Orbit Determination of Chang’E-6 ICUBE-Q CubeSat and Orbit Evolution Analysis

Abstract

This study focuses on the Pakistan ICUBE-Q CubeSat carried by the Chang’E-6 mission，systematically analyzing its orbital characteristics，dynamic environment，and measurement methods，with particular emphasis on the primary perturbative factors affecting its orbital variations. In the absence of range and Very Long Baseline Interferometry (VLBI) support，a three-way Doppler velocity measurement model was proposed for orbit determination，and the velocity measurement errors were thoroughly analyzed. Additionally，an orbit determination strategy suitable for sparse observation modes was designed，and error assessment was conducted. Furthermore，a detailed analysis of the long-term orbital evolution of the CubeSat was performed. The results indicate that the Root Mean Square (RMS) of the three-way Doppler velocity residuals was 2 mm/s，and the orbit determination accuracy achieved a position precision better than 1 km. The CubeSat’s orbit was primarily influenced by lunar non-spherical gravitational perturbations and Earth’s point-mass gravity，with three-body gravitational effects playing a significant role in its orbital evolution. Orbital evolution predictions reveal that the CubeSat’s perilune distance is expected to decrease to less than the lunar radius by April 2025. This study provides valuable insights into orbit determination and evolution analysis for microsatellites in deep space exploration missions.

Keywords

Chang’E-6 / ICUBE-Q / orbit determination / orbit perturbation / orbit evolution