Patent ID: 7540143

Claim:
An apparatus for a thermal rocket engine cycle, comprising: a propellant tank; a plurality of pressure balls for receiving fluid propellant discharged from the propellant tank, each of said plurality of pressure balls in fluid communication with said propellant tank; means for heating and thereby pressurizing the propellant prior to discharging the propellant from the respective pressure ball, connected to said plurality of pressure balls; a pressurization line for recycling to the propellant tank a heated portion of the propellant to maintain pressure in said propellant tank; means for heating the propellant discharged from the pressure balls; and an exhaust nozzle for discharging propellant from said means for heating the propellant discharged from the pressure balls, to create thrust; wherein each of said plurality of pressure balls is provided with an inlet valve for passing therethrough propellant before entering the respective pressure ball and an outlet valve for passing therethrough propellant after discharging from the respective pressure ball, such that operation of the inlet valve and outlet valve, combined with the heating of the propellants in the pressure balls achieves a pumping action of propellant fluid.