JP7599391B2 - Satellite constellation forming method, satellite constellation, and analysis device - Google Patents

Description

The present disclosure relates to a method for forming a satellite constellation, a satellite constellation, and an analysis device.

The emergence of mega-constellations and the dramatic increase in the number of objects in orbit due to the increase in debris have increased the risk of collisions in space, and a method for avoiding collisions is needed.
There is a plan to build a mega-constellation that will place several thousand satellites at the same orbital altitude. However, in a mega-constellation in which one of the four dimensions, time and three spatial dimensions, is artificially aligned by making the orbital altitudes the same in the vast space, there is a concern about the risk of collision within the mega-constellation. In particular, in a mega-constellation consisting of several thousand satellites that adopt inclined circular orbits, there is a risk of collision between satellites at the intersections where the orbital altitudes are the same on the intersection lines of multiple orbital planes formed in the mid-latitude zone. Therefore, it is necessary to avoid collision between satellites by appropriately shifting the timing at which each satellite passes the intersection. Since satellites fly at a ground speed of 7 km/s or more, a collision risk may occur even if the timing of the satellite's passage is shifted from a safe timing by just a few seconds. It is technically difficult to operate a mega-constellation on a regular basis without allowing an error of even a few seconds for all of the several thousand satellites that make up the mega-constellation.
In particular, there is a need for a method for forming a satellite constellation that avoids collisions at orbital nodes in the process of injecting a new satellite into an orbit at a predetermined phase in a predetermined orbital plane.

International Publication No. 2020/240825

Patent Document 1 discloses a technology for avoiding collisions between satellites. However, the technology disclosed in Patent Document 1 has the problem that when a new satellite is launched into orbit, the intersection of the orbital plane of the newly launched satellite and other orbital planes in the mid-latitude band must be identified as a danger area before the newly launched satellite can operate its propulsion device, making it impossible to avoid collisions between the newly launched satellite and satellites that make up the satellite constellation.

The present disclosure aims to provide a method for forming a satellite constellation in which, when a new satellite is launched into orbit in a mega-constellation in which several thousand satellites fly at the same orbital altitude, the orbital plane of the newly launched satellite is identified as a dangerous area at the mid-latitudes where it intersects with other orbital planes, and the newly launched satellite then operates its propulsion device, thereby avoiding collisions between the newly launched satellite and satellites that constitute the satellite constellation.

The satellite constellation formation method according to the present disclosure includes:
n (n is an integer of 2 or more) orbital planes are evenly arranged in the longitude direction, and up to m (m is an integer of 2 or more) satellites fly at flight orbit altitudes in each of the n orbital planes so that their phase angles are even,
m or less satellites are in regular operation in each of n or less orbital planes,
A method for forming a satellite constellation in a satellite constellation in which satellites in a normally operating satellite are flying synchronously in an orbit of a target satellite and an orbit adjacent to the orbit of the target satellite such that a phase offset angle indicating an angle difference in an orbital plane from when a satellite in an orbit adjacent to the orbit of the target satellite moves north over the equator until when a satellite in the orbit of the target satellite moves north over the equator is shifted by (360/(m×n))×i degrees (phase offset i is an integer of 0 to m−1),
A satellite to be newly orbitally injected into the satellite constellation is equipped with an analysis device,
the analysis device uses a phase offset model that models the phase offset i and a relative flight position on each of the nth or lower orbital plane,
In the phase offset model, orbital planes and relative phases of satellites that are at risk of collision are identified as danger regions;
The analysis device receives orbit information of each satellite in normal operation, and derives a phase offset angle and a phase offset i of the orbit injection satellite with respect to each of the normally operating satellites based on the received orbit information and the orbit information of the orbit injection satellite;
The method is a method for allowing the orbital injection satellite to reach an orbital injection position by operating a propulsion device of the orbital injection satellite before passing through a danger area indicated by the phase offset model, thereby avoiding a risk of collision between the orbital injection satellite and a satellite constituting the satellite constellation.

According to the present disclosure, in a mega-constellation in which several thousand satellites fly at the same orbital altitude, when a new satellite is launched into orbit, a method for forming a satellite constellation can be provided in which the intersection of the orbital plane of the newly launched satellite and other orbital planes in the mid-latitudes is identified as a danger area and the newly launched satellite operates its propulsion device, thereby avoiding collisions between the newly launched satellite and satellites that constitute the satellite constellation.

