Satellite constellation maintenance method, ground equipment, command transmission method, and command transmission program

Abstract

To solve the problem that a succeeding satellite for replenishing missing satellites occurring to random orbital positions of a random orbital plane are desired to put into the orbit by batch launch of many satellites in a satellite constellation maintenance method.SOLUTION: A satellite constellation maintenance method is a method by which a replenishing satellite belonging to a layer whose orbital altitude is one layer lower than a missing layer raises the orbital altitude to that of the missing layer and replenishes satellite missing when the satellite missing occurs in the missing layer that is not a lowermost layer of layers composing a satellite mega constellation in the satellite mega constellation composed of 100 or more satellites and comprising a group of three or more layers of satellites.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for maintaining a satellite constellation, ground equipment, a command transmission method, and a command transmission program.

Background Art

[0002] In a mega-constellation satellite group, in the initial deployment stage, a group of satellites flying on the same orbital plane can be launched together, so cost reduction is possible by suppressing the number of rocket launches. In addition, in order to disperse the relative longitude angles of a large number of orbital planes with different normal vectors, a great deal of time and propulsion are usually required. Therefore, it is common to launch satellites together for each orbital plane in the initial deployment stage of a mega-constellation. As a specific example, in Starlink (registered trademark) of SPACE-X, about 2,500 satellites are deployed at each of three orbital altitudes near 340 km of orbital altitude, and a plan to form a mega-constellation of about 7,500 satellites in total near 340 km of orbital altitude has been announced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The satellite constellation maintenance method relating to this disclosure is: In a satellite megaconstellation consisting of more than 100 satellites and comprising three or more layers of satellite constellations, This method compensates for a satellite loss in a missing layer, which is a layer other than the lowest layer that makes up the aforementioned satellite megaconstellation, by having a replacement satellite, which belongs to a layer with an orbital altitude one level lower than the missing layer, raise its orbital altitude to the orbital altitude of the missing layer. [Effects of the Invention]

[0007] According to this disclosure, a satellite constellation maintenance method is provided for a satellite constellation consisting of 100 or more satellites, in which successor satellites are placed into orbit after the initial satellite constellation has been established due to satellite failure or the end of their lifespan, and the method provides a satellite constellation maintenance method that places successor satellites into orbit at a low cost by launching a large number of satellites at once to replace missing satellites that occur at random orbital positions in random orbital planes. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing a schematic representation of the satellite constellation maintenance system 100 according to Embodiment 1. [Figure 2] A diagram showing an example configuration of the satellite constellation maintenance system 100 according to Embodiment 1. [Figure 3] A diagram showing an example configuration of satellite 30 according to Embodiment 1. [Figure 4] A diagram showing an example configuration of the ground equipment 500 according to Embodiment 1. [Figure 5] A diagram showing an example configuration of the satellite constellation maintenance system 100 according to Embodiment 1. [Figure 6] A diagram showing the risk of collision between the rocket and satellite 30. [Figure 7] The diagram shows the process of inserting satellite 30 into orbit at the lowest level. [Figure 8] A diagram showing the separation of satellite 30 from the rocket. [Figure 9] A diagram showing the separation of satellite 30 from the rocket. [Figure 10] This figure shows how the satellite constellation maintenance system 100 according to Embodiment 1 replenishes missing satellites. [Figure 11] A diagram showing an example configuration of the ground equipment 500 according to a modified example of Embodiment 1. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals. In the description of the embodiments, the description of the same or corresponding parts will be omitted or simplified as appropriate. Also, the size relationships of the components in the following drawings may differ from those of the actual components. The arrows in the drawings mainly indicate the flow of data or processing. In addition, in the description of the embodiments, directions or positions such as "up," "down," "left," "right," "front," "back," "front," and "back" may be indicated. These notations are used for the convenience of explanation only and do not limit the arrangement and orientation of components such as devices, equipment, or parts. Furthermore, "part" may be replaced with "circuit," "process," "procedure," "processing," "means," or "circuitry" as appropriate.

[0010] Embodiment 1. This embodiment will now be described in detail with reference to the drawings.

