Electrical disturbances caused by charging of cables in spacecraft can impair electrical systems for long periods of time. Space components are charged by electrons, protons and heavier ions trapped in the radiation belts of the earth. The protons, alpha particles, and heavier ions impact only electrical components with sizes in the micron and sub-micron range. The electric fields generated by electrons can exceed the limits for dielectric breakdown in cables in space-based systems with inadequate shielding. When the charge is transferred to sensitive circuit boards, damages can be irreversible.

Modeling tools that aid in designing electrical systems against Electrical Charge Electromagnetic Pulse (ECEMP) is thus critical, especially for high performance systems orbiting the earth for long periods of time. ESADDC and DICTAT are tools developed by the European Space Agency (ESA) that incorporate much of the relevant physics. Each has their own individual merits. This paper presents another modeling tool, Space Electrons Electromagnetic Effects (SEEE) developed at Boeing. The SEEE tool differs from the ESADDC and DICTAT in that the electric field, charge, and current are determined analytically and thus provide the user with solutions in about 1/1000 of the time it would take to solve the same stiff non-linear differential equations numerically and provide values agreeing with laboratory measurements within 30% of the transient voltages taken by ESA. In addition, unlike numerical methods, the analytic solutions for charge, electric field, and current offer an insight into the parameters affecting the charging equilibrium values.

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