Achieving cryogenic temperatures in deep space using a coating

There is a current need to develop coatings that can reject more than 99% of the sun's irradiance to enable cryogenic storage and superconductor operation in space. Such a coating is proposed, composed of broadband scatterers on a metallic reflecting layer, yielding a surface that backscatters most of the solar spectrum yet still emits far-IR radiation. A model is presented with results, showing that a properly designed coating may potentially backscatter more than 99.9% of the sun's energy and allowing temperatures below 50 K to be achieved. (C) 2016 Optical Society of America