Abstract: A passive device for stabilizing the pointing direction of a spacecraft of the type comprising a pair of panels that are symmetrical about a gyroscopic stabilization axis, each panel having an auxiliary flap that is at least partially reflecting. Each of the auxiliary flaps is spaced apart from the plane of the corresponding panel and is disposed relative thereto in such a manner that during rotation of the spacecraft about the stabilization axis the area of the flaps that is illuminated by the sun's rays emitted along the solar ray direction Z.sub.s is modulated during rotation by the shadow of the corresponding panel.