A supersonic combustor as a component of a rocket nozzle offers improved utilization of available chemical energy that may be released from combustion gasses flowing through the rocket nozzle. A subsonic combustor compresses and sub-sonically accelerates an exothermically reacting combustion gas up to a nozzle throat. The supersonic combustor expands and super-sonically accelerates the exothermically reacting combustion gas beyond the nozzle throat. The dimensions of the supersonic combustor may be selected such that the supersonic combustor achieves a slow rate of cooling of the combustion gasses without creating Shockwaves within the supersonic combustor. A supersonic discharge expands and super-sonically accelerates the now substantially non-reacting combustion gas through a supersonic discharge of the rocket nozzle. The momentum of the combustion gas leaving the supersonic discharge propels the rocket nozzle in the opposite direction due to the principle of conservation of momentum.