A heating device for a drive unit in a motor vehicle includes at least one heating element and at least one sensor by means of which a predetermined behavior of the vehicle user preceding the start of the drive unit can be detected. The sensor interacts with the heating element in such a manner that it is switched on when the sensor detects the predetermined behavior. The predetermined behavior may be one or more of the following: inserting an ignition key in an ignition lock of the motor vehicle; actuating a shifting, clutch or braking device of the motor vehicle; or a behavior through which an anti-theft device of the motor vehicle can be triggered.

A method utilizing a rotating disc gasifies and pressurizes liquid propellants for use in rocket propulsion systems. The method is carried out by: a) increasing the tangential kinetic energy and pressure of liquid propellants by driving them from the center of the rotating disc to the periphery of the disc; b) gasifying the propellants at the periphery of the disc by partial combustion; and c) decreasing the tangential kinetic energy of the gasified propellants by driving them from the periphery to the center of the disc. The single rotating disc gasifies oxidant and fuel simultaneously, without relative movement between the components of the disc which include a structural disc (2), plates (3), compression ducts (4) and (5) and expansion ducts (6) and (10). The various ducts transport the propellants as shown by the arrows in FIG. 1.