[0011] ***Explanation of the structure*** Figure 1 shows a schematic diagram of the satellite constellation maintenance system 100 according to this embodiment. The satellite constellation maintenance system 100 comprises a satellite constellation 20 and ground facilities 500, as shown in this figure. In this specification, artificial satellites may also be simply referred to as satellites. This embodiment focuses on the property that when there are multiple mega-constellation satellite groups with many satellites 30 flying in multiple orbital planes, gaps in high-altitude satellite groups can be easily filled from lower-altitude satellite groups. Furthermore, this embodiment focuses on the property that when launching a rocket to place a satellite 30 into orbit, the method of placing it into the lowest-altitude satellite group is rational from the standpoint of ensuring flight safety. In this embodiment, focusing on these properties, gaps in satellite groups at multiple orbital altitudes are filled sequentially from low Earth orbit altitudes, and for the gaps in the lowest layer, replacement satellites are placed into orbit by launching a new rocket.

[0012] A satellite constellation 20 is typically a satellite megaconstellation comprising 100 or more satellites 30. Specific examples of satellite constellation 20 are disclosed in [Reference 1] and [Reference 2]. Specific examples of megaconstellations are disclosed in [Reference 3]. The satellite constellation maintenance system 100 appropriately incorporates the functions disclosed in these references. The satellite constellation 20 typically consists of a low-altitude satellite group 21, a medium-altitude satellite group 22, and a high-altitude satellite group 23. Each of the low-altitude satellite group 21, the medium-altitude satellite group 22, and the high-altitude satellite group 23 is a satellite megaconstellation typically composed of 100 or more satellites 30 and can be regarded as a layer. Although a specific example in which the satellite constellation 20 is composed of three layers of satellite megaconstellations is described in this specification, the satellite constellation 20 may be composed of four or more layers of satellite megaconstellations. Each satellite 30 included in the high-altitude satellite group 23 provides communication services and the like to users existing on the ground as a specific example. Each satellite 30 constituting the medium-altitude satellite group 22 waits at an orbital altitude lower than the orbital altitude of the high-altitude satellite group 23. Each satellite 30 constituting the low-altitude satellite group 21 waits at an orbital altitude lower than the orbital altitude of the medium-altitude satellite group 22. The high-altitude satellite group 23 corresponds to the layer with the highest orbital altitude, the medium-altitude satellite group 22 corresponds to the layer with the second-highest orbital altitude, and the low-altitude satellite group 21 corresponds to the layer with the lowest orbital altitude. In each layer, the orbits of the satellites 30 constituting each layer are appropriately dispersed.

[0013] [Reference 1] Japanese Patent Application Laid-Open No. 2021-054167 [Reference 2] Japanese Patent Application Laid-Open No. 2021-070342 [Reference 3] International Publication No. 2021 / 060492 Pamphlet

[0014] The ground facility 500 includes a communication device 950 and a satellite control device 501, and controls the satellite constellation 20 by communicating with each satellite 30. The satellite control device 501 is a computer that generates various commands for controlling each satellite 30, and includes hardware such as a processing circuit and an input / output interface. The processing circuit generates various commands. An input device and an output device are connected to the input / output interface. The satellite control device 501 is connected to the communication device 950 via the input / output interface. The communication device 950 communicates with each satellite 30. Specifically, the communication device 950 transmits various commands to each satellite 30.

[0015] Figure 2 shows an example configuration of the satellite constellation maintenance system 100 according to this embodiment. The satellite constellation maintenance system 100 is equipped with a computer. Although Figure 2 shows the configuration of one computer, in reality, each of the multiple satellites 30 that make up the satellite constellation 20, and each of the ground equipment 500 that communicates with the satellites 30, are equipped with a computer. The computers equipped in each of the multiple satellites 30 and each of the ground equipment 500 that communicate with the satellites 30 work together to realize the functions of the satellite constellation maintenance system 100 according to this embodiment. Below, an example of the configuration of the computer that realizes the functions of the satellite constellation maintenance system 100 will be described.

[0016] The satellite constellation maintenance system 100 comprises a satellite 30 and ground facilities 500. The satellite 30 is equipped with a satellite communication device 32 that communicates with a communication device 950 of the ground facilities 500.

[0017] The satellite constellation maintenance system 100 includes a processor 910, as well as other hardware such as memory 921, auxiliary storage device 922, input interface 930, output interface 940, and communication device 950. The processor 910 is connected to and controls the other hardware via signal lines.

