05/06/2006

One of the most promising systems of new generation spacecraft protection is the Hybrid Thermal Protection System or "Hybrid-TPS". This system is being developed by the Advanced Ceramics Laboratory of the Institute of Materials Science at the National Centre of Scientific Research (NCSR) "Demokritos" in cooperation with the European Space Agency and enterprises in Greece and Europe.

When spaceships return to earth from space, intense heat is created by friction between the spacecraft, travelling at very high speeds, and the atmosphere. In order to protect the spaceship, special protective tiles are used. However, these tiles are fragile. That was the main cause behind the Columbia spacecraft’s destruction in January 2003, with the tragic death of all seven astronauts. Some of the tiles had cracked during take-off causing gases at very high temperatures to make their way into the metallic capsule during landing. These hot gases partially melted the capsule, which led to the explosion and destruction of the Columbia.

In the past few years, Dr Giorgos Bekinis, responsible for the Laboratory of Advanced Ceramics, and his co-worker Dr Galina Xanthopoulou, have been developing special heat-proof insulating advanced ceramic materials, using the method of controlled burning (SHS method), to be used at very high temperatures. These materials are patent protected and were presented at the 3rd International Planetary Probe Workshop, which took place on July 2005 in Anavissos.

The system is destined for robotic probes and the sections of aircraft capsules subjected to the most extreme conditions. It consists of multiple layers of fortified light ceramics combined with special synthetic fortified polymers that absorb the intense heat via their controlled ventilation. The system, in Greece, can be produced in the form of multiple-layered tiles and can be used for many atmospheric penetrations, as is required in space missions involving the retrieval of samples (e.g. rocks) from other planets.

The successful development of the Hybrid-TPS will have significant economic benefits for Greece. The tiles are planned to be manufactured by a Greek high-tech company, which will be formed for that very purpose. It is worth noting that the “Huygens” spacecraft’s heat-protection system reached a total cost in excess of 5 million euro and was for one use only.

Before returning to Greece in 1990, Dr Georgios Bekinis, worked for many years as a researcher at the University of Cambridge in England and at research centres and universities in South Africa and Israel. Dr Galina Xanthopoulou has been a partner researcher at the Advanced Ceramics Laboratory since 1997, when she came to Greece from the former U.S.S.R. She is a pioneer of the SHS method for the production of advanced ceramics and catalytic systems and she has worked in the development of protective ceramic materials for Russian spaceships.

Source: NCSR "Demokritos"