier-Stokes code. Finally a sensitivity analysis by varying the launch-padlo cationa ndt he final orbit inclinationa nd altitude has been performed and the influence of each guidancea ndc ontrol parametero n the optimal climb trajectory has been emphasized.