[0018] The satellite constellation maintenance system 100 includes a satellite constellation maintenance unit 110 as a functional element. The functions of the satellite constellation maintenance unit 110 are realized by hardware or software.

[0019] The satellite constellation maintenance unit 110 has the function of performing processes to maintain the satellite constellation 20.

[0020] The processor 910 is a device that executes the satellite constellation maintenance program. The satellite constellation maintenance program is a program that implements the functions of the satellite constellation maintenance unit 110. The processor 910 is an integrated circuit (IC) that performs arithmetic processing. Specific examples of the processor 910 include the CPU, DSP (Digital Signal Processor), and GPU (Graphics Processing Unit).

[0021] Memory 921 is a storage device that temporarily stores data. Specific examples of memory 921 include SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory). The auxiliary storage device 922 is a storage device for storing data. A specific example of the auxiliary storage device 922 is an HDD (Hard Disk Drive). Alternatively, the auxiliary storage device 922 may be a portable storage medium such as an SD (Secure Digital) memory card, CF (CompactFlash (registered trademark)), NAND flash, flexible disk, optical disk, compact disk, Blu-ray (registered trademark) disk, or DVD (Digital Versatile Disk).

[0022] The input interface 930 is a port to which input devices such as a mouse, keyboard, or touch panel are connected. Specifically, the input interface 930 is a USB (Universal Serial Bus) terminal. Alternatively, the input interface 930 may be a port connected to a LAN (Local Area Network). Output interface 940 is a port to which the cable of an output device, such as a display, is connected. Specifically, output interface 940 is a USB terminal or an HDMI® (High Definition Multimedia Interface) terminal. Specifically, the display is an LCD (Liquid Crystal Display).

[0023] The communication device 950 has a receiver and a transmitter. Specifically, the communication device 950 is a communication chip or NIC (Network Interface Card). The satellite constellation maintenance system 100 communicates with the ground equipment 500 and the satellite 30 via the communication device 950.

[0024] The satellite constellation maintenance program is loaded into the processor 910 and executed by the processor 910. Memory 921 stores not only the satellite constellation maintenance program but also the OS (Operating System). The processor 910 executes the satellite constellation maintenance program while simultaneously running the OS. The satellite constellation maintenance program and the OS may also be stored in auxiliary storage. The satellite constellation maintenance program and OS stored in auxiliary storage are loaded into memory 921 and executed by the processor 910. Note that part or all of the satellite constellation maintenance program may be incorporated into the OS.

[0025] The satellite constellation maintenance system 100 may have multiple processors that replace the processor 910. These multiple processors share the task of executing the satellite constellation maintenance program. Each processor is a device that executes the satellite constellation maintenance program, just like the processor 910.

[0026] Data, information, signal values, and variable values ​​used, processed, or output by the satellite constellation maintenance program are stored in memory 921, auxiliary storage device 922, or registers or cache memory within the processor 910.

[0027] The satellite constellation maintenance program causes a computer to execute each process, procedure, or process, where "unit" in "satellite constellation maintenance unit 110" is replaced with "process," "procedure," or "process." The satellite constellation maintenance method is performed by the satellite constellation maintenance system 100 executing the satellite constellation maintenance program. Any of the programs described herein may be provided on a computer-readable recording medium or storage medium. Alternatively, any of the programs described herein may be provided as a program product.

[0028] Figure 3 shows an example of the configuration of the satellite 30 according to this embodiment. Satellite 30 comprises a satellite control device 31, a satellite communication device 32, a propulsion device 33, an attitude control device 34, and a power supply device 35. Satellite 30 also comprises other components that realize various functions, but with reference to Figure 3, the satellite control device 31, satellite communication device 32, propulsion device 33, attitude control device 34, and power supply device 35 will be described. The satellite control device 31 is a computer that controls the propulsion system 33 and the attitude control device 34, and is equipped with processing circuits. Specifically, the satellite control device 31 controls the propulsion system 33 and the attitude control device 34 according to various commands transmitted from the ground equipment 500. The satellite communication device 32 is a device that communicates with the ground equipment 500. Specifically, the satellite communication device 32 transmits various data related to its own satellite to the ground equipment 500. The satellite communication device 32 also receives various commands transmitted from the ground equipment 500. The propulsion device 33 is a device that provides thrust to the satellite 30 and changes the speed of the satellite 30. Specifically, the propulsion device 33 is an electric propulsion system. Specifically, the propulsion device 33 is an ion engine or a Hall thruster. The attitude control device 34 is a device for controlling attitude elements such as the attitude of the satellite 30, its angular velocity, and its line of sight. The attitude control device 34 changes each attitude element in a desired direction, or maintains each attitude element in a desired direction. The attitude control device 34 comprises attitude sensors, actuators, and a controller. The attitude sensors include devices such as a gyroscope, Earth sensor, solar sensor, star tracker, thruster, and magnetic sensor. The actuators include devices such as attitude control thrusters, momentum wheels, reaction wheels, and control moment gyroscopes. The controller controls the actuators according to the measurement data from the attitude sensors or various commands from the ground equipment 500. The power supply unit 35 is equipped with devices such as solar cells, batteries, and a power control device, and supplies power to each device mounted on the satellite 30.

