Pitch stability considerations of 3 U cubesats for differential drag exploitation in VLEO

Very Low Earth Orbit (VLEO) is a space region of increasing interest for satellite missions due to its advantages in Earth observation and telecommunications, but aerodynamic forces in this rarefied environment strongly affect satellite lifetime and attitude dynamics. On the other hand, the relevance of aerodynamic effects may be exploited to enable propellantless maneuvers, so it is crucial to identify stable attitude configurations that maximize differential drag effects. In this study, the aerodynamic behavior of 3 U CubeSats equipped with lateral panels of different shapes is analyzed, with a focus on pitch stability. The Direct Simulation Monte Carlo (DSMC) method is employed to evaluate the lift CL, drag CD and pitch moment CMz coefficients for various panel configurations. The novel contribution of this work lies in combining this high-fidelity aerodynamic analysis with a systematic investigation of center-of-mass displacement to map out passively stable pitch attitudes. Results confirm that CL and CD are primarily dependent on the exposed surface area rather than panel shape. Stable pitch configurations are identified by examining the aerodynamic force application points across different angles of attack. Reasonable displacements of the center of mass (∼ 3–4 cm) allow for the achievement of stable configurations between 0 deg and 75 deg, enabling drag-based in-plane maneuvers through differential aerodynamic forces. These findings provide insights into CubeSat attitude control in VLEO, offering design strategies to enhance stability and reduce reliance on active control systems.