Device and method for feeding a rocket motor

The invention relates to a device for feeding a propellant chamber (10) of a rocket engine (100) in first and second propellant. According to the invention, a first feed circuit (16) of the propellant chamber (10) comprises a turbo pump (22) with at least one pump (22a) for pumping the first propellant component from a first reservoir (12) and a turbine (22b) mechanically coupled to said pump (22a). The first power supply circuit connects a pump outlet to an inlet of the turbine through a heat exchanger (24) configured to heat the first propellant with a heat generated by the propellant chamber to drive the turbine. According to the invention, a second feed circuit (18) is configured to supply the propellant chamber in the second propellant component from a second reservoir (14) that is configured to be pressurized. The invention also relates to a method for supplying a thrust chamber of a rocket engine in a first and second propellant.