English: The spacecraft and (magnetic) field source shown as a small purple dot, from which the magnetic field lines expand as shown by black lines. The magnetic field lines are compressed by the oncoming plasma wind and form a magnetopause and bow shock shown in blue. Ions in the oncoming plasma wind are mostly deflected by the bow shock, while some get through to the magnetopause and are deflected there, while a few make it to the spacecraft and field source. A magnetospheric bubble with lower density than the exterior regions forms. Under certain conditions, ions deflecting from on the bow shock/magnetopause create a Wind Force on the magnetic field that in turn creates a Magnetic Field Force that acts on the field source attached to the spacecraft to create the Spacecraft Force, which accelerates the spacecraft.