Abstract: A propulsion and positioning system for a vehicle comprises a first gyroscope mounted for precession about an axis remote from the center of said gyroscope. A support structure connects the gyroscope to the vehicle. Gyroscopes are used to cause the first gyroscope to follow a path which involves at least one precession-dominated portion and at least one translation-dominated portion, wherein in the precession-dominated portion, the mass of the first gyroscope is transferred and associated movement of the mass of the remainder of the system in a given direction occurs, and, in the translation-dominated portion, the mass of the first gyroscope moves with an associated second movement of the mass of the remainder of the system in substantially the opposite direction, wherein the movement owing to the translation-dominated portion and is larger than the movement owing to the precession-dominated portion of the motion, hence moving the system.