Re-usable space launch systems, where does Europe stand? Challenges in the design of vertical-landing launch vehicles from an aerothermodynamic perspective.

Abstract

The first successful landing of a SpaceX booster stage in 2015 fundamentally changed conventional approaches to the design and construction of space launch vehicles. It demonstrated that reusable, vertically landing launch systems have the potential to significantly reduce the cost of delivering payloads to orbit, while also providing greater mission flexibility and sustainability. Despite numerous subsequent flights, many associated aerothermodynamic phenomena remain insufficiently understood. One particularly challenging issue is the interaction between the engine exhaust plumes and the surrounding atmosphere during reverse flight in a retro-burn maneuver. As part of several European technology development programs, DLR is investigating the complex flow fields around rocket stages during return flight using high-fidelity numerical simulations and wind tunnel experiments. The primary objectives are to predict thermal loads on the fuselage structure and to characterize aerodynamic performance and vehicle controllability. This presentation provides an overview of typical aerodynamic and aerothermodynamic phenomena associated with vertically landing rocket stages. Selected results from numerical simulations and wind tunnel experiments are presented, with particular emphasis on thermal load predictions.