[0029] The processing circuits provided in the satellite control device 31 will now be described. The processing circuit may be dedicated hardware, or it may be a processor that executes a program stored in memory. In a processing circuit, some functions may be implemented by dedicated hardware, while the remaining functions are implemented by software or firmware. In other words, a processing circuit can be implemented using hardware, software, firmware, or a combination thereof. Dedicated hardware specifically includes single circuits, complex circuits, programmed processors, parallel programmed processors, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), or combinations thereof.

[0030] Figure 4 shows an example of the configuration of the ground equipment 500 according to this embodiment. Ground equipment 500 programmatically controls numerous satellites 30 across all orbital planes. Ground equipment 500 is an example of ground equipment. Ground equipment consists of ground stations such as ground antenna equipment, communication equipment connected to the ground antenna equipment, or computers, and ground equipment such as servers or terminals connected to the ground stations via a network. Ground equipment may also include communication equipment mounted on mobile devices such as aircraft, self-propelled vehicles, or mobile terminals.

[0031] The ground equipment 500 forms a satellite constellation 20 by communicating with each satellite 30. The ground equipment 500 is provided in the satellite constellation maintenance system 100. The ground equipment 500 includes a processor 910, as well as other hardware such as memory 921, auxiliary storage device 922, input interface 930, output interface 940, and communication device 950. The processor 910 is connected to and controls the other hardware via signal lines. The hardware of the ground equipment 500 is the same as that described for the satellite constellation maintenance system 100 shown in Figure 2. Figures 2 and 4 describe the hardware provided in the ground equipment 500. However, hardware with similar functions may be provided in systems, satellites, devices, or equipment other than the satellites 30 and the ground equipment 500.

[0032] The ground equipment 500 includes, as functional elements, an orbit control command generation unit 510 and a satellite analysis unit 520. The functions of the orbit control command generation unit 510 and the satellite analysis unit 520 are realized by hardware, software, or a combination thereof.

[0033] The communication device 950 transmits and receives signals to track and control each satellite 30 that make up the satellite constellation 20. The communication device 950 also transmits orbit control commands 51 to each satellite 30.

[0034] The satellite analysis unit 520 analyzes the status of the satellite constellation 20 and the status of the satellites 30, etc. Specifically, the satellite analysis unit 520 determines whether any satellites 30 constituting the low-altitude satellite group 21 are missing, and also determines whether the satellites 30 constituting the low-altitude satellite group 21 are functioning normally.

[0035] The orbit control command generation unit 510 generates orbit control commands 51 to be transmitted to the satellite 30. Specifically, the orbit control command generation unit 510 appropriately transmits commands to the satellite 30 instructing it to execute processes to realize the satellite constellation maintenance method. The method by which the orbit control command generation unit 510 transmits commands corresponds to the command transmission method. The program that causes the orbit control command generation unit 510 to transmit commands corresponds to the command transmission program. The command transmission program may be part of the satellite constellation maintenance program. The computer in the ground equipment 500 executes the command transmission program. The command transmission program causes the ground equipment 500 to appropriately transmit commands to the satellite 30 to realize the satellite constellation maintenance method. In this way, the orbit control command generation unit 510 and the satellite analysis unit 520 realize the functions of the satellite constellation maintenance unit 110. In other words, the orbit control command generation unit 510 and the satellite analysis unit 520 correspond to specific examples of the functions of the satellite constellation maintenance unit 110.