1 is a diagram showing an outline of a satellite constellation forming system 100 according to a first embodiment. 1 is a diagram showing an example of the configuration of a satellite constellation forming system 100 according to a first embodiment. FIG. 2 is a diagram showing a configuration example of a satellite 30 according to the first embodiment. FIG. 2 is a diagram showing a configuration example of a ground facility 500 according to the first embodiment. 1 is a diagram showing an example of the configuration of a satellite constellation forming system 100 according to a first embodiment. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of 0. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of 1. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of two. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of three. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of four. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of five. FIG. 13 is a diagram showing a phase offset model with seven orbital planes and a phase offset of six. FIG. 13 shows a phase offset model with eight orbital planes and a phase offset of six. FIG. 13 shows a phase offset model with nine orbital planes and a phase offset of three. A diagram showing danger areas at mid-latitude crossings. 1 is a diagram showing a circular orbit in which eight satellites 30 fly in equal phase. A diagram showing the collision risk at the point where orbital planes with different normal vectors intersect. 1A and 1B are diagrams showing the phase shift of the flight position of satellite 30 for each orbital plane, where (a) is a diagram with no phase shift, (b) is a diagram with a phase shift of 9 degrees, (c) is a diagram with a phase shift of 18 degrees, (d) is a diagram with a phase shift of 27 degrees, and (e) is a diagram with a phase shift of 36 degrees. 19A and 19B are diagrams showing the state in which the track surfaces shown in FIG. 18 are superimposed, where FIG. 19A shows a case in which there is no inclination, and FIG. 19B shows a case in which there is an inclination. 19A and 19B are diagrams showing the orbital surfaces shown in FIG. 18 with an orbital inclination angle, where (a) is a diagram showing orbital surface 1, (b) is a diagram showing orbital surface 2, (c) is a diagram showing orbital surface 3, (d) is a diagram showing orbital surface 4, (e) is a diagram showing orbital surface 5, (f) is a diagram showing a first orbital surface, (g) is a diagram showing a second orbital surface, (h) is a diagram showing a third orbital surface, (i) is a diagram showing a fourth orbital surface, and (j) is a diagram showing a fifth orbital surface. 1A and 1B are diagrams illustrating orbital intersections, where (a) is a diagram showing a first orbital surface, (b) is a diagram showing a second orbital surface, (c) is a diagram showing a third orbital surface, (d) is a diagram showing a fourth orbital surface, (e) is a diagram showing a fifth orbital surface, (f) is a diagram showing the first orbital surface, (g) is a diagram showing the second orbital surface, (h) is a diagram showing the third orbital surface, (i) is a diagram showing the fourth orbital surface, and (j) is a diagram showing the fifth orbital surface. 1A is a diagram showing the points where the orbital altitudes coincide on the intersection line between orbital planes, (a) is a diagram showing the first orbital plane, (b) is a diagram showing the second orbital plane, (c) is a diagram showing the third orbital plane, (d) is a diagram showing the fourth orbital plane, (e) is a diagram showing the fifth orbital plane, (f) is a diagram showing the first orbital plane, (g) is a diagram showing the second orbital plane, (h) is a diagram showing the third orbital plane, (i) is a diagram showing the fourth orbital plane, and (j) is a diagram showing the fifth orbital plane. 1A is a diagram showing the points where the orbital altitudes coincide on the intersection line between orbital planes, (a) is a diagram showing a first orbital plane, (b) is a diagram showing a second orbital plane, (c) is a diagram showing a third orbital plane, (d) is a diagram showing a fourth orbital plane, and (e) is a diagram showing a fifth orbital plane. 1A is a diagram showing the points where the orbital altitudes coincide on the intersection line between orbital planes, (a) is a diagram showing a first orbital plane, (b) is a diagram showing a second orbital plane, (c) is a diagram showing a third orbital plane, (d) is a diagram showing a fourth orbital plane, and (e) is a diagram showing a fifth orbital plane. A diagram explaining the overview of machine learning. FIG. 13 is a diagram showing a configuration example of a ground equipment 500 according to a modified example of the first embodiment.

Hereinafter, the embodiments of the present disclosure will be described 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. In addition, the size relationship of each component in the following drawings may differ from the actual one. The arrows in the drawings mainly indicate the flow of data or the flow of 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 written in this way only for the convenience of explanation, and do not limit the arrangement and orientation of components such as devices, instruments, or parts.
Furthermore, the term "part" may be appropriately interpreted as a "circuit,""step,""procedure,""processing,""means," or "circuitry."

Embodiment 1.
Hereinafter, the present embodiment will be described in detail with reference to the drawings.

***Configuration Description***
FIG. 1 shows an outline of a satellite constellation forming system 100 according to this embodiment.
As shown in the figure, the satellite constellation forming system 100 includes a satellite constellation 20 and a ground facility 500. In this specification, an artificial satellite may be simply referred to as a satellite.

The satellite constellation 20 is a satellite mega-constellation that typically includes 100 or more satellites 30. Examples of the satellite constellation 20 are disclosed in [Reference 1] and [Reference 2]. An example of a mega-constellation is disclosed in [Reference 3]. The satellite constellation forming system 100 appropriately includes the functions disclosed in these references.
Each satellite 30 included in the satellite constellation 20 provides, as a specific example, communication services to users on the ground.

[Reference 1]
JP 2021-054167 A [Reference 2]
JP 2021-070342 A [Reference 3]
International Publication No. 2021/060492

The ground equipment 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 the various commands. An input device and an output device are connected to the input/output interface. The satellite control device 501 is connected to a 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.

FIG. 2 shows an example of the configuration of a satellite constellation forming system 100 according to this embodiment.
The satellite constellation forming system 100 includes a computer. Although Fig. 2 shows the configuration of one computer, in reality, a computer is provided for each of the multiple satellites 30 constituting the satellite constellation 20 and for each of the ground facilities 500 that communicate with the satellites 30. The computers provided for each of the multiple satellites 30 and for each of the ground facilities 500 that communicate with the satellites 30 work together to realize the functions of the satellite constellation forming system 100 according to this embodiment. An example of the configuration of a computer that realizes the functions of the satellite constellation forming system 100 will be described below.

The satellite constellation forming system 100 includes a satellite 30 and a ground facility 500. The satellite 30 includes a satellite communication device 32 that communicates with a communication device 950 of the ground facility 500.

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

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

The satellite constellation forming unit 110 has the function of executing processing to form the satellite constellation 20.

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

The memory 921 is a storage device that temporarily stores data. Specific examples of the memory 921 include a static random access memory (SRAM) and a dynamic random access memory (DRAM).
The auxiliary storage device 922 is a storage device that stores data. A specific example of the auxiliary storage device 922 is a hard disk drive (HDD). The auxiliary storage device 922 may also be a portable storage medium such as a secure digital (SD) (registered trademark) memory card, a compact flash (CF) (compact flash), a NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a digital versatile disk (DVD).

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

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

The satellite constellation formation program is read into the processor 910 and executed by the processor 910. The memory 921 stores not only the satellite constellation formation program but also an OS (Operating System). The processor 910 executes the satellite constellation formation program while executing the OS. The satellite constellation formation program and the OS may be stored in an auxiliary storage device. The satellite constellation formation program and the OS stored in the auxiliary storage device are loaded into the memory 921 and executed by the processor 910. Note that a part or all of the satellite constellation formation program may be incorporated into the OS.

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

The data, information, signal values and variable values used, processed or output by the satellite constellation formation program are stored in memory 921, auxiliary storage device 922, or in a register or cache memory within processor 910.

The satellite constellation forming program causes a computer to execute each process, procedure, or step, where "part" is replaced with "process,""procedure," or "step" in the satellite constellation forming unit 110. Also, the satellite constellation forming method is a method performed by the satellite constellation forming system 100 executing the satellite constellation forming program.
Any of the programs described herein may be provided in a form stored in a computer-readable recording medium or storage medium, or may be provided as a program product.

