Safety aspects of CMC materials and hot structures

Abstract

There is a growing demand for reusability of future space re-entry vehicles and an associated tendency towards further increase of the maximum operational temperatures of hot structures and thermal protection system elements. This is mainly driven by advanced aerodynamic vehicle shaping, higher weight and mission profiles as is shown typically ba NASA's X-38. As there is no alternative material available other than ceramic matrix composites like C/SiC and C/C for such kinds of hot primary structures the question is obvious where the operational limits of the materials and the related structures are and how safe operation of the hot structural elements can be guaranteed. This paper deals with the special material dependent problems and the general design approach of fibre ceramic components to enhance the system safety already during the initial lay out.