Observation satellite

Abstract

To observe a space object under a suitable condition in an observation satellite.SOLUTION: An observation satellite observes an artificial satellite or a space object such as a debris of flying in the vicinity of a stationary orbit by surrounding around the earth. The observation satellite has an observation device and a propulsion device, and descends an orbital altitude of the observation satellite by controlling the propulsion device so as to decelerate the observation satellite. The observation satellite operates the observation device in the sky on the back side of the earth on the side not exposed to sunlight from local sun time (LST) 18:00 to next morning LST 06:00 while the observation satellite is moving to the east to the space object by increasing a surrounding speed of the observation satellite to a rotation speed of the earth according to descends of the orbit altitude.SELECTED DRAWING: Figure 51

Description

[Technical field]

[0001] The present disclosure relates to space situation monitoring business equipment, ground equipment, space traffic business equipment, space traffic management systems, and observation satellites. [Background technology]

[0002] In recent years, large-scale satellite constellations ranging from hundreds to thousands of satellites have been proposed. In addition, in space traffic control (STM), there is an increasing need to create international rules to avoid the risk of collisions caused by the coexistence of multiple satellite constellations.

[0003] Patent Document 1 discloses a technique for forming a satellite constellation consisting of multiple satellites in the same circular orbit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-114159 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a satellite constellation, the orbital altitudes of different orbital planes are generally all the same. Therefore, there is a risk of collision between satellites flying in different orbital planes at the same orbital altitude. As the number of orbital planes and the number of satellites in each orbital plane increase, the collision risk increases, which is an issue.

[0006] The present disclosure aims to observe space objects under favorable conditions using an observation satellite. [Means for solving the problem]

[0007] The observation satellite according to the present disclosure is an artificial satellite that orbits the Earth and flies near a geostationary orbit, or an observation satellite that observes space objects, such as debris, which is information about space objects, Equipped with observation equipment and propulsion equipment, Decreasing the orbital altitude of the observation satellite by controlling the propulsion device so as to decelerate the observation satellite; As the orbital altitude decreases, the orbital speed of the observation satellite increases relative to the Earth's rotation speed, causing the observation satellite to move eastward relative to the space object and move toward the Local Sun. The observation equipment is operated in the sky above the other side of the Earth, which is the side not exposed to sunlight, between 18:00 LST and 06:00 LST the following morning. Effect of the Invention

[0008] The observation satellite according to the present disclosure has the advantage of being able to observe space objects under favorable conditions. [Brief description of the drawings]

[0009] [Figure 1] An example of multiple satellites providing global communications services to the ground. [Diagram 2] An example of multiple satellites in a single orbital plane providing an Earth observation service. [Diagram 3] FIG. 2 is a schematic diagram showing an example of a plurality of orbital planes of a satellite constellation according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing another example of a plurality of orbital planes of the satellite constellation according to the first embodiment. [Diagram 5] 2 shows an example of multiple satellites flying in one of the orbital planes of a satellite constellation according to the first embodiment. [Figure 6] FIG. 1 is a configuration diagram of a satellite constellation forming system according to a first embodiment. [Figure 7] FIG. 2 is a diagram showing the operation of the satellite constellation forming system according to the first embodiment. [Figure 8] FIG. 11 is a diagram showing the relative altitude differences of a plurality of orbital planes according to the second embodiment. [Figure 9] FIG. 13 is a diagram showing a ground service range of a comparative example. [Figure 10] FIG. 11 is a diagram showing a ground service range according to the third embodiment. [Figure 11] FIG. 13 is a diagram showing an orbital plane that satisfies the conditions for a sun-synchronous orbit according to a fourth embodiment. [Figure 12] 13 shows an example of a satellite constellation formed by a satellite constellation forming system according to a fifth embodiment. [Figure 13] FIG. 2 is a schematic diagram illustrating an example of a collision condition in a satellite constellation. [Figure 14] FIG. 2 is a schematic diagram illustrating an example of a collision condition in a satellite constellation. [Figure 15] 23 shows an example of a satellite constellation formed by a satellite constellation forming system according to the sixth embodiment. [Figure 16] FIG. 13 is a diagram showing the terrestrial service range provided by a satellite constellation in accordance with a seventh embodiment. [Figure 17] FIG. 13 is a diagram showing the timing of polar passing in a satellite constellation according to a seventh embodiment when the number of orbital planes is an even number. [Figure 18] FIG. 13 is a diagram showing the timing of polar passing in a satellite constellation according to a seventh embodiment when the number of orbital planes is an odd number. [Figure 19] A diagram showing the concept of de-orbiting by free fall. [Figure 20] A diagram showing the collision risk when a satellite de-orbits above a satellite constellation. [Figure 21] A diagram showing the change in orbital altitude due to acceleration and deceleration of a satellite. [Figure 22] A diagram showing the change in orbital inclination angle due to thrust from a thruster. [Figure 23] FIG. 23 is a diagram showing the configuration of ground equipment according to a tenth embodiment. [Figure 24] 23 shows an example of a satellite constellation formed by a satellite constellation forming system according to the sixth embodiment. [Diagram 25] FIG. 22 is a schematic diagram showing a specific example of a satellite constellation 20 according to an eleventh embodiment. [Figure 26] An example of the configuration of satellites in a satellite constellation formation system. [Figure 27] An example of the configuration of ground equipment for a satellite constellation formation system. [Figure 28] An example of the functional configuration of a satellite constellation formation system. [Figure 29] 23 shows an example of the overall configuration of a space traffic management system according to embodiment 12. [Diagram 30] 23 shows a configuration example of a space traffic management device according to embodiment 12. [Diagram 31] FIG. 11 is a diagram showing a satellite arrangement in an orbital plane as a comparative example of the space traffic management processing example 2. [Diagram 32] FIG. 23 is a diagram showing a satellite arrangement in an orbital plane in Example 2 of a space traffic management process according to the twelfth embodiment. [Diagram 33] A diagram showing multiple orbital planes with the same normal vector but different orbital altitudes. [Diagram 34] A diagram showing the intrusion of a high-altitude mega-constellation satellite into a dense area (dangerous area) during the satellite orbit descent process. [Diagram 35] FIG. 23 is a diagram showing a space traffic management process for avoiding intrusion into a crowded area during a satellite orbit descent process in accordance with a twelfth embodiment. [Diagram 36] FIG. 23 shows the configuration of an observation system 100 in a thirteenth embodiment. [Figure 37] FIG. 23 is a configuration diagram of an observation satellite 200 according to a thirteenth embodiment. [Figure 38] FIG. 23 is a diagram showing Example 1(1) of the observation method in the thirteenth embodiment. [Figure 39] FIG. 23 is a diagram showing Example 1(2) of the observation method in the thirteenth embodiment. [Diagram 40] FIG. 23 is a diagram showing Example 1(3) of the observation method in the thirteenth embodiment. [Diagram 41] FIG. 23 is a diagram showing Example 1(4) of the observation method in the thirteenth embodiment. [Diagram 42] FIG. 23 is a diagram showing Example 1(5) of the observation method in the thirteenth embodiment. [Diagram 43]FIG. 23 shows Example 2(1) of the observation method in the thirteenth embodiment. [Diagram 44] FIG. 23 is a diagram showing Example 2(2) of the observation method in the thirteenth embodiment. [Diagram 45] FIG. 23 is a diagram showing Example 2(3) of the observation method in the thirteenth embodiment. [Figure 46] FIG. 23 is a diagram showing Example 2(4) of the observation method in the thirteenth embodiment. [Figure 47] FIG. 23 is a diagram showing Example 2(5) of the observation method in the thirteenth embodiment. [Figure 48] FIG. 23 is a configuration diagram of a communications satellite 120 in a fourteenth embodiment. [Figure 49] FIG. 23 is a configuration diagram of an observation satellite 110 according to a fourteenth embodiment. [Figure 50] FIG. 23 is an explanatory diagram of data processing by a fisheye lens camera in a fourteenth embodiment. [Figure 51] FIG. 23 is a diagram showing the following observation satellites according to embodiment 14. [Figure 52] FIG. 23 is a diagram showing the following observation satellites according to embodiment 14. [Diagram 53] FIG. 23 is a diagram showing an example of the operation of a camera equipped with a fisheye lens in accordance with the fourteenth embodiment. [Figure 54] 23A to 23C are diagrams showing another example of the operation of the camera equipped with a fisheye lens in accordance with the fourteenth embodiment. [Figure 55] A diagram in which information about a space object is plotted on a graph with distance on the horizontal axis and azimuth on the vertical axis. [Figure 56] A diagram in which information about a space object is plotted on a graph with distance on the horizontal axis and azimuth on the vertical axis. [Figure 57] 23 shows an example of the operation of a camera equipped with a fisheye lens in accordance with embodiment 14. [Figure 58] Graph corresponding to FIG. 57. [Figure 59] 23A to 23C are graphs corresponding to an example of the operation of a camera equipped with a fisheye lens in accordance with the fourteenth embodiment. [Figure 60] 23A to 23C are graphs corresponding to an example of the operation of a camera equipped with a fisheye lens in accordance with the fourteenth embodiment. [Figure 61]23 shows an example of a functional configuration of a space traffic management system according to embodiment 12. [Figure 62] 23 is an example of a space information recorder for a mega constellation business device relating to embodiment 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 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 relationship between the sizes of the components in the following drawings may differ from the actual relationship. In addition, in the description of the embodiments, directions or positions such as "upper", "lower", "left", "right", "front", "rear", "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 the components such as devices, instruments, or parts.

[0011] Embodiment 1 FIG. 1 is a diagram showing an example in which multiple satellites cooperate to provide communication services across the entire globe (Earth 70) to the ground. FIG. 1 shows a satellite constellation 20 that provides global communication services. The communication service range of each of the multiple satellites flying at the same altitude in the same orbital plane overlaps with the communication service range of the succeeding satellite, so that such multiple satellites can provide communication services to a specific point on the ground by alternating between the multiple satellites on the same orbital plane in a time-division manner. However, communication services can be provided only in a single orbital plane, which is limited to the area directly below the satellite orbit. Therefore, another orbital plane that rotates in an east-west direction with respect to the earth is provided adjacent to the satellite, and communication services are also provided by multiple satellites on that orbital plane. By providing adjacent orbital planes in this way, communication services to the ground between the adjacent orbits can be provided in a wide area. Similarly, by distributing a large number of orbital planes approximately evenly around the earth, communication services to the ground can be provided over the entire globe. From the perspective of a specific point on the ground, each satellite flies away in a short time. However, if multiple satellites in orbit provide communication services by alternating in a time-division manner, it becomes possible to provide continuous communication services to any point on the ground. In this case, each satellite transmits and receives necessary signals and information using an inter-satellite communication method in order to share communication services with its successor satellite.

[0012] When communication services are provided by a satellite constellation orbiting in low earth orbit, the service area of ​​all satellites covers the entire globe, and communication services for any ground user are shared and continued by satellites that fly one after another, taking over signals and information. This ultimately allows for continuous communication services to be provided to ground users. By equipping each satellite with inter-satellite communication functions in addition to satellite-to-ground communication functions, it becomes possible for signals and information to be taken over between satellites passing nearby. The handover of signals and information that contributes to the mission coordination of communication services is hereafter referred to as handover.

[0013] In a satellite constellation, the orbital altitudes of the different orbital planes are generally all the same. Since the ground speeds of satellites flying at the same orbital altitude are similar, the coverage area of ​​the earth moves according to the satellite ground speed while maintaining the relative positions of the coverage areas of each satellite. If the coverage areas of subsequent satellites in the same orbital plane or satellites in adjacent orbital planes comprehensively cover the earth's surface, the coverage area is always maintained as seen from any point on the earth.

[0014] FIG. 2 is a diagram showing an example of an Earth observation service provided by multiple satellites in a single orbital plane. FIG. 2 shows a satellite constellation 20 that realizes earth observation services. In the satellite constellation of FIG. 2, satellites equipped with earth observation equipment, such as optical sensors or radio wave sensors such as synthetic aperture radar, fly in the same orbital plane at the same altitude. In this way, in a satellite group in which the imaging range of the ground is delayed and subsequent satellites overlap, multiple satellites in orbit take turns in a time-division manner to capture ground images for a specific point on the ground, thereby providing earth observation services. However, services can be provided in a single orbital plane only in the vicinity directly below the satellite orbit. In contrast, if another orbital plane that rotates in the east-west direction with respect to the earth is placed adjacent to the satellite and a similar service is provided by multiple satellites at the same time, it becomes possible to cover the ground services between the adjacent orbits in a planar manner. In the same way, if multiple orbital planes are arranged approximately evenly around the earth, it becomes possible to provide comprehensive earth observation services over the entire globe. From a specific point on the ground, each satellite flies away in a short time, but if multiple satellites in orbit take turns in a time-division manner to provide services, it becomes possible to provide earth observation services to any point on the ground at any time.

[0015] ***Configuration Description*** The satellite constellation forming system 100 according to the present embodiment forms a satellite constellation 20 having a plurality of orbital planes 21. Furthermore, in each of the plurality of orbital planes 21, a plurality of satellites 30 fly at the same orbital altitude.

[0016] Here, a brief description will be given of the satellite constellation 20 formed by the satellite constellation forming system 100 according to this embodiment. The satellite constellation 20 according to this embodiment is composed of a satellite group 300 consisting of a plurality of satellites 30 in each orbital plane 21. In the satellite constellation 20 according to this embodiment, the satellite group 300 cooperate to provide services. Specifically, the satellite constellation 20 refers to a satellite constellation consisting of one satellite group provided by a communications business service company as shown in FIG. 1. Also, the satellite constellation 20 refers to a satellite constellation consisting of one satellite group provided by an observation business service company as shown in FIG. 2.

[0017] FIG. 3 is a schematic diagram showing an example of a plurality of orbital planes 21 of a satellite constellation 20 according to this embodiment. 3, each of the multiple orbital planes 21 in the satellite constellation 20 exists in substantially the same plane. As an example, each orbital plane 21 may have 20 or more satellites flying as the multiple satellites.

[0018] FIG. 4 is a diagram showing another example of a plurality of orbital planes 21 of a satellite constellation 20 according to the present embodiment. In Fig. 4, each of the multiple orbital planes 21 in the satellite constellation 20 exists on a different plane from each other. In Fig. 4, the orbital inclination angle of each of the multiple orbital planes 21 is approximately 90 degrees, but the orbital planes are offset. That is, the multiple orbital planes 21 intersect with each other. As an example, each orbital plane 21 may have 20 or more satellites flying as the multiple satellites. Also, the satellite constellation 20 in Fig. 4 may have 20 or more orbital planes 21, as an example.

[0019] FIG. 5 shows an example of multiple satellites 30 flying in one of the orbital planes 21 of a satellite constellation 20 according to this embodiment. Multiple satellites 30 flying at the same altitude in the same orbital plane fly at the same relative speed while maintaining the relative phase in the orbital plane, so multiple satellites 30 flying at the same altitude in the same orbital plane will not collide.

