Control systems for missiles

A missile comprises a nose portion 14 rotatable relative to a body portion of the missile. Variable-incidence control surfaces 16, 17 and 19, 18 (not shown) are provided for rotating the nose portion and for exerting a thrust thereon to produce a steering effect on the missile. An actuator mechanism for the control surfaces is provided in the body portion of the missile and comprises electromagnetic coils 27, 22, armatures 47, 40 in cooperating relation with the coil, and springs 49, 42 for biasing the armature to a limiting position in the absence of energisation of the coil. Upon energisation of the coil by a control signal, the armature moves against the spring to pivot the control surfaces by an amount representative of the control signal amplitude.