Liquid rocket

A rocket engine suitable for using for an educational program uses a liquid phase propellant (102A) having a predetermined boiling point and a heating substance (102B) having a temperature higher than the boiling point. The engine has an inner wall (103B) having a circumferential surface; an outer wall (103D) surrounding the inner wall (103B), the outer wall (103D) having an interior surface spaced from the circumferential surface of the inner wall (103B) by a predetermined distance such that the space between the circumferential surface and the interior surface form a mixing chamber (103E) having an opening (103F); and an injector (103A) for injecting the liquid-phase propellant and the heating substance into the mixing chamber (103E) so that the propellant is evaporated by the heating substance thereby creating a jet stream moving from the opening (103F) of the mixing chamber (103E) to the outside.