DLR Reusability Flight Experiment ReFEx

The German Aerospace Center (DLR) is currently developing the Reusability Flight Experiment (ReFEx). The successor of the already performed hypersonic flight experiments SHEFEX I and II shall be launched on a Brazilian VSB-30 sounding rocket in 2022 and shall achieve a re-entry velocity of more than Mach 5. The main goals of the project are the demonstration of a controlled autonomous re-entry flight from hypersonic velocity down to subsonic range and the testing of the key technologies required for future reusable first stage systems. Utilizing Concurrent Engineering (CE) approach the fundamental feasibility of this sophisticated flight experiment has been investigated by the entire ReFEx team. All required systems, including sensors and actuators as well as their interfaces have been defined and different options were assessed regarding matters such as the scientific output, complexity, risk and cost. The current configuration of ReFEx has a re-entry mass of about 400 kg, a length of 2.7 m and a wingspan of 1.1 m. This paper provides a system overview and addresses the Reusable Launch Vehicles (RLV) technologies Guidance, Navigation and Control as well as Flight Instrumentation. Furthermore the mission design (launch & re-entry) and the main challenges regarding the mission realization are addressed