Modeling resonance characteristics of the Chang'e-7 lander modulated by solar panel rotation under lunar south-pole thermal environment

TL;DR

This study models the Chang'e-7 lander's resonance behavior under lunar south-pole thermal conditions, revealing significant frequency drift caused by thermal and rotational effects, which impacts seismic data interpretation.

Contribution

Developed a high-fidelity finite-element model to analyze the lander's resonance characteristics influenced by thermal variations and solar panel rotation.

Findings

Fundamental frequency drifts from 0.64 Hz to 0.87 Hz with temperature changes.

Resonance band overlaps with primary seismic observation window.

Fundamental mode remains robust despite material uncertainties.

Abstract

The Chang'e-7 (CE-7) mission will deploy the first seismometer at the lunar south pole to detect moonquakes and probe lunar interior structures in 2026 winter. However, the lander's vibration response to the extreme temperature cycles of the polar environment remains unclear, complicating the analysis of noise sources in seismic records. Here, we developed a high-fidelity finite-element model of the CE-7 lander to characterize its resonant behavior under the coupled influence of solar panel rotation and extreme thermal variations. Numerical results reveal that the lander's fundamental frequency (~0.76 Hz) at room temperature drifts significantly between 0.64 Hz and 0.87 Hz when the outside temperature varies from -180 to +80 {\deg}C. This frequency drift is primarily driven by thermally induced stiffness changes in the solar array supporting bracket, whereas geometric reconfiguration due to rotation plays a secondary role. Crucially, this resonance band directly overlaps with the primary seismic observation window (usually <1.0 Hz). Sensitivity analysis further confirms that the fundamental mode remains structurally robust despite material property uncertainties. These findings establish an essential theoretical baseline for identifying and filtering lander-induced resonant noise, which will be immediately applicable upon the acquisition of the first in-situ seismic datasets from the south pole of the Moon, ensuring the high fidelity of accurate lunar interior detection.