ELECTRODYNAMIC INTERACTIONS BETWEEN A SPACE STATION AND THE IONOSPHERIC PLASMA ENVIRONMENT

A general analysis of the electrodynamic interactions between a space station with two exposed charged platforms and the ionospheric plasma is presented. We show that this problem can be separated into a far-field problem, concerned with the electromagnetic interference surrounding the entire space station, and a near-field problem, concentrated on the interactions in the vicinity of the biased platforms. Computer particle simulations as well as approximate analysis were carried out in the near field of the charged platform. Results of the plasma flowfield, the presheath and sheath structure, and current collection characteristics are obtained. The near-field solution is used to construct the perturbation current source in the far-field problem, which is solved by application of plasma fluid theory. It is found that the space station will generate a radiation field composed of the Alfven waves forming a ''wing'' structure. Based on our analysis, a global description of the space station's electrodynamic environment is obtained.