Optimal Design and Control of Hybrid Rockets for Access to Space

A nested direct/indirect method is used to find the optimal design of hybrid rockets for suborbital missions. The direct optimization of the parameters which affect the engine design is coupled with the trajectory indirect optimization. Different propellant combinations are analyzed. First, the simplest blowdown feed system is considered. A more complex pressurization system with an additional gas tank, which allows a phase with constant propellant tank pressure, is then analyzed. The optimization procedure provides the engine design and the trajectory, which maximize the mission performance index.