US Patent 7354017 Projectile trajectory control system

Trajectory is controlled by a control system having fins that de-spin a section of the control system relative to a projectile or missile. The control system also includes aero-surfaces that produce a lift when brought to rotation speed of about 0 Hz relative to a reference frame and a brake that couples the guidance package to the rotational inertia of the projectile or missile. In one example, no electric motor is used in the trajectory control system, saving weight and increasing reliability.