The material should have behaved differently
NASA's Orion spacecraft, which is part of the Artemis lunar program, appears to have major heat shield problems.
The ship has so far completed its only unmanned test flight. This happened at the end of 2022. The flight was overall successful, and NASA noted that the ship exceeded their expectations. However, after the spacecraft returned, NASA revealed that Orion's heat shield was more damaged than they expected. Now we can see how severe the damage was.
As you can see, the shield was indeed damaged very significantly. The shield uses AVOCAT polymer resin, which must gradually break down during reentry through a process called ablation. Simply put, it should evaporate and break off into small fragments. Instead, fairly large pieces of protection simply tore off, forming cavities. This type of damage is not only not the norm, but also poses a threat to the ship and crew. In addition, large debris from the shield can damage parachutes.
NASA engineers are reportedly currently assessing whether the vehicle's reentry trajectory or the shield design itself can be altered to avoid such damage.