the invention relates to a universal propulsion powerplant and impulse drive unit having a uni - directional linear impulse output for accelerating , lifting , guiding and braking land , water , air and space vehicles . the propulsion powerplant , being a self - contained unit , comprises a rotary source of torque , an impulse drive unit for receiving and converting torque from the rotary torque source into a uni - directional linear impulse output , a clutch means for coupling the rotary torque source to the impulse drive unit , a means for changing the magnitude of the uni - directional linear impulse output and a means for changing the direction of the uni - directional linear impulse output . the impulse drive unit comprises pairs of conjugate contra - rotating energy cells for converting torque into the uni - directional linear impulse output of the powerplant wherein mass members move along endless paths in defined planar orbits around the rotational axes of the cells . for each mass member , during one segment of the orbit thereof , energy is absorbed from the torque source whereby the kinetic energy of the member is increased as the member moves outwardly from the center of its respective orbit with an inherent motion of a substantially unconstrained body . the uni - directional linear impulse powerplant output is produced as the mass member is constrained by a surface of the impulse drive unit to move inwardly toward the center of its orbit whereby the kinetic energy of the member is reduced and a resultant linear impulse is imparted to the surface by the mass member .