Shock-Layer Radiative Heating for MSR Sample Retrieval Lander With 8 Km/S Entry

This study investigates the radiative heating environment of the Mars Sample Return (MSR) Sample Retrieval Lander (SRL), set for potential 2031 launch from Earth with a Mars entry velocity near 8 km/s. This speed presents a significant change compared to prior Mars missions, such as Mars Science Laboratory (MSL), InSight, and Mars 2020, which typically experienced entry velocities around 6 km/s. Consequently, the SRL is subjected to a markedly different radiative heating regime, where CO 4th-Positive bands emerge as the dominant radiation mechanism under these entry conditions. We quantified the nominal radiative heating environment and assessed both the parametric uncertainty in the radiative heating model and the experimentally-anchored shock-tube informed bias. The analysis revealed that parametric uncertainty can reach as high as 160% for the heatshield and 50% for the backshell. The shock-tube informed bias indicated an increase in nominal radiative heating by 10% on the forebody and 24% on the afterbody. To address the substantial uncertainties in the nonequilibrium models, we compiled the best available nominal modeling parameters along with their uncertainties. Our findings emphasize the critical role of CO dissociation rate as the primary contributor to uncertainty on the forebody, while CO2 dissociation rate is the dominant factor on the backshell.