Space Shuttle was a reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration (NASA). It resulted from shuttle design studies conducted by NASA and the US Air Force in the 1960's and was first proposed as a part of second generation Space Transportation System (STS) of space vehicles to follow the Apollo program in September 1969.
Thermal Protection System (TPS) is one of the most important component of a space shuttle. It is the barrier that protects the space shuttle orbiter during the searing at 1,650 degrees Celsius of atmospheric reentry. TPS is needed because The orbiter's aluminum structure could not withstand temperatures over 175 °C without structural failure. Aerodynamic heating during reentry would push the temperature well above this level in areas, so an effective insulator was needed.
1. Reinforced Carbon - Carbon (RCC) - used where reentry temperature exceeded 1,260 °C. The strength of carbon–carbon with unidirectional reinforcement fibres is up to 700 MPa. The material has a density between 1.6–1.98 g/cm3.
2. High - temperature Reusable Surface Insulation (HRSI) tiles - used where reentry temperature was below 1260 °C. It has an areal density of 9.2 kg/m2.
3. Flexible Insulation Blankets (FIB) - used where reentry temperature was below 649 °C. This white low-density fibrous silica batting material had a quilt-like appearance, and replaced the vast majority of the LRSI tiles. They required much less maintenance than LRSI tiles yet had about the same thermal properties.
4 . Low - temperature Reusable Surface Insulation (LRSI) tiles - 1200 °C (operating temperature). It has an areal density of 3.98 kg/m2.
5. Advanced Flexible Reusable Surface Insulation (AFRSI) - 648 °C (operating temperature). It is more durable, less fabrication, less installation time and costs, and a weight reduction.
6. Felt Reusable Surface Insulation (FRSI) - 700 °C (operating temperature). It has an areal density of 1.6 kg/m2.
References:
https://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system
https://en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbon
https://www.nap.edu/read/5115/chapter/6#44
http://depts.washington.edu/matseed/mse_resources/Webpage/Space%20Shuttle%20Tiles/Space%20Shuttle%20Tiles.htm
Image retrieved from https://www.nasa.gov/feature/space-shuttle-overview