FIG. 3 shows an example of the configuration of a satellite 30 according to this embodiment.
The 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. The satellite 30 also comprises other components that realize various functions, but the satellite control device 31, the satellite communication device 32, the propulsion device 33, the attitude control device 34, and the power supply device 35 will be described with reference to FIG.
The satellite control device 31 is a computer that controls the propulsion device 33 and the attitude control device 34, and includes a processing circuit. Specifically, the satellite control device 31 controls the propulsion device 33 and the attitude control device 34 in accordance with various commands transmitted from the ground facility 500.
The satellite communication device 32 is a device that communicates with the ground facility 500. Specifically, the satellite communication device 32 transmits various data related to its own satellite to the ground facility 500. In addition, the satellite communication device 32 receives various commands transmitted from the ground facility 500.
The propulsion device 33 is a device that provides propulsive force to the satellite 30 and changes the speed of the satellite 30. Specifically, the propulsion device 33 is an electric propulsion device. Specifically, the propulsion device 33 is an ion engine or a Hall thruster.
The attitude control device 34 controls the attitude of the satellite 30, the angular velocity of the satellite 30, and the line of sight (Line of Sight).
The attitude control device 34 is a device for controlling attitude elements such as a satellite attitude sensor, an actuator, and a controller. The attitude control device 34 changes each attitude element to a desired direction. Alternatively, the attitude control device 34 maintains each attitude element in a desired direction. The attitude control device 34 includes an attitude sensor, an actuator, and a controller. The attitude sensor is a device such as a gyroscope, an earth sensor, a sun sensor, a star tracker, a thruster, and a magnetic sensor. The actuator is a device such as an attitude control thruster, a momentum wheel, a reaction wheel, and a control moment gyro. The controller controls the actuator according to measurement data of the attitude sensor or various commands from the ground equipment 500.
The power supply unit 35 includes devices such as a solar cell, a battery, and a power control device, and supplies power to each device mounted on the satellite 30 .

The processing circuitry provided in the satellite control device 31 will now be described.
The processing circuitry may be dedicated hardware or may be a processor that executes a program stored in a memory.
In the processing circuit, some functions may be realized by dedicated hardware and the remaining functions may be realized by software or firmware, i.e. the processing circuit may be realized by hardware, software, firmware or a combination thereof.
The dedicated hardware may specifically be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these.

FIG. 4 shows an example of the configuration of a ground facility 500 according to this embodiment.
The ground equipment 500 controls programs of the multiple satellites 30 in all orbital planes. The ground equipment 500 is an example of a ground device. The ground equipment is composed of a ground station such as a ground antenna device, a communication device connected to the ground antenna device, or a computer, and ground equipment as a server or terminal connected to the ground station via a network. The ground equipment may also include a communication device mounted on a moving object such as an aircraft, a self-propelled vehicle, or a mobile terminal.

The ground equipment 500 forms the satellite constellation 20 by communicating with each satellite 30. The ground equipment 500 is provided in the satellite constellation forming system 100. The ground equipment 500 includes a processor 910 and other hardware such as a memory 921, an auxiliary storage device 922, an input interface 930, an output interface 940, and a communication device 950. The processor 910 is connected to the other hardware via a signal line and controls the other hardware. The hardware of the ground equipment 500 is similar to that described in the satellite constellation forming system 100 shown in FIG. 2. In FIG. 2 and FIG. 4, the hardware provided in the ground equipment 500 is described. However, hardware having similar functions may be provided in a system, satellite, device, or facility other than the satellite 30 and the ground equipment 50.

The ground equipment 500 has, as its 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 of these.

The communication device 950 transmits and receives signals to track and control each satellite 30 in the group of satellites that make up the satellite constellation 20. The communication device 950 also transmits orbit control commands 51 to each satellite 30.

The satellite analysis unit 520 analyzes the state of the satellite constellation 20 and the state of the satellites 30. As a specific example, the satellite analysis unit 520 determines whether there is a risk of collision between the satellites 30.

The orbit control command generating unit 510 generates an orbit control command 51 to be transmitted to the satellite 30. Specifically, the orbit control command generating unit 510 transmits a command to the satellite 30 to realize the following operation example. Note that the method by which the orbit control command generating unit 510 transmits a command corresponds to a command transmission method. A program that causes the orbit control command generating unit 510 to transmit a command corresponds to a command transmission program. The command transmission program may be a part of a satellite constellation formation program. The command transmission program causes the ground equipment 500 to appropriately transmit a command to the satellite 30 requesting that the satellite constellation formation method be performed.
In this way, the orbit control command generation unit 510 and the satellite analysis unit 520 realize the functions of the satellite constellation formation unit 110. In other words, the orbit control command generation unit 510 and the satellite analysis unit 520 correspond to a specific example of the functions of the satellite constellation formation unit 110.

FIG. 5 is a diagram showing an example of the functional configuration of a satellite constellation forming system 100 according to this embodiment.
The satellite 30 further includes a satellite constellation forming unit 110b that forms the satellite constellation 20. The satellite constellation forming unit 110b of each of the multiple satellites 30 and the satellite constellation forming unit 110 provided in each of the ground facilities 500 work together to realize the functions of the satellite constellation forming system 100 according to this embodiment. The satellite constellation forming unit 110b of the satellite 30 may be provided in the satellite control device 31.
The satellite constellation forming unit 110b also includes an analysis device 40. The analysis device 40 analyzes the orbits of each satellite 30 that constitutes the satellite constellation 20. Note that satellites 30 other than the satellite 30 that is newly inserted into orbit do not need to include the analysis device 40.

