fibrous insulation (TUFI) tiles, a stronger, tougher tile which came into use in 1996. Used in high and low temperature areas.
* Felt reusable surface insulation (FRSI). White Nomex felt blankets on the upper payload bay doors, portions of the mid fuselage and aft fuselage sides, portions of the upper wing surface and a portion of the OMS/RCS pods. Used where temperatures stayed below .

Each type of TPS had specific heat protection, impact resistance,