Arcing generated electromagnetic fields associated with a high-voltage power system of the space station

Abstract

A large spacecraft such as the planned space station requires a relatively large amount of electrical power for its routine operation. For example, the power required by the space station is expected to be about 300 kW. This high power requirement entails a power system operating at a high voltage. The space station will operate at about 160 V. Such a large voltage in conjunction with the grounding scheme of the solar cell arrays, would make the potential of the space station structure highly negative with respect to the ionospheric plasma. Since the structure of the station is insulated by a 3-/spl mu/m thick coating of Al/sub 2/O/sub 3/ and the plasma shields the potential, the large negative potential drops across the thin insulating layer, creating an intense electric field (/spl sim/5/spl times/10/sup 7/ V/m) in it. This raises the possibility of dielectric breakdown and arcing from the space station structure to the ionospheric plasma. Laboratory simulations of the arcing have shown large arc currents (/spl sim/1500 A) with a rise time of about 0.1 ms and a total duration of about /spl sim/1 ms. Such a large arc current can affect the operation of the power system and generates electromagnetic waves, which cause concerns about electromagnetic interference. In this paper we report the results from a study on the electromagnetic fields generated by the arc. This problem is modeled as the radiation from a monopole antenna having a transient current in a magnetized plasma.