a system and method for producing and controlling high thrust and desirable specific impulse from a continuous fusion reaction is disclosed . the resultant relatively small rocket engine will have lower cost to develop , test , and operate that the prior art , allowing spacecraft missions throughout the planetary system and beyond . the rocket engine method and system includes a reactor chamber and a heating system produce fusion reactions the stable plasma . magnets produce a magnetic field that confines the stable plasma . a fuel injection system and a propellant injection system are included . cold propellant into a gas box for converting a cold propellant into a warm propellant plasma at one end of the reactor chamber . the propellant and fusion products are directed out of the reactor chamber through a magnetic nozzle and are detached from the magnetic field lines producing thrust .