DEVELOPMENT OF A HYBRID NAVIGATION SYSTEM FOR THE THIRD SHARP EDGE FLIGHT EXPERIMENT (SHEFEX-3)

Kurzfassung

The SHEFEX-2 rocket was successfully launched in June, 2012 from Andoya Rocket Range in Norway by the German Aerospace Center. The main purpose of this mission was to investigate possible new shapes for future launcher or re-entry vehicles, specifically, shapes with faceted surfaces and sharp edges. The rocket was unguided during the propelled flight phases and actively controlled during reentry with canards. The SHEFEX-3 mission is proposed to further pursue the technology development for reentry vehicles using the extended flight experiment and shall be launched in 2016 in a suborbital trajectory. The accurate control of the SHEFEX-3 vehicle using control flaps and moving masses requires a high-accuracy measurement of the angle of attack and the side slip angle. Both angles can only be derived from the flight path and an accurate inertial attitude measurement. The first can be achieved by using GPS measurements. The second can not be provided by an inertial navigation system due to the fact that drifts resulting from launch vibrations exceed the tolerance of the system. Therefore, a star tracker and sun sensors are utilized to update the attitude information shortly before re-entry. The presented work will describe the concept of the integrated hybrid navigation system. A special focus is also placed on the analysis of how the attitude sensors can be integrated into the SHEFEX-3 probe.