Small Launcher Enabled by Hybrid Rocket Motor Technology

Abstract

In this paper, we present a small launcher for payloads <10kg and orbits of 350-400 km as well as for suborbital flights with larger payload. Currently there is an increasing demand for small launchers, demand that is increased especially by the nano-satellite expanding missions as well as a strategy shift to smaller and more efficient payloads. Advancements in electronics helped this direction by creating smaller and more powerful computers and communication equipments that can be fitted on smaller satellites with performances at least equal with the ones from the previous generation. We propose a three stage small launcher powered by solid-hybrid-hybrid combination. We investigate the full flight dynamics of the launcher with internal ballistic models for the hybrid rocket motors. The relatively new proposal is to use hybrid rocket motor technology for the second and third stage due to its lower cost of manufacturing as well as simplicity compared to liquid rocket motors. At the same time the performance promise from hybrid rocket motors and their throttable capabilities makes them ideal candidates for upper stage propulsion. Detailed discussion is performed related to the performance of hybrid rocket motors and its influence on launcher lift capability. We also show the preliminary design of such hybrid rocket motors as upper stage propulsion units and propose several fuel/oxidizer pairs based on both technical performances as well as cost parameters. LOX and solid methane are proposed as best oxidizer and fuel candidates in order to obtain a high specific impulse for the upper stages. Next we present a full 6 DOF model for the flight of the launcher as well as simulation results for various flight scenarios ending with different payloads on different orbits. Discussion is performed on guidance and control systems illustrating the main limitations and the option to use as many as possible COTS due to their availability and low design-production cycle. The paper ends with a discussion related to optimization procedures for a small launcher due to its importance on launcher performances and price of operation.