Characterization of ablator recession and thermal response using non-intrusive techniques

Abstract

The main goal of this study is the investigation of the recession augmentation of cork-based ablators in particle-laden Martian flow environment in the arc-heated facility L2K. The thermal response of the P50 cork-based ablator is assessed through recession and material temperature measurements. An innovative laser-based technique was employed to measure the in situ, time-resolved evolution of material thickness due to ablation, swelling, and erosion. The results were compared with 3D surface scans. Sample temperatures were monitored using infrared thermography and embedded thermocouples. In the tests, a slightly simplified Martian atmosphere (97% CO2 and 3% N2) was used. The high-enthalpy flow was loaded with micrometric magnesium oxide particles moving at approximately 2000 m/s. Flow conditions without particles were also studied for comparison. The particle-induced erosion was evaluated by comparing conditions with and without particles. In the presence of particles, the increased surface recession causes higher in-depth temperature due to material thinning. For this reason, the design of cork-based heat shields for Martian missions around dust storms requires increased safety factors.