A satellite platform compatible with ion and Hall electric propulsion configurations

Abstract

The present invention discloses a satellite platform compatible with ion and Hall electric propulsion configurations, wherein the electric propulsion subsystem mainly includes two thruster modules, a tank supply module and a power supply module. The electric propulsion system of the present invention can use ion and Hall full configurations to complete satellite orbit change and the north-south position keeping, east-west position keeping and angular momentum unloading tasks of the satellite during orbit, and can also use ions or Hall alone to complete the above tasks. When ion or Hall electric propulsion is configured alone, the unconfigured functional modules can be directly removed, and the layout of other instruments and equipment on the platform does not need to be adjusted. The maximum envelope of the platform is compatible with the 4200C fairing, and the equipment sensitive to the electric propulsion plume (such as optical sensors, solar wings, etc.) is all outside the plume field. The ion electric propulsion has a high specific impulse and low working fluid consumption, and the Hall electric propulsion has a large thrust and a short orbit change time. The platform configuration based on the layout scheme is flexible, has a strong mission adaptability, and simplifies the technical status control of the platform.

Description

Technical Field

[0001] The invention relates to a satellite platform compatible with ion and Hall electric propulsion configurations, and belongs to the technical field of spacecraft design. Background Art

[0002] Electric propulsion is a propulsion technology that uses electrical energy to convert into kinetic energy for spacecraft. Compared with chemical propulsion technology, the specific impulse of electric propulsion systems is significantly improved, which can significantly reduce the amount of propellant used in spacecraft, and bring benefits including reducing the launch weight of spacecraft, improving the payload capacity of spacecraft, extending the working life of spacecraft, and increasing the flight distance of spacecraft, significantly improving the all-round capabilities of spacecraft.

[0003] Taking the initial mass of a satellite of 2000kg as an example, the propellant consumption during the 15-year life span can be saved by about 190kg to 340kg after the use of electric propulsion; and when the initial mass of a satellite is 4000kg, the propellant consumption during the 15-year life span can be saved by about 500kg to 770kg after the use of electric propulsion. The saved weight of the satellite can carry more payloads, improving the economic benefits of the satellite, or low-weight satellites can save more launch costs and reduce the cost of satellite launches.

[0004] At present, the mainstream geosynchronous orbit public satellite platforms in service abroad, such as Boeing's BSS-702 platform, Maxar's LS-1300 platform, Lockheed Martin's LM2100 platform, Europe's TAS's SpaceBus Neo platform, and Airbus Defense and Space's Eurostar Neo platform, have all adopted electric propulsion systems.

[0005] The most widely used in orbit at present are ion electric propulsion systems and Hall electric propulsion systems. Hall thrusters have a relatively simple structure, small size, lower specific impulse than ion thrusters, and require a larger amount of propellant, but have greater thrust and shorter orbit change time; ion thrusters have a relatively complex structure, large size, higher specific impulse than Hall thrusters, require a smaller amount of propellant, but have lower thrust and longer orbit change time.

[0006] The interface between the electric propulsion system and the spacecraft is complex. Currently, foreign satellite platforms are designed for specific types of electric propulsion systems. In order to improve the market competitiveness of satellite platforms, compatibility design can be carried out to make the platform compatible with full or optional ion and Hall electric propulsion configurations. The configuration is determined according to project requirements. This can greatly improve the flexibility of platform applications, achieve the optimal configuration for different tasks, and greatly enhance the comprehensive competitiveness of satellite platforms. Summary of the invention

[0007] The technical problem solved by the present invention is: to overcome the insufficiency of the adaptability of the electric propulsion mission of the existing platform, and to propose a satellite platform compatible with ion and Hall electric propulsion configurations. Under any configuration, the satellite can complete the orbit change and the north-south position keeping, east-west position keeping and angular momentum unloading tasks while the satellite is in orbit. When the ion or Hall electric propulsion is configured separately, the unconfigured functional modules can be directly removed, and the layout of other instruments and equipment of the platform does not need to be adjusted, which greatly improves the mission adaptability of the platform and simplifies the technical status control of the platform.

[0008] The technical solution of the present invention is: a satellite platform structure compatible with ion and Hall electric propulsion configurations, wherein the electric propulsion system is installed on the satellite body, mainly including a thruster module, a tank supply module, and a power module. The satellite body includes a back floor, a carrier docking frame, a satellite cabin, and a satellite partition, and is characterized in that:

[0009] Each thruster module includes a deployable thrust vector adjustment mechanism, an ion thruster and / or a Hall thruster, and the ion thruster and / or the Hall thruster are mounted on the outer surface of the back floor through the deployable thrust vector adjustment mechanism; there are two thruster modules, and their mounting positions are symmetrical about the normal center of the back floor passing through the center point;

[0010] The tank supply module includes a gas cylinder, a pressure regulating module, and a flow control module, which are used to provide propellant to the thruster module and control the thruster flow;

[0011] The power module is used to supply power to the thruster module.

