Spacecraft charging model: Two Maxwellian approximation
Abstract
The ambient plasma environment at geosynchronous orbit is assumed to be represented by a twocomponent MaxwellBoltzmann particle distribution. Given this, the equations for ambient electron and ion currents to the spacecraft are easily integrated. Likewise, the secondary and backscattered currents can be expressed as integrals. The potential at which the currents balance gives the potential between the spacecraft and ambient plasma. The model is compared with actual data from ATS5 and is found to agree within plus or minus 1, 200 V over a range of 0 to minus 10,000 V. The model is readily applicable to the simple environmental model of Garrett and DeForest (1979) and can be calibrated to any given satellite. Simple algorithmic expressions are also developed for the backscattered and secondary currents as a function of temperature and potential which promise a significant decrease in computer time without a significant loss in accuracy.
 Publication:

Environmental Research Paper Air Force Geophysics Lab
 Pub Date:
 July 1979
 Bibcode:
 1979hafb.rept.....T
 Keywords:

 MaxwellBoltzmann Density Function;
 Plasma Density;
 Spacecraft Charging;
 Computer Programs;
 Current Density;
 Ion Distribution;
 Particle Size Distribution;
 Launch Vehicles and Space Vehicles