Reusability of launcher vehicles by the method of SpaceX

Abstract

This work is mainly based on the Master thesis of Sven Stappert and has been extended with results of other works performed simultaneously. It focuses on the investigation of the commercial space company SpaceX and their method of applying reusability to space launch vehicles by landing vertically with the help of their own engines. The impact of the method at technical, economical and logistical levels have been considered in order to gain a deeper understanding of the potential of the reusability method used by SpaceX Falcon 9 and soon Falcon Heavy. For that purpose, several DLR programmes were used to model the launcher vehicles and consider the influence of reusability. In addition, a trajectory computation program tosca was extended to enable the optimisation of powered descent trajectories as performed by Falcon 9. After establishing an aerodynamic and structural model of the launcher and a model of the propellant feed systems, all missions performed by SpaceX between December 2015 and May 2016 have been recalculated to validate the model of Falcon 9 FT (or Falcon 9 v1.2). The performances for these different trajectories have been computed and the loss compared to a fully expendable flight estimated. Based on these results economical aspects have been analysed. Both a model of the development costs and of the launch service costs have been established. The influence of re-usability on a simplified business model has been studied.