[0020] The configuration of a satellite constellation forming system 100 according to this embodiment will be described with reference to FIG. The satellite constellation forming system 100 includes a computer. Although Fig. 6 shows the configuration of one computer, in reality, a computer is provided for each of the multiple satellites 30 that make up the satellite constellation 20 and for each of the ground facilities that communicate with the satellites 30. The computers provided for each of the multiple satellites 30 and for each of the ground facilities 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.

[0021] The satellite constellation forming system 100 includes a processor 910, as well as 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.

[0022] The satellite constellation forming system 100 includes, as a functional element, a satellite constellation forming unit 110. The functions of the satellite constellation forming unit 110 are realized by hardware or software.

[0023] 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 digital signal processor (DSP), and a graphics processing unit (GPU).

[0024] 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 HDD. The auxiliary storage device 922 may also be a portable storage medium such as an SD (registered trademark) memory card, CF, NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD. Note that HDD is an abbreviation for Hard Disk Drive. SD (registered trademark) is an abbreviation for Secure Digital. CF is an abbreviation for CompactFlash (registered trademark). DVD is an abbreviation for Digital Versatile Disk.

[0025] 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 an HDMI (registered trademark) (High Definition Multimedia Interface) terminal. Specifically, the display is an LCD (Liquid Crystal Display).

[0026] 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 performs communication between the ground equipment and the satellites, or between the satellites themselves, via the communication device 950.

[0027] The satellite constellation forming program is read into the processor 910 and executed by the processor 910. The memory 921 stores not only the satellite constellation forming program but also an OS (Operating System). The processor 910 executes the satellite constellation forming program while executing the OS. The satellite constellation forming program and the OS may be stored in an auxiliary storage device. The satellite constellation forming 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 forming program may be incorporated into the OS.

[0028] The satellite constellation forming system 100 may include a plurality of processors replacing the processor 910. These plurality of processors share the task of executing the satellite constellation forming program. Each of the processors is a device that executes the satellite constellation forming program, just like the processor 910.

[0029] Data, information, signal values ​​and variable values ​​used, processed or output by the satellite constellation formation program are stored in memory 921, secondary storage device 922, or in registers or cache memory within processor 910.

[0030] The "unit" of the satellite constellation forming unit 110 may be read as a "processing," "procedure," or "step." Also, the "processing" of the satellite constellation forming process may be read as a "program," "program product," or "computer-readable storage medium on which a program is recorded." The satellite constellation forming program causes a computer to execute each process, procedure, or step of the above-mentioned satellite constellation forming unit, where "unit" is replaced with "process," "procedure," or "step." Also, the satellite constellation forming method is a method performed by the satellite constellation forming system 100 executing the satellite constellation forming program. The satellite constellation forming program may be provided by being stored in a computer-readable recording medium or a storage medium, or may be provided as a program product.

[0031] ***Explanation of Operation*** The operation of the satellite constellation forming system 100 according to this embodiment will be described with reference to FIG.

[0032] In step S101, parameters are set in the satellite constellation forming system 100 so that the orbital altitudes of the orbital planes 21 of the satellite constellation 20 are different from each other. In step S102, the satellite constellation forming unit 110 forms a satellite constellation 20 in which the orbital planes 21 of the multiple orbital planes have different orbital altitudes. The satellite constellation forming unit 110 forms the satellite constellation 20 in which the orbital planes 21 have different orbital altitudes, using preset parameters. As an example, 20 or more satellites may fly as the multiple satellites on each orbital plane 21. Also, the satellite constellation 20 in FIG. 4 may have 20 or more orbital planes 21, as an example.

[0033] A more detailed explanation will be given of a case where the satellite constellation forming unit 110 forms a satellite constellation 20 (see FIG. 4) in which the orbital planes 21 of the multiple orbital planes exist on different planes. As described above, the multiple satellites 30 of the satellite constellation 20 in FIG. 4 provide services to points on the ground in a time-division alternating manner.

[0034] To prevent collisions by flying at different orbital altitudes, it is necessary to consider not only the size and shape of the two objects, but also the accuracy of position determination during tracking and control on the ground. For example, if the size of the object is about 1m and its exact position is known, a collision can be avoided by maintaining an altitude difference of 3m or more. However, if there are errors in the four elements of position coordinates and time (x, y, z, t), the possibility of collision remains.

[0035] It is considered that a satellite constellation operator can maintain the position determination accuracy of its satellites at any time of about 100 m. Therefore, by setting the altitude difference between different orbital planes to 200 m or more, the satellite constellation 20 having a plurality of orbital planes 21 with different orbital altitudes according to this embodiment can be formed. Alternatively, by setting the altitude difference between different orbital planes to 300 m or more with a margin, the satellite constellation 20 having a plurality of orbital planes 21 with different orbital altitudes according to this embodiment can be formed. If the satellite constellation 20 has about 20 orbital planes, the satellite constellation forming unit 110 can construct the satellite constellation 20 with an altitude difference of about 6 km.

[0036] On the other hand, if a satellite operator who does not possess a method for improving satellite positioning avoids collisions based on public information, it is expected that the positioning accuracy at any time will deteriorate from 500 m to about 1 km. For this reason, by setting the altitude difference between different orbital planes to 2 km or more, it is possible to form a satellite constellation 20 having a plurality of orbital planes 21 with different orbital altitudes according to this embodiment. Alternatively, by setting the altitude difference between different orbital planes to 3 km or more with a margin, it is possible to form a satellite constellation 20 having a plurality of orbital planes 21 with different orbital altitudes according to this embodiment. If the satellite constellation 20 has about 20 orbital planes, the satellite constellation forming unit 110 can construct the satellite constellation 20 with an altitude difference of about 60 km. In recent years, a technology for monitoring objects in orbit known as SSA (Space Situation Awareness) has been attracting attention. If this leads to improved monitoring accuracy, known as the Space Fence concept, it will be possible for satellite operators who do not have a method for improving satellite positioning to realize satellite constellations with reduced altitude differences.

[0037] Next, a more detailed explanation will be given of a case where the satellite constellation forming unit 110 forms a satellite constellation 20 (see FIG. 3) in which each of the orbital planes 21 of the multiple orbital planes exists on the same plane. As described above, the multiple satellites 30 of the satellite constellation 20 in FIG. 3 provide services to points on the ground in a time-division alternating manner.

[0038] Unlike communication services, the earth observation service realized by the satellite constellation 20 in FIG. 3 does not necessarily need to continue the service at all times. On the other hand, the earth observation service requires "the ability to capture images of any point anywhere, any time." For this reason, it is preferable to configure the satellite constellation 20 with satellites equipped with earth observation equipment equipped with a device that changes the viewing direction at least in the cross-track direction perpendicular to the satellite's traveling direction. In this way, by providing the satellite with a viewing direction changing function that includes the distance between adjacent orbits above the equator, it becomes possible to capture images of any point on the globe at any time and anywhere. Compared to a satellite constellation using individual fixed-view earth observation equipment, there is an effect that the satellite constellation can be constructed with a smaller number of orbital planes, which makes it possible to reduce the system construction cost. In addition, the imaging field of view does not necessarily have to be covered in the direction of satellite flight, and if imaging is possible by changing the field of view of subsequent satellites or satellites in adjacent orbital planes, it may be possible to reduce the number of satellites in the same orbital plane. If the field of view change range is about 2,000 km on the Earth's surface, it may be possible to cover the entire globe with just two or three satellites per orbital plane.

[0039] ***Other configurations*** In this embodiment, the functions of the satellite constellation forming unit 110 are realized by software. As a modification, the functions of the satellite constellation forming unit 110 may be realized by hardware.

[0040] The satellite constellation forming system 100 includes an electronic circuit in place of the processor 910 . The electronic circuit is a dedicated electronic circuit that realizes the functions of the satellite constellation forming unit 110. The electronic circuit is specifically a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, or an FPGA. GA is an abbreviation of Gate Array. ASIC is an abbreviation of Application Specific Integrated Circuit. FPGA is an abbreviation of Field-Programmable Gate Array. The functions of the satellite constellation forming unit 110 may be realized by one electronic circuit, or may be distributed across multiple electronic circuits. As another modification, some of the functions of the satellite constellation forming unit 110 may be realized by electronic circuits, and the remaining functions may be realized by software.

[0041] Each of the processor and the electronic circuit is also called a processing circuitry. That is, in the satellite constellation forming system 100, the function of the satellite constellation forming unit 110 is realized by the processing circuitry.

[0042] ***Explanation of the Effects of the Present Embodiment*** In the satellite constellation forming system according to the present embodiment, multiple satellites in orbit provide services to a specific point on the ground by alternating in a time-division manner. In any orbital plane, multiple satellites fly at the same altitude and at approximately equal intervals. Furthermore, a satellite constellation is formed that is made up of multiple orbital planes with different orbital altitudes.

[0043] In the satellite constellation forming system according to this embodiment, satellites flying at the same altitude in the same orbital plane fly at the same relative speed while maintaining the relative phase in the orbital plane, so they will not collide. Also, in different orbital planes, there is a possibility of collision at the intersection of two planes, but satellites flying at different orbital altitudes will not collide. In this way, if the orbital altitudes are different in different orbital planes, there is an advantage that the risk of collision can be avoided for all satellites in the satellite constellation. As with the satellite constellation according to the present embodiment, satellites flying in the same orbital plane at different orbital altitudes do not collide with each other, even between different satellite constellations. Therefore, the basic concept according to the present embodiment is also effective in collision avoidance for multiple satellite constellations. In STM, where the need for international rule-making in the congested outer space has been appealed in recent years, there is an effect of providing a method for multiple satellite constellations to coexist and avoid collisions. In other words, according to the satellite constellation forming system according to the present embodiment, there is an effect of being able to avoid satellite collisions even when a huge number of satellites, such as several thousand, are densely concentrated at nearby altitudes.

[0044] Embodiment 2 In this embodiment, the following mainly describes differences or additions from embodiment 1. Note that the same components as those in embodiment 1 are given the same reference numerals, and the description thereof may be omitted.

[0045] In this embodiment, a mode will be described in which the satellite constellation forming unit 110 forms a satellite constellation 20 in which the relative altitude difference between adjacent orbital planes in a plurality of orbital planes forms a sinusoidal shape.

[0046] FIG. 8 is a diagram showing the relative altitude differences of a plurality of orbital planes according to this embodiment. FIG. 8 shows the relative altitude difference between each orbital plane in a satellite constellation 20 having 17 orbital planes. The vertical axis shows that orbital plane 1 has the highest altitude and the altitude decreases in descending order, and does not show distance. FIG. 8 shows that when orbital plane 1 is used as the base, the orbital altitude difference between adjacent orbital planes 1 and 2, the orbital altitude difference between orbital planes 2 and 3, and so on are plotted, forming a sine wave.

[0047] If the altitudes of adjacent orbital planes differ significantly, the handover distance for inter-satellite communications becomes far, and the driving angle range for mutually orienting the communication antennas becomes wide, which is a disadvantage. In contrast, according to the satellite constellation 20 of this embodiment, the altitude difference between adjacent orbits is limited, so the relative difference changes gradually. This makes it easier to carry out handover that contributes to mission coordination with nearby satellites.

[0048] In addition, in an earth observation satellite, for example, the image quality of an optical sensor depends on the satellite altitude, so that a small difference in altitude between adjacent orbits has the effect of obtaining high-quality images with no inconsistency between image scenes. A satellite constellation equipped with an optical sensor capable of acquiring images of the Earth's surface and imaging a wider area than the adjacent orbital distance above the equator can acquire images of the entire globe. Since the resolution and observation width of an optical sensor depend on the orbital altitude, a satellite constellation using an optical sensor with the same specifications will have the highest resolution and the smallest observation width when imaging at the lowest orbital altitude. Therefore, if the observation width of an optical sensor at the lowest orbital altitude above the equator is greater than the adjacent orbital distance, it will be possible to comprehensively image the Earth's surface, including above the equator.

[0049] If the altitudes of adjacent orbits differ significantly, discontinuity accompanied by differences in resolution at the seams of images is likely to become apparent. However, in the satellite constellation forming system according to this embodiment, the altitude difference between adjacent orbits is limited, so that there is an effect that global image data with good image quality can be acquired without noticeable seams of images. In addition, there is a characteristic that the greater the difference in satellite altitude, the faster the relative movement speed of the ground service area becomes. Therefore, in the satellite constellation forming system according to this embodiment, the amount of relative movement of adjacent service areas can be minimized, so that data transfer to a subsequent satellite, called handover in communications, becomes easy, and there is an effect that errors are easily suppressed.

[0050] Embodiment 3 In this embodiment, the following mainly describes differences or additions from embodiments 1 and 2. Note that the same components as those in embodiments 1 and 2 are given the same reference numerals, and the description thereof may be omitted.

[0051] In this embodiment, the satellite constellation forming unit 110 forms the satellite constellation 20 in which the radius of the ground service range per satellite is equal to or greater than approximately √2 / 2 the distance between adjacent orbits above the equator. Specifically, in this satellite constellation 20, the radius of the ground service range per satellite in the orbital plane with the lowest orbital altitude ensures coverage of approximately √2 / 2 or more of the distance between adjacent orbits above the equator.

[0052] FIG. 9 is a diagram showing a ground service range of a comparative example. When the relative position of the satellite is optimal, if the radius of the ground service range is secured to be equal to the distance between adjacent orbits above the equator, the service range can cover the entire globe. Also, if the satellite altitude is the same in all orbital planes, the relative relationship of the service area is maintained, so it is possible to continue the service covering the entire globe at all times. However, in orbital planes with different orbital altitudes, the satellite's traveling speed differs depending on the satellite altitude, so the service area secured comprehensively when the relative position of the satellite is optimal may move relative to the satellite, resulting in a gap P, that is, an area that cannot be served.

[0053] Figure 9 shows the ground service ranges of three orbital planes. The radius ra of the ground service range is half the distance Ra between adjacent orbits above the equator. In this case, as shown in Figure 9, if the ground service range of the middle orbital plane shifts 45 degrees forward, an area that cannot be serviced (a gap) will be created.

[0054] FIG. 10 is a diagram showing a ground service range according to this embodiment. In Fig. 10, the radius rb of the ground service range is √2 / 2 of the distance Rb between adjacent orbits above the equator. In this case, as shown in Fig. 10, even if the ground service ranges of each orbital plane are shifted by 45 degrees, no area (gaps) that cannot be serviced will occur.

[0055] As described above, according to the satellite constellation forming system of this embodiment, even when the satellite relative arrangement is in the worst state, that is, when the service area of ​​the adjacent orbit is located approximately 45 degrees forward, no gap in the service area occurs. Therefore, according to the satellite constellation forming system of this embodiment, even if the service area of ​​the adjacent orbit moves relatively in the satellite flight direction, it is possible to continue the service without interruption and comprehensively cover the entire globe.

[0056] Embodiment 4 In this embodiment, a description will be given mainly of differences or additions from embodiments 1 to 3. Note that the same components as those in embodiments 1 to 3 are given the same reference numerals, and the description thereof may be omitted.

[0057] In this embodiment, the satellite constellation forming unit 110 forms a satellite constellation 20 in which the orbital altitude of each of a plurality of orbital planes satisfies the condition of a sun-synchronous orbit. Also, the satellite constellation forming unit 110 forms a satellite constellation 20 in which the orbital altitude of each of a plurality of orbital planes is composed of only sun-synchronous quasi-recurrent orbits.

