Estimating Material and Environmental Parameters for Spacecraft Charging using van allen probes Data

Spacecraft charging is a major application of space-weather research since charging can lead to spacecraft anomalies, which can range from inconsequential (single event upsets, memory bit flipping) to catastrophic (damage to sensitive electronics and total loss of the spacecraft). Un- fortunately, current direct spacecraft-charging calculations are extremely limited due to unknown critical environment and material parameters. To address this problem, we developed an optimization inverse technique approach to use available spacecraft-charging data to estimate key envi- ronmental and material parameter values for the Van Allen Probes. We implement our optimization technique to a simplified spacecraft charging model, based on the orbit-motion-limited (OML) theory. A mathematical analysis shows that we can uniquely estimate the parameters whenever the charging becomes negative by manipulating the equations of OML. We apply an optimization technique for the estimation of the parameters and show the impact of noise in observations for the optimization.