The so called Sharp Edge Flight Experiment hypersonic flight of SHEFEX-II had the aim to investigate advanced technology for atmospheric re-entry under real conditions. Key technologies for re-entry with reusability of the vehicle and landing in a predefined small destination corridor are thermal protection systems as well as active flight control and navigation systems.
Within the project period of 6 years, the Institute for Flight Systems developed all necessary hard-and software-components which are required for the active flight control system. Since the configuration of the re-entry vehicle corresponds to the configuration of a classical sounding rocket payload, which is made of different experiment modules, a special module comprising the canards, electromechanical actuators and the necessary power supply has been developed. Major challenges for the hardware were the exposed temperatures during re-entry, the high level of vibration caused by the two stage solid-propellant rocket boosters and the requirements for the dynamics and accuracy of the actuators.
Since no real flight data was available for the configuration of SHEFEX-II, large uncertainties were taken into account for the design of the control laws. As a result, a robust controller was designed which conducted the experiment safely.
As payload of a Brazilian solid propellant two stage sounding rocket, SHEFEX was launched from Andøya rocket range and reached an apogee high of 176km. During the re-entry flight a speed ten times higher than the speed of sound has been reached, whereby the flight control system completed all preplanned maneuvers. The result of the flight is a comprehensive set of measurement data, which is under evaluation and shall help to improve the body of knowledge for active controlled re-entry vehicles.