*** Operation Description ***
<Operation Example 1 According to First Embodiment>
This operation example corresponds to a method for forming a satellite constellation.
In this operation example, in the satellite constellation 20, n (n is an integer of 2 or more) orbital planes are evenly arranged in the longitude direction, and up to m (m is an integer of 2 or more) satellites 30 fly at flight orbit altitudes in each of the n orbital planes so that the phase angles are even, and m or less satellites 30 are in regular operation in each of the n or less orbital planes. Also, in the satellite constellation 20, when each of the satellites 30 in regular operation is treated as a target satellite, the satellites 30 fly synchronously in the orbit of the target satellite and in the orbit adjacent to the orbit of the target satellite so that the phase offset angle indicating the in-orbit angle difference from when the satellite 30 in the orbit adjacent to the orbit of the target satellite moves north over the equator to when the satellite 30 in the orbit of the target satellite moves north over the equator is shifted by (360/(m×n))×i degrees (phase offset i is an integer of 0 to m−1).
In addition, the orbiting satellite, which is a satellite 30 newly inserted into the satellite constellation 20, is equipped with an analysis device 40. The analysis device 40 uses a phase offset model that models the phase offset i and the relative flight position in each of the orbital planes of n planes or less. In the phase offset model, the orbital planes where there is a risk of collision between the satellites 30 and the relative phase of the satellite 30 are identified as dangerous areas. In addition, since the phase offset model does not specifically specify the orbital inclination angle, it does not mention latitude, and as for longitude, the relative longitude in the sky above the equator is determined according to the number of orbital planes. The analysis device 40 receives orbit information of each satellite 30 in normal operation, and derives the phase offset angle and phase offset i of the orbiting satellite with respect to each satellite 30 in normal operation based on the received orbit information and the orbit information of the orbiting satellite. The analysis device 40 may be equipped with a phase offset model.
The orbital injection satellite operates the propulsion device 33 of the orbital injection satellite before passing through the danger area indicated by the phase offset model, thereby avoiding the risk of collision between the orbital injection satellite and the satellites 30 constituting the satellite constellation 20, and reaches the orbital injection position. Specific examples of a method for the orbital injection satellite to avoid the collision risk include operating the propulsion device 33 to change the timing of passing through the danger area, or operating the propulsion device 33 to avoid passing through the danger area. The orbital injection position may be any position as long as it is a position suitable for the orbital injection satellite to be injected.

When m satellites 30 fly in one orbital plane with equal phase angles, the phase angle is 360/m degrees.
In the satellite constellation 20 with an orbital inclination angle of 90 degrees, all the satellites 30 in all the orbital planes pass through the North Pole and the South Pole, respectively. Therefore, in order to avoid collisions between the satellites 30 at the poles, for any orbital plane, the satellites 30 in all the other orbital planes must pass through one by one within a range of 360/m degrees, which is the phase angle from when a satellite 30 passes through the pole until the satellite 30 following the satellite 30 passes through the pole. When the number of orbital planes is n, collisions between the satellites 30 at the poles do not occur if a satellite 30 flying in any orbit passes through and then a satellite 30 flying in an adjacent orbital plane passes through every 360/(m×n) degrees. Here, to explain the relationship between a certain orbital plane and an adjacent orbital plane to the certain orbital plane, there may be one or more orbital planes between the certain orbital plane and the adjacent orbital plane.
As a method for realizing that satellites 30 flying in adjacent orbital planes pass every 360/(m×n) degrees by focusing on the timing when satellites 30 flying in each orbital plane move northward above the equator, there are variations in phase offset according to the number of orbital planes. In this variation, since the timing when each satellite 30 passes the flight orbit altitude at the intersection of multiple orbital planes differs depending on the phase offset, it is necessary to select an optimal phase offset to avoid collision between satellites 30. The flight orbit altitude is the orbit altitude at which the satellite 30 flies, and may be within a certain range.
The phase offset angle, phase offset i, and phase offset model will be described below using an example of the satellite constellation 20 having seven orbital planes.
6 shows a phase offset model in which the phase offset angle is 0 degrees and the value of the phase offset i is 0. Here, the phase offset i value of 0 is also expressed as phase offset 0.
In all seven orbital planes, the phase offset is 0 when the timing of the satellite 30 moving north above the equator is synchronized.

In orbital plane 1, there is a phase angle of 360/m degrees from when the first satellite passes north over the equator until the subsequent second satellite flies over the equator. There are seven variations in which satellites 30 flying in adjacent orbital planes pass through a phase angle of 360/(m×n) degrees, which is equal n divisions between the phase angles, with a time difference, from phase offset 0 to phase offset 6, depending on the arrangement order of the orbital planes.
FIG. 7 shows a phase offset model where the phase offset i has a value of one.
In phase offset 1, after a satellite 30 flying in orbital plane 1 passes north over the equator, a satellite 30 flying in an adjacent orbital plane passes north over the equator with a phase difference delay of 360/(m×n) degrees.

Similarly, phase offset models corresponding to phase offset 2 to phase offset 6 are shown in FIGS.
In phase offset i, after a satellite 30 flying in orbital plane 1 passes north over the equator, a satellite 30 flying in an adjacent orbital plane passes north over the equator with a phase difference delay of (360/(m×n))×i degrees.
As exemplified in the seven orbital planes, the phase offset model models the relative flight position of the satellite 30 for each orbital plane. The seven orbital planes means that the number of orbital planes is seven.

Next, the danger region will be explained using a phase offset model of eight orbital planes.
FIG. 13 shows a phase offset model with eight orbital planes and six phase offsets.
In the orbital plane 5, the phase offset of the fifth satellite is the same as the phase offset of the second satellite in the orbital plane 1. That is, the diagonal line pattern shown in the orbital planes 1 to 4 and the diagonal line pattern shown in the orbital planes 5 to 8 are the same starting from the equator. However, since the orbital planes 1 and 5 are different, the satellite 30 in the orbital plane 1 does not collide with the satellite 30 in the orbital plane 5 at the timing of moving north over the equator. However, as the lower part of the phase offset model shows the equator, the northern end, the equator, the southern end, and the equator in that order, the timing of the fifth satellite in the orbital plane 5 moving north over the equator coincides with the timing of the satellite 30 flying in the orbital plane 1 moving south over the equator. Therefore, it is shown that the satellite 30 flying north on the orbital plane 5 and the satellite 30 flying south on the orbital plane 1 are in a dangerous region where they collide. Note that FIG. 13 shows only one example of a dangerous region, and there are other dangerous regions in FIG. 13. As a specific example, all satellites 30 shown side-by-side in orbital plane 1 and orbital plane 5 fall within the risk region.

