Inertial electrostatically confined air-breathing electric thruster

Abstract

The application provides an inertial electrostatic confinement air-breathing electric thruster, which is characterized by comprising an anode grid, a cathode grid, a grid fixing part, a shell, a transmission group and a gas distributor; the anode grid and the cathode grid are connected together through the grid fixing part; the shell is composed of a shell front end, a shell rear end and a thruster fixing part, and the thruster is closed by the shell and fixed on a satellite through the thruster fixing part; the transmission group is an opening structure of the thruster shell, and is controlled by a motor; when air is needed, the motor drives two connecting rods to open the thruster shell; when gas is needed, the shell is closed; and the gas distributor uniformly transports the input gas into the thruster. The application increases the working mode of the inertial electrostatic confinement thruster, and makes the thruster better applied to low-orbit satellites, and increases the use range and working life of the thruster.

Description

Technical Field

[0001] This invention belongs to the field of aerospace electric propulsion technology and relates to an inertial electrostatic confinement air-breathing electric thruster. Background Technology

[0002] Orbital satellites play a crucial role in observation, communication, positioning, and the Internet of Things. Low Earth orbit (LEO) satellites, due to their closer proximity to the Earth, offer higher resolution in optical observations, are simpler to manufacture, and are more effective at detecting weak targets and achieving refined identification during microwave or electronic observations, making them highly valuable. Therefore, many countries, including the United States and Japan, are researching LEO and VLEO satellites. However, because the atmosphere remains in LEO (below 300 km), air damping is significant, causing rapid orbital altitude decay and shorter satellite lifespans. Therefore, researching suitable propulsion systems for LEO satellites to help maintain orbit is crucial for extending satellite lifespan and facilitating better observation activities. Electric propulsion, with its high specific impulse, high control precision, small size, and low mass, is a suitable solution, and much related research has been conducted both domestically and internationally. At higher altitudes, where atmospheric pressure is lower than that of inertial electrostatic confinement thrusters, a gas collection device can be used to collect and pressurize atmospheric air to supply the thruster, providing a preliminary solution for LEO satellite propulsion. Inertial electrostatic confinement thrusters are also suitable for deep space propulsion, meeting the requirements of high efficiency and long lifespan in deep space propulsion. Since there is no atmospheric environment in deep space propulsion, they can carry tanks to provide the required working gas to the thruster.

[0003] Electric propulsion is a propulsion method that generates thrust by ionizing a propellant and then accelerating the ejected propellant. It was first proposed by an American scientist in 1906 and has since made great progress through research by researchers from various countries. It has advantages such as high specific impulse, high efficiency, high control precision, and long lifespan. It can be applied to many fields where traditional propulsion methods cannot meet the requirements, such as near-space propulsion and deep space propulsion, and has great development prospects. Today, the theory and application of electric propulsion are relatively mature, but it still faces problems such as low ionization rate and cathode ablation loss.

[0004] Inertial electrostatic confinement thrusters (IGFTs) are applications of inertial electrostatic confinement devices, originally used in nuclear fusion, to space propulsion systems. They offer advantages such as simple structure, ablation resistance, no hollow cathode, and long lifespan. The concept of IGFTs was proposed in 1993 by George H. Miley of the University of Illinois at Urbana-Champaign. The device has a simple structure, typically spherical. During operation, the anode grid is grounded, and the cathode grid is connected to a voltage of several hundred to several thousand negative volts. The device is filled with a working gas. The primary discharge mechanism is glow discharge between the cathode and anode. Ions generated by the weak spontaneous ionization of the gas are accelerated towards the cathode under the influence of the electric field. Because the cathode grid has a high ion throughput, high-energy ions can pass through it, bombarding more neutral particles and triggering secondary electron emission. Cations decelerate and accumulate at the center of the cathode grid, forming a virtual anode. Secondary electrons are confined inside the cathode grid, continuously discharging and forming a stable plasma.

[0005] Inertial electrostatic confinement thrusters can be used for both low Earth orbit (LEO) spacecraft and deep space propulsion, thus allowing for the design of a thruster suitable for both space environments. The LEO thruster described in CN 116101516 A has an air supply device that meets the thruster's operational requirements. However, since LEO thrusters can also operate under atmospheric pressure in LEO, using the thruster described in CN 116101516A would prevent the use of air as propellant in LEO, leading to continued consumption of propellant in the tanks and reducing the thruster's operational lifespan. Summary of the Invention

[0006] This invention provides an inertial electrostatic confinement air-breathing electric thruster, comprising an anode grid (1), a cathode grid (2), a grid fixing component (3), a housing (4), a transmission assembly (5), and a gas distributor (6).

