Preliminary design for a hybrid propulsion mini launcher

Small-, Mini-, Micro, Nano- and Pico- are the new prefixes that are changing the satellite concepts and market. Miniaturization of hardware and tools like additive manufacturing and automation are making the so called ” Second SmallSat Revolution” possible. Keywords as low-cost, shorter design to launch time, flexibility are the reason why the interest on these kind of satellites is increasing, especially for LEO constellations. In the coming years it is expected that the SmallSats market will surely grow up. To make this possible an innovation is necessary also in the launch services. Ridesharing can no more be the unique access to space for SmallSats, but it is necessary to develop new dedicated Mini Launchers to avoid a slowdown of the market. Mini-LV must have the same characteristics of low cost and flexibility. In this scenario HyImpulse is born, with the aim to provide a low cost, flexible, reliable and green launch service with hybrid propulsion technology developed by HyImpulse in cooperation with Deutsches Zentrum fur Luft- und Raumfahrt in Lampoldshausen with new liquefying paraffin-based fuels. In this work the design methodology for the Mini Launch Vehicles (Mini-LV) is presented. The starting point has been to use empirical laws to obtain a possible mass fraction range of each subsystem's component and a stage mass breakdown. Then the preliminary design of each subsystem has been done to develop a mass model of the vehicle and to evaluate its performance. More detailed analysis has been conducted about pressure vessels and external structures, nozzle choice in relation to the operative altitude range and hybrid rocket engine performance and sizing. All of these analysis have been merged in a "Stage Optimization Tool" developed in order to find the main design parameter of each stage among the physically feasible configurations, maximizing the payload to bring into the target orbit and respecting the design constraints.