Next, a phase offset model with nine orbital planes and a phase offset of three is shown in FIG. 14. Here, when the number of orbital planes is an even number, there is an orbital plane whose normal vector is 180 degrees opposite to the normal vector of each orbital plane, so there is a risk of collision between the satellite 30 of each orbital plane and the satellite 30 of the orbital plane whose normal vector is 180 degrees opposite to the normal vector of each orbital plane in the equator. When the number of orbital planes is an odd number, there is no orbital plane with such a relationship for each orbital plane, so the danger area that occurs when the number of orbital planes is an even number does not occur. However, when the number of orbital planes is a multiple of three, orbital planes whose normal vectors are opposite to each other occur every 60 degrees in the longitude direction. FIG. 14 shows that there is a risk of collision above the equator when phase offsets overlap between orbital planes whose normal vectors are opposite to each other.
From Fig. 14, it can be seen that the phase offsets are synchronized in each of the orbital planes 1, 4, and 7. In other words, the diagonal line patterns shown on the orbital planes 1 to 3, the diagonal line patterns shown on the orbital planes 4 to 6, and the diagonal line patterns shown on the orbital planes 7 to 9 are the same starting from the equator. In other words, the timing at which the satellite 30 passes over the equator overlaps between these patterns. Note that the grid points filled with black in Fig. 14 indicate danger areas. From Fig. 14, it can be seen that the successor satellites in different orbital planes pass over the equator at the same time. Therefore, if the longitudes at which the successor satellites fly coincide due to the relative relationship with the earth's rotation speed, the successor satellites in different orbital planes will collide with each other.
In the satellite constellation 20 configured with an inclined circular orbit, two points formed at flight orbit altitudes on the intersection line of any two orbital planes are formed in a lattice pattern in the mid-latitudes. If two satellites 30 pass through the lattice-shaped points at the same time, there is a risk that the two satellites 30 will collide with each other.
The arrangement of the points formed in a grid depends on the orbital inclination angle and the longitudinal separation angle of the longitudinal components of the normal vectors of the two orbital planes, so that if the phase offsets are synchronized, there is a risk of the satellites 30 colliding with each other in the mid-latitudes, creating a danger zone.
FIG. 15 shows a specific example of a danger area in the mid-latitude band. In FIG. 15, all danger areas that are intersections of two orbits with different normal vectors are shown, that is, all danger areas in the worst state of phase offset in all combinations of orbital planes are shown. By ensuring an appropriate phase offset, it is possible to shift the passing timing of each satellite 30 in the danger area shown in FIG. 15 and eliminate the danger area. In addition, when an error occurs in the passing timing within the tolerance range, the danger area shown in FIG. 15 can be eliminated if there is a sufficient margin. However, as shown by black circles in FIG. 13 and FIG. 14, there are danger areas that cannot be eliminated because the passing timing of the satellites 30 overlap.

A representative example of orbital information is the orbital elements (Keplerian Elements) based on Kepler's laws, which are composed of the following:
Epoch: Epoch (year and day)
Mean Motion (circulation/day) or Semi-major Axis (km)
Eccentricity: Eccentricity (unitless)
Orbital inclination angle: Inclination (degrees)
Right Ascension of Ascending Node: RAAN (Right Ascension of Ascending Node) (degrees)
Argument of Perigee (degrees)
Mean periapsis angle: Mean Anomaly (degrees)

The analysis device 40 of the satellite injected into orbit may receive information indicating each of the orbital elements of all the satellites 30 as information indicating the orbital elements of the satellites 30 in normal operation. However, the amount of information indicating each of the orbital elements of all the satellites 30 is enormous. Therefore, as a specific example, the analysis device 40 of the satellite injected into orbit may obtain orbital information of one representative satellite that is representative of the satellites 30 in normal operation, and then obtain information indicating the relative phase with respect to the representative satellite as information indicating the flight positions of the other satellites 30 flying in the same orbital plane as the representative satellite, or may receive information indicating the relative angle between the orbital planes and the phase offset as information indicating the flight positions of the satellites 30 flying in an orbital plane different from the orbital plane in which the representative satellite flies.

A specific implementation method for operating the propulsion device 33 to change the timing of passing through the dangerous area to avoid the collision risk will be described. If the satellite 30 uses the propulsion device 33 to increase its speed in the direction of satellite 30's travel, the orbital altitude of the satellite 30 will increase, and if the satellite 30 uses the propulsion device 33 to decelerate in the direction of satellite 30's travel, the orbital altitude of the satellite 30 will decrease. By using this property, the satellite 30 moves in the altitude direction, changing the timing of passing through the dangerous area, and collision between satellites 30 can be avoided. In addition, if the satellite 30 operates the propulsion device 33 in a direction outside the orbital plane when passing near the equator, the orbital inclination angle will change. By using this property, the satellite 30 moves in a direction perpendicular to the altitude, and passes a position different from the dangerous area, and collision between satellites 30 can be avoided.
When the orbital plane on which the satellite 30 is newly injected into orbit is defined as a new injection orbital plane, and the phase offset at which all the satellites 30 in regular operation fly on the new injection orbital plane is defined as phase offset i, the phase offset of the satellite 30 newly injected into orbit on the new injection orbital plane is phase offset i, and the fixed position of the satellite 30 newly injected into orbit is a position where there are no satellites 30 in regular operation already flying. After reaching the fixed position, the satellite 30 newly injected into orbit matches its flight speed with all the satellites 30 in regular operation. As a result, the satellite 30 newly injected into orbit can fly in synchronization with the other satellites 30 in the new injection orbital plane at the same orbital altitude at a fixed phase interval, and the process of injecting the satellite 30 into the new injection orbital plane is completed without colliding with the other satellites 30 in the new injection orbital plane.