[0058] FIG. 11 is a diagram showing an orbital plane that satisfies the conditions for a sun-synchronous orbit according to this embodiment. For optical Earth observation satellites, it is desirable to continue observations under conditions where the angle of incidence of sunlight is nearly the same. For this reason, satellite orbits known as sun-synchronous satellites are often used. The orbit of a sun-synchronous satellite is one in which the orbital plane rotates once a year in sync with the revolution of the Earth, and the angle between the normal to the orbital plane and the direction of the Sun is roughly constant. In addition, the orbit of a sun-synchronous satellite is one in which the Earth's Local Sun Time (LST) remains the same throughout the year. The orbital altitudes where the conditions for a sun-synchronous orbit are met exist intermittently. In this embodiment, a satellite constellation 20 is formed whose orbital plane is composed of only orbital altitudes that meet the conditions for a sun-synchronous orbit. With such a satellite constellation 20, each orbital plane can continue to provide service at the desired LST, and a satellite constellation without a collision risk can be realized.

[0059] The brightness and S / N characteristics of images taken by optical sensors change depending on the angle of incidence of sunlight. For this reason, sun-synchronous orbits are often used to provide continuous Earth observation services under the condition of a constant angle of incidence of sunlight on the orbital plane. Furthermore, the orbital plane between LST 10:00 and 11:00 is often used because it can ensure sufficient light and there is no direct reflection from the sea surface. However, a constellation of satellites near LST 10:30 alone cannot capture images "anytime, anywhere." Therefore, it is effective to increase the frequency of imaging by combining constellations of satellites in orbital planes with different LSTs.

[0060] For example, in addition to LST10:30, add orbital planes at LST9:00 and LST12:00. In this case, it is possible to image roughly every 90 minutes, and assuming that it takes about 90 to 100 minutes for a low-orbit satellite to orbit the Earth once, this has the effect of improving the frequency of imaging any given point, including the imaging opportunity for the next orbit. Furthermore, if the number of satellites in the same orbital plane increases, it will be possible to cover the entire area, and if LSTs are evenly distributed using the same concept, imaging will in principle be possible "anytime, anywhere." Incidentally, an optical sensor that can only capture visible images cannot capture images at night, but an infrared sensor or radio wave sensor can capture images at any time, including nighttime.

[0061] A satellite constellation equipped with an optical sensor capable of acquiring images of the Earth's surface and imaging a wider area than the distance between adjacent orbits above the equator can acquire images of the entire globe. Since the resolution and observation width of an optical sensor depend on the orbital altitude, in the case of a satellite constellation employing an optical sensor of the same specifications, the highest resolution and the smallest observation width are obtained when imaging at the lowest orbital altitude. Therefore, if the observation width of the optical sensor at the lowest orbital altitude above the equator is greater than the distance between adjacent orbits, comprehensive imaging of the Earth's surface including the equator is possible. In addition, if the altitudes of adjacent orbits differ significantly, discontinuity due to differences in resolution at the seams of images is likely to become apparent. However, even in this embodiment, by adopting the satellite constellation according to the second embodiment, it is possible to obtain global image data with good image quality without noticeable seams of images by limiting the altitude difference between adjacent orbits.

[0062] ***Modification of this embodiment*** As a modified example of this embodiment, a mode will be described in which the satellite constellation forming unit 110 forms a satellite constellation 20 in which the orbital altitude of each of a plurality of orbital planes is composed of only sun-synchronous quasi-recurrent orbits.

[0063] A sun-synchronous subrecurrent orbit is an orbit in which the satellite's ground projection line revisits the orbit after multiple orbits, and is often used for Earth observation satellites. The orbital altitudes that meet the conditions for a sun-synchronous subrecurrent orbit are a subset of the orbital altitudes that meet the conditions for a sun-synchronous orbit. The satellite constellation 20, in which the orbital altitudes of each of a plurality of orbital planes are composed only of sun-synchronous quasi-recurrent orbits, makes it easier to plan operations, image capture, and data processing for repeated, regular observation of the same point over a long period of time using an earth observation satellite. Moreover, it has the effect of realizing a satellite constellation without a collision risk.

[0064] If the number of recurrence days is not important, the orbital altitude of the sun-synchronous quasi-recurrence orbit can be, for example, about 540 km (recurrence every 15 days), about 539 km (recurrence every 14 days), about 537 km (recurrence every 13 days), about 535 km (recurrence every 12 days), about 533 km (recurrence every 11 days), and about 530 km (recurrence every 10 days). With these six orbital planes, a satellite constellation of 20 can be realized with a maximum altitude difference of about 10 km. Also, for example, if the orbit is configured with only a 13-day recurrence orbit, then satellite constellation 20 can be realized with six orbital planes and a maximum altitude difference of approximately 115 km if it is configured with orbits of approximately 537 km, approximately 514 km, approximately 491 km, approximately 467 km, 445 km, and approximately 422 km.

[0065] Embodiment 5. In this embodiment, the following mainly describes differences or additions from embodiment 1. Note that the same components as those in embodiment 1 are given the same reference numerals, and the description thereof may be omitted.

[0066] FIG. 12 is a diagram showing an example of a satellite constellation 20 formed by the satellite constellation forming system 100 according to this embodiment. The satellite constellation 20 according to the present embodiment is composed of a group of satellites 300. In the satellite constellation 20, the group of satellites 300 cooperate with each other to provide services. The satellite constellation 20 has a plurality of orbital planes 21 in which a plurality of satellites 30 fly at the same orbital altitude. Moreover, in the satellite constellation 20 according to this embodiment, the orbital altitudes of the orbital planes 21 of the multiple orbital planes are the same, and the orbital planes 21 of the multiple orbital planes exist in different planes from each other.

[0067] In the satellite constellation 20 shown in Fig. 12, the orbital inclination angle of each of the multiple orbital planes 21 is approximately 90 degrees, and each of the multiple orbital planes 21 exists on a different plane from each other. Therefore, in the satellite constellation 20 shown in Fig. 12, the multiple orbital planes 21 intersect in the polar regions.

[0068] 13 and 14 are schematic diagrams showing an example of collision conditions in a satellite constellation. Satellites flying at the same altitude in the same orbital plane will not collide because they fly at the same speed while maintaining the relative phase in the orbital plane. However, satellites flying at the same orbital altitude in different orbital planes may collide at the intersection points where the orbital altitudes match on the orbital plane intersection lines, as shown in Figures 13 and 14. In particular, as shown in Figure 14, low-orbit satellites flying at orbital altitudes of about 100 km to 2000 km and with an orbital inclination of about 90 degrees have intersection points near the poles, so there is a risk of collision near the North and South Poles.

[0069] However, if the satellites pass through the intersections at different times, the two objects will not collide. The satellite constellation forming unit 110 forms a satellite constellation 20 in which the two objects will not collide. Specifically, the time at which a satellite flying in each of the orbital planes passes through an intersection between different orbital planes is a multiple of "waiting time T1 until the next satellite arrives / number of orbital planes" in the same orbital plane, and the satellite passing times do not coincide at any intersection between any two orbital planes.

[0070] The satellite constellation 20 shown in Fig. 12 has an orbital inclination angle of about 90 degrees and has multiple orbital planes that are different from each other. In this satellite constellation 20, all satellites in all orbital planes pass near the polar regions. Therefore, the satellite constellation forming unit 110 makes the satellites fly at intervals of "waiting time T1 until the next satellite arrives / number of orbital planes" in the same orbital plane, and staggers the polar pass times of the satellites in the multiple orbital planes. Specifically, assuming that it takes about 100 minutes for a low earth orbit satellite to complete one orbit, if 20 satellites fly per orbital plane, it takes about 5 minutes from when a satellite passes a specific point until the succeeding satellite arrives. If there are 20 orbital planes, the satellite constellation 20 according to this embodiment can be realized by shifting the satellites by 15 seconds, which is approximately equal intervals of 300 seconds.

[0071] In the satellite constellation 20 formed by the satellite constellation forming system 100 according to this embodiment, multiple satellites in the same orbital plane fly synchronously at the same altitude, and satellites in different orbital planes also have the same orbital altitude and maintain the same satellite speed. Therefore, if the satellites in each orbital plane are initially set to pass through the intersection at different timings in all orbital planes, the relative timing is always maintained, which has the effect of avoiding the risk of collision between any two satellites in all orbital planes.

[0072] In this embodiment, an example of timing in which the waiting time until the arrival of the subsequent satellite is evenly distributed according to the number of orbital planes has been shown, but there are various ways to select the interval for shifting the polar crossing timing and the order of the orbital planes.

[0073] Embodiment 6 In this embodiment, differences or additional points from embodiment 5 will be mainly described. Note that the same components as those in embodiment 5 are given the same reference numerals, and the description thereof may be omitted.

[0074] 15 and 24 are diagrams showing examples of a satellite constellation 20 formed by the satellite constellation forming system 100 according to this embodiment. In the satellite constellation 20 shown in Figures 15 and 24, the orbital inclination angle of each of the multiple orbital planes 21 is not approximately 90 degrees, and each of the multiple orbital planes 21 exists on a different plane from each other. In this satellite constellation 20, any two orbital planes intersect at a point other than the polar regions. Therefore, the satellite constellation forming unit 110 forms the satellite constellation 20 so that the time at which a satellite of each of the orbital planes passes through an intersection between different orbital planes is a multiple of "waiting time T1 until the next satellite arrives / number of orbital planes" of the same orbital plane, and the satellite passing times do not coincide at any intersection of any two orbital planes.

[0075] As shown in FIG. 15 and FIG. 24, the intersections of multiple orbital planes with an orbital inclination angle of more than 90 degrees move away from the polar regions according to the orbital inclination. In addition, depending on the combination of orbital planes, intersections may exist at various positions including near the equator. Therefore, compared to the satellite constellation of the fifth embodiment, the locations where collisions may occur are more diverse. However, since the number of intersections does not increase, the collision probability does not increase according to the diversification of locations. When many satellites fly synchronously on the same orbital plane, if the satellite passing timing of the two orbital planes is shifted at a specific intersection in order to avoid collisions between two specific orbital planes, the satellites in these two orbits will not collide with each other. However, it should be noted that there remains a risk that a subsequent satellite will collide with a satellite in another orbital plane. It is necessary to check by exhaustive testing for any orbital planes that the intersection passing timing does not match, and if the problem cannot be solved by timing adjustment, it is necessary to change either the orbital plane or the number of satellites in one orbital plane. Note that if it is confirmed that there are no collisions at all intersections, the satellites in all orbital planes and between the orbital planes will operate synchronously thereafter, which has the effect of avoiding the risk of collision.

[0076] In this embodiment, an example of timing in which the waiting time until the arrival of the subsequent satellite is evenly distributed according to the number of orbital planes has been shown, but there are various ways to select the interval for shifting the polar crossing timing and the order of the orbital planes.

[0077] Here, as a specific example, an example of an earth observation satellite adopting a sun-synchronous quasi-recurrent orbit with an orbital inclination of about 98 degrees and an orbital period of about 98 minutes will be described. When a multi-satellite constellation is constructed using this orbit, all orbital planes will not meet in the polar regions because the orbital inclination is inclined at about 98 degrees. However, there is always an intersection line between two different orbital planes, and an intersection point exists at the same altitude, so a collision risk still exists. Furthermore, since a collision risk exists in all combinations of two different orbital planes, in this embodiment, collisions are avoided by shifting the satellite pass timing at an intersection point between any two planes. Furthermore, there are also earth observation satellites that fly at an orbital inclination angle of about 45 degrees, and in this orbit, they become sun-synchronous satellites. In the case of a low orbital inclination angle, the intersection of two different orbital planes is located at a low latitude, and there is a possibility that intersections will occur at multiple latitudes. Depending on the combination of the number of orbital planes and the number of satellites flying in one orbital plane, collisions cannot always be avoided. Therefore, in the satellite constellation 20 according to this embodiment, a combination of the number of orbital planes and the number of satellites per orbital plane that does not cause collisions at all intersections of two orbital planes is found, and then the passing timing at each intersection is maintained to avoid collisions. If the number of satellites increases extremely, the brute-force collision avoidance calculations become complicated, so the first embodiment in which the satellites are configured using different orbital planes may be adopted.

[0078] Embodiment 7 In this embodiment, differences or additional points from embodiment 5 will be mainly described. Note that the same components as those in embodiment 5 are given the same reference numerals, and the description thereof may be omitted.

[0079] In this embodiment, a method of shifting the waiting time of satellites in the satellite constellation 20 of Fig. 14 where multiple orbital planes intersect at the polar regions will be described. In this embodiment, when the multiple orbital planes are numbered in the order in which they are arranged, the waiting time until the arrival of the succeeding satellite at the polar crossing timing is shifted by about half in the odd-numbered orbital planes and the even-numbered orbital planes. By forming the satellite constellation 20 in this way, the terrestrial service range is alternately arranged between the adjacent odd-numbered and even-numbered planes, which has the effect of rationally covering the terrestrial surface service range.

[0080] FIG. 16 is a diagram showing the surface service range of the satellite constellation 20 according to this embodiment. Figure 16 shows an example in which the number of orbital planes is 18, and the angle of the orbital planes changes by 10 degrees relative to each other. For the polar crossing timing, the waiting time until the arrival of the succeeding satellite is divided into 18 equal parts, and the polar crossings are shifted from timing 1 for odd-numbered planes and from timing 10 for even-numbered planes. As a result, the ground service area alternates between even-numbered and odd-numbered planes to fill in the gaps, which has the effect of comprehensively covering the Earth's surface.

[0081] FIG. 17 is a diagram showing polar passing timings when the number of orbital planes in the satellite constellation 20 according to this embodiment is an even number. FIG. 18 is a diagram showing the polar passing timing when the number of orbital planes in the satellite constellation 20 according to this embodiment is an odd number. As shown in Figures 17 and 18, in the satellite constellation 20 according to this embodiment, it is preferable that the number of orbital planes is an odd number. In the example of Figure 17, the service area of ​​plane 1 adjacent to plane 18 may be adjacent to each other, which may cause inconsistency in global coverage. Therefore, by making the number of orbital planes an odd number as shown in Figure 18, the terrestrial service areas of the last plane and plane 1 are alternately arranged like the others, which has the effect of rationally covering the global area.

[0082] Embodiment 8 In this embodiment, the following description will be mainly focused on the points added to the embodiments 1 to 7. Note that the same components as those in the embodiments 1 to 7 are given the same reference numerals, and the description thereof may be omitted.

[0083] In this embodiment, a variation of a debris removal method that allows a satellite to de-orbit (leave its orbit) while avoiding collisions will be described.

[0084] FIG. 19 is a diagram illustrating the concept of de-orbiting by free fall. FIG. 20 is a diagram showing the collision risk when a satellite above the satellite constellation 20 de-orbits.

[0085] <Debris removal method example 1> The debris removal method of Example 1 according to this embodiment includes a capture device or external force application device for changing the orbital plane of a failed satellite that has become uncontrollable due to a malfunction or the like before the failed satellite descends and passes through an orbital plane where satellites are densely packed, and a propulsion device for propelling the failed satellite.