[0036] Figure 5 shows an example of the functional configuration of the satellite constellation maintenance system 100 according to this embodiment. Satellite 30 further includes a satellite constellation maintenance unit 110b that forms a satellite constellation 20. The satellite constellation maintenance unit 110b of each satellite 30 and the satellite constellation maintenance unit 110 provided in each of the ground facilities 500 work together to realize the functions of the satellite constellation maintenance system 100 according to this embodiment. The satellite constellation maintenance unit 110b of satellite 30 may also be provided in the satellite control device 31.

[0037] ***Explanation of operation*** As shown in Figure 6, when a satellite constellation 20 consisting of three or more layers of satellites is formed, there is a risk of collision between the rocket and the satellites 30 that make up the satellite constellation 20 when a newly launched rocket passes through the altitude zone where each layer is formed. The hazardous areas shown in Figure 6 are areas where there is a risk of collision. Therefore, in the satellite constellation maintenance system 100, as shown in Figure 7, after the satellite constellation 20 is formed, satellites 30 are placed into orbit only from the lowest layer of the satellite constellation 20 by rocket launch. At this time, there may be any number of satellites 30 to be placed into orbit.

[0038] Here, we will explain the method of placing satellite 30 into orbit at the lowest level by rocket launch. In this process, satellite 30 is placed into orbit at an orbital altitude lower than the lowest level by rocket launch, and each placed satellite 30 increases its orbital altitude to become a satellite belonging to the lowest level.

[0039] Figure 8 shows a specific example of separating satellite 30 from a launched rocket. This figure will be used to explain the procedure for separating satellite 30 from the rocket. First, for a while after launch, the rocket flies with its satellite payload positioned forward of the flight path. At launch, the satellite payload is covered by a fairing, and it carries multiple satellites 30 as a group of separated satellites. Next, the rocket opens its fairing at a certain point. Next, the rocket changes its orientation so that the satellite payload is positioned behind the direction of flight. Next, the rocket separates the satellites 30 mounted on its payload section one by one. In this process, the rocket separates the satellites 30 in the order that are at the front in the direction of flight's rear. The rocket may also decide whether or not to separate a satellite 30 considering the rocket's orbital altitude.

[0040] Figure 9 shows the state of each satellite 30 after it has separated from the rocket. At the time of separation, each satellite 30 has a different orbital altitude, and therefore the orbital periods of each satellite 30 are different. In addition, each satellite 30 rises to a predetermined orbital altitude, but the relative angle of the orbital plane changes while each satellite 30 is reaching that predetermined orbital altitude. Each satellite 30 adjusts its relative angle by appropriately utilizing these properties. The method of launching a rocket to place at least some of the satellites 30 that make up the lowest layer of the satellite constellation 20 into orbit is equivalent to a rocket launch method. The rocket is, in specific cases, a large rocket capable of carrying a large number of satellites 30. A large number of satellites 30 means, in specific cases, 40 or more satellites 30. A method of maintaining a satellite constellation involves launching a rocket to an orbital altitude lower than the orbital altitude of the lowest layer among the layers constituting the satellite constellation 20, thereby placing satellites 30 into orbit, and each placed satellite 30 increasing its orbital altitude to become a satellite belonging to the lowest layer, thereby replenishing the lowest layer with satellites 30.

[0041] Furthermore, regarding movement between adjacent orbits, it is possible to move to the desired orbit by changing the orbital altitude every 30 satellites, utilizing the effect of different orbital periods. Even if the orbital plane where satellite 30 is missing is random, it is reasonable to launch replacement satellites simultaneously to multiple missing locations in adjacent orbits. Furthermore, even if the missing positions of satellite 30 within the orbital plane are random, by adjusting the phase within the orbital plane, satellite 30 can be placed into orbit at a position that facilitates orbital insertion regardless of the order of satellite 30 within the orbital plane, or satellite 30 can be placed into orbit at a desired orbital position.

