• Asma, Cem
• Babou, Y.
• Hubin, Annick
• Magin, T. E.
• Chazot, Olivier
• Helber, Bernd

Abstract

Future space exploration missions beyond Earth's orbit, such as sample returns from Mars, will use ablative <br/>materials for the thermal protection system in order to shield the spacecraft from the severe heating during <br/>reentry. In this paper, we present the results of an elaborate test campaign on a lightweight carbon composite <br/>ablator with the aim of defining a procedure for material response characterization in a 1.2-MW inductively <br/>heated Plasmatron facility, suitable to reproduce the hypersonic flight boundary layer environment. Three <br/>different test gases were used, including air, nitrogen, and argon, at surface temperatures exceeding 3300 K. <br/>A comprehensive experimental setup was developed including a nonintrusive technique to measure surface <br/>recession by means of a high-speed camera. Surface degradation was strongly test gas dependent, while mass <br/>loss was mainly driven by in-depth decomposition of phenolic resin. Emission spectroscopy helped us identify <br/>C2 as a product of dissociating hydrocarbons, as well as cyanogen, suggesting surface nitridation. Melt flow <br/>at the surface and silicon emission indicated degradation of the glass microspheres used as additional filler. <br/>In air plasma, oxidation was inferred to be the main mechanism for ablation.

Topics

• density
• surface
• Carbon
• melt
• glass
• glass
• Nitrogen
• composite
• Silicon
• resin
• decomposition
• spectroscopy