<Operation Example 2 According to First Embodiment>
This operation example corresponds to an extended operation example of the operation example according to the first embodiment, and corresponds to a satellite constellation forming method.
In this operation example, each of the n orbital planes constituting the satellite constellation 20 is an inclined circular orbit. The analysis device 40 also records in advance in a database, as a danger area, the positions of intersections formed at the satellite flight altitude among the intersection lines of the multiple orbital planes on which the normally operating satellite 30 flies, and which are formed in the mid-latitude band. The satellite flight altitude is the altitude at which the satellite 30 flies, and may be a certain range of orbital altitudes. The database may be recorded in the analysis device 40 or the ground facility 500.

Here, we will explain the case where m = 8 and n = 5 as an example of a satellite constellation 20 in which orbital planes corresponding to n-plane inclined circular orbits are evenly arranged with a phase shift of 360/n degrees in the longitude direction, and m satellites 30 are evenly arranged and flying on each orbital plane with a phase shift of 360/m degrees.

FIG. 16 shows a schematic diagram of a circular orbit in which eight satellites 30 fly in equal phase, as viewed from the normal direction to the orbital plane.
If the satellites 30 are evenly spaced at phase angles of 45 degrees within one orbital plane, the eight satellites 30 fly at the same altitude while maintaining the same phase, so there is no risk of the satellites 30 colliding with each other within the same orbital plane.

Figure 17 shows how there is a risk of collision between satellites 30 at the points where orbital planes with different normal vectors intersect. Here, it is assumed that the orbital altitudes of the satellites 30 are the same at each of the two points where there is a risk of collision. As a means of eliminating the risk of collision, it is effective to shift the timing of passing through the two points on the line of intersection. By focusing on the timing of each satellite 30 passing over the equator, if the timing of passing over the equator of all satellites 30 in the five orbital planes differs from one another, the risk of collision between satellites 30 at the intersections can be eliminated.

If five orbital planes in which the longitude components of the normal vectors are evenly distributed are arranged as viewed from the normal direction, and the flying positions of satellites 30 on each orbital plane are shifted evenly with respect to the equatorial plane, the result is as shown in Figure 18. (a) to (e) of Figure 18 show the phases shifted by 360/(m×n) degrees.
Figure 19(a) shows the five orbital planes shown in Figure 18 superimposed with their normal vectors aligned, while Figure 19(b) is a similar diagram to Figure 19(a), showing the orbits as viewed from the north pole when they are inclined orbits.
By shifting the phase by 9 degrees for each orbital plane, the timing at which the satellites 30 pass over the equator differs for each of the five orbital planes. Therefore, the total of 40 satellites, eight of which are on each orbital plane, will not collide with each other above the equator. When an even number of satellites 30 are evenly spaced and flying within one orbital plane, the timing at which the satellites 30 located at opposing positions within that orbital plane pass over the equator will be the same, but these satellites 30 are not subject to collision within that orbital plane.

Next, the effect of differences in the normal vectors of the inclined orbit will be explained.
If all five orbital planes shown in FIG. 18 were tilted in the same direction by an amount equivalent to the orbital inclination angle and viewed from the North Pole, they would appear as shown in FIGS. 20(a) to 20(e).
Furthermore, if the longitudinal component of the normal vector is equally distributed and tilted, it will become as shown in (f) to (j) of Figure 20. Here, each orbital plane is named the kth orbital plane (k is an integer between 1 and 5). Since there are five orbital planes, each orbital plane is rotated by 72 degrees in the longitudinal direction.
When the first orbital surface is taken as a reference, the intersections of each of the second to fifth orbital surfaces with the first orbital surface are drawn as shown in (a) to (e) of FIG. 21.
If a star is placed at the northernmost point of the orbital plane to indicate the inclination of the orbital plane, it will look like Figure 21(f) to (j).
The points at which the orbital altitudes coincide on the intersection of the orbital planes are shown in the northern and southern hemispheres as shown in (a) to (e) of Figure 22. The arrows indicate the flight direction of the satellite 30.
If the phases of the eight satellites on each orbital plane are displayed, they will look like those shown in (f) to (j) of Figure 22.
If the satellites 30 going north from the Antarctic are indicated as "ascending", the satellites 30 going south from the Antarctic are indicated as "descending", the characters indicating the satellites 30 flying in the first orbital plane are written on the top, and the characters indicating the satellites 30 flying in the other orbital planes are written on the bottom, it will look like Figure 23. From Figure 23, it can be seen that all of the intersections are between satellites 30 going north from the Antarctic and satellites 30 going south from the Antarctic.
Even if the timing of passing the equator is different for all satellites 30, there is a risk of collision between the satellites 30 at an intersection point between the orbit of a satellite 30 moving north and an orbit of a satellite 30 moving south that occurs in the mid-latitude zone other than above the equator. This is because, when each orbital plane is viewed from above the equator with the longitude directions of the normal vectors aligned, satellites 30 in different orbital planes at the same latitude move north and south at the same time, as shown in (b) of Figure 19. However, since the intersection point of two different orbits is known in advance as described above, it is possible to set the intersection point so that the satellites 30 flying on each of the two orbits do not pass through the intersection point at the same time in the early design stage.
In the case of combining five orbital planes on which eight satellites 30 fly, there is no combination in which the satellites pass through an intersection at the same time as shown in FIG. 24, so collisions between the satellites 30 do not occur during normal operation.
In this manner, in the satellite constellation forming system 100, during the design stage of the satellite constellation 20, it is confirmed that the satellites 30 will not collide with each other at any of the nodes under ideal operating conditions.

Furthermore, in the satellite constellation forming system 100, it is confirmed at the design stage that the satellites 30 will not collide with each other at any intersection point even if there is a change within the design tolerance in at least one of the phase angle between the satellites 30 in the orbital plane, the separation angle of the normal vector components in the longitude direction between the orbital planes, the orbital altitude, the eccentricity, and the orbital inclination.

