Effects of Charged Particles on the Motion of an Earth Satellite

Using a model of the upper atmosphere in which the principal atmospheric constituent (for both atoms and ions) changes with increasing altitude from atomic oxygen to helium and then to atomic hydrogen, the charge on a conducting spherical satellite and the drag due to charged particles are estimated for altitudes below the hydrogen region. The effects of photoelectric emission and the earth's magnetic field are included in the calculations. It is found that the contribution of charged particles to the satellite drag may be neglected in the oxygen region. In the helium region the drag due to charged particles may be significant, particularly for large satellites and in cases where the photoelectric emission current is significant. A method of estimating this drag is presented. A comprehensive survey of the literature concerning satellite charge and the resulting drag is included, and the existing contradictions are explained. The conclusions regarding drag are applicable to satellites large with respect to the debye length.