[0012] Furthermore, the deployable thrust vector adjustment mechanism provides two side-by-side installation positions for the thrusters, the inner installation position is for installing a larger ion thruster, and the outer installation position is for installing a smaller Hall thruster. The outer installation structure is designed to be removable. When only the ion thruster is configured, the outer installation structure is removed; when only the Hall thruster is configured, the Hall thruster is connected to the inner installation structure using a Hall adapter bracket, and the outer installation structure is removed at the same time.

[0013] Furthermore, in the tank supply module, the gas cylinders are one or two pairs, and the gas cylinders are completely identical. Each pair of gas cylinders is installed on the inner surface of the back floor, just above the transport docking frame, and is symmetrical about the axis center of the transport docking frame.

[0014] Furthermore, the bottom of the gas cylinder is installed just above the transport docking frame, and the mounting screws are directly passed through the back floor to connect with the transport docking frame.

[0015] Furthermore, in the tank supply module, there is one pressure regulating module, which is installed on the satellite partition.

[0016] Furthermore, in the tank supply module, the flow control module includes two groups of ion flow control modules and / or two groups of Hall flow control modules, wherein every two groups of ion flow control modules or every two groups of Hall flow control modules are symmetrically installed on the east and west sides of the back floor, and each group of ion flow control modules or Hall flow control modules is used to perform flow control on the ion thrusters or Hall thrusters on the same side.

[0017] Furthermore, the power supply module includes two ion power supply modules and / or two Hall power supply modules, and the power supply modules are centrally installed in the satellite cabin to supply power to the ion thrusters and / or Hall thrusters.

[0018] Furthermore, the gas cylinder is a xenon gas cylinder.

[0019] The electric propulsion system of the present invention can use ion and Hall full configuration to complete satellite orbit change and north-south position maintenance, east-west position maintenance and angular momentum unloading tasks during the satellite's on-orbit period. It can also use ions or Hall alone to complete the above tasks. When ion or Hall electric propulsion is configured alone, the unconfigured functional modules can be directly removed, and the layout of other instruments and equipment on the platform does not need to be adjusted. The maximum envelope of the platform is compatible with the 4200C fairing, and equipment sensitive to the electric propulsion plume (such as optical sensors, solar wings, etc.) is all outside the plume field. The ion electric propulsion has a high specific impulse and the Hall electric propulsion has a small size. The platform configuration based on this layout scheme is flexible, has a strong mission adaptability, and simplifies the technical status control of the platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the thruster module layout (full configuration);

[0021] Figure 2 This is a schematic diagram of the thruster module layout (single ion);

[0022] Figure 3 This is a schematic diagram of the thruster module layout (single Hall);

[0023] Figure 4 This is a schematic diagram of the xenon cylinder layout;

[0024] Figure 5 This is a schematic diagram of the xenon cylinder and flow control submodule layout (full configuration);

[0025] Figure 6 This is a schematic diagram of the xenon gas bottle and flow control submodule layout (single ion);

[0026] Figure 7 This is a schematic diagram of the xenon cylinder and flow control submodule layout (single Hall);

[0027] Figure 8 This is a schematic diagram of the layout of the power module and the pressure regulation module (when fully configured); DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0029] The instruments and equipment of the electric propulsion system can be divided into the following three functional modules according to the functions they realize: thruster module: composed of a deployable thrust vector adjustment mechanism 1, an ion thruster 2 and (or) a Hall thruster 3, wherein the deployable thrust vector adjustment mechanism 1 is used to realize the functions of thruster installation and fixation, thrust direction adjustment, etc.; tank supply module: realizes the storage, pressure regulation and flow control functions of electric propulsion working fluid; power supply module: converts the input electrical energy into various voltages and currents required for the operation of the thruster.

