Neutralizing charged-up spacecraft

The problem of spacecraft charging is examined. The mechanism by which a spacecraft acquires a charge with respect to the ambient space environment is discussed. Methods used to avoid spacecraft dysfunction due to charging, including the use of electron and ion emitters, adequately conducting surfaces, and dielectric materials with high secondary-emission coefficients, are described. Special attention is given to the development, in the context of the Scatha program, of a computerized model which will allow the calculation of spacecraft potential for a given set of conditions.