[0086] The sun-synchronous quasi-recurrent orbit from 10:00 LST to 11:00 LST has a relationship between the solar incidence angle and the orbital plane that is suitable for imaging by optical sensors for Earth observation, and is a dense orbital plane in which many optical Earth observation satellites fly. The orbital altitude is suitable for high-resolution imaging, and is concentrated at around 500km to 1000km where atmospheric resistance is low. However, there are also cases where ultra-low altitude satellites fly at orbital altitudes of around 200km.

[0087] There are cases where a satellite constituting the satellite constellation 20 described in the first to seventh embodiments malfunctions and becomes uncontrollable. In this case, the malfunctioning satellite passes through a dense orbital plane while changing its orbital altitude in the process shown in FIG. 19, from a high altitude such as an orbital altitude of 1000 km to 2000 km, through which the malfunctioning satellite free falls and disappears after entering the Earth's atmosphere. In this case, as shown in FIG. 20, the malfunctioning satellite may meet with a group of satellites at multiple orbital altitudes, so there is a high risk of collision. Therefore, by using the debris removal method according to the present embodiment, if the orbital plane is changed in advance so as not to pass through a dense orbit, it is possible to avoid collisions in the dense orbit.

[0088] FIG. 21 is a diagram showing the change in orbital altitude due to acceleration and deceleration of a satellite. FIG. 22 is a diagram showing the change in orbital inclination angle due to thrust from a thruster. One effective example of a debris removal method is to capture a malfunctioning satellite using a debris collection satellite equipped with a capture device for capturing other satellites and a propulsion device for providing thrust to the other satellites, and then artificially change the orbit using the propulsion device. If the satellite accelerates in the direction of travel, the orbital altitude temporarily rises, and the orbital plane rotates around the Earth's approximate axis due to the effect of perturbation in a cycle different from that of the dense orbit, making it possible to avoid the dense orbital plane. If the satellite decelerates in the direction of travel, the orbital altitude temporarily drops, and the orbital plane rotates around the Earth's approximate axis due to the effect of perturbation in a cycle different from that of the dense orbit, making it possible to avoid the dense orbital plane. Depending on the time allowance until the malfunctioning satellite is predicted to pass through the dense orbit, a collision avoidance method can be selected, either to descend before meeting with the dense orbit or to descend after passing through the dense orbit. This has the effect of reliably avoiding collisions. However, the method using perturbation has the disadvantage of a long residence time, so a method of actively firing the propulsion device to rotate the orbital plane in the out-of-plane direction is also possible. In this case, a large amount of propellant is consumed, so the debris removal method, including the propulsion tank, becomes large.

[0089] The recovery of the satellite itself corresponds to the recovery of a so-called cooperative target. Therefore, it is effective for the debris recovery satellite to be equipped with attachments that are compatible with the debris removal method in advance to facilitate capture. In addition, it is effective for the debris recovery satellite to transmit information informing the position of the satellite itself or the capture target, making it easier for the satellite to approach or join the target. However, there are exceptions in cases where the satellite has lost control and is rotating.

[0090] <Debris removal method example 2> The debris removal method of Example 2 according to this embodiment includes a capture device or external force imparting device for changing the orbital plane of an object floating at an altitude of about 100 km to 2000 km while describing an elliptical orbit, before the object passes through the orbital plane that constitutes the satellite constellation, and a propulsion device for imparting a thrust to the object. Note that the external force imparting device may include not only "force" but also "torque" or even "change in mass characteristics" associated with merging as "external force". The external force imparting device is also called an external disturbance imparting device.

[0091] Removing obstacles is an issue in STM. If the orbital plane of an object flying in an elliptical orbit coincides with the orbital plane of many satellites flying in a nearly circular orbit at a specific orbital altitude, the risk of collision becomes very high. The debris removal method of Example 2 according to this embodiment has the effect of safely removing obstacles with a high collision risk.

[0092] Specific examples of debris removal methods are the same as those in <Debris Removal Method Example 1>. In <Debris Removal Method Example 1>, in order to capture the satellite itself, it is possible to equip it in advance with attachments that make it easy to capture as a so-called cooperative target. However, floating objects other than the satellite itself are so-called non-cooperative targets, and are difficult to capture, such as objects with complex shapes, rotating objects, heavy objects, or objects that do not have an appropriate structure for capture. For this reason, the capture device that should be equipped must be highly advanced. Specific examples that can be realized include a method of grasping with a robot, a method of enveloping the target with a capture net-like device, and a method of piercing and pulling a harpoon-like rod with a wire.

[0093] Embodiment 9 In this embodiment, differences or additional points from the embodiments 1 to 8 will be mainly described. Note that the same components as those in the embodiments 1 to 8 are given the same reference numerals, and the description thereof may be omitted.

[0094] In this embodiment, we will explain a variation of a satellite constellation construction method in which the debris removal method described in example 1 or example 2 of the debris removal method of embodiment 8 is applied to a satellite constellation constructed by the satellite constellation formation system described in embodiments 1 to 7.

[0095] <Example 1 of satellite constellation construction method> In example 1 of the satellite constellation construction method according to the present embodiment, the satellites are injected into orbit at an orbital altitude that is different from the orbital altitude at which the satellites in the nearby orbital plane fly, in a different orbital plane near the orbital plane of the components that make up the satellite constellation 20. In example 1 of the satellite constellation construction method, the satellites are added by increasing or decreasing speed to change the orbital altitude and the angle of the orbital plane about the Earth's axis.

[0096] In the process of launching satellites in order to build a given satellite constellation, there is a high collision risk in the process of launching an additional satellite into an orbital plane after many satellites have been launched. In the example 1 of the satellite constellation building method according to the present embodiment, it is possible to significantly reduce the collision risk at launch by launching an additional satellite into an orbit with a slightly shifted orbital plane angle of the satellite already launched. Furthermore, it is possible to reduce the collision risk during the transitional phase by gradually approaching the desired orbit from a satellite altitude that does not match the satellite altitude already launched.

[0097] <Example 2 of satellite constellation construction method> In the satellite constellation construction method example 2 according to the present embodiment, a database is provided that collects in advance information on the orbit, orbital altitude, number of flying satellites, etc., adopted by other countries' systems or similar systems. In the satellite constellation construction method example 2 according to the present embodiment, a satellite is put into orbit at an orbital altitude different from that at which the satellites in the nearby orbital plane fly, which is different from the orbital plane in which the existing satellites fly and is in a different orbital plane in the vicinity of the orbital plane of the component. In the satellite constellation construction method example 2 according to the present embodiment, a component satellite is added by increasing or decreasing the speed to change the orbital altitude and the angle of the orbital plane about the Earth's axis.

[0098] According to the second example of the satellite constellation construction method of the present embodiment, there is an advantage that a satellite constellation can be constructed without a collision risk in an environment in which multiple satellite constellations are constructed and the entire space is congested.

[0099] In addition, in the first example of the satellite constellation construction method, a data processing device for the orbit and position of the satellite is provided on the ground. In addition, in the second example of the satellite constellation construction method, a data processing device for the orbit and position of a flying object in space is provided on the ground.

[0100] Embodiment 10 In this embodiment, the following description will be mainly focused on the points added to the embodiments 1 to 9. Note that the same configurations as those in the embodiments 1 to 9 are given the same reference numerals, and the description thereof may be omitted.

[0101] In this embodiment, a variation of a ground facility 500 that transmits an orbit control command 51 to a satellite 30 that constitutes the satellite constellation 20 and has reached the end of its design life will be described. The orbit control command 51 is a command to deorbit the satellite 30 by operating a propulsion device equipped in the satellite 30.

[0102] <Example 1 of Ground Equipment 500> FIG. 23 is a diagram showing a configuration of example 1 of the ground equipment 500 according to the present embodiment. The configuration of example 1 of the ground equipment 500 is similar to that of embodiment 10.

[0103] The communication device 950 transmits and receives signals for tracking and controlling the satellites 30 that make up the satellite constellation 20 . The orbit control command transmitter 510 transmits an orbit control command 51 to a satellite 30 that is to be de-orbited due to, for example, reaching the end of its designed life. The analysis and prediction unit 520 analyzes and predicts the passing orbit of the satellite 30 after receiving the deorbit command.

[0104] As a specific example, a case will be described in which the analysis prediction unit 520 determines that the satellite 30 will pass through an orbital plane of a congested orbit in a sun-synchronous orbit near LST 10:30 at an orbital altitude of 500 km to 800 km. At this time, the orbit control command transmission unit 510 transmits to the satellite 30 an orbit control command 51 for performing an active de-orbit operation to avoid a collision risk by shifting the timing of passing through the congested orbit or the orbital plane. When the satellite 30 receives the orbit control command 51, the satellite 30 increases or decreases the orbital altitude by increasing or decreasing the satellite speed by the orbit control device provided in the satellite 30. Alternatively, the satellite 30 changes the orbital inclination angle by applying acceleration in an out-of-plane direction of the orbital plane by thrusting the thruster in a direction approximately perpendicular to the satellite traveling direction. In this way, the satellite 30 performs an active de-orbit operation to avoid a collision risk by shifting the timing of passing through the congested orbit or the orbital plane.

[0105] In constructing mega-constellations, as a measure to prevent the total amount of debris in space from increasing indefinitely, the necessity of making PMD (Post-Mission Disposal) mandatory and deorbiting, for example, 99% or more of satellites from orbit is being discussed. In addition, since the probability that a satellite will be in good condition at the end of its life must be taken into consideration, the necessity of ADR (Active Debris Removal), which uses external methods to deorbit satellites that cannot be deorbited autonomously due to the end of their life or loss of function due to a malfunction, is also being discussed. However, PMD and ADR only appeal to the necessity of a method of letting the debris fall freely and burn up in the atmosphere, and do not provide a method of avoiding the case of passing through a congested orbit on the way down. In addition, in the case of geostationary orbit satellites, when the risk of debris collision is predicted, there are cases where the satellite that is hit takes action to avoid the collision by publishing the predicted orbit information of the debris along with a collision warning. However, in the case of low-orbit satellites, when a different satellite constellation is constructed, there is a high risk that the avoidance action of the satellite that is hit will become a secondary collision cause. In other words, there is a risk of collision with satellites in front and behind when parallel parking, or collision with a group of satellites at different altitudes in the same plane. In addition, there is a high possibility that many satellites that will be hit will pass through the area in a short period of time. If multiple satellites take evasive action simultaneously, it will become difficult to predict the behavior of nearby satellites, resulting in a risk of a collision. In addition, as a result of the evasive maneuvers, the LST may move not only in its orbital altitude and in-plane phase, but also in relation to the rotation of the orbital plane, which may make it difficult to return to its original position or may pose a risk of disrupting the continuity of the services intended by the satellite constellation. In addition, there may be a large number of satellites flying around, such as experimental CubeSats, which do not have avoidance capabilities. In addition, if the accuracy of orbit prediction due to free fall is poor, the area and time period in which a collision warning should be issued may become wide and long, causing the struck satellite to issue collision warnings frequently and making it unable to respond.

[0106] According to the first example of the ground facility 500 according to the present embodiment, even during the altitude reduction due to de-orbiting, orbit control during the descent is possible, which has the effect of avoiding passage through congested orbits and thus avoiding collisions. In addition, there is an effect of avoiding collisions even if the collided satellite does not take evasive action.

[0107] <Example 2 of Ground Equipment 500> In Example 2 of the ground facility 500 of this embodiment, a capture command 52 and an orbit control command 51 for deorbiting a malfunctioning satellite that has lost its orbit control function are transmitted to the debris collection satellite 31. The debris collection satellite 31 is, for example, a satellite equipped with a device for recovering a satellite that has lost its orbit control function due to a malfunction. The debris collection satellite 31 is equipped with a capture device for capturing the malfunctioning satellite and a propulsion device.

[0108] Example 2 of the ground equipment 500 transmits a capture command 52 and an orbit control command 51 to the debris collection satellite 31 to deorbit the failed satellite by operating the capture device and propulsion device equipped on the debris collection satellite. The communication device 950 transmits and receives signals for tracking, controlling and operating the debris collection satellite. The orbit control command transmitter 510 transmits an orbit control command 51 or a capture command 52 . The analysis and prediction unit 520 analyzes and predicts the passing orbit of the debris collection satellite in a state in which the failed satellite has been captured.

[0109] As a specific example, a case will be described in which the analysis prediction unit 520 determines that the debris collection satellite 31 will pass through an orbital plane of a congested orbit in a sun-synchronous orbit near LST 10:30 at an orbital altitude of 500 km to 800 km. At this time, the orbit control command transmission unit 510 transmits an orbit control command 51 to the debris collection satellite 31 to perform active de-orbit operation to avoid collision risk by shifting the timing of passing through the congested orbit or the orbital plane. When the debris collection satellite 31 receives the orbit control command 51, the satellite 30 increases or decreases the orbital altitude by increasing or decreasing the satellite speed by the orbit control device of the satellite 30. Alternatively, the satellite 30 changes the orbital inclination angle by applying acceleration in the out-of-plane direction of the orbital plane by thrusting the thruster in a direction approximately perpendicular to the satellite's traveling direction. In this way, the debris collection satellite 31 performs active de-orbit operation to avoid collision risk by shifting the timing of passing through the congested orbit or the orbital plane.

[0110] According to the second example of the ground facility 500 according to the present embodiment, the constituent satellites of the satellite constellation are equipped in advance with facilities such as attachments for capturing the debris collection satellites. Therefore, the second example of the ground facility 500 according to the present embodiment is effective in collecting the constituent satellites of the satellite constellation.

[0111] <Example 3 of Ground Equipment 500> In example 3 of the ground equipment 500 according to this embodiment, the communication device 950 sends and receives signals for tracking, controlling and operating a debris collection satellite equipped with a device for collecting rocket debris flying above a congested orbit with an orbital altitude of 800 km or more. The orbit control command transmitter 510 transmits a capture command and an orbit control command to the debris collection satellite to deorbit the rocket remains by operating the capture device and propulsion device equipped on the debris collection satellite. The analysis and prediction unit 520 analyzes and predicts the passing orbit of the debris collection satellite in a state in which the failed satellite has been captured.

[0112] As a specific example, a case will be described in which the analysis prediction unit 520 determines that the satellite will pass through an orbital plane of a congested sun-synchronous orbit near LST 10:30 at an orbital altitude of 500 km to 800 km. In Example 3 of the ground facility 500 according to this embodiment, the orbit control device equipped on the satellite increases or decreases the satellite speed to raise or lower the orbital altitude, or changes the orbital inclination by applying acceleration in the out-of-plane direction of the orbital plane by thrusting the thruster in a direction approximately perpendicular to the satellite's traveling direction. Then, Example 3 of the ground facility 500 according to this embodiment performs active de-orbit operation to avoid collision risk by shifting the timing of passing through a congested orbit or the orbital plane.

