Heat resistance of heat-retention lagging materials’ optical measurement method for orbital spaceship "Buran"

Orbital spaceship’s heat-insulation is working in high-temperature stream. That’s why, the materials it is made of should have corresponding optical characteristics for effective re-emission of the heat received by its lagging, and to be heat-resistant. Optical characteristics’ analysis of one type of the heat-retention lagging for orbital spaceship "Buran" has been conducted. Reflection ρ(λ), absorption α(λ) and admission τ(λ) spectral ratios were measured in the range of wave-length λ=0,3-1,1 micrometers by the temperature of 20-1000 °С. Full conversion of optical spectrum after cooling down for temperatures up to 1000 °С is observed. Research of optical spectrum’s conversion has determined that the heat resistance temperature of thermal-insulation tile type EVC-4M1U-3 exceeds 1000 °С that proves the possibility of its nonexpendable use.