[0030] The following aspects need to be considered comprehensively when laying out the functional modules of the electric propulsion system:

[0031] The overall efficiency of the electric thruster is as high as possible, thereby reducing the working fluid demand during the on-orbit period and reducing the volume and weight of the storage and supply module;

[0032] The interference force and interference torque of the electric thruster are as small as possible to ensure that the attitude control accuracy of the satellite during the electric propulsion operation meets the index requirements;

[0033] Avoid adverse effects of electric thruster plumes on optically sensitive equipment, solar panels and other off-satellite equipment, or reduce their effects to an acceptable range during the satellite's lifespan;

[0034] Avoid adverse effects of heat flow from the electric thruster on surrounding components during operation, or reduce the effects to an acceptable range;

[0035] When laying out the storage and supply modules, the change in the satellite's center of mass caused by the consumption of electric propulsion fluid during the satellite's in-orbit period should be minimized to avoid causing difficulties in the satellite's attitude control and increasing additional fluid consumption;

[0036] The weight of the working fluid container in a full state is tens to hundreds of kilograms, and the installation location must have good strength and rigidity;

[0037] Ensure that the layout of the electric propulsion system is compatible with the available envelope of the launch fairing;

[0038] As a variable configuration of the platform, the layout of each module of the electric propulsion system must be comprehensively considered to ensure that when the configuration changes, the layout of other instruments and equipment of the platform can remain unchanged, the center of mass position of the platform is stable, and the center of mass position does not deviate greatly due to changes in equipment.

[0039] Among the above three functional modules, the thruster module has the greatest impact on the platform layout. The main reasons are as follows: the layout of the thruster module determines the on-orbit application strategy of the electric propulsion system, and then determines the selection of solar panels (related to power requirements), the configuration of the control subsystem (related to application strategy) and the layout of sensors (avoiding thruster plumes); the layout of the thruster module determines the working efficiency of the electric propulsion system, and then determines the working fluid consumption during the service life and the size of the working fluid storage container (gas cylinder or tank); the layout of the thruster module determines the structural design and material selection of related parts (related to the stiffness and strength of the platform structure); the layout of the thruster module is related to the compatibility with the launch envelope (related to the available space of the fairing).

[0040] Based on the above reasons, when designing the layout of the electric propulsion system, the layout of the thruster module should be determined first, and then the layout of the remaining three functional modules of the electric propulsion system should be carried out.

[0041] (1) Layout of thruster modules

[0042] Each thruster module includes a deployable thrust vector adjustment mechanism 1, an ion thruster 2 and (or) a Hall thruster 3. The ion thruster 2 and (or) the Hall thruster 3 are installed on the outer surface of the satellite back floor 10 through the deployable thrust vector adjustment mechanism 1. The installation positions of the two thruster modules are symmetrical about the Z axis center of the satellite mechanical coordinate system.

[0043] The function of the deployable vector adjustment mechanism is to adjust the thrust direction of the electric thruster. It is deployed after entering orbit. During the orbit change process, the thrust vector is always pointed in the -Z direction of the satellite to ensure that there is no loss in the angular efficiency of the thrust vector. During the position maintenance process, the thrust vector always passes through the center of mass of the satellite, thereby reducing the interference force and interference torque during the operation of electric propulsion.

[0044] The deployable thrust vector adjustment mechanism 1 provides two side-by-side installation positions for the electric thruster, the inner installation position is installed with a larger ion thruster 2, and the outer installation position is installed with a smaller Hall thruster 3. The outer installation structure is designed to be detachable. When only the ion thruster 2 is configured, the outer installation structure is removed; when only the Hall thruster 3 is configured, the Hall thruster 3 is connected to the inner installation structure using a Hall adapter bracket 5, and the outer installation structure is removed at the same time.

[0045] This layout makes the installation, adjustment and testing of the thruster module extremely convenient, and the platform's outer envelope is compatible with the carried 4200C fairing. When working, all optically sensitive equipment and solar wings are outside the main plume beam of the thruster.

[0046] When fully configured, the layout of the thruster module is shown in Figure 1 ;

[0047] When ion electric propulsion is configured alone, the layout of the thruster module is shown in Figure 2 ;

[0048] When Hall electric propulsion is configured alone, the layout of the thruster module is shown in Figure 3 ;

[0049] (2) Layout of tank supply modules

[0050] In the present invention, the tank supply module is composed of a gas cylinder (working fluid container), a pressure regulating module 16, a flow control module and related pipelines and cables. In the embodiment, the gas cylinder is a xenon gas cylinder.

[0051] In order to improve the structural strength and rigidity of the installation position of the electric thruster module, and at the same time ensure that the change in the satellite's center of mass caused by the consumption of electric propulsion fluid while the satellite is in orbit is as small as possible, and to leave enough space for the installation of instruments and equipment on the satellite's south plate 7 and north plate 8, four xenon cylinders 13 are symmetrically installed at the four corners of the back floor 10, directly above the carrier docking frame 4, and 300 mm away from the south plate 7 and the north plate 8. The symmetrical arrangement of the four xenon cylinders 13 ensures that the consumption of electric propulsion fluid will not cause changes in the satellite's lateral center of mass. At the same time, the 300 mm space can cover the height of the equipment and leave enough operating space, which is convenient for the assembly operation of the instruments on the south plate 7 and the north plate 8 after the xenon cylinders 13 are installed.