[0007] The anode grid (1) and cathode grid (2) are spherical mesh structures, but not centrally symmetrical. One end of the grid is enlarged into a circle to form a channel for ion ejection. During installation, the circular channels of the two grids are installed on the same side, and the grids are made of conductive metal materials.

[0008] The grid fixing component (3) is a fixing structure used to fix the anode grid (1) and the cathode grid (2). It has two identical fixing components (3-1) and (3-2), which fit together during installation. The two grid fixing components are cylindrical with longitudinal sections and grooves installed at the connection points of the two grids. When fixing the grids, the grooves are inserted into the grids for fixation. The fixing components are made of insulating plastic material and must have sufficient strength to support the grid structure.

[0009] The outer casing (4) consists of a front end (4-1), a rear end (4-2), and a thruster mounting component (4-3). Its basic function is to enclose the thruster and secure it to the satellite via the thruster mounting assembly. The front end (4-1) and rear end (4-2) are semi-circular shells; when combined, the grid can be fitted inside. Bolt holes are provided at the connection point of the two shells for easy fixing. The front end also has four openable and closable "windows" controlled by a motor. One end of the thruster mounting component (4-3) is a groove that fits into the anode grid, while the other end is a hole for connecting the thruster to the satellite. During installation, one end of the thruster mounting component connects to the anode grid, and the other end passes through the outer casing and connects to the satellite via the connecting hole. The outer casing is made of quartz material.

[0010] The transmission assembly (5) consists of a motor and a connecting rod. The connecting rod connects the motor and the closable window of the thruster housing, and its basic function is to control the opening and closing of the housing.

[0011] The gas distributor (6) has a gas inlet and multiple gas outlets. The gas outlets are located inside the thruster housing and are arranged in a ring, which can evenly transport the incoming gas into the thruster housing.

[0012] The anode grid and the cathode grid are connected together by a grid fixing component, which consists of two identical structures, one part of which is connected to the cathode grid and the other part of which is connected to the anode grid, and they are fixed by a fitting structure.

[0013] The cathode grid must have an ion throughput greater than 90% to prevent ions from colliding with the grid and reducing the thruster's power. Except for the enlarged mesh at the thruster tail, the other mesh openings must be symmetrically distributed; otherwise, beam leakage will occur because the plasma sheath cannot confine the ions. The cathode grid radius is 15% to 50% of the anode grid radius, and the anode is grounded while the cathode is connected to a voltage of several hundred to several thousand negative volts.

[0014] The anode grid and the housing are connected together by a thruster fixture. The thruster fixture consists of two identical structures that can be fitted together with the anode grid. The thruster fixture also has connecting holes to facilitate the fixing of the thruster.

[0015] The transmission assembly is the opening structure of the thruster housing. It is controlled by a motor. When air intake is needed, the motor drives two connecting rods to open the thruster housing, and when air supply is needed, the housing is closed.

[0016] The beneficial effects of this invention compared to the prior art are as follows:

[0017] This invention adds an inertial electrostatic confinement thruster operating mode, enabling the thruster to be better applied to low-Earth orbit satellites and increasing the thruster's application range and service life. Attached Figure Description

[0018] Figure 1 This is an overall view of an inertial electrostatic confinement air-breathing electric thruster.

[0019] Figure 2 This is a schematic diagram of the assembly of cathode grid, anode grid, and grid fixing components.

[0020] Figure 3 This is a schematic diagram of the anode grid-shell assembly.

[0021] The labels in the diagram are explained as follows:

[0022] 1: Anode grid; 2: Cathode grid; 3: Grid fixing component

[0023] 4: Outer casing; 5: Transmission assembly; 6: Gas distributor

[0024] 3-1: Fixing component 3-2: Fixing component

[0025] 4-1: Front end of the outer casing 4-2: Rear end of the outer casing 4-3: Thruster mounting component Detailed Implementation