[0042] Using Figure 10, the operation of the satellite constellation maintenance system 100 when a satellite goes missing in the high-altitude satellite group 23 will be explained. Note that a satellite goes missing due to failure or reaching the end of its lifespan. First, among the satellites 30 belonging to the medium-altitude satellite group 22, a satellite 30 that is flying at a position relatively close to where the missing satellite was flying is selected as a replacement satellite. Next, the selected replacement satellite raises its orbital altitude to the orbital altitude of the high-altitude satellite group 23 and adjusts its orbit as appropriate to replace the missing satellite. At this point, the selected replacement satellite is no longer a satellite 30 belonging to the medium-altitude satellite group 22, so a satellite goes missing in the medium-altitude satellite group 22. Next, in the same manner, a satellite 30 belonging to the low-altitude satellite group 21 replaces the missing satellite that occurred in the medium-altitude satellite group 22 as a replacement satellite. In this way, the satellite constellation maintenance system 100 maintains the satellite constellation 20 by adding satellites to the high-altitude satellite group 23 in a bucket brigade manner, sequentially increasing the altitude from the lower layers to the middle layers and then from the middle layers to the upper layers. Alternatively, the replacement satellites may increase their orbital altitude without waiting for a missing satellite to occur in a higher layer, for example, by having satellites 30 belonging to each of multiple layers simultaneously increase their orbital altitude. When a satellite is lost in a missing layer, which is a layer other than the lowest layer that makes up the satellite constellation 20, a replacement satellite 30 belonging to a layer with an orbital altitude one level lower than the missing layer raises its orbital altitude to the orbital altitude of the missing layer to compensate for the loss, which is equivalent to a satellite constellation maintenance method. In addition, in the satellite constellation maintenance method, in each layer with an orbital altitude lower than the orbital altitude of the missing layer, one of the satellites 30 may be selected as a replacement satellite, and the selected replacement satellite may raise its orbital altitude to the orbital altitude of a layer one level higher than the layer to which the replacement satellite belongs.

[0043] ***Explanation of the effects of Embodiment 1*** As described above, according to this embodiment, even if a satellite 30 is lost in a random orbital plane, a large number of satellites in orbital planes are dispersed and flying in a lower layer than the layer to which the lost satellite 30 belongs. Therefore, according to this embodiment, satellites 30 belonging to the lower layer can increase their orbital altitude to replenish the lost satellite 30, and a satellite 30 in the most suitable nearby orbital plane can be selected as the replacement satellite 30, taking into consideration the location of the lost satellite 30. Furthermore, in this embodiment, random and sequential gaps in a group of satellites orbiting at multiple orbital altitudes are replenished by launching them all together from the lowest layer using rockets. Therefore, according to this embodiment, a large number of satellites 30 can be launched at once by rocket launch, thus reducing the cost required to replenish the satellites 30. Moreover, according to this embodiment, successor satellites can be rationally replenished in projects such as Starlink®.

[0044] ***Other configurations*** <Example 1> In this embodiment, the functions of the satellite constellation maintenance unit 110 are implemented in software. As a modified example, the functions of the satellite constellation maintenance unit 110 may be implemented in hardware. Figure 11 shows this modified example.

[0045] The ground equipment 500 is equipped with an electronic circuit 909 in place of the processor 910. The electronic circuit 909 is a dedicated electronic circuit that enables the functions of the satellite constellation maintenance unit 110. Specifically, the electronic circuit 909 is a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA (Gate Array), an ASIC, or an FPGA. The functions of the satellite constellation maintenance unit 110 may be implemented by a single electronic circuit or by distributing them across multiple electronic circuits. As another variation, some functions of the satellite constellation maintenance unit 110 may be implemented by the electronic circuit 909, while the remaining functions are implemented by software.

[0046] The processor 910, electronic circuit 909, memory 921, and auxiliary storage device 922 are collectively referred to as the processing circuit. In other words, in the satellite constellation maintenance system 100, the functions of the satellite constellation maintenance unit 110 are realized by the processing circuit.

[0047] ***Other Embodiments*** Although Embodiment 1 has been described, multiple parts of this embodiment may be combined and implemented. Alternatively, this embodiment may be implemented partially. Furthermore, this embodiment may be modified in various ways as needed, and may be implemented as a whole or in parts in any combination. The embodiments described above are essentially preferred examples and are not intended to limit the disclosure, its applications, or the scope of use. The procedures described may be modified as appropriate. [Explanation of symbols]

[0048] 20 Satellite constellation, 21 Low-altitude satellite group, 22 Medium-altitude satellite group, 23 High-altitude satellite group, 30 Satellite, 31 Satellite control device, 32 Satellite communication device, 33 Propulsion device, 34 Attitude control device, 35 Power supply device, 51 Orbit control command, 100 Satellite constellation maintenance system, 110, 110b Satellite constellation maintenance unit, 500 Ground equipment, 501 Satellite control device, 510 Orbit control command generation unit, 520 Satellite analysis unit, 909 Electronic circuit, 910 Processor, 921 Memory, 922 Auxiliary storage device, 930 Input interface, 940 Output interface, 950 Communication device.

