SMARTEES - Reusable multifunctional components for aggressive environments in space applications
The offer describes a novel multi-layered protection based on advanced ceramics and foam for use in a space-critical re-entry heat shield. The design is based on the integration of conventional and non-conventional parts to create a Thermal Protection System (TPS) technology sample with multifunctional properties such as oxidation protection, thermal protection and in-plane controlled thermal conductance.
A multi-partner consortium led by Tecnalia and funded under the EC FP7 Space programme (reference: 262749) has developed ceramic composite based structures suitable for applications in aggressive environments (oxidative and high temperatures), specifically for the hot parts of space vehicles during orbital re-entry (reusable launcher vehicles, RLVs). Specifications and requirements for the development work were selected and defined from the ARV (Advanced Reusable Vehicle) project, which foresees the implementation of a cargo transportation capability (ISS cargo upload and download) in support of ISS operations beyond 2016.
The technology consists of a new reusable solution based on multifunctional hybrid concept with very high insulation and environmental protection capability during the atmospheric re-entry.
The novel design and material combinations can be described in three zones. The external layer has oxidative resistance at re-entry, the middle layer has high thermal conductivity to distribute heat homogeneously, whilst the third and innermost layer is designed for thermal insulation.
The multi-layer materials were joined to a sandwich material structure developed by the team. This sandwich consists of two skins of qualified ceramic matrix composites (CMCs) with thermo-structural properties and a silicon carbide foam core that provides additional thermal insulation. These systems were then attached to metallic structural frames made of titanium alloys.
Innovations & Advantages
Currently, the EU is dependent on other countries for critical thermal protection systems (TPSs), or heat shields. Developing independent access to critical space technology is a pillar of EU space research. Scientists ground-tested a novel reusable TPS based on multifunctional hybrid ceramic materials that provide excellent insulation and oxidation resistance.
Two solutions were developed for the two heat regimes under consideration:
- LC1 ? max temperature of 1300�C; heat flux of 0.3 MW/m2.
- LC2 ? max temperature of between 1700 and 1800 �C; heat flux of 0.8 MW/m2.
The technology solution for LC1 consists of a SiC multilayer for the exposed top layer, whilst the solution for LC2 incorporates a SiC/ZrB2 multilayer with ZrB2 layers intercalated among SiC layers. Both LC1 and LC2 solutions use an integrated CMC upper skin?SiSiC foam?CMC lower skin sandwich structure. These consist of a continuous carbon fiber reinforced Cf/SiC material with a 2D-0�/90� architecture and customized SiSiC foam with a defined pore size and orientation. The metallic standoff is based on a Ti6Al4V alloy. A fibrous ceramic phase has been used to fill the SiSiC foam to enhance the insulation properties of the layer. Suitable joining techniques have been developed for all material interconnections.
Multilayer materials have been tested up to and beyond the limits described by the two thermal load cases. A full assembly sample has been tested under LC1 conditions. The suitability of the selected concept, the selected materials, and the applied joining technology has been successfully demonstrated.
Current and Potential Domains of Application
Current: Re-usable thermal protective system for space re-entry vehicles.
- Volumetric receivers in thermo-solar applications (concentrated solar power - CSP)
- Inner core of high temperature heat exchangers (to recover heat from exhaust gases in heavy industries)
- Fusion ? rear support structure for first wall materials