area aft of the reinforced carbon-carbon nose cap to the nose landing
gear doors has sustained damage (tile slumping) during flight operations
from impact during ascent and overheating during re-entry. This
area, which previously was covered with high-temperature reusable
surface insulation tiles, will now be covered with reinforced carbon-carbon.
The low-temperature thermal protection system tiles on Columbia's
midbody, payload bay doors and vertical tail were replaced with
advanced flexible reusable surface insulation blankets.
Because of evidence of plasma flow on the lower wing trailing
edge and elevon landing edge tiles (wing/elevon cove) at the outboard
elevon tip and inboard elevon, the low-temperature tiles are being
replaced with fibrous refractory composite insulation (FRCI-12)
and high-temperature (HRSI-22) tiles along with gap fillers on Discovery
and Atlantis. On Columbia only gap fillers are installed in this