Ablative Coat Protects Against Brief, Intense Heating

An ablative composite coating has been developed to protect a steel substrate against a short-duration exposure to supersonic stream of hot gases and molten ceramic particles. In the original application, the short-duration hot, abrasive flow is resultant from the shuttle solid-fuel rocket motor exhaust during launch. The steel substrate to be protected is a holddown-post blast shield on a space-shuttle mobile launcher platform. The maximum temperature in the rocket blast exceeds 5,500 °F (≈3,000 °C), and the heat load on the blast shield can exceed 8,000 Btu/ft2s (≈91 MW/m2s). Other components and launch accessories exposed to similar intense, short-duration, heat loads could also be protected by use of similar composite coatings.