Analysis of Aerodynamic Stability Under Rarefied Flow Conditions for Mars Aeroassisted Orbit Transfer

Targeting the atmospheric aerobraking technology requirements for future Mars sample return missions, this study employed the Direct Simulation Monte Carlo （DSMC） method to numerically simulate the Mars atmospheric aerobraking process, based on a simplified configuration of the Tianwen-1 probe. Firstly, the aerodynamic heating characteristics and static stability of the probe were analyzed at an altitude of 120 km in the Martian atmosphere with a 5-degree angle of attack. Secondly, at the same altitude, the aerodynamic heating characteristics and static stability of four different geometric configurations of solar arrays and antennas were compared. Finally, the dynamic stability of the four configurations was evaluated. The research results indicate that: A reasonable geometric configuration can significantly enhance the aerodynamic stability of the probe. Apart from the configuration with vertically deployed solar arrays and the antenna oriented along the flow direction （the fourth geometry）, which failed to achieve static stability, the other three configurations all possess static stability, with no significant impact on heat flux density, pressure distribution, or drag characteristics. Among them, the configuration with vertically deployed solar arrays and the antenna oriented against the flow direction （the second geometry） demonstrated superior dynamic stability.