Smart thermal protection systems

Smart materials and systems could represent an interesting alternative to current TPS for future RLVs(reusable launch vehicle). Smart systems can be defined as systems able to "feel" their thermomechanical environment and to change their basic physical properties to "react or adapt" to the environment so that the effects are reduced. A ESA Contract work has been performed by INASMET-TECNALIA to study smart TPS concepts based on EVEREST SSTO laucher specifications. The identification of smart concepts, study their feasibility and selection by comparison to a selection criteria list. The Smart active TPS studied were: Sensor/actuator to vibration damping control by piezoceramics able to sustain 650oC. TPS Health monitoring within piezoelectric based on emitted/received microvibrations. Actuation (moving, tilting, owering) "morphing" tiles for aerothermodynamic changes. TPS monitoring: thermal sensitive coatings. Phase change materials for temperature control (hot/cold parts attachments). In situ repair: Selfhealing materials (micro-capsules dispersed on metallic parts, doped ceramics to react with oxygen producing glasses) Materials with adaptable properties (FGM) functional graded materials Adapting CTE on stand-offs. Tailoring thermal conductivity A proof-of-concept of the two most promising smart concepts selected were manufactured and evaluated on representative environment.