Multi-mode propulsion system

A multimode propulsion system, comprising:

• at least one propellant ejector system for ejecting a first propellant, each comprising:
• a high speed fluid ejection nozzle coupled to a propellant supply, and
• a propellant-air mixing system comprising at least one fluid intake member having an inlet end and an outlet end, the inlet end being in fluidic communication with the fluid ejection nozzle to receive the first propellant ejected from the nozzle,
• the propellant-air mixing system being convertible between a closed position and an open position, wherein in the open position the inlet entrains air to be mixed with the propellant to form a propellant-air mixture and in the closed position the air entrainment is blocked,
• wherein the first propellant is an oxidizer and/or a fuel;
• wherein the at least one fluid intake member comprises a plurality of concentric fluid intake ducts, arranged in series, each intake duct having an inlet and an outlet, wherein the inlet of each intake duct has a cross sectional area greater than a cross sectional area of the outlet of a preceding intake duct, thereby providing an annular gap between adjacent intake ducts, and inlets of one or more of said intake ducts are convertible between an open and closed positions;
• at least one combustor positioned downstream of the at least one propellant ejector system for combusting a fuel, said combustor having an inlet portion in fluidic communication with the outlet end of the propellant-air mixing system for receiving the first propellant ejected by the propellant ejector system, and an outlet portion to exhaust combustion products, the combustor further being connected to an ignition source;
• optionally, at least one propellant injector positioned downstream of the propellant ejector system for injecting a second propellant into the combustor, wherein the second propellant is a fuel and/or an oxidizer;
• and
• an exhaust nozzle downstream of the outlet portion of the combustor,
• wherein the fuel for combustion in the combustor is a solid fuel provided in the combustor, a fuel injected from the at least one propellant injector, and/or a fuel ejected from the propellant ejector system.