Ablating Material

A material, especially a coating material, designed to provide thermal protection to a body in a fluid stream through loss of mass.

Ablating materials are used on the surfaces of some re-entry vehicles to absorb heat by removal of mass, thus blocking the transfer of heat to the rest of the vehicle and maintaining temperatures within design limits. Ablating materials absorb heat by increasing in temperature and changing in chemical or physical state. The heat is carried away from the surface by a loss of mass (liquid or vapour). The departing mass also blocks part of the convective heat transfer to the remaining material in the same manner as transpiration cooling.

See also: Ablate, Ablating Nose Cone.