Simulation of the Potential of a CubeSat designed for Accurate Plasma Measurement in LEO

This paper presents the estimation of CubeSat charging in low Earth orbit (LEO) environment. The satellite will be equipped with a series of thin cylindrical Langmuir probes to access plasma parameters with a large temporal cadence. The electrostatic cleanliness basically requires the use of conductive surface elements to avoid differential charging and possible in homogeneities and disturbances of the plasma. However, this does not prevent the spacecraft to charge with respect to the neutral environment because electron mobility is much larger than ions', and also due to the wake effect created by supersonic ions combined with the satellite geometry. In this context, the thin sheath theory is only approximate at getting the plasma parameters. This paper presents efforts to estimate numerically charging levels of a typical CubeSat using the Spacecraft Plasma Interaction Software (SPIS). It also presents preliminary experiments of a mock-up equipped with Langmuir probes and with an electron emitter.