Model of plasma dynamics and electromagnetic pulses associated with hypervelocity particle impacts on satellites

We present the first results from a model that describes the interaction of a hypervelocity particle with a spacecraft, which can result in electrical damage. Though a meteoroid impact on a spacecraft can cause mechanical damage, a hypervelocity impact will result in the vaporization and ionization of the meteoroid and part of the spacecraft, forming a plasma that rapidly expands into the surrounding vacuum. We propose a mechanism for the generation of an electromagnetic pulse by this plasma. This electromagnetic pulse could be the source of electrical anomalies on a number of satellites. We also present a model of the impact process and plasma expansion. We use this model to predict the total charge generated, plasma temperature profile, density profile, expansion speed, and the spectrum of radiation from the limited information known about the meteoroid impact. The total charge generated, which is calculated from first principles, is overestimated since the plasma expands in a state of partial ionization, but the dependence on projectile mass and velocity agrees well with experiment. Plasma temperatures of up to 25 eV and expansion speeds of up to 40 km/s are predicted. The model is most accurate for high velocity impacts (>;30 km/s).