Thermal insulation is enhanced by reducing the radiative contribution to heat transfer.

A further improvement has been made to reduce the high-temperature thermal conductivities of the aerogel-matrix composite materials described in “Improved Silica Aerogel Composite Materials” (npo-44287), NASA Tech Briefs, Vol. 32, No. 9 (September 2008), page 50. Because the contribution of infrared radiation to heat transfer increases sharply with temperature, the effective high-temperature thermal conductivity of a thermal-insulation material can be reduced by opacifying the material to reduce the radiative contribution. Therefore, the essence of the present improvement is to add an opacifying constituent material (specifically, TiO₂ powder) to the aerogel-matrix composites.