SPUD – A Versatile Tool For Modelling Solid Propulsion Stages

SPUD (Solid Propulsion Unit Design) is an easy-to-use multi-platform tool for the preliminary design and the performance prediction of propulsion stages powered by solid propellant rocket motors. It features an intuitive graphical user interface with convenient grouping of the input parameters and analysis results. By providing a few mission inputs such as vehicle initial mass, mission velocity gain, and required payload mass, the program identifies the design parameters according to the envelope, ambient and propulsive constraints and the designer choices, determines the mass budget of the overall solid propulsion stage, and predicts the theoretical rocket performance of the solid stage. Moreover, the program allows the user to identify existing solid rocket motors that can accomplish the mission requirements. The results of calculation can also be used within more complex mission analysis studies. The calculation method is based on several reduced order models for the treatment of ballistic analysis, grain geometry calculations, mass budget estimation, spin stabilized AOCS design etc.