Claims

1. In a satellite megaconstellation consisting of more than 100 satellites, comprising a satellite constellation with three or more layers, and in which successor satellites to replace any missing satellites after the initial satellite constellation is established are placed into orbit by a simultaneous launch of more than 40 satellites, The 40 or more satellites are placed into orbit by launching a rocket to an orbital altitude lower than the orbital altitude of the lowest layer among the layers constituting the aforementioned satellite megaconstellation. If a satellite is lost in a missing layer, which is a layer other than the lowest layer among the layers constituting the satellite megaconstellation, a satellite belonging to a layer with an orbital altitude one level lower than the missing layer is selected as a replacement satellite, and the orbital altitude of the selected replacement satellite is raised to the orbital altitude of the missing layer to compensate for the satellite loss. A satellite constellation maintenance method comprising: selecting one satellite as another replacement satellite in each layer with an orbital altitude lower than the layer to which the selected replacement satellite belongs; raising the orbital altitude of the selected replacement satellite to the orbital altitude of a layer one level higher than the layer to which the selected replacement satellite belongs; thereby sequentially replacing the satellite gaps caused by replacement in layers one level higher than the layer to which the selected replacement satellite belongs; At each orbital altitude from the layer one level lower than the missing layer to the layer in which the 40 or more satellites were placed into orbit, multiple satellite groups in different orbital planes are dispersed and flying in their respective orbital planes. The selected replacement satellite is a satellite in an orbital plane selected based on its proximity to the location where the satellite loss occurred. The other selected replacement satellites are satellites in an orbital plane selected based on their proximity to the location of the satellite loss caused by replacement in a layer with an orbital altitude one level higher than the layer to which the other selected replacement satellites belong. A method for maintaining a satellite constellation, wherein each of the 40 or more satellites, after being placed into orbit, increases its orbital altitude to become a satellite belonging to the lowest layer, thereby replenishing the lowest layer with satellites.

2. Ground equipment for communicating with satellites that constitute a satellite megaconstellation consisting of 100 or more satellites, comprising a satellite constellation with three or more layers, and in which successor satellites to replace any missing satellites after the initial satellite constellation is launched into orbit by a simultaneous launch of 40 or more satellites, If a satellite is lost in a missing layer, which is a layer other than the lowest layer among the layers constituting the satellite megaconstellation, a satellite belonging to a layer with an orbital altitude one level lower than the missing layer is selected as a replacement satellite, and a command is sent to the selected replacement satellite instructing it to raise its orbital altitude to the orbital altitude of the missing layer to compensate for the satellite loss. Ground equipment that transmits a command to the selected other supplementary satellite to sequentially fill the gaps in satellites caused by supplementation in the layer one level higher in orbital altitude than the layer to which the selected supplementary satellite belongs, by selecting one of the satellites as another supplementary satellite in each layer with an orbital altitude lower than the layer to which the selected other supplementary satellite belongs, and raising the orbital altitude of the selected other supplementary satellite to the orbital altitude of the layer one level higher in orbital altitude than the layer to which the selected other supplementary satellite belongs. The 40 or more satellites are placed into orbit by launching a rocket to an orbital altitude lower than the orbital altitude of the lowest layer among the layers constituting the aforementioned satellite megaconstellation. At each orbital altitude from the layer one level lower than the missing layer to the layer in which the 40 or more satellites were placed into orbit, multiple satellite groups in different orbital planes are dispersed and flying in their respective orbital planes. The selected replacement satellite is a satellite in an orbital plane selected based on its proximity to the location where the satellite loss occurred. The other selected replacement satellites are satellites in an orbital plane selected based on their proximity to the location of the satellite loss caused by replacement in a layer with an orbital altitude one level higher than the layer to which the other selected replacement satellites belong. Ground equipment that, after each of the 40 or more satellites is placed into orbit, increases its orbital altitude to become a satellite belonging to the lowest layer, thereby replenishing the lowest layer with satellites.