[0026] The thruster body uses a 200mm diameter anode grid and a 98mm diameter cathode grid, made of aluminum. A grid fastener is used to secure the cathode and anode grids together, with one end connected to the cathode grid and the other to the anode grid. The two parts of the fastener are ultimately fitted together, with a total length of 64mm. The thruster fastener is then installed on the anode grid, similarly, with one end connected to the anode grid and the perforated end facing outwards. A jet nozzle is located at the rear of the housing; during installation, the jet nozzles of the housing and grid are aligned. The gas distributor is installed at the front of the housing. The transmission assembly is mounted on the housing, with the end of the connecting rod connected to a movable part of the housing, controlling its opening and closing. A 5KV voltage is applied between the anode and cathode grids. When the thruster is in a low orbit (below 300km, air pressure at 0.01Pa), the outer casing opens, and air enters through the open casing. At this time, the gas distributor does not work. When the thruster is in a higher orbit (above 300km, below 0.01Pa), the thruster jet in the intake state gradually disappears. At this time, the thruster casing closes, and the thruster actively supplies gas from the gas distributor to the thruster.

[0027] The thruster grid is made of aluminum alloy, but other metal materials such as stainless steel can also be used, depending on the manufacturing and processing requirements.

[0028] The thruster housing is made of plastic, but other non-conductive materials may also be used.

[0029] The diameter of the anode grid is 200mm, which can be adjusted according to actual size requirements, but the radius of the cathode grid must be 15% to 50% of the radius of the anode grid.

[0030] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An inertial electrostatic confinement air-breathing electric thruster, characterized in that: It consists of an anode grid (1), a cathode grid (2), a grid fixing component (3), a housing (4), a transmission assembly (5), and a gas distributor (6); wherein, the anode grid and the cathode grid are connected together by the grid fixing component; the housing (4) consists of a front end (4-1), a rear end (4-2), and a thruster fixing component (4-3), which encloses the thruster and fixes the thruster to the satellite through the thruster fixing assembly; the transmission assembly is the opening structure of the thruster housing, which is controlled by a motor. When air intake is required, the motor drives two connecting rods to open the thruster housing, and when air supply is required, the housing is closed; the gas distributor (6) evenly transports the introduced gas into the thruster; The front end (4-1) and rear end (4-2) of the outer shell are semi-circular shells, which are combined to fit the grid. Bolt holes are provided at the connection between the two shells to facilitate fixing the shells together. The front end of the shell also has four openable and closable skylights, which are controlled by a motor. The gas distributor (6) has a gas inlet and multiple gas outlets, which are located inside the thruster housing and are arranged in a ring.

2. The inertial electrostatic confinement air-breathing electric thruster according to claim 1, characterized in that: The anode grid (1) and cathode grid (2) are spherical mesh grid structures, but they are not centrally symmetrical. One end of the grid is enlarged into a circle to form a channel for easy ion ejection. During installation, the circular channels of the two grids are installed on the same side.

3. The inertial electrostatic confinement air-breathing electric thruster according to claim 1, characterized in that: The grid fixing component (3) is a fixing structure used to fix the anode grid (1) and the cathode grid (2). It has two identical fixing components, and the two parts are fitted together during installation. The two grid fixing components are cylindrical longitudinal sections with grooves installed at the connection of the two grids. When fixing the grid, the grooves are embedded into the grid for fixing.

4. An inertial electrostatic confinement air-breathing electric thruster according to claim 1, characterized in that: One end of the thruster mounting (4-3) is a groove that fits into the anode grid, and the other end is a hole for connecting the thruster to the satellite. During installation, one end of the thruster mounting is connected to the anode grid, and the other end passes through the housing and is connected to the satellite through the connection hole. The housing is made of quartz material.

5. An inertial electrostatic confinement air-breathing electric thruster according to claim 1 or 2, characterized in that: The ion throughput of the cathode grid is greater than 90%; except for the enlarged mesh at the tail of the thruster, the other mesh openings must be symmetrically distributed; the radius of the cathode grid is 15% to 50% of the radius of the anode grid, and the anode is grounded while the cathode is connected to a negative voltage.

6. An inertial electrostatic confinement air-breathing electric thruster according to claim 1 or 2, characterized in that: The anode grid (1) and the cathode grid (2) are made of conductive metal materials.

7. An inertial electrostatic confinement air-breathing electric thruster according to claim 1 or 3, characterized in that: The material used for the fence fasteners is an insulating plastic material.

8. An inertial electrostatic confinement air-breathing electric thruster according to claim 1, characterized in that: The thruster housing is made of plastic or other non-conductive materials.

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