Thermal coating erosion in a simulated Martian landing environment

An experimental and computational research program was implemented to quantify the thermal coating erosion that results from supersonic jets impinging on the surface of Mars during landing. Soil entrainment and acceleration in the impinging plume-flows result in high velocity particulate flux that can cause degradation of space-use thermal coatings. Computational fluid dynamics in conjunction with particle tracking simulations were used to determine the range of impact velocities expected during landing. The landing environment was simulated in a subscale particle erosion laboratory experiment with test coupons subjected to representative Martian soil media flux. Direct measurement of Mars rover white paint erosion has been obtained for a range of silica particle sizes (5–300 μm), impact velocities from 130 to 265 m/s, impingement angles from 30 to 90°, and mass loading of 10–240 mg/cm2. The post-erosion microstructure, absorptivity, and emissivity of the coating were also measured.

Research highlights▶ We model the aerodynamic environment of engine plumes impinging the surface of Mars. ▶ Acceleration of Mars soil particles in the flow field creates an erosive environment. ▶ A test program was conducted to expose thermal coatings to the particulate erosion. ▶ We measure the degradation in thermal coating properties as a result of the erosion. ▶ Erosion is maximized at non-normal incidence and impact energy.