FIELD: angular motion control systems including swivel optical instruments carried on case of space vehicle rotating relative to observed reference point, solar batteries in particular which are connected with space vehicle through electromechanical drive. SUBSTANCE: structural member is rotated relative to case of space vehicle in direction opposite to direction of rotation of this case relative to observed reference point. In case of absence of reference point, members are rotated in direction coinciding with direction of turn of space vehicle case, provided the following requirements are satisfied: reference point is not shaded, angular velocity of turn of space vehicle is more than that of rotation of extended member relative to space vehicle case. As far as solar batteries are concerned, reference point is considered to be out of field of view if normal to plane of solar battery panels is deviated from Sun by angle exceeding permissible value. EFFECT: increased time of presence of reference point (Sun) within field of view on board space vehicle which is placed in emergency twist; enhanced informativeness of observation. 3 cl, 1 dwg