[0113] Rocket debris does not usually have a capture attachment for the debris collection satellite, and it is difficult to capture it because it rotates in orbit, so the technical difficulty is higher than that of the ground facility 500, example 2. According to the ground facility 500, example 3, the capture device can be a method of wrapping it in a net-like object like a cast net, a method of piercing and pulling a harpoon-like rod with a wire, or a method of adhering to the outer skin of the capture target with a sticky substance or adhesive. Even if a satellite constellation component satellite equipped with a capture attachment is de-orbited, if it is allowed to fall freely without attitude control, the attitude becomes unstable, so there is a high possibility that the debris collection satellite cannot easily access the capture attachment. In such a case, the capture device of the ground facility 500, example 3, according to the present embodiment, is effective.

[0114] <Example 4 of Ground Equipment 500> Here, as explained in Examples 1 to 3 of the ground equipment 500, a case will be described in which the analysis prediction unit 520 determines that the satellite will pass through a polar dense area of ​​another satellite constellation constructed at a low altitude during descent to de-orbit the satellite or to de-orbit for debris collection. In Example 4 of the ground facility 500, the orbital inclination angle is changed by applying acceleration in the out-of-plane direction of the orbital plane by jetting the thrusters in a direction approximately perpendicular to the satellite's traveling direction so that the orbital inclination angle is different from that of the satellite constellation. As a result, in Example 4 of the ground facility 500, active de-orbit operation is performed to avoid the risk of collision by changing the inclination of the orbital plane from the congested orbit or by shifting the passing timing.

[0115] Examples 1 to 3 of the ground equipment 500 can not only cover the avoidance of congested orbits near LST 10:30, but can also avoid collisions when passing through the polar congested areas.

[0116] Any combination of the above-mentioned examples 1 to 4 of the ground equipment 500 may be implemented. For example, the following ground equipment can be implemented.

[0117] The ground facility includes a communication device that transmits and receives signals for tracking and controlling the satellites that make up the satellite constellation, an orbit control command transmitter that transmits an orbit control command, and an analysis and prediction unit that analyzes and predicts the passing orbit of the satellite after receiving a de-orbit command. The ground facility transmits the orbit control command to de-orbit the satellite that has reached the end of its design life by operating a propulsion device equipped on the satellite. When analytical predictions reveal that the satellite will pass through a polar dense area or a congested orbital plane of another satellite constellation constructed at a low altitude during descent to deorbit the satellite or to deorbit the satellite for debris collection, the ground facility performs active deorbit operation to avoid the risk of collision. Specifically, the ground facility performs active deorbit operation to avoid the risk of collision by changing the inclination of the orbital plane from that of the congested orbit by applying acceleration in an out-of-plane direction of the orbital plane by thrusting the thrusters in a direction approximately perpendicular to the satellite's direction of travel so that the orbital inclination angle is different from that of the satellite constellation, thereby changing the inclination of the orbital plane from that of the congested orbit or by shifting the timing of the passage.

[0118] The ground facility includes a communication device for transmitting and receiving signals to track, control and operate the debris collection satellite equipped with a device for recovering a satellite that has failed and lost its orbit control function, an orbit control command transmitter, and an analysis and prediction unit for analyzing and predicting the passing orbit of the debris collection satellite in a state in which the failed satellite has been captured. The ground facility transmits a capture command and an orbit control command to the debris collection satellite to deorbit the failed satellite by operating the capture device and propulsion device equipped on the debris collection satellite. When analytical predictions reveal that the satellite will pass through a polar dense area or a congested orbital plane of another satellite constellation constructed at a low altitude during descent to deorbit the satellite or to deorbit the satellite for debris collection, the ground facility performs active deorbit operation to avoid the risk of collision. Specifically, the ground facility performs active deorbit operation to avoid the risk of collision by changing the inclination of the orbital plane from that of the congested orbit by applying acceleration in an out-of-plane direction of the orbital plane by thrusting the thrusters in a direction approximately perpendicular to the satellite's direction of travel so that the orbital inclination angle is different from that of the satellite constellation, thereby changing the inclination of the orbital plane from that of the congested orbit or by shifting the timing of the passage.

[0119] The ground facility includes a communication device that transmits and receives signals to track, control and operate the debris collection satellite equipped with a device for collecting rocket debris flying above a congested orbit with an orbital altitude of 800 km or more, an orbit control command transmitter, and an analysis and prediction unit that analyzes and predicts the passing orbit of the debris collection satellite in a state where it has captured the failed satellite. The ground facility transmits a capture command and an orbit control command to the debris collection satellite to deorbit the rocket debris by operating the capture device and propulsion device equipped on the debris collection satellite. When analytical predictions reveal that the satellite will pass through a polar dense area or a congested orbital plane of another satellite constellation constructed at a low altitude during descent to deorbit the satellite or to deorbit the satellite for debris collection, the ground facility performs active deorbit operation to avoid the risk of collision. Specifically, the ground facility performs active deorbit operation to avoid the risk of collision by changing the inclination of the orbital plane from that of the congested orbit by applying acceleration in an out-of-plane direction of the orbital plane by thrusting the thrusters in a direction approximately perpendicular to the satellite's direction of travel so that the orbital inclination angle is different from that of the satellite constellation, thereby changing the inclination of the orbital plane from that of the congested orbit or by shifting the timing of the passage.

[0120] Here, the effects of this embodiment will be further described. The general method for deorbiting a low-orbit satellite is to operate its thrusters in the opposite direction to the satellite's direction of travel to lower its orbital altitude and burn it up by re-entering the atmosphere. However, the mega-satellite constellations currently being planned have orbital altitudes of over 1000 km, which are higher than low-orbit satellites, so there is a risk of collision with satellites flying at lower orbital altitudes when deorbiting at the end of their life or when they fail. In addition, megasatellite constellations are configured with a variety of orbital planes, and since many satellites fly in formation in each orbital plane, the orbital paths that satellites pass through when deorbiting are also diverse. The probability of collision is particularly high when there is a possibility of passing through congested areas of low-orbit satellites, such as near LST10:30 in a sun-synchronous orbit or in the polar regions. If deorbiting relies on free fall, the orbital plane will rotate as the altitude gradually decreases, so a satellite deorbited from any orbital plane may pass through a congested orbit of sun-synchronous satellites. In addition, when deorbiting a satellite in a satellite constellation whose orbital plane passes near the polar regions and has an inclination of approximately 90 degrees, the orbital inclination remains roughly the same even if the orbital altitude is lowered, so there is a high probability of collision with a polar orbit satellite in a lower orbit.

[0121] In this embodiment, in order to avoid passing through a congested orbital plane, the rotation of the orbital plane is used to accelerate the descent before passing through the congested orbit, or conversely, the orbital plane is made quiet to fall after the congested orbital plane has passed, thereby avoiding collisions. As a method for changing the timing of passing through a congested orbital plane, if the satellite to be deorbited is accelerated, the orbital altitude increases and the timing of the descent can be delayed. If the satellite is decelerated, the descent of the orbital altitude accelerates, so the timing of the descent can be advanced. In addition, since the orbital plane rotates due to perturbation depending on the residence time at the orbital altitude, it becomes possible to wait for the passage of the congested orbit. In addition, since the orbital inclination angle can be changed by operating the thruster in a direction perpendicular to the traveling direction when the satellite to be deorbited passes through the ascending node or descending node, the rotation of the orbital plane can also be accelerated.

[0122] In particular, in Example 4 of the ground facility 500, the orbital inclination angle is intentionally changed to change the orbital plane so as not to pass through the polar regions at altitudes where congestion occurs in the polar regions, thereby avoiding collisions. As a method for changing the orbital inclination angle, the orbital inclination angle can be effectively changed by operating the thrusters in a direction perpendicular to the direction of travel when the satellite to be de-orbited passes through the ascending node or descending node.

[0123] Next, the effects of the above-mentioned first to tenth embodiments will be further described. In recent years, plans for large-scale satellite constellations involving several thousand satellites have been announced, but there is a risk that satellites flying at the same altitude will collide at two points where the satellite altitudes coincide on the intersecting line of the orbital planes. In large-scale constellations, the probability of collision is extremely high, especially in the polar regions where all orbital planes intersect with a high probability. A well-known example of a large number of satellites flying in the same orbital plane is the geostationary orbit satellites that fly above the equator at an altitude of about 36,000 km, with about 300 satellites flying in the same orbital plane. Because they are synchronized with the rotation of the Earth, they appear to be stationary in space when viewed from the ground, but because they fly in a nearly circular orbit at the same altitude, satellites in geostationary orbit do not collide and continue to operate. Also, because the angle from the Earth is only about 1 to 2 degrees apart, it seems like they are close to each other, but the distance between two satellites in orbit is far enough apart.

[0124] In contrast, low-earth-orbit satellite constellations, which have been increasing in recent years, have several thousand satellites even in a single constellation, and the total number of satellites in a multi-satellite constellation concept approaches 10,000. The orbital altitude is about 1 / 20 to 1 / 100 of that of a geostationary satellite, and the distance between the two satellites is much closer, so there is a higher risk of collision compared to geostationary orbit. In addition, unlike geostationary orbits, because different orbital planes are used simultaneously, there is a possibility of collisions at the intersection of the two planes. In a satellite constellation with an orbital inclination of nearly 90 degrees, multiple orbital planes intersect near the Earth's axis, and all satellites pass over the Antarctic and North Pole, so there is a high possibility of collisions if the orbital altitudes coincide. In addition, the sun-synchronous orbits between 10:00 and 11:00 LST, which are often used by Earth observation satellites, often have orbital planes in which satellites are densely packed, and there is a high risk of collision if an object that gradually changes its orbital altitude enters the same orbital plane. In addition, in the completed form of the satellite constellation, a collision will not occur unless the position coordinates and time of any two satellites coincide at the same time, i.e. (x1, y1, z1, t1) = (x2, y2, z2, t2). Therefore, collisions can be avoided by artificially manipulating the orbital altitude or timing, or the phase in the orbital plane. However, during the transitional stage of constructing a satellite constellation, there is a high risk of collision in the process of adding a new satellite to the constellation. In addition, if a satellite flying at a higher altitude than many satellite constellations experiences an uncontrollable malfunction and falls freely, there is a high risk of collision if it passes through a dense orbital plane while changing altitude, as it may meet with multiple groups of satellites at orbital altitudes within the same orbital plane.

[0125] Because outer space is so vast, the absolute probability of a collision is still small, but if a collision does occur, it will cause large-scale destruction, and the large amount of debris that is scattered will collide with satellites flying nearby, causing secondary damage. In the worst case scenario, there is a concern that the entire nearby orbit will be violated due to a chain reaction of collisions and destruction. If the entire nearby orbit were to be violated and a large amount of debris were to become airborne, there would be a risk that no satellites would be able to operate for a long period of time, which would have a negative impact on social life as a whole, as our dependence on space infrastructure increases. In addition, satellites themselves are expensive, and the total cost of launching them by rocket and operating them is enormous, so a collision would result in huge economic losses. Furthermore, because multiple satellites work together to achieve goals such as communication services, the loss of a satellite due to a collision will result in the interruption of the originally intended service and a deterioration in quality.

[0126] In the above-mentioned first to tenth embodiments, collisions of satellite constellations can be avoided by providing methods such as a combination of orbital planes with different altitudes, a method of artificially shifting the time of intersection, a method of removing a malfunctioning satellite, and a method of inserting a new satellite into orbit.

[0127] Embodiment 11 In this embodiment, the following description will be mainly focused on the points added to the embodiments 1 to 10. Note that the same components as those in the embodiments 1 to 10 are given the same reference numerals, and the description thereof may be omitted.

[0128] As described in the first embodiment, the satellite constellation forming system 100 is composed of the satellite group 300, which cooperates to form the satellite constellation 20 that provides services. The satellite constellation forming system 100 forms the satellite constellation 20 having a plurality of orbital planes in which a plurality of satellites fly at the same orbital altitude in each orbital plane 21. The satellite constellation forming unit 110 according to this embodiment forms a satellite constellation 20 in which the orbital altitudes of the orbital planes 21 are different from one another and each orbital plane has an orbital inclination angle that makes the orbital periods of the orbital planes 21 equal to one another. For example, each of the orbital planes is a sun-synchronous orbit as shown in FIG.

[0129] The satellite constellation forming system 100 has parameters set so that the orbital altitudes of the orbital planes 21 of the satellite constellation 20 are different from each other, and each orbital plane has an orbital inclination angle such that the orbital periods of the orbital planes 21 of the multiple orbital planes are equal to each other. Then, using the set parameters, the satellite constellation forming unit 110 forms a satellite constellation 20 in which the orbital altitudes of the orbital planes 21 are different from each other and each orbital plane has an orbital inclination angle such that the orbital periods of each of the orbital planes 21 of the multiple orbital planes are equal to each other.

[0130] FIG. 25 is a schematic diagram showing a specific example of a satellite constellation 20 according to this embodiment. Sun-synchronous orbital planes have the same orbital period even if they have different orbital altitudes. Below are examples of multiple orbital planes with different orbital altitudes that result in a sun-synchronous orbit. The constraints for sun synchronization are largely determined by the correlation between the orbital altitude and the orbital inclination, so a sun-synchronous orbit can be formed by appropriately setting the orbital inclination according to the orbital altitude. Orbital altitude 1000km: Orbital inclination approximately 99.5° Orbital altitude 1100km: Orbital inclination approximately 99.9° Orbital altitude 1200km: Orbital inclination approximately 100.4° Orbital altitude 1300km: Orbital inclination approximately 100.9° Orbital altitude 1400km: Orbital inclination approximately 101.4° Orbital altitude 1500km: Orbital inclination approximately 102.0°

[0131] For example, if the orbital planes for the above six orbital altitudes are set as shown below in the LST, a group of orbital planes that differ from each other in the latitude direction by approximately 30 degrees will be formed, and the relative angles between these orbital planes will always be maintained. In other words, six orbital planes with the same orbital period will be formed. Sun-synchronous orbit at 1000km altitude: LST06:00 Sun-synchronous orbit at an altitude of 1100 km: LST08:00 Orbit altitude 1200km, sun-synchronous orbit: LST10:00 Sun-synchronous orbit at 1300km altitude: LST12:00 Orbit altitude 1400km, sun-synchronous orbit: LST14:00 Sun-synchronous orbit at 1500km altitude: LST16:00

[0132] Here, a sun-synchronous orbit has been shown as a typical example in which the orbital periods are equal, but even in the case of a sun-asynchronous orbit, it is possible to select multiple orbital altitudes that similarly result in equal orbital periods.

[0133] In addition, the satellite constellation forming unit 110 may form a satellite constellation 20 in which the orbital altitudes of each of the multiple orbital planes 21 are different from each other and each orbital plane has an orbital inclination angle at which the rotation of each of the multiple orbital planes 21 is synchronized.

[0134] Next, a ground facility 500 that tracks and controls the satellite constellation 20 constructed by the satellite constellation forming system 100 according to this embodiment will be described. The ground equipment 500 according to this embodiment adjusts the altitude of each satellite so as to maintain the relative phase of the multiple satellites in each of the multiple orbital planes, and generates commands to adjust the orbital altitude and orbital inclination of each orbital plane so as to maintain the relative angle between the multiple orbital planes, and transmits the commands to each satellite in the satellite constellation.

