Lightweight heat shield protects superfast aircraft

While passengers endure 19 hour non-stop flights from London to Sydney, aerospace researchers are working on ways to speed up flight. Materials scientists from Florida State University (FSU) reports in the journal Carbon that they have developed a thin, lightweight material that they believe could help shield aircraft from the intense heat that they would experience flying at  around five times the speed of sound.

Hypersonic flight has always been dogged with problems of high temperatures, caused by friction from air resistance. In experimental ramjet-powered flights in the 1960s, high temperatures caused by shock waves that melted parts of the aircraft. But as with all materials problems in aerospace, light weight is crucial. Increasingly, builders of fast jets, rockets and satellite launchers are turning to lightweight carbon composites, but these tend to behave poorly at high temperatures so attention is turning to heat shield materials. But these too have to be light, and current materials tend to form heat shields that are thicker than the material they are protecting. "Right now, our flight systems are becoming more and more high-speed, even going into hypersonic systems, which are five times the speed of sound," said Professor Richard Liang, director of the High Performance Materials Institute at FSU, who led the research. "When you have speeds that high, there's more heat on a surface. Therefore, we need a much better thermal protection system." _____________________________________________________________________