The orbit injection satellite is not synchronized with the phase offset i of the group of satellites in regular operation. Therefore, there is a risk that the orbit injection satellite will collide with the satellite 30 flying in the other orbital plane at the intersection with the other orbital plane in each of the southern and northern hemispheres. Therefore, the analysis device 40 equipped in the orbit injection satellite receives the orbit information of the other satellite 30, whose orbit information is known and which is in regular operation, and derives the separation angle in the longitude direction between the orbital plane of the orbit injection satellite and the orbital plane of the other satellite 30. Since the orbital inclination angle is known, the position of the intersection is derived from the separation angle of the orbital plane and the orbital altitude. Therefore, in the transitional stage of orbit injection, all intersection points where the orbit of the orbit injection satellite intersects with the other orbital planes are identified as risk areas.
The operation of operating the propulsion device 33 before passing through the danger zone to change the timing of passing through the danger zone to avoid the risk of collision between satellites 30 and reaching a predetermined position is similar to the operation shown in Operation Example 1 according to this embodiment. As a specific example, the predetermined position is the orbit insertion position.

According to this operation example, by shifting the flight position of the satellite 30 for each orbital plane, it is possible to eliminate the risk of collision between satellites 30 moving northward and between satellites 30 moving southward.

<Operation Example 3 According to First Embodiment>
This operation example corresponds to an operation example that expands the operation example 1 or operation example 2 according to the first embodiment, and corresponds to a satellite constellation forming method. In this operation example, a mesh communication network is formed in the satellite constellation 20 by forming a circular communication network and a circular or spiral communication network. The circular communication network is formed by providing each satellite 30 flying on the target orbital plane with a communication device that communicates with at least one of the satellites 30 located in front and behind the satellite 30 in the direction of travel when each orbital plane of the satellite constellation 20 is set as a target orbital plane. The communication device may be a satellite communication device 32. The circular or spiral communication network is formed by providing at least one of the satellites 30 flying on the target orbital plane with a communication device that communicates with at least one of the satellites 30 flying on an orbit adjacent to the target orbital plane. The orbital insertion satellite obtains information transmitted via the mesh communication network as orbit information of the satellite 30 in normal operation.

After reaching a predetermined orbital plane, the orbiting satellite is connected to the mesh communication network by establishing communication with a satellite 30 flying in at least one of the front and rear of the traveling direction in the orbital plane that the satellite reached. The orbiting satellite may enter between two adjacent satellites 30 among the satellites 30 that form the ring-shaped communication network, and reconstruct the ring-shaped communication network by establishing communication with the satellites 30 before and after it in the ring-shaped communication network.
If the orbital injection satellite is connected to a mesh communication network, it can receive on-board orbital information of other satellites 30, and can autonomously transfer orbits to reach a predetermined position while autonomously avoiding collisions with other satellites 30.
In addition, a communication network in the longitude direction is a spiral communication network if the timing of satellites 30 passing over the equator in all orbital planes is synchronized and if satellites 30 passing over the equator in adjacent orbits form a communication network. However, this situation is not recommended because there is a risk of collision between satellites 30 since the phase offset is 0.
A spiral communication network is formed when a communication network is formed between satellites 30 in adjacent orbits where the phase offset between the satellites 30 is the same phase offset i other than 0, since the timing at which the satellites 30 pass over the equator differs for each orbital plane. It is also possible to form a ring-shaped communication network by combining communications between satellites 30 in adjacent orbits where the phase offsets are different from each other.

<Operation Example 4 According to First Embodiment>
This operation example corresponds to a satellite constellation formation method. The analysis device 40 generates data used to control the propulsion device 33 of the orbital injection satellite by applying the result derived by the analysis device 40 to an inference model generated based on performance data indicating the performance of a new satellite being injected into the satellite constellation 20 in the past. The learning data of the inference model may be data on a satellite constellation 20 different from the satellite constellation 20 that injects the orbital injection satellite into orbit, or may be data on a satellite 30 different from the orbital injection satellite. The performance data may include data indicating the result derived by the analysis device 40 and control data of the propulsion device 33 of the satellite 30 newly injected into orbit in the past. The performance data may be used as the learning data. The inference model is a model that is machine-learned by a machine learning method such as deep learning based on the past orbital transfer performance of successful orbit injection. The analysis device 40 may use a prepared inference model, or may generate an inference model using actual data. The inference model takes the result derived by the analysis device 40 as input, and outputs data used to control the propulsion device 33. The analysis device 40 may be equipped with an inference model.
The orbiting satellite operates its propulsion device 33 according to the data generated by the analysis device 40 .
In the satellite constellation forming method shown in the operation examples 1 to 3 according to the first embodiment, in which the orbital injection satellite changes the timing of passing through the danger area or avoids passing through the danger area to avoid collision between the satellites 30 by operating the propulsion device 33, if the speed is increased to avoid collision, the orbital altitude increases and the ground speed decreases. Therefore, there is a problem that the orbital injection satellite cannot reach the desired orbital position. Therefore, the orbital injection satellite needs to decelerate at an appropriate timing to return to the orbital altitude. In addition, when the orbital injection satellite operates the propulsion device 33 in a direction outside the orbital plane at the equinox, the orbital inclination angle of the orbital injection satellite differs from the desired orbital inclination angle. Therefore, after passing through the danger area, the orbital injection satellite needs to operate the propulsion device 33 in a direction to return the orbital inclination angle to the original at the equinox.
Furthermore, even in the process of returning at least one of the orbital altitude and orbital inclination of the orbital injection satellite after the orbital injection satellite has passed through the danger zone, the orbital injection satellite needs to avoid the risk of collision with a satellite 30 flying in a different orbital plane.
In the satellite constellation 20 in which m satellites 30 are injected into each of n orbital planes, in the process of returning at least one of the orbital altitude and orbital inclination of the satellite 30 injected into orbit after passing through a dangerous area, the relative relationship between the other orbital planes and the other satellites 30 to avoid the risk of collision with the satellite 30 flying in another orbital plane is the same for each satellite 30 injected into orbit. Therefore, if the operational record of the propulsion device 33 when the satellite 30 is newly injected into orbit is successfully reproduced by machine learning using AI (Artificial Intelligence), there is an effect that the satellite 30 can be newly injected into orbit with low risk.
FIG. 25 shows how an inference model used in this operation example is generated. The inference model is created using on-orbit data, a phase offset model, a danger area database, and danger avoidance operation results. The on-orbit data includes, as a specific example, the startup information of the satellite 30 to be controlled and the startup information of other satellites 30. The danger avoidance operation results include, as a specific example, the operation profile, the avoidance profile, and the return profile of the propulsion device 33. The inference model outputs a prediction of passage through a danger area and an operation command for the propulsion device 33. FIG. 25 shows how the satellite 30 moves from a position at time T _n to a position at time T _n+1 by operating the propulsion device 33 according to the operation command output by the inference model. The inference model infers the flight position of the satellite group in normal operation based on the result of the operation command for the propulsion device 33, infers the danger area, and also outputs an operation command for the propulsion device 33 based on the result of inferring the danger area. The inference model also outputs information indicating the flight position that changes by operating the propulsion device 33 according to the output operation command.
The teacher model does not need to include the hazard avoidance operation record. If various error factors on orbit are not taken into consideration, the theoretical operating conditions of the propulsion device 33 and the change in the flight position of the satellite 30 can be determined even without the operation record of the propulsion device 33. The purpose of deep learning using the operation record of the propulsion device 33 is to learn the relationship between the factors assumed in the ground design stage and unexpected factors that could not be reflected in the simulation of the propulsion device 33, and the operation record of the propulsion device 33 on orbit.
According to this operation example, an analysis device can be provided that uses AI to machine-learn the success rate of orbital insertion.

