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Biologically Inspired Radiation-Reflecting Ablators (BIRRA)

Principal Investigator: Sylvia Johnson

Radiative heating during reentry becomes very significant as vehicles get larger and enter at high speeds. The specifics of the radiation depend on upon vehicle characteristics, speed and the atmosphere. Radiative heating occurs very early during reentry and at specific wavelengths, dependent upon the atmosphere. Thermal protection systems capable of dealing with such heat fluxes can be very heavy. An alternative is to make a heat shield that can reflect the radiation. One approach to radiation reflection is through photonic effects. Photonic effects rely on ordered structures of the same size as the radiation, and although it is possible to fabricate such structures it is currently time consuming and expensive.

An alternative approach is to use the ordered structures that are found in nature to make materials that can be used to reflect radiation. This project is exploring that approach to forming radiation-reflecting materials.