Ablative vs Non-Ablative Heat Shield

Shield Type

Re-entry Heating

Heat rate 300 W/cm²

Tile Damage

STANDBY

Surface temp

–

Structure temp

–

Shield material left

–

Mission time

–

How it works

An ablative shield deliberately chars and vaporizes its own outer layer. Pyrolysis is endothermic and the escaping gas blows the hot boundary layer away from the surface, so most of the incoming heat is carried off with the lost material instead of conducting inward — the structure stays cool even at extreme heat rates, at the cost of thickness consumed every flight.

A reusable ceramic tile shield instead radiates heat back out from a high-emissivity surface (Stefan–Boltzmann: hotter surface radiates faster). It loses no mass and survives repeated flights, but only within a rated heating envelope — push past it and there's no sacrificial buffer, so structure temperature runs away. A crack removes the insulating margin entirely: hot plasma reaches bare structure directly, which is what happened to Columbia.

Heat rate — convective heating at the stagnation point, in W/cm² (Apollo peaked near 500-1000, Shuttle tiles were rated far lower).
Auto re-entry profile — ramps heat rate up and back down over a full pass instead of holding it steady.
Crack tile — only available in tile mode; simulates a breach that lets plasma bypass the insulation.

Plasma shock layer Shield / char / tile Bond layer Structure (color = temp)

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.