[0052] The bottom of the xenon bottle 13 is installed just above the carrier docking frame 4, and the mounting screws are directly connected to the carrier docking frame 4 through the back floor 10. On the one hand, the center of mass of the satellite is lowered, and on the other hand, the force transmission path of the xenon bottle 13 is shortened, making the structural design lighter. The top of the xenon bottle 13 is connected to the south plate 7 and the north plate 8, the north and south partitions 9 and the east and west plates 6 through the bottle bracket 17. The layout position of the xenon bottle 13 on the back floor 10 is shown in FIG. Figure 4 .

[0053] When ion electric propulsion is configured alone, because of the high specific impulse and small amount of working fluid, only two xenon cylinders 13 are needed to meet the requirements. At this time, the two xenon cylinders 13 on the diagonal are not configured, and the configuration change of the xenon cylinders 13 will not cause the change of the satellite's lateral center of mass.

[0054] The function of the flow control submodule is to provide the required flow of working fluid for various working modes of the electric thruster. In the present invention, two groups of ion flow control modules 11 and two groups of Hall flow control modules 12 are symmetrically installed on the east and west sides of the satellite back floor 10. The flow control submodules are completely symmetrical in the platform layout position, thereby ensuring that the lateral center of mass of the entire satellite is basically unchanged in the single ion or single Hall state.

[0055] When fully configured, the layout of the xenon cylinder 13 and the flow control submodule back floor 10 is shown in Figure 5 .

[0056] When ion electric propulsion is configured alone, the layout of the xenon bottle 13 and the back floor 10 of the flow control submodule is shown in FIG. Figure 6 .

[0057] When Hall electric propulsion is configured alone, the layout of the xenon cylinder 13 and the back floor 10 of the flow control submodule is shown in FIG. Figure 7 .

[0058] The pressure regulating module 16 is mainly composed of a pressure reducing gas cylinder, a regulating valve and related pipelines (such as the electric propulsion pipeline 18). Its function is to adjust the high-pressure working medium in the gas cylinder to the pressure required for the normal operation of the flow control submodule. The pressure regulating submodule is relatively large in size. In the present invention, it is installed on the north and south partitions 9 of the satellite. The specific layout is shown in Figure 8 .

[0059] (3) Layout of power modules

[0060] In the present invention, the power module includes two ion power modules 14 and (or) two Hall power modules 15. The four power modules are centrally installed in the satellite cabin. Each power module supplies power to the ion thruster 2 and (or) Hall thruster 3 on the same side. The specific installation position of the power unit depends on the heat consumption of the power unit and the required heat dissipation area when the electric propulsion system is working. In the present invention, the electric propulsion power unit is installed on the south plate 7, such as Figure 8 When ion propulsion or Hall electric propulsion is configured separately, the power supply is configured accordingly.

[0061] Taking a medium-capacity geosynchronous orbit satellite platform under development in China as an example, the implementation mode and implementation effect of the present invention are described:

[0062] The platform can adopt an ion electric propulsion system based on an ion thruster with a diameter of about 30 cm, a thrust of 160 mN, and a specific impulse of 3500, or a Hall electric propulsion system based on a Hall thruster with a diameter of about 15 cm, a thrust of 265 mN, and a specific impulse of 1650.

[0063] Assume that the satellite launch mass m based on this platform is 2100kg, the average value of the Z-axis center of mass height in the middle of its life is about 1300mm, and for simplicity, assume that the lateral (X and Y-axis) center of mass coordinates are both 0mm. The orbit change efficiencies of Hall thrusters and ion thrusters are both 0.99, and the thrust vectors of Hall thrusters and ion thrusters (in the satellite YOZ plane and passing through the center of mass) are 50° and 45° with the Y-axis respectively. The working efficiency η of the north-south position maintenance is about 0.65 and 0.70 respectively.

[0064] The track change speed increment is 2600m / s.

[0065] The total velocity increment during the satellite position maintenance period of 15 years is 770m / s.

[0066] When using ion electric propulsion:

[0067] The total propellant consumption and orbit change time during the orbit change are:

[0068] m p =m·(1-e -Δv / Igη )=2100×(1-exp(-2600 / 3500 / 9.8 / 0.99))≈155kg.