[0135] <Example 5 of Ground Equipment 500> FIG. 23 is a diagram showing a configuration of Example 5 of the ground facility 500 which is the ground facility 500 according to the present embodiment. The configuration of the fifth example of the ground equipment 500 is similar to that of the first example of the ground equipment 500 of the tenth embodiment.

[0136] The communication device 950 transmits and receives signals for tracking and controlling the satellites 30 that make up the satellite constellation 20 . The orbit control command transmitter 510 transmits to the satellite 30 an orbit control command 51 that adjusts the altitude of each satellite so as to maintain the relative phase of the multiple satellites in each of the multiple orbital planes, and adjusts the orbital altitude and orbital inclination of each orbital plane so as to maintain the relative angle between the multiple orbital planes.

[0137] ***Explanation of the Effects of the Present Embodiment*** The orbital periods of orbital planes with different orbital altitudes and the same orbital inclination angle are different. Therefore, the relative angle between the orbital planes changes over a long period of operation. As a result, when multiple satellites cooperate to provide a service, the satellite configuration may change, causing a risk of disruption to the service. In addition, when the orbital plane is adjusted using a separate thruster to maintain an appropriate orbital configuration, there is a risk that the service may not be able to continue during the adjustment period. According to the satellite constellation forming system of this embodiment, the relative relationship between the orbital planes is maintained, so it is possible to avoid the risk of collision while continuing to provide services without any problems.

[0138] Embodiment 12 In this embodiment, the following mainly describes additions or differences from embodiments 1 to 11. Note that the same components as those in embodiments 1 to 11 are given the same reference numerals, and descriptions thereof may be omitted.

[0139] ***Configuration Description*** FIG. 26 shows an example of the configuration of a satellite 30 in a satellite constellation forming system 600. Here, the configuration of the satellites 30 that form the satellite constellation forming system 600 will be described. The satellite 30 comprises a satellite control device 310, a satellite communication device 32, a propulsion device 33, an attitude control device 34, and a power supply device 35. The satellite 30 comprises other components that realize various functions, but in Fig. 6, the satellite control device 310, the satellite communication device 32, the propulsion device 33, the attitude control device 34, and the power supply device 35 will be described. The satellite 30 is an example of a space object 60.

[0140] The satellite control device 310 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 310 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 thrust to the satellite 30 and changes the speed of the satellite 30. Specifically, the propulsion device 33 is an apogee kick motor, a chemical propulsion device, or an electric propulsion device. The apogee kick motor (AKM) is an upper stage propulsion device used to put an artificial satellite into orbit, and is also called an apogee motor (when a solid rocket motor is used) or an apogee engine (when a liquid engine is used). Chemical propulsion systems are thrusters that use monopropellant or bipropellant fuels. Electric propulsion systems are ion engines or Hall thrusters. An apogee kick motor is a device used for orbital transfer, and can be a type of chemical propulsion system. The attitude control device 34 is a device for controlling attitude elements such as 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 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 the measurement data of the attitude sensor or various commands from the ground equipment 500. The power supply unit 35 includes devices such as solar cells, batteries, and a power control device, and supplies power to each device installed on the satellite 30.

[0141] The processing circuitry provided in the satellite control device 310 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 complex circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination of these. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array.

[0142] FIG. 27 shows an example of the configuration of the ground facility 500 provided in the satellite constellation forming system 600. The ground equipment 500 controls programs of multiple satellites 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.

[0143] The ground equipment 500 forms the satellite constellation 20 by communicating with each satellite 30. The ground equipment 500 is provided in the space traffic management device 200. 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 the hardware of the satellite constellation forming system 100 described in FIG. 6.

[0144] The ground facility 500 includes, as functional elements, an orbit control command transmission unit 510 and an analysis and prediction unit 520. The functions of the orbit control command transmission unit 510 and the analysis and prediction unit 520 are realized by hardware or software.

[0145] The communication device 950 transmits and receives signals for tracking and controlling each satellite 30 of the group of satellites 300 that make up the satellite constellation 20. The communication device 950 also transmits orbit control commands 55 to each satellite 30. The analysis and prediction unit 520 analyzes and predicts the orbit of the satellite 30 . The orbit control command transmitter 510 generates the orbit control command 55 to be transmitted to the satellite 30 . The orbit control command transmission unit 510 and the analysis prediction unit 520 realize the functions of the satellite constellation formation unit 11. That is, the orbit control command transmission unit 510 and the analysis prediction unit 520 are an example of the satellite constellation formation unit 11.

[0146] FIG. 28 is a diagram showing an example of the functional configuration of the satellite constellation forming system 600. The satellite 30 further includes a satellite constellation forming unit 11b that forms the satellite constellation 20. The satellite constellation forming unit 11b of each of the multiple satellites 30 and the satellite constellation forming unit 11 provided in each of the ground facilities 500 work together to realize the functions of the satellite constellation forming system 600. The satellite constellation forming unit 11b of the satellite 30 may be provided in the satellite control device 310.

[0147] FIG. 29 shows an example of the overall configuration of a space traffic management system 800 according to this embodiment. The space traffic management system 800 includes a plurality of space traffic management devices 200 . Each of the multiple space traffic control devices 200 is implemented in the business device 40 of each of multiple operators that manage space objects 60 flying in space. The multiple space traffic control devices 200 are connected to each other by communication lines.

[0148] FIG. 30 is a diagram showing an example of the configuration of a space traffic control device 200 according to this embodiment. The space traffic control device 200 communicates with other business devices 40. The space traffic control device 200 may be mounted on a ground facility 701. The space traffic control device 200 may also be mounted on a satellite constellation forming system 600.

[0149] The business device 40 provides information about a space object 60, such as an artificial satellite or debris. The business device 40 is a computer of an operator that collects information about a space object 60, such as an artificial satellite or debris. The business equipment 40 includes equipment such as a megaconstellation business equipment 41, a LEO constellation business equipment 42, a satellite business equipment 43, an orbital transfer business equipment 44, a debris removal business equipment 45, a rocket launch business equipment 46, and an SSA business equipment 47. LEO is an abbreviation for Low Earth Orbit. SSA is an abbreviation for Space Situational Awareness. The SSA business is also called the space situational awareness business or the SSA management business. The SSA business equipment is also called the space situational awareness business equipment or the SSA management business equipment.

[0150] The megaconstellation business device 41 is a computer of a megaconstellation business operator that operates a large-scale satellite constellation, that is, a megaconstellation business. The LEO constellation business equipment 42 is a computer of a LEO constellation operator that operates a low earth orbit constellation, i.e., a LEO constellation business. The satellite business device 43 is a computer of a satellite operator that manages one to several satellites. The orbital transfer business device 44 is an orbital transfer business computer that issues space object intrusion warnings to satellites. The debris removal business device 45 is a computer of a debris removal business operator that carries out the business of collecting debris. The rocket launch business device 46 is a computer of a rocket launch business operator that carries out the rocket launch business. The SSA business equipment 47 is a computer of an SSA business operator that performs an SSA business, i.e., a space situational awareness business.

[0151] Business device 40 may be any other device that collects information about space objects such as artificial satellites or debris and provides the collected information to space traffic management system 800. In addition, when space traffic control device 200 is mounted on a public server of SSA, space traffic control device 200 may be configured to function as the public server of SSA.

[0152] Space traffic control device 200 includes a processor 910, as well as 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. Processor 910 is connected to the other hardware via signal lines and controls the other hardware.

[0153] Space traffic control device 200 includes, as examples of functional elements, space traffic control unit 120 and storage unit 140. In storage unit 140, rule information 515 and dense area identification information 525 are stored.

[0154] The functions of the space traffic control unit 120 are realized by software. The storage unit 140 is provided in the memory 921. Alternatively, the storage unit 140 may be provided in the auxiliary storage device 922. Moreover, the storage unit 140 may be provided separately in the memory 921 and the auxiliary storage device 922.

[0155] The space traffic control unit 120, for example, manages the space object 60 according to the rule information 515. Alternatively, the space traffic control unit 120 uses the dense area identification information 525 to manage the space object 60 according to the rule information 515.

[0156] The processor 910 is a device that executes a space traffic control program. The space traffic control program is a program that realizes the functions of each component of the space traffic control device 200 and the space traffic control system 800.

[0157] The hardware of the space traffic control device 200 is similar to the hardware of the satellite constellation forming system 100 described in FIG.

[0158] The space traffic management program is loaded into the processor 910 and executed by the processor 910. Memory 921 stores not only the space traffic management program but also an OS (Operating System). Processor 910 executes the space traffic management program while executing the OS. The space traffic management program and the OS may be stored in an auxiliary storage device 922. The space traffic management program and the OS stored in the auxiliary storage device 922 are loaded into the memory 921 and executed by the processor 910. Note that part or all of the space traffic management program may be incorporated into the OS.

[0159] Space traffic control device 200 may include multiple processors that replace processor 910. These multiple processors share the task of executing a program. Each processor is a device that executes a program, just like processor 910.

[0160] The "parts" of each part of the space traffic control device may be read as "processing," "procedure," "means," "stage," or "step." In addition, the "processing" of the passage determination process, the alarm generation process, and the alarm notification process may be read as "program," "program product," or "computer-readable recording medium on which a program is recorded." "Processing," "procedure," "means," "stage," or "step" may be read as interchangeable with one another. The space traffic management program causes a computer to execute each process, procedure, means, stage, or step of the space traffic management system, where "part" is replaced with "process," "procedure," "means," "stage," or "process." Also, the space traffic management method is a method performed by space traffic management device 200 executing the space traffic management program. The space traffic management program may be provided in a form stored in a computer-readable recording medium. Also, each program may be provided as a program product.

[0161] <Functional overview of the space traffic management system according to this embodiment> Sun-synchronous orbits are commonly used in Earth observation, and are particularly densely populated with the following areas: - Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km. - Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km. - Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km. Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km.

[0162] Since the orbital inclination angle of a sun-synchronous orbit is close to 90 degrees, satellites flying at the same orbital altitude have their orbital planes intersecting at the polar regions, increasing the risk of collision. Therefore, as a rule of STM (Space Traffic Management), if satellites in orbital planes with different normal vectors are required to use different orbital altitudes and orbital intersections are eliminated, the collision probability during normal operations will be zero and the collision risk will be eliminated. In reality, collision risk does occur during non-regular operations such as orbit insertion and deorbit, but if the collision probability during normal operations is zero, the effect is to dramatically reduce the risk.

[0163] Another method to avoid collisions is to shift the timing of polar crossings through artificial control, but since many operators in many countries operate satellites in sun-synchronous orbits, there remains a risk of collisions if they do not cooperate with each other. There is also the issue that if an unforeseen accident, such as a debris collision, occurs and human control becomes impossible, there is a high risk of collision. Therefore, if the collision probability during normal operation is zero, it has the effect of being able to avoid collision accidents even if human control becomes impossible.

[0164] Specifically, as shown in Figures 29 and 30, a space traffic management system 800 according to this embodiment executes a space traffic management process for implementing space traffic management of space objects 60, using information such as rule information 515 and dense area identification information 525. That is, in the space traffic management system 800, a plurality of space traffic control devices 200 manage the traffic of space objects 60, using rule information 515 and dense area identification information 525 that are common to the plurality of space traffic management devices 200. The rule information 515 is also referred to as a space traffic management rule 501.

[0165] <Space traffic management processing example 1> The space traffic management unit 120 performs space traffic management processing for the space object 60 such that satellites in orbital planes with different normal vectors adopt different orbital altitudes.

[0166] Specifically, the rule information 515 includes information that indicates a rule that satellites in orbital planes with different normal vectors adopt different orbital altitudes. The space traffic management unit 120 manages the space object 60 according to the rule information 515 .

[0167] According to the space traffic management processing example 1, satellites in orbital planes with different normal vectors adopt different orbital altitudes, which has the effect of eliminating the collision probability in polar regions and eliminating the collision risk during normal operation.

[0168] <Space traffic management processing example 2> The space traffic management unit 120 performs space traffic management processing for the space object 60 so that multiple satellites with the same normal vector and flying at the same orbital altitude fly while maintaining a relative phase angle that results in approximately equal spacing within the orbital plane.

[0169] Specifically, the rule information 515 contains information that represents a rule that multiple satellites that have the same normal vector and fly at the same orbital altitude fly while maintaining a relative phase angle that results in approximately equal spacing within the orbital plane. The space traffic management unit 120 manages the space object 60 according to the rule information 515 .

[0170] FIG. 31 is a diagram showing a satellite arrangement in an orbital plane in a comparative example of the second example of space traffic management processing. FIG. 32 is a diagram showing a satellite arrangement in an orbital plane in the second example of the space traffic management processing according to the present embodiment. FIG. 33 is a diagram showing multiple orbital planes with the same normal vector but different orbital altitudes.

[0171] As shown in Figures 31 and 32, multiple satellites flying at the same orbital altitude in the same orbital plane can avoid collisions by flying in sync. However, if multiple satellites managed by different operators fly without managing the relative phase angles, there is a risk of collision. According to the space traffic management processing example 2, a plurality of satellites flying in the same orbital plane are identified using the space traffic management rule 501, and the plurality of satellites flying at the same orbital altitude fly while maintaining a relative phase angle that makes them approximately equally spaced in the orbital plane. This has the effect of avoiding collisions.

[0172] <Space traffic management processing example 3> The dense area identification information 525 is information for identifying the following areas as dense areas. - Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km. - Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km. - Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km. Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km. -Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km. -Areas above 80 degrees south latitude and with orbital altitudes between 500km and 1000km. The orbits around LST10:30 and LST13:30 are frequently used by the constellation of optical satellites or the A-Train, a group of Earth observation satellites. The orbits around LST06:00 and LST18:00 are frequently used by the constellation of radar satellites equipped with synthetic aperture radar.

[0173] The rule information 515 includes space traffic management rules 501 that indicate rules for operators managing satellites flying in congested areas to disclose satellite information. Space traffic management unit 120 uses dense area identification information 525 and rule information 515 to realize a means for operators managing satellites flying in the same orbital plane to exchange information about flight safety measures.

[0174] In the space traffic management processing example 3, the space traffic management device 200 has the congested area identification information 525. The space traffic management device 200 also has the space traffic management rules 501 by which operators who manage satellites flying in the congested area disclose satellite information, and a means by which operators who manage satellites flying in the same orbital plane can exchange information about flight safety measures. Since it is dangerous for multiple operators to fly satellites in this orbit without control, satellite orbit information is made public as a traffic rule, and an environment is created in which measures to ensure flight safety can be coordinated. Therefore, according to Example 3 of the space traffic management process, it is possible to avoid collisions. As a means for exchanging information about flight safety measures, the space traffic management system 800 may be provided with a chat function on its portal, or a message may be sent to host a coordination meeting.

[0175] <Space traffic management processing example 4> The space traffic control unit 120 uses the dense area identification information 525 to capture the space object 60 before it enters any of the dense areas during the process of leaving the orbit and re-entering the atmosphere, thereby achieving collision avoidance during orbit descent. Such a method of achieving collision avoidance during orbit descent is called an orbit descent collision avoidance operation method. A specific example of the crowded area is similar to that described in Example 3 of the space traffic management process.

