Attitude Orientation and Distribution of Millimeter-Scale Space Debris Considering Shape Effects

Currently, space debris environment engineering models typically simplify millimeter-sized debris as homogeneous spheres, neglecting the influence of debris shape on orbital evolution and subsequent risk assessment. To improve these models, this paper proposes the use of cylindrical debris instead of spherical debris. Specifically, cylinders with varying aspect ratios are employed to represent different debris shapes, and cylinders of differing densities are spliced together to simulate non-homogeneous debris characteristics. Three representative debris shapes are selected, and their attitude dynamics under non-homogeneous conditions are modeled. Finally, this study analyzes the attitude dynamics of these three debris types in the low Earth orbit (LEO) environment and summarizes the distribution of their nutation angles. Results show that, due to aerodynamic torque, the nutation angle distribution of non-homogeneous debris is positively skewed, with the concentration value being less than 90°. Moreover, the stronger the aerodynamic torque effect, the greater the degree of skewness. In contrast, the nutation angles of homogeneous debris cluster around 90°, exhibiting a symmetrical distribution. This study provides a method for calculating the attitude distribution of space debris, making it possible to incorporate debris attitude as a factor in environment engineering models.