[0069] Δt=Δm / (F p / I / g) = 155 / (0.16*2 / 3500 / 9.8) = 192 days

[0070] The total propellant consumption during the 15-year station-keeping life is:

[0071] m p =m·(1-e -Δv / Igη )=(2100-155)×(1-exp(-770 / 3500 / 9.8 / 0.70))≈61kg.

[0072] When using Hall electric propulsion:

[0073] The total propellant consumption and orbit change time during the orbit change are:

[0074] m p =m·(1-e -Δv / Igη )=2100×(1-exp(-2600 / 1650 / 9.8 / 0.99))≈314kg.

[0075] Δt=Δm / (F p / I / g) = 314 / (0.265*2 / 1650 / 9.8) = 110 days

[0076] The total propellant consumption during the 15-year station-keeping life is:

[0077] m p =m·(1-e -Δv / Igη )=(2100-314)×(1-exp(-770 / 1650 / 9.8 / 0.65))≈126kg.

[0078] In order to meet the 15-year north-south position maintenance requirements, when using ion electric propulsion, the total amount of propellant carried should be 155kg+61kg=216kg, that is, 2 xenon gas bottles of the same size are set, each with a capacity of 120kg, and the orbit change time is: 192 days; when using Hall electric propulsion, the total amount of propellant carried should be 314kg+126kg=440kg, that is, 4 xenon gas bottles of the same size are set, each with a capacity of 120kg. The orbit change time is: 110 days;

[0079] With the same takeoff weight, service life and payload power, when equipped with ion electric propulsion, the payload carrying weight of this medium-capacity geosynchronous orbit satellite platform is 224kg higher than that with Hall electric propulsion, but the orbit change time is 82 days longer; the platform can flexibly select the electric propulsion configuration according to the payload weight and orbit entry time, and the configuration layout design does not need to be adjusted, so it has strong mission adaptability.

[0080] The contents not described in detail in the present invention are well known to those skilled in the art.

Claims

1. A satellite platform compatible with ion and Hall electric propulsion configurations, wherein the electric propulsion system is installed on the satellite body, including a thruster module, a tank supply module, and a power module. The satellite body includes a back floor, a carrier docking frame, a satellite cabin, and a satellite partition, characterized in that: Each of the thruster modules comprises a deployable thrust vector adjustment mechanism, an ion thruster and / or a Hall thruster, and the ion thruster and / or the Hall thruster are mounted on the outer surface of the back floor through the deployable thrust vector adjustment mechanism; there are two thruster modules, and their mounting positions are symmetrical about the normal center passing through the center point of the back floor; The deployable thrust vector adjustment mechanism provides two side-by-side installation positions for the thrusters, the inner installation position is for installing a larger ion thruster, and the outer installation position is for installing a smaller Hall thruster. The outer installation structure is designed to be removable. When only the ion thruster is configured, the outer installation structure is removed. When only the Hall thruster is configured, the Hall thruster is connected to the inner mounting structure using the Hall adapter bracket, and the outer mounting structure is removed at the same time; The tank supply module includes a gas cylinder, a pressure regulating module, and a flow control module, and is used to provide propellant to the thruster module and control the thruster flow; The power supply module is used to supply power to the thruster module.

2. The satellite platform according to claim 1, characterized in that: In the tank supply module, the gas cylinders are one or two pairs, and the gas cylinders are completely identical. Each pair of gas cylinders is installed on the inner surface of the back floor, directly above the transport docking frame, and symmetrically about the axis of the transport docking frame.

3. The satellite platform according to claim 2, characterized in that: The bottom of the gas cylinder is installed just above the transport docking frame, and the mounting screws are directly passed through the back floor to be connected to the transport docking frame.

4. The satellite platform according to claim 1, characterized in that: In the tank supply module, there is one pressure regulating module installed on the satellite partition.

5. The satellite platform according to claim 1, characterized in that: In the tank supply module, the flow control module includes two groups of ion flow control modules and / or two groups of Hall flow control modules, wherein each two groups of ion flow control modules or each two groups of Hall flow control modules are symmetrically installed on the east and west sides of the back floor, and each group of ion flow control modules or Hall flow control modules is used to control the flow of the ion thrusters or Hall thrusters on the same side.

6. The satellite platform according to claim 1, characterized in that: The power supply module includes two ion power supply modules and / or two Hall power supply modules, and the power supply modules are centrally installed in the satellite cabin to supply power to the ion thruster and / or the Hall thruster.

7. The satellite platform according to claim 1, characterized in that: The gas cylinder is a xenon gas cylinder.

Images