How much heat can the tiles take and how much heat dissipates off the tile?

ANSWER from Dian Hardison on March 30, 1999: The shuttle tiles have as much as 93% porosity (i.e., very lightweight) and low thermal expansion, so low thermal conductivity. There are three different kinds of black tiles: Reinforced carbon-carbon (RCC) protects areas where temperatures exceed 2,300 F during entry. Black high-temperature reusable surface insulation (HRSI) tiles protect areas where temperatures are below 2,300 F. Black tiles called fibrous refractory composite insulation (FRCI) were developed later in the thermal protection system program. FRCI tiles replace some of the HRSI tiles in selected areas of the orbiter. During re-entry, the highest temperature of the tile on the belly has been 1793 degrees F. The highest temperature of the reinforced carbon nose cap and wing leading edges have been 2590 degrees F and 2608 degrees F respectively. After re-entry, the tiles begin to transfer their heat to the Orbiter skin. The highest skin temperature on the belly has been 244 ...  more