[0176] FIG. 34 is a diagram showing the intrusion of a high-altitude mega-constellation satellite into a crowded area (dangerous area) during the process of satellite orbit descent. FIG. 35 is a diagram showing a space traffic management process for avoiding intrusion into a crowded area during a satellite orbit descent process according to this embodiment.

[0177] Specifically, the rule information 515 includes space traffic management rules 501 that indicate rules for capturing the space object 60 before it enters any of the crowded regions during the process of leaving the orbit and re-entering the atmosphere, thereby realizing collision avoidance during orbit descent. The collision avoidance during orbit descent is also called active de-orbit operation. The space traffic management unit 120 uses the dense area identification information 525 and the rule information 515 to capture the space object 60 before it enters any of the dense areas during the process of leaving the orbit and re-entering the atmosphere, thereby achieving collision avoidance operations during orbit descent.

[0178] A specific explanation will be given with reference to FIG. (1) The space traffic control device 200 of the mega-constellation business equipment 41 predicts that a high-altitude mega-constellation satellite will become a malfunctioning satellite and invade a congested area (dangerous area). This intrusion prediction information is shared with all the space traffic control devices 200 of the space traffic management system 800 via communication lines. (2) The space traffic management device 200 of the debris removal business device 45 captures the space object 60 before it enters any of the crowded areas based on the rule information 515, and realizes collision avoidance operations during orbital descent. Specifically, a rapid-response debris removal satellite is launched. (3) The rapid-response debris removal satellite will capture and combine with the malfunctioning satellite, and then re-enter the atmosphere while avoiding congested areas. This will enable collision avoidance during orbital descent.

[0179] Here, a supplementary explanation of the space traffic management system according to this embodiment will be provided with reference to Figures 61 and 62.

[0180] FIG. 61 shows an example of the functional configuration of a space traffic management system according to this embodiment. FIG. 62 is an example of a space information recorder of a megaconstellation business device according to this embodiment.

[0181] The space traffic management system includes a plurality of space traffic management devices 200 connected to each other via a common communication line. The space traffic management device 200 is provided in each of the megaconstellation business device, the space object business device, and the collision avoidance support business device.

[0182] <Mega constellation business equipment> The space traffic management device 200 of the mega constellation business equipment includes a space information recorder 101, a danger warning device 102, a danger analysis device 103 that analyzes the orbits of space objects, a danger avoidance action support device 104, and danger avoidance action implementation plan information 105.

[0183] The space information recorder 101 of the megaconstellation business device records the orbital information of the satellites that make up the megaconstellation. The space information recorder 101 is orbital forecast information. The space information recorder 101 includes public orbit information 61 associated with a satellite constellation ID that identifies a satellite constellation, and real-time high-precision orbit information 63 associated with a satellite ID that identifies a satellite. The public orbit information 61 is orbit information that can be made public to other business devices. The public orbit information 61 sets constituent satellite information such as the number of satellites constituting the satellite constellation and satellite IDs, as well as upper and lower limits of the orbital altitude of the satellite constellation and upper and lower limits of the orbital inclination angle of the satellite constellation. The real-time high-precision orbit information 63 is the predicted orbit information and the actual orbit information for each satellite that constitutes the satellite constellation.

[0184] The danger warning device 102 warns of the danger of approach or collision with a space object. The danger warning device 102 has orbit information associated with a space object ID that identifies the space object. The danger warning device 102 also has disclosure condition information that sets disclosure conditions for the orbit information.

[0185] The risk analysis device 103 performs trajectory analysis of a space object. For example, the risk analysis device 103 is an example of a collision analysis unit that analyzes a collision between a specific space object S and an individual satellite that constitutes a megaconstellation satellite group.

[0186] The danger avoidance action support device 104 plans the allocation of roles for avoidance actions of space objects. For example, the danger avoidance action support device 104 is an example of a countermeasure planning unit that plans collision avoidance measures when a collision between a megaconstellation and a specific space object S is predicted. In the danger avoidance action implementation plan information 105, an avoidance action plan formulated by the danger avoidance action support device 104 is set.

[0187] Fig. 62 is an example of a space information recorder of the megaconstellation business device according to the present embodiment 1. In Fig. 62, in particular, the details of real-time high-precision orbit information 63 are described. Forecast orbit information and actual orbit information are set in correspondence with the satellite ID in the real-time high-precision orbit information 63. The forecast orbit information and actual orbit information are set in real time with high precision.

[0188] <Space object business equipment> The space traffic management device 200 of the space object business device includes a space information recorder 101. The space object business device manages satellites of a normal satellite constellation, or satellites for which it is not appropriate to disclose their orbital information or whose orbital information is kept secret. Therefore, the space information recorder 101 of the space traffic management device 200 of the space object business device includes non-disclosed orbital information 62 associated with a space object ID, which is the ID of a specific space object S.

[0189] The private orbit information 62 contains predicted orbit information for the space object S. The predicted orbit information contains an epoch, orbital elements, and predicted errors.

[0190] <Collision avoidance support business equipment> The space traffic management device 200 of the collision avoidance assistance business device includes a space information recorder 101, a danger warning device 102, and a danger analysis device 103.

[0191] The space information recorder 101 of the collision avoidance assistance business device records the private orbit information 62 of the space object S received from the space object business device via a communication line. The private orbit information 62 of the space object S is associated with a space object ID that represents the ID of the space object S. In addition, the space information recorder 101 of the collision avoidance support business device records the public orbit information 61 associated with the satellite group ID received from the mega constellation business device. The public orbit information 61 includes orbit information or flight area information of the mega constellation.

[0192] In this manner, the database provided in the space traffic management device 200 of the collision avoidance assistance business device records the following information: - Private orbital information 62 of a particular space object S received via a communication line from a space object business device. - Orbital information or flight area information of satellites in a satellite constellation obtained from mega-constellation business equipment.

[0193] The risk analysis device 103 performs trajectory analysis of a space object. The risk analysis device 103 is an example of an orbit analysis unit 431 that performs trajectory analysis of a specific space object S. The risk analysis device 103 analyzes, for example, whether the specific space object S will enter an orbital altitude region in which a group of satellites of a satellite constellation fly.

[0194] The danger warning device 102 reports the approach of a space object or the risk of collision. The danger warning device 102 is an example of a reporting unit that reports an intrusion warning and non-public orbit information 62 of the specific space object S to the megaconstellation operator via a communication line when it is predicted that the specific space object S will intrude into the orbital altitude region in which the satellite constellation satellites fly. The communication line may be kept confidential by using an encryption key.

[0195] In the above embodiment, the following SSA business device has been described. The SSA business equipment is a business equipment by which the SSA operator manages space object information, A space traffic control device is provided which is compatible with space traffic control devices provided in a plurality of business devices that manage space objects; A space traffic control system is provided in which space traffic control devices equipped in a plurality of business devices are connected to each other via communication lines, and the space traffic control device is connected to the space traffic control system.

[0196] The space traffic control device A space information recorder that records the orbital information of space objects and A risk analysis device; A danger warning device that reports abnormal approach, collision, or intrusion of a space object into a danger zone and A danger avoidance action support device, Hazard avoidance action plan information, Security management information; It has all or part of the above.

[0197] The SSA business device uses the information on multiple space objects acquired by the space information recorder. The risk analysis device performs an approach, collision, or intrusion analysis; When a dangerous approach, collision, or intrusion is foreseen, The danger warning device notifies the business equipment of the space object involved of the danger.

[0198] The SSA business device is a space object management company that is the party that reported the danger by the danger warning device, Adjusting a danger avoidance behavior by the danger avoidance behavior support device; Disclose information on risk avoidance action implementation plans.

[0199] The SSA business device will report the danger alert to the debris removal business device or the megaconstellation business device, Request action to avoid danger.

[0200] The SSA business unit will report the danger alert to the space insurance business unit, Supports damage compensation measures in the event of a collision accident.

[0201] The SSA business equipment is a business equipment by which the SSA operator manages space object information, A space traffic control device is provided which is compatible with space traffic control devices provided in a plurality of business devices that manage space objects; A space traffic management system is connected to the space traffic management device by a communication line between space traffic management devices equipped in a plurality of business devices, In addition, it is connected to the space traffic control equipment equipped in the specific business equipment via a secret line.

[0202] Such an SSA business device has the advantage that, when the user of the SSA information is a space object management company that requires confidentiality, or when information about a space object being monitored needs to be kept confidential, it can exchange information only with necessary business devices based on the need-to-know principle.

[0203] The SSA business equipment is a business equipment by which the SSA operator manages space object information, A space traffic control device is provided which is compatible with space traffic control devices provided in a plurality of business devices that manage space objects; A space traffic control system is provided in which space traffic control devices equipped in a plurality of business devices are connected to each other via communication lines, and the space traffic control device is connected to the space traffic control system.

[0204] A business device for managing space object information by an SSA operator, The hazard warning device can provide rocket launch plan trajectory information or trajectory information of a space object that is deorbited and descending to its orbit. Report to mega-constellation operators.

[0205] In the above embodiment, the following space transportation business device has been described.

[0206] The space traffic management system is a space traffic management system that manages space traffic and includes a spaceplane control system and a collision avoidance support system, and also has the functions of an SSA system.

[0207] Space traffic management equipment includes control equipment installed in spaceports for spaceplanes and other shuttles. Here, we assume that the U.S. Federal Aviation Administration (FAA) is in charge of space traffic management. The FAA is an air traffic control organization that does not own space objects, but does carry out traffic management.

[0208] In the above embodiment, the following debris removal business device and ground facility have been described.

[0209] The debris removal business equipment is used by debris removal businesses that remove space objects. A debris removal business device that manages a debris removal satellite, The debris removal satellite comprises a capture device for capturing a space object, a propulsion device, an orbit control device, and a communication device; The space object During the process of leaving orbit and re-entering the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km Before you enter any of the The space object will be captured and collision avoidance operations will be performed during orbital descent.

[0210] The debris removal business equipment is used by debris removal businesses that remove space objects. A debris removal business device that manages a debris removal satellite, The debris removal satellite is a responsive satellite that is prepared for launch and stands by on the ground, After the space object is predicted to enter a satellite-dense area. launching said space object into a predicted trajectory; Capture the space object Collision avoidance operations will be carried out during orbital descent.

[0211] The ground facilities are used by debris removal companies that use debris removal satellites to remove space objects. A ground facility that operates and controls the debris removal satellite, Space objects During the process of leaving orbit and re-entering the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km If the analysis predicts that the vehicle will pass through one of the following: Send a command to the orbit control device equipped on the debris removal satellite. By increasing or decreasing the satellite's orbital altitude by increasing or decreasing its speed, or by changing the orbital inclination by applying acceleration in the out-of-plane direction of the orbital plane by thrusting the thrusters in a direction roughly perpendicular to the satellite's direction of travel, the timing of passing through a congested orbit or the orbital plane can be shifted to avoid the risk of collision. Collision avoidance operations will be carried out during orbital descent.

[0212] The ground facilities are used by debris removal companies that use debris removal satellites to remove space objects. A ground facility that operates and controls the debris removal satellite, The debris removal satellite is equipped with a capture device that restrains a space object in six degrees of freedom; The above ground equipment A means for analyzing a center of gravity position of the debris removal satellite in a state where the space object has been captured is provided; Send a command to the orbit control device equipped on the debris removal satellite. The thrust vector of the thruster passes through the center of gravity of the captured state. Operates and controls the orbit control system.

[0213] The ground facilities are used by debris removal companies that use debris removal satellites to remove space objects. A ground facility that operates and controls the debris removal satellite, The debris removal satellite is a responsive satellite that is prepared for launch and stands by on the ground, After the space object is predicted to enter a satellite-dense area. launching said space object into a predicted trajectory; Capture the space object Collision avoidance operations will be carried out during orbital descent.

[0214] The debris removal business equipment is used by debris removal businesses that remove space objects. A debris removal business device that manages a debris removal satellite, The ground equipment is provided.

[0215] The debris removal business equipment is used by debris removal businesses that remove space objects. A debris removal business device that manages a debris removal satellite, A space traffic control device is provided which is compatible with space traffic control devices provided in a plurality of business devices that manage space objects; A space traffic control system is provided in which space traffic control devices equipped in a plurality of business devices are connected to each other via communication lines, and the space traffic control device is connected to the space traffic control system.

[0216] The space traffic control device A space information recorder that records the orbital information of space objects and A danger warning device for space objects approaching danger zones; A risk analysis device; A danger avoidance action support device, Hazard avoidance action plan information, Security management information; Debris removal business equipment that is equipped with all or part of the above.

[0217] The debris removal business equipment is equipped with the space traffic control equipment. Obtaining prediction information on approach or collision of multiple space objects by a danger warning device, The orbital information of the approaching space object and the orbital information of the approaching space object are acquired by a space information recorder, The risk analysis device analyzes the time and orbital position when the risk is predicted, Debris removal satellites will be used to carry out risk avoidance actions.

[0218] The debris removal business equipment is equipped with the space traffic control equipment. The danger warning device obtains information on the intrusion of space objects into the danger zone, The orbital information of the approaching space object and the orbital information of the approaching space object are acquired by a space information recorder, The risk analysis device analyzes the time and orbital position when the risk is predicted, The danger avoidance action support device will coordinate between businesses involved in danger avoidance, Develop a risk avoidance action plan, Debris removal satellites will be used to carry out risk avoidance actions.

[0219] In the above embodiment, the following debris removal business device and ground facility have been described.

[0220] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, The satellites have the same normal vector and fly at the same orbital altitude, and are equipped with a space object management unit that manages the satellite group so that they fly while maintaining a relative phase angle that results in approximately equal spacing within the orbital plane. Mega-constellation satellite business equipment.

[0221] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, The satellite group is equipped with a space object management unit that manages the satellite group so that satellites in orbital planes with different normal vectors adopt different orbital altitudes. Mega-constellation satellite business equipment.

[0222] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A satellite constellation forming system in which a group of satellites cooperate to provide services, forming a satellite constellation having a plurality of orbital planes in each of which a plurality of satellites fly at the same nominal orbital altitude, By controlling the orbital altitude and passing timing of satellites flying in an area where multiple orbital planes intersect, Continue providing services while avoiding collisions Equipped with a satellite constellation formation unit Mega-constellation satellite business equipment.

[0223] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A satellite constellation forming system in which a group of satellites cooperate to provide services, forming a satellite constellation having a plurality of orbital planes in each of which a plurality of satellites fly at the same nominal orbital altitude, After a collision with a space object in orbit or a rocket in launch or a satellite in orbital transfer or debris is predicted, By controlling the orbits of the satellites and the timing of their passage, Continue providing services while avoiding collisions Equipped with a satellite constellation formation unit Mega-constellation satellite business equipment.

[0224] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, During the process of the mega-constellation satellites leaving their orbits and re-entering the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km before the satellite enters any of the The satellite is equipped with a space object management unit that operates to avoid collisions during orbital descent. Mega-constellation satellite business equipment.

