Rocket engine, propulsion system and propulsion method for vehicles, in particular for space vehicles

A rocket engine (2) for vehicles, in particular for space vehicles, has:- a convergent-divergent nozzle (12) configured to guide a propellant flow in a given direction (D1) and having a minimum passage section (Smin);- a reaction chamber (5) arranged upstream of the convergent-divergent nozzle (12) and in which the propellant is subject to a chemical reaction that generates energy in the form of heat;- an ionization device (6), which is configured to ionize the propellant and comprises at least a first ionization station arranged in the area of the reaction chamber (5); and- a plasma propulsion engine accelerator (7) downstream of the convergent-divergent nozzle (12).