Thermal and Mechanical Design of the Expert C/C-SiC Nose

Abstract

The EXPERT mission will be carried out as a sub-orbital flight of the EXPERT vehicle reaching a velocity of 5 km/s. The vehicle is designed as an aerodynamic probe to gather in-flight data concerning the aerothermodynamic environment of re-entry vehicles. For that purpose, scientific payloads are measuring in the very front of the vehicle but also right up to it´s base. Since the quality of the data is depending on an undisturbed flowfield, the choice was made for a nosecap of C/C-SiC, a ceramic matrix composite that can withstand the heat loads in the stagnation area very well. Another aspect of selecting a C/C-SiC nose concerns the fact that it is also the carrier structure for a number of sensors that have to be integrated structurally. The loads acting on the nose are severe, with heat loads up to 1.5 MW/m² and simultaneous pressure of more than 150 kPa as well as a deceleration load of 17g. The German Aerospace Center (DLR) in Stuttgart will manufacture the cap. The paper describes the thermal and mechanical design of the nose after adjustment to the latest set of loads.