Surface Charging Considerations for Composite Materials Used in Spacecraft Applications

Graphite composites remain a preferred structural material for modern spacecraft applications despite the growing library of charging data on the surface charging properties of composites and resin. Additional ground test data obtained at a number of relevant temperatures and electron beam current densities extends the collective community knowledge on the charging properties of graphite composites in geostationary earth orbit environments. New data and analyses demonstrate that some common composite materials are susceptible to surface charging at the low current densities (<100 nA/cm ) expected for lightly shielded or blanketed applications. Scaling results also demonstrate that electrostatic discharge transients occurring on graphite composite surface fail to follow familiar scaling laws.