Bi-modal propulsion systems and related methods are generally described. In some embodiments, a bi-modal propulsion system may employ a single propellant for both chemical thruster(s), operating at elevated pressures, and electrical thruster(s) (e.g., electro spray thruster), operating at reduced pressures. The propellant pressure may be reduced to a desired operational range of the electrical thruster(s) using any appropriate construction including, for example, capillaries configured to reduce the pressure of the propellant to an operational range of the electrical thruster(s). In some embodiments, the reduced pressure of the propellant may be lower than a vapor pressure of at least one volatile component of the propellant, leading to the formation of bubbles within the propellant line. The presence of alternating gas and liquid phases along a flow path between a propellant tank and the electrical thruster(s) may help to electrically insulate the electrical thruster from the rest of the system.

A dual mode engine for propelling a spacecraft, including a combustion chamber having a flange end, an open nozzle end, and an enclosed chamber portion extending therebetween, a propellant tank in fluidic communication with the combustion chamber, an electronic controller, a power source operationally connected to the electronic controller, and a fluid flow motivator operationally connected to the electronic controller and connected in fluidic communication with the propellant tank. The engine further includes a chemical propulsion portion further including a propellant inlet port operationally connected to the combustion chamber and disposed adjacent the flange end, an ignition trigger electrode positioned in the combustion chamber adjacent the propellant inlet port and operationally connected to the electronic controller and operationally connected to the power source, wherein the propellant inlet port is fluidically connected to the propellant tank. The engine also includes an electric propulsion portion, further including at least two spaced electrodes for ionizing the propellant positioned in the combustion chamber adjacent the nozzle end, a plurality of attitude control thrusters operationally connected to the electronic controller and in fluidic communication with the propellant tank, and a plurality of respective valves, each respective valve fluidically connected between a respective attitude control thruster and the propellant tank, wherein the propellant inlet port is fluidically connected to the propellant tank.

A spacecraft propulsion system includes at least one chemical thruster operable with a liquid propellant, at least one electric thruster operable with an inert gas, and a first quantity n of pressurant tanks, each of the n pressurant tanks having a substantially identical volume. The propulsion system results from assembling a plurality of subassemblies, such that a first selectable number e of the first quantity of pressurant tanks are manifolded together with the at least one electric thruster, and a second selectable number c of the first quantity of pressurant tanks are manifolded together with the at least one chemical thruster. The first selectable number e is an integer in the inclusive range of 1 to n, and c=n?e.

A vehicle for supersonic or hypersonic flight comprises a thermal rocket engine (1b) with a nozzle (2) and an active cooling system (8). The active cooling system cools a heat shield (6, 7). A working fluid absorbs heat inside the active cooling system and the heated working fluid expands through the nozzle to create thrust. Such a vehicle is suitable to fly a multi-skip trajectory, a boost-glide trajectory, a trajectory with a cruise phase or a re-entry into an atmosphere, for example.

A dual mode engine for propelling a spacecraft, including a combustion chamber having a flange end, an open nozzle end, and an enclosed chamber portion extending therebetween, a propellant tank in fluidic communication with the combustion chamber, an electronic controller, a power source operationally connected to the electronic controller, and a fluid flow motivator operationally connected to the electronic controller and connected in fluidic communication with the propellant tank. The engine further includes a chemical propulsion portion further including a propellant inlet port operationally connected to the combustion chamber and disposed adjacent the flange end, an ignition trigger electrode positioned in the combustion chamber adjacent the propellant inlet port and operationally connected to the electronic controller and operationally connected to the power source, wherein the propellant inlet port is fluidically connected to the propellant tank. The engine also includes an electric propulsion portion, further including at least two spaced electrodes for ionizing the propellant positioned in the combustion chamber adjacent the nozzle end, a plurality of attitude control thrusters operationally connected to the electronic controller and in fluidic communication with the propellant tank, and a plurality of respective valves, each respective valve fluidically connected between a respective attitude control thruster and the propellant tank, wherein the propellant inlet port is fluidically connected to the propellant tank.

Method and apparatus for controlling pressure in a pressure vessel. A plurality of valves between a pressure source and a pressure vessel can be selectively opened or turned off, singularly or in combinations, to control pressure in the pressure vessel. A maximum pressure threshold and a minimum pressure threshold can be established based on operating considerations of the pressure vessel. One or more of the valves can be turned on when the pressure in the pressure vessel reaches the minimum pressure threshold. One or more of the valves can be turned off when the pressure in the pressure vessel reaches the maximum pressure threshold.

Method and apparatus for controlling pressure in a pressure vessel. A plurality of valves between a pressure source and a pressure vessel can be selectively opened or turned off, singularly or in combinations, to control pressure in the pressure vessel. A maximum pressure threshold and a minimum pressure threshold can be established based on operating considerations of the pressure vessel. One or more of the valves can be turned on when the pressure in the pressure vessel reaches the minimum pressure threshold. One or more of the valves can be turned off when the pressure in the pressure vessel reaches the maximum pressure threshold.

A vehicle for supersonic or hypersonic flight comprises a thermal rocket engine (1b) with a nozzle (2) and an active cooling system (8). The active cooling system cools a heat shield (6, 7). A working fluid absorbs heat inside the active cooling system and the heated working fluid expands through the nozzle to create thrust. Such a vehicle is suitable to fly a multi-skip trajectory, a boost-glide trajectory, a trajectory with a cruise phase or a re-entry into an atmosphere, for example.

A debris removal satellite includes a capture device, a thruster of a chemical propulsion method, and a propellant tank to store chemical fuel. A solar array wing is operable in an orbit at an orbital altitude higher than a congested orbit region congested with satellites forming a satellite constellation. The debris removal satellite is built in advance for future use as a satellite to be launched, and when a debris intrusion alarm to give a warning about intrusion of debris into the congested orbit region is issued, propellant is loaded into the propellant tank and the debris removal satellite is launched by a rocket built in advance for future use as a launch rocket. The debris removal satellite captures capture-target debris at an orbital altitude higher than the congested orbit region, and operates a propulsion device with the capture-target debris being captured.

A debris removal satellite includes a capture device, a thruster of a chemical propulsion method, and a propellant tank to store chemical fuel. A solar array wing is operable in an orbit at an orbital altitude higher than a congested orbit region congested with satellites forming a satellite constellation. The debris removal satellite is built in advance for future use as a satellite to be launched, and when a debris intrusion alarm to give a warning about intrusion of debris into the congested orbit region is issued, propellant is loaded into the propellant tank and the debris removal satellite is launched by a rocket built in advance for future use as a launch rocket. The debris removal satellite captures capture-target debris at an orbital altitude higher than the congested orbit region, and operates a propulsion device with the capture-target debris being captured.