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In the frame of contracts to ESTEC an advanced adaptive high temperature insulation and an innovative safety enhancing secondary protection have been developed and tested by HPS. Both solutions can be used together to create a new thermal protection concept in order to make it lighter, cheaper and safer.

Thermal protection technologies based on ablators and segmented ceramic heat shields have been developed in Europe with the last two decades. The successful re-entry flights of HUYGENS, ARD and MIRKA indicate the progress achieved up to now. To stimulate the identification and assessment of novel alternatives to conventional thermal protection materials and constructions an exploratory study on Smart TPS has been launched by ESA. This new point-of-view in the field of winged re-entry and launcher technology resulted initially in 35 ideas. Subsequent concept drafting reduced this number to 11 feasible concepts and a few further developments put on a technology watch list. This paper presents an overview and brief discussion of the most relevant Smart TPS materials and concepts identified and elaborated in this exploratory activity which will be completed by some breadboard testing.

Multi-layer insulations consisting of stacks of reflecting foils reveal extremely low thermal conductances under vacuum conditions. Therefore, to improve the thermal performance of a pure foam and to reduce the area related mass, experimental and analytical investigations have been extended to a combined advanced multi-layer/foam insulation concept which consists of a stack of reflecting screens separated by thin foam layers. The predicted thermal performance of this improved insulation concept is compared with test results.

When gas conductance/natural convection plays a major role as heat transfer path, microporous insulations reveal distinct advantages compared to Multi-Layer Insulations (MLI). For re-entry vehicles as e. g. HERMES or capsules silica and ceramic microfiber insulations have been investigated by DASA/ERNO in a temperature range up to 650 °C or, respectively, up to 1200 °C. In the frame of an ESTEC funded study three types of microporous insulations - microfiber, microsphere and polyimide foam - have been analytically and experimentally investigated as candidates for the internal insulation of a MARS-lander in a carbon-dioxide atmosphere for temperatures ranging from - 110 °C to 50 °C. This paper compares the test results with analytical heat transfer calculations and describes methods to improve the thermal insulation performance.

Actively cooled and re-radiative leading edges were investigated as typical thermal protection elements for thermally high loaded areas of advanced launchers. A performance trade-off led to the selection of a C/SiC thermostructural concept. Mechanical and thermal analyses demonstrated the adequacy of the selected design. Manufacturing leading edge demonstrators with a small nose radius, different thicknesses of the outer skin and the integration of stringers was realised with good surface smoothness and contour accuracy. Thermal cycle tests with temperatures up to 1000°C in an oxidising environment were performed without any visible damage.

Rosetta, the ESA-NASA Comet Nucleus Sample Return (CNSR) mission, which will bring cometary material to Earth could be the key to understanding the chemical and physical process that marked the beginning of the Solar System. A major mission requirement is to keep the material samples on the in-situ temperature level to prevent any phase changes or alteration of its chemical composition. Since the a-priori knowledge of the extraterrestrial cometary surface is not very detailed before the implementation of the mission, and the implications on the spacecraft design as well as onto the mission scenario itself are mandatory, an engineering database for the expected thermal environment has been established. For that purpose a simplified thermal comet model has been created, applying the ESATAN software package. The model comprises thirteen material and comet parameters governing die cometary superficial heat balance as well as the cometary shape and mechanics.

The future deployment of a network of measurement stations on the surface of MARS is presently prepared. The MARS environment is characterised by large daily and seasonal temperature fluctuations in low density atmosphere with carbondioxide as its main constituent. Typical environmental conditions for some locations are presented. Due to geometrical and mass constraints highly efficient and reliable thermal insulations are required for the thermal control of MARS stations which are powered by solar energy. ERNO has investigated the thermal performance of two candidate porous insulations in the frame of an ESTEC technology contract. The paper presents methods to predict the heat transfer modes of both insulations in a Martian environment analytically. Experimental measurements have been performed and evaluated in order to validate the analytical predictions. Based on these results the insulation design concept is reviewed.