***Other configurations***
<Modification 1>
In this embodiment, the functions of the satellite constellation forming unit 110 are realized by software. As a modified example, the functions of the satellite constellation forming unit 110 may be realized by hardware. Figure 26 shows this modified example.

The ground equipment 500 includes an electronic circuit 909 in place of a processor 910 .
The electronic circuit 909 is a dedicated electronic circuit that realizes the functions of the satellite constellation forming unit 110 .
Specifically, the electronic circuit 909 is a single circuit, a composite 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 forming unit 110 may be realized by a single electronic circuit, or may be realized by distributing the functions among multiple electronic circuits.
As another modification, some of the functions of the satellite constellation forming unit 110 may be realized by the electronic circuit 909, and the remaining functions may be realized by software.

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

***Other embodiments***
Although the first embodiment has been described, it is possible to combine a plurality of parts of the present embodiment. Alternatively, it is possible to partially implement the present embodiment. In addition, the present embodiment may be modified in various ways as necessary, and may be implemented in any combination, either as a whole or in part.
The above-described embodiment is essentially a preferred example, and is not intended to limit the scope of the present disclosure, its applications, and uses. The described procedure may be modified as appropriate.

20 Satellite constellation, 30 Satellite, 31 Satellite control device, 32 Satellite communication device, 33 Propulsion device, 34 Attitude control device, 35 Power supply device, 40 Analysis device, 51 Orbit control command, 100 Satellite constellation formation system, 110, 110b Satellite constellation formation 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 (8)

n (n is an integer of 2 or more) orbital planes are evenly arranged in the longitude direction, and up to m (m is an integer of 2 or more) satellites fly at flight orbit altitudes in each of the n orbital planes so that their phase angles are even,
m or less satellites are in regular operation in each of n or less orbital planes,
A method for forming a satellite constellation in a satellite constellation in which satellites in a normally operating satellite are flying synchronously in an orbit of a target satellite and an orbit adjacent to the orbit of the target satellite such that a phase offset angle indicating an angle difference in an orbital plane from when a satellite in an orbit adjacent to the orbit of the target satellite moves north over the equator until when a satellite in the orbit of the target satellite moves north over the equator is shifted by (360/(m×n))×i degrees (phase offset i is an integer of 0 to m−1),
A satellite to be newly orbitally injected into the satellite constellation is equipped with an analysis device,
the analysis device uses a phase offset model that models the phase offset i and a relative flight position on each of the nth or lower orbital plane,
In the phase offset model, orbital planes and relative phases of satellites that are at risk of collision are identified as danger regions;
The analysis device receives orbit information of each satellite in normal operation, and derives a phase offset angle and a phase offset i of the orbit injection satellite with respect to each of the normally operating satellites based on the received orbit information and the orbit information of the orbit injection satellite;
A method for forming a satellite constellation in which the orbital injection satellite reaches an orbital injection position by operating a propulsion device of the orbital injection satellite before the orbital injection satellite passes through a danger area indicated by the phase offset model, thereby avoiding a risk of collision between the orbital injection satellite and satellites constituting the satellite constellation. each of the n orbital planes is an inclined circular orbit;
2. The satellite constellation forming method according to claim 1, wherein the analysis device records in advance in a database as danger areas the positions of intersections formed at satellite flight altitudes among the intersections of multiple orbital planes in which satellites in regular operation fly, and which are formed in the mid-latitudes. In the satellite constellation,
When each orbital plane of the satellite constellation is regarded as a target orbital plane, each satellite flying on the target orbital plane is provided with a communication device for communicating with a satellite located at least either in front of or behind the satellite in the direction of flight, thereby forming a circular communication network; and
At least one of the satellites flying on the target orbital plane is provided with a communication device for communicating with at least one of the satellites flying on an orbit adjacent to the target orbital plane, thereby forming a circular or spiral communication network, thereby forming a mesh communication network;
3. The method of forming a satellite constellation according to claim 1, wherein the orbital injection satellite obtains information transmitted via the mesh communication network as orbital information of a satellite in regular operation. the analysis device generates data to be used for controlling a propulsion device of the orbital injection satellite by applying a result derived by the analysis device to an inference model generated based on performance data showing performance of newly injecting a satellite into the orbit of a satellite constellation in the past;
4. The method for forming a satellite constellation according to claim 1, wherein the orbital injection satellite operates a propulsion device of the orbital injection satellite in accordance with the data generated by the analysis device. The satellite constellation formation method according to claim 4, wherein the performance data includes data indicating the results derived by the analysis device and control data for the propulsion device of a satellite that was newly launched into orbit in the past. A satellite constellation formed by the satellite constellation forming method according to any one of claims 1 to 5. An analysis device equipped with the phase offset model described in claim 1. An analysis device equipped with the inference model described in claim 4 or claim 5.

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