What material primarily composed the High-Temperature Reusable Surface Insulation (HRSI) black tiles on the Space Shuttle?
Answer
Silica fiber
The black HRSI tiles, designed for the hottest areas covered by the tile system, were composed primarily of nearly pure silica fiber, making them exceptional insulators.

Related Questions
What material formed the heat shield for early crewed missions returning from the Moon, like the Apollo Command Module?What material primarily composed the High-Temperature Reusable Surface Insulation (HRSI) black tiles on the Space Shuttle?Which advanced material was utilized for the absolute hottest zones of the Space Shuttle, such as the wing leading edges and nose cap?How does an ablative heat shield primarily manage the immense heat flux during atmospheric entry?What key structural characteristic gave the black HRSI silica tiles their incredible insulating capability relative to their mass?What material system remains the material of choice for missions involving very high entry speeds, such as returning from Mars, due to its single-use efficiency?What is the primary trade-off associated with the Space Shuttle's reusable Thermal Protection System (TPS) compared to monolithic ablative shields?What is the essential difference in the composition of PICA compared to the pure silica material of the HRSI tiles?Which areas of the Space Shuttle Orbiter were protected by the Carbon-Carbon (CC) composite?What is the key economic reason modern routine LEO capsules might favor advanced ablative shields over fragile reusable silica tiles?