A method and a computer software program for predicting and modeling ion flux colliding with an ion-propelled vehicle traversing a magnetic field predicts a colliding ion path based upon an ion exhaust velocity, an ion charge-to-mass ratio, and a localized magnetic field vector. An ion-propelled vehicle path is predicted based upon a selected trajectory and a vehicle velocity vector. An ion plume is transformed based upon the predicted colliding ion path. The ion-propelled vehicle is projected into the transformed ion plume. The flux is calculated at a silhouette of the projected vehicle.