Description Reusable launch systems offer the potential for economic and commericial benefits, though many design and operational barriers still exist.  The conceptual design phase is a critical for examining possible vehicle and operational designs at a system level, assessing the different trade-offs both from a technical point-of-view, and a commerical one.  This project first develops an analytical model for simulating the dynamics of a spaceplane, with a 2-element control (angle of attack, and throttle). Along with the dynamic model, an aerodynamic model is also programmed based on a database of known points, and integrated into a trajectory optimisation software in Matlab. This is used to generate an optimal control law for different possible missions for the vehicle, and to assess various trade-offs.  Key Objectives 1- Derive the equations of motion for a 3DOF dynamic and control model for atmospheric and space flight 2- Develop a software model for the flight dynamics that will work within a Matlab optimisation framework 3- Develop a software model for the aerodynamics based on published data that will work within a Matlab optimisation framework 4- Integrate both models into an trajectory optimisation framework 5- Generate optimised trajectories for a number of mission scenarios