Research on Electromagnetic Radiation Characteristics of Charging and Discharging in Geostationary Orbit Satellites

Charging and discharging effects are among the primary factors leading to anomalies and failures of geostationary orbit (GEO) satellites. In addition to causing material degradation and the burnout of high-voltage solar arrays, the strong electromagnetic pulses (EMPs) generated during discharge can interfere with electromagnetic-sensitive onboard equipment, resulting in operational interference, performance degradation, or even damage to the equipment—and in extreme cases, complete satellite failure. To investigate the electromagnetic characteristics of satellite surface charging and discharging, as well as the associated electromagnetic radiation characteristics, during geomagnetic substorms, this study selects typical electrostatic discharge (ESD) risk sources for spacecraft. Based on a comprehensive satellite ESD test platform, seven sets of antenna sensors covering different frequency bands were deployed inside and outside a vacuum chamber to measure the key parameters of electromagnetic radiation characteristics during ESD under a simulated GEO environment. The results indicate that the energy of the discharge current on the surface of GEO satellites is concentrated in the frequency band below 30 MHz, while the energy of the discharge electromagnetic radiation field is distributed between 10 and 50 MHz. Furthermore, based on the test results of discharges with different intensities, the finite integration technique (FIT) was employed to simulate the time-domain waveforms of electromagnetic radiation pulses and the frequency characteristics of high-frequency electromagnetic wave energy distribution in both the near-field and far-field regions of satellite discharge within a 10-m free space. These simulation results provide accurate input parameters for the experimental verification and evaluation of electromagnetic coupling during satellite charging and discharging, as well as technical support for the detection and localization of discharge sources based on the spectral characteristics of discharge EMP signals.