Spacecraft Discharge Time Constants Determined From Electron‐Flux Suppression During Sounding‐Radar Operation at Mars
Spacecraft discharge time constants are calculated from measurements of electron differential flux before and during operation of an ionospheric sounding radar. Determining these time constants provides insight into how the operation of a sounding radar affects the surrounding plasma's interaction with the spacecraft. The analysis is enabled by the fixed‐frequency operation mode of a sounding radar which enhances resonant interaction with the ambient plasma. This mode's effect on measured energy spectra of ion and electron fluxes is described. Measurements of electron fluxes disturbed by radar operation serve as input to a model of spacecraft discharge for calculating capacitive discharge time constants. A case study using electron fluxes measured at Mars yields discharge time constants in the range 0.6–0.8 ms and reveals that a residual potential around V remains on the spacecraft long after radar operation ceases. The minimum spacecraft potential cannot be determined with these data and model due to the narrow energy range of electrons in the ambient plasma.
Funding
Solar wind influence on terrestrial planets' upper atmospheres: unveiling their close interaction
Science and Technology Facilities Council
Find out more...STFC Grant. Grant Number: ST/W0089X/1
Swedish National Space Agency. Grant Number: Dnr 20/137
European Space Agency. Grant Number: RFP/3-17233/21/ES/JD
Italian Space Agency. Grant Number: 2024-40-HH.0
History
Author affiliation
College of Science & Engineering Physics & AstronomyVersion
- VoR (Version of Record)