3. A command transmission method to be executed by ground equipment communicating with satellites that constitute a satellite megaconstellation consisting of 100 or more satellites, comprising a satellite constellation of three or more layers, and in which successor satellites to replace any missing satellites after the initial satellite constellation is launched into orbit by a simultaneous launch of 40 or more satellites, If a satellite is lost in a missing layer, which is a layer other than the lowest layer among the layers constituting the satellite megaconstellation, a satellite belonging to a layer with an orbital altitude one level lower than the missing layer is selected as a replacement satellite, and a command is sent to the selected replacement satellite instructing it to raise its orbital altitude to the orbital altitude of the missing layer to compensate for the satellite loss. A command transmission method for transmitting a command to the selected other supplementary satellites, which instructs that in each of the layers with orbital altitudes lower than the layer to which the selected supplementary satellites belong, one satellite be selected as another supplementary satellite, and that the orbital altitude of the selected other supplementary satellites be raised to the orbital altitude of a layer with an orbital altitude one level higher than the layer to which the selected other supplementary satellites belong, thereby sequentially filling the gaps in satellites caused by supplementation in the layer with an orbital altitude one level higher than the layer to which the selected other supplementary satellites belong, The 40 or more satellites are placed into orbit by launching a rocket to an orbital altitude lower than the orbital altitude of the lowest layer among the layers constituting the aforementioned satellite megaconstellation. At each orbital altitude from the layer one level lower than the missing layer to the layer in which the 40 or more satellites were placed into orbit, multiple satellite groups in different orbital planes are dispersed and flying in their respective orbital planes. The selected replacement satellite is a satellite in an orbital plane selected based on its proximity to the location where the satellite loss occurred. The other selected replacement satellites are satellites in an orbital plane selected based on their proximity to the location of the satellite loss caused by replacement in a layer with an orbital altitude one level higher than the layer to which the other selected replacement satellites belong. A command transmission method for supplementing the lowest layer by having each of the 40 or more satellites, after being placed into orbit, increase its orbital altitude to become a satellite belonging to the lowest layer.

4. A command transmission program executed by a computer in ground equipment that communicates with satellites constituting a satellite megaconstellation consisting of 100 or more satellites, comprising a satellite constellation with three or more layers, and in which successor satellites to replace any missing satellites after the initial satellite constellation is launched into orbit by a simultaneous launch of 40 or more satellites, The aforementioned ground equipment, If a satellite is lost in a missing layer, which is a layer other than the lowest layer among the layers constituting the satellite megaconstellation, a satellite belonging to a layer with an orbital altitude one level lower than the missing layer is selected as a replacement satellite, and a command is sent to the selected replacement satellite instructing it to raise its orbital altitude to the orbital altitude of the missing layer to compensate for the satellite loss. A command transmission program that, in each of the layers with orbital altitudes lower than the layer to which the selected supplemental satellite belongs, selects one satellite as another supplemental satellite, and raises the orbital altitude of the selected other supplemental satellite to the orbital altitude of a layer one level higher than the layer to which the selected other supplemental satellite belongs, thereby sending a command to the selected other supplemental satellite to sequentially fill the gaps in satellites that have been lost due to supplementation in the layer one level higher than the layer to which the selected other supplemental satellite belongs. The 40 or more satellites are placed into orbit by launching a rocket to an orbital altitude lower than the orbital altitude of the lowest layer among the layers constituting the aforementioned satellite megaconstellation. At each orbital altitude from the layer one level lower than the missing layer to the layer in which the 40 or more satellites were placed into orbit, multiple satellite groups in different orbital planes are dispersed and flying in their respective orbital planes. The selected replacement satellite is a satellite in an orbital plane selected based on its proximity to the location where the satellite loss occurred. The other selected replacement satellites are satellites in an orbital plane selected based on their proximity to the location of the satellite loss caused by replacement in a layer with an orbital altitude one level higher than the layer to which the other selected replacement satellites belong. A command transmission program that, after each of the 40 or more satellites is placed into orbit, increases its orbital altitude to become a satellite belonging to the lowest layer, thereby replenishing the lowest layer with a satellite.

Images