Abstract: The invention relates to a control moment gyro comprising a wheel support structure (12) which is mounted on a base (10) by means of a motor, which is used to rotate the support structure around a first axis (z), and bearing a wheel (14) which is equipped with means of driving the wheel spinner at a high speed around a second axis (x) perpendicular to the first. The aforementioned support structure or gimbal comprises a tubular part which rotates on the base and a flange which is disposed on only one side of the wheel and which is fixed to (i) said wheel and (ii) the tubular part. The diameter of the wheel and the point at which the wheel is fixed to the flange are proportioned such that the wheel penetrates the tubular part.