Experimental investigation of ablation and pyrolysis processes of carbon-phenolic ablators in atmospheric entry plasmas

The thermochemical equilibrium model generally underpredicted experimental recession rates, particularly at low pressure (15 hPa). Stronger mechanical failure of the material was ruled out as experiments at the same test conditions in nitrogen plasmas did not show any significant recession. Micrographs did not indicate internal oxidation of the material, neither was spallation observed during the low pressure experiments.