To provide a system capable of offering energy storage, attitude maneuver and momentum control of a space flying body in a geometrical manner.

A system provides energy storage, attitude maneuver and momentum control of a space flying body using a pair of gimbal flywheels 30. Two flywheels 30 are arranged with their rotational axes substantially corresponding to the pitch axis P of the space flying body, so that they are rotated at different or the same speeds in opposite or the same directions 36, 38 to accumulate desired momentum of the space flying body. Angle momentum can be gradient from a alignment well known about the space flying mainbody. The system allows the reduced weight and the reduced cost of a conventional space flying body.