English: The figure plots the normalized effective sail area normalized by the coil area for the Magsail kinematic model (MKM) from Gros and for Zubrin for loop current a curve fit parameter plotted versus the spacecraft velocity relative to the speed of light assuming an Interstellar medium (ISM) plasma density of 1.7x10^-22. Also plotted is the MHD applicability test of ion gyroradius divided by magnetopause radius < 1 on the secondary axis. Note that MHD applicability occurs at < 1%. For comparison, the 2004 Fujita model as a function of from the MHD applicability test section of the magnetic sail article is also plotted. Note that the Gros model predicts a more rapid decrease in effective area than this model. The normalized values of and track closely until 10% after which point the Zubrin magsail model becomes increasingly optimistic and the MKM model is applicable instead. Since the models track closely up to 10%, with the kinematic model underestimating effective sail area only for small values of (hence underestimating force),the MKM model is a good approximation for predicting generation of force both the MHD and kinematic region.