Expert Open Flap Assembly and its Instrumentation

Abstract

The open flap assembly of the EXPERT capsule consists of a CMC flap and a metallic cavity. The ballistic re-entry trajectory of EXPERT causes severe aerothermal and mechanical loads on these components. Two of the four flaps are instrumented with five pressure ports each, fourteen thermocpules for the first flap and ten for the second flap. In addition, heat flux sensors, thermocouples and a pressure port are integrated into the cavities, which are exposed to the thermal radiation from the rear surfaces of the flaps. Special attention was paid to the flap pressure port, which consists of CMC and metallic components. The successful aerothermal qualification test confirmed the reliability of the design and the numerical simulations performed with the ANSYS tool. Some problems encountered during the first severe vibration tests on the electronic box required a design change. The new mechanical design of the PCB card mounting based on a detailed structural analysis was successful and all components of the Payload passed the vibration and shock tests.