[0225] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A ground facility comprising: a communication device for transmitting and receiving signals for tracking and controlling satellites constituting a satellite constellation; an orbit control command transmitting unit for transmitting an orbit control command; and an analysis and prediction unit for analyzing and predicting a passing orbit of the satellite after receiving a de-orbit command, the ground facility transmitting the orbit control command for de-orbiting a satellite that has reached the end of its design life by operating a propulsion device equipped on the satellite, The orbit control command transmission unit is When the analysis prediction unit determines that the satellite will pass through the orbital plane of the satellite constellation, the satellite's orbit control device increases or decreases the satellite's speed to raise or lower the orbital altitude, or changes the orbital inclination by applying acceleration in the out-of-plane direction of the orbital plane by thrusting the thruster in a direction approximately perpendicular to the satellite's traveling direction, thereby shifting the timing of passing through the congested orbit or the orbital plane to avoid a collision risk. The ground equipment transmits the orbit control command to carry out a collision avoidance operation during orbit descent. Mega-constellation satellite business equipment.

[0226] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A space traffic management system is provided in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line to form a space traffic management system, The space traffic management device includes: Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km as a dense region; and rule information, which is a space traffic management rule that indicates the rules for an operator managing satellites flying in the dense area to disclose satellite information; and a space object management unit that uses the dense area identification information and the rule information to realize a means for operators managing satellites flying in the same orbital plane to exchange information on flight safety measures. Mega-constellation satellite business equipment.

[0227] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A space traffic management system is provided in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line to form a space traffic management system, The space traffic management device includes: Equipped with a space information recorder that records satellite orbital information, In addition to this Space traffic management rules information, A risk analysis device; A danger warning device; A danger avoidance action support device, Hazard avoidance action plan information, Security management information; Comprising all or part of Mega-constellation satellite business equipment.

[0228] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A space traffic management system is provided in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line to form a space traffic management system, The space traffic management device includes rule information that indicates a rule that a plurality of satellites having the same normal vector and flying at the same orbital altitude fly while maintaining a relative phase angle that results in a roughly uniform arrangement within an orbital plane; Rule information for satellites in orbital planes with different normal vectors to adopt different orbital altitudes; A mega-constellation satellite business device equipped with

[0229] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, A space traffic management system is provided in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line to form a space traffic management system, The space traffic management device includes: During the process of the mega-constellation satellites leaving their orbits and re-entering the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km before the satellite enters any of the The satellite is operated to avoid collisions during its orbital descent. Mega-constellation satellite business equipment.

[0230] A satellite constellation forming system is a satellite constellation that is formed by a group of satellites that cooperate to provide a service, and the satellite constellation has a plurality of orbital planes in which a plurality of satellites fly at the same orbital altitude in each orbital plane, A satellite constellation forming system comprising: a satellite constellation forming unit that forms the satellite constellation in which the orbital altitudes of each of the plurality of orbital planes are different from each other.

[0231] A satellite constellation forming method for a satellite constellation forming system that forms a satellite constellation having a plurality of orbital planes in which a plurality of satellites fly at the same orbital altitude, the satellite constellation being configured with a group of satellites that provide services in cooperation with each other, comprising: A satellite constellation forming method, in which a satellite constellation forming unit forms the satellite constellation in which the orbital altitudes of each of the multiple orbital planes are the same and each of the multiple orbital planes exists on a different plane from each other, the satellite pass time at which a satellite flying on each orbital plane passes an intersection of the multiple orbital planes is a multiple of a time deviation value obtained by dividing the waiting time until the next satellite arrives in the same orbital plane by the number of orbital planes of the multiple orbital planes, and the satellite pass times do not coincide at any intersection of any two of the multiple orbital planes.

[0232] A debris removal method that includes a capture device or external force application device and a propulsion device for changing the orbital plane of an object before the object descends from above the orbital plane in which the satellite flies and passes through said orbital plane.

[0233] In a satellite constellation construction method, the debris removal method described in the above is applied to a satellite constellation constructed by a satellite constellation formation system, A satellite constellation construction method in which a component satellite is added by launching it into an orbital plane that is close to the orbital plane of the component satellites but at an orbital altitude different from the orbital altitude at which the satellites in the nearby orbital plane fly, and then accelerating or decelerating the satellite to change the orbital altitude and the angle of the orbital plane around the Earth's axis.

[0234] A ground facility comprising: a communication device for transmitting and receiving signals for tracking and controlling satellites constituting a satellite constellation; an orbit control command transmitting unit for transmitting an orbit control command; and an analysis and prediction unit for analyzing and predicting a passing orbit of the satellite after receiving a de-orbit command, the ground facility transmitting the orbit control command for de-orbiting a satellite that has reached the end of its design life by operating a propulsion device equipped on the satellite, The orbit control command transmission unit is When the analysis prediction unit determines that the satellite will pass through the orbital plane of the satellite constellation, the ground equipment transmits the orbit control command, which performs active de-orbit operation to avoid a collision risk by changing the orbital inclination angle by increasing or decreasing the satellite speed to increase or decrease the orbital altitude, or by applying acceleration out of the orbital plane by thrusting the thrusters in a direction approximately perpendicular to the satellite's traveling direction, thereby shifting the timing of passing through a congested orbit or the orbital plane.

[0235] A ground facility comprising: a communication device for transmitting and receiving signals for tracking, controlling and operating a debris collection satellite equipped with a device for recovering a satellite that has failed and lost its orbit control function; an orbit control command transmitting unit; and an analysis and prediction unit for analyzing and predicting the passing orbit of the debris collection satellite in a state in which the failed satellite has been captured; and transmitting a capture command and an orbit control command to the debris collection satellite to cause the failed satellite to deorbit by operating a capture device and a propulsion device equipped on the debris collection satellite, When analytical predictions reveal that the satellite will pass through the orbital plane of a congested sun-synchronous orbit near LST 10:30 at an orbital altitude of 500 to 800 km, the ground equipment performs active de-orbit operation to avoid the risk of collision by changing the orbital inclination angle by increasing or decreasing the satellite's speed by accelerating or decreasing the orbital altitude, or by changing the orbital inclination angle by applying acceleration out of the orbital plane by thrusting the thrusters in a direction roughly perpendicular to the satellite's direction of travel, thereby shifting the timing of the passage of the congested orbit or the orbital plane.

[0236] A space traffic management system in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line, Each of the plurality of space traffic control devices comprises: rule information indicating a rule that satellites in orbital planes with different normal vectors adopt different orbital altitudes; a space object management unit that manages the space object in accordance with the rule information; A space traffic management system equipped with

[0237] A space traffic management system in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line, Each of the plurality of space traffic control devices comprises: rule information that indicates a rule that a plurality of satellites having the same normal vector and flying at the same orbital altitude fly while maintaining a relative phase angle that results in a roughly uniform arrangement within the orbital plane; a space object management unit that manages the space object in accordance with the rule information; A space traffic management system equipped with

[0238] A space traffic management system in which a space traffic management device provided in each business device of a plurality of business operators that manage space objects is connected by a communication line, Each of the plurality of space traffic control devices comprises: When a space object leaves its orbit and enters the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km before the space object enters either A space traffic management system equipped with a space object management unit that captures the space object and performs collision avoidance operations during orbital descent.

[0239] A space object management unit provided in a business device for managing space objects, During the process of the space object leaving its orbit and re-entering the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km before the space object enters either A space object management unit that captures the space object and performs collision avoidance operations during orbital descent.

[0240] A method for avoiding collisions during orbital descent in a space traffic management system in which space traffic management devices provided in each business device of a plurality of businesses that manage space objects are connected by a communication line, comprising: a space object control unit of each of the plurality of space traffic control devices, When a space object leaves its orbit and enters the atmosphere, Sun-synchronous orbit near LST10:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST13:30, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST06:00, orbit altitude between 500km and 1000km, Sun-synchronous orbit near LST18:00, orbit altitude between 500km and 1000km, Areas above 80 degrees north latitude and with orbital altitudes between 500km and 1000km, Areas with latitudes of 80 degrees south or higher and orbital altitudes of 500km to 1000km before the space object enters either A method for collision avoidance during orbital descent, which captures the space object and performs collision avoidance operation during orbital descent.

[0241] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, Manage the satellite constellation forming system Mega-constellation satellite business equipment.

[0242] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, Executing the satellite constellation formation method Mega-constellation satellite business equipment.

[0243] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, Adopt the above-mentioned satellite constellation construction method Mega-constellation satellite business equipment.

[0244] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, The above-mentioned ground equipment is provided. Mega-constellation satellite business equipment.

[0245] A mega-constellation satellite business device that is a business device that manages a constellation of 100 or more satellites, The space traffic management system includes a space traffic management device. Mega-constellation satellite business equipment.

[0246] A constellation satellite business device that is a business device that manages a constellation of 10 or more satellites, The above-mentioned ground equipment is provided. Constellation satellite business equipment.

[0247] A constellation satellite business device that is a business device that manages a constellation of 10 or more satellites, The space traffic management system includes a space traffic management device. Constellation satellite business equipment.

[0248] A satellite business unit that is a business unit that manages fewer than 10 satellites, The above-mentioned ground equipment is provided. Satellite business equipment.

[0249] A satellite business unit that is a business unit that manages fewer than 10 satellites, The space traffic management system includes a space traffic management device. Satellite business equipment.

[0250] A mega-constellation satellite business unit, which is a business unit that manages a constellation of 100 or more satellites; or A constellation satellite business unit, which is a business unit that manages a constellation of 10 or more satellites; or A satellite business unit is a business unit that manages a constellation of fewer than 10 satellites. And, Adopt the above-mentioned collision avoidance operation method during orbit descent Satellite business equipment.

[0251] A debris removal satellite business device having a means for capturing a space object, Adopt the above debris removal method Debris removal business equipment.

[0252] A debris removal satellite business device having a means for capturing a space object, The above-mentioned ground equipment is provided. Debris removal business equipment.

[0253] A debris removal satellite business device having a means for capturing a space object, The space traffic management system includes a space traffic management device. Debris removal business equipment.

[0254] A debris removal satellite business device having a means for capturing a space object, The space object management unit is provided. Debris removal business equipment.

[0255] A debris removal satellite business device having a means for capturing a space object, Adopt the above-mentioned collision avoidance operation method during orbit descent Debris removal business equipment.

[0256] A business device for managing space object information by an SSA operator, The space traffic management system includes a space traffic management device. SSA business equipment.

[0257] A business device that manages information on space objects, including space stations, space transport vehicles, and spacecraft, other than satellites and rockets, Adopt the above-mentioned collision avoidance operation method during orbit descent Space object business equipment.

[0258] A space traffic management system that includes a space plane control system and a collision avoidance support system, The space traffic management system includes a space traffic management device. Space transportation business equipment.

[0259] Embodiment 13 In this embodiment, the following will be mainly described with respect to additions or differences from the embodiments 1 to 12. Note that the same configurations as those in the embodiments 1 to 12 are given the same reference numerals, and the description thereof may be omitted.

[0260] The configuration for observing the space object 110 will be described with reference to FIGS.

[0261] ***Configuration Description*** The configuration of the observation system 100 will be described with reference to FIG. The observation system 100 is a system for observing a space object 110 . "Observation" includes concepts such as "monitoring" or "filming."

[0262] A space object 110 is an object that exists in space. A specific example of a space object 110 is space debris. A space object 110 orbits the Earth 101 in a geostationary orbit 103 .

[0263] The observation system 100 includes an observation satellite 200 . The observation satellite 200 is an artificial satellite that orbits the Earth 101 . The observation satellite 200 orbits the Earth 101 in a geostationary orbit 103 or near the geostationary orbit 103 . The observation satellite 200 optically photographs the space object 110 from an altitude different from the altitude at which the space object 110 is located.

[0264] The altitude of geostationary orbit 103 is approximately 36,000 kilometers. Artificial satellites called geostationary satellites orbit in a geostationary orbit 103 in sync with the rotation of the Earth 101. That is, a geostationary satellite orbits the geostationary orbit 103 once per day. In other words, a geostationary satellite orbits the geostationary orbit 103 once every 24 hours. Space object 110, like a geostationary satellite, orbits geostationary orbit 103 once per day. The observation satellite 200 orbits the geostationary orbit 103 or in the vicinity of the geostationary orbit 103 once a day. The directions in which the space object 110 and the observation satellite 200 orbit are the same as the direction in which a geostationary satellite orbits.

[0265] Light from the sun 102 is called sunlight. The side of the Earth 101 that receives sunlight is referred to as the near side of the Earth 101 . The side of the Earth 101 that is not exposed to sunlight is referred to as the backside of the Earth 101. In FIG. 36, a space object 110 and an observation satellite 200 each orbit around the near side of the Earth 101 .

[0266] The configuration of the observation satellite 200 will be described with reference to FIG. The observation satellite 200 comprises an observation device 201 , a satellite control device 202 , a communication device 203 , a propulsion device 204 , an attitude control device 205 , and a power supply device 206 .

[0267] The observation device 201 is a device for observing the space object 110 . The observation device 201 optically captures images of the space object 110 flying at an altitude different from the orbital altitude of the observation satellite 200. Specifically, the observation device 201 is a visible optical sensor. The observation device 201 generates observation data. The observation data is data obtained by observation performed by the observation device 201. For example, the observation data corresponds to data representing an image in which the space object 110 is captured.

[0268] The satellite control device 202 is a computer that controls the observation satellite 200 . The satellite control device 202 controls the observation device 201, the propulsion device 204, and the attitude control device 205 according to a predetermined procedure or in accordance with various commands transmitted from ground facilities.

[0269] The communication device 203 is a device that communicates with ground facilities. The communication device 203 transmits observation data to the ground equipment and receives various commands transmitted from the ground equipment.

[0270] The propulsion device 204 is a device that provides thrust to the observation satellite 200 and changes the speed of the observation satellite 200 . In particular, the propulsion device 204 is an electric propulsion device, for example, an ion engine or a Hall thruster.

[0271] The attitude control device 205 is a device for controlling the attitude elements of the observation satellite 200 . The attitude control device 205 changes the attitude elements of the observation satellite 200 in a desired direction, or maintains the attitude elements of the observation satellite 200 in a desired direction. Specifically, the attitude elements of the observation satellite 200 are the attitude of the observation satellite 200, the angular velocity of the observation satellite 200, and the line of sight of the observation device 201. The attitude control device 205 includes an attitude sensor, an actuator, and a controller. The attitude sensor is a gyroscope, an earth sensor, a sun sensor, a star tracker, a thruster, a magnetic sensor, or the like. The actuator is an attitude control thruster, a momentum wheel, a reaction wheel, a control moment gyro, or the like. The controller controls the actuator by executing a control program based on the measurement data obtained by the attitude sensor or according to a control command from the ground equipment.

[0272] The power supply unit 206 includes a solar cell, a battery, a power control device, and the like, and supplies power to each device of the observation satellite 200 .

[0273] The satellite control device 202 will now be described in more detail. The satellite controller 202 includes processing circuitry. The processing circuit may be a dedicated hardware or a processor that executes a program stored in a memory. The processing circuit functions as an observation control unit that controls the propulsion device 204. 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 be, for example, a single circuit, multiple circuits, a programmed processor, parallel programmed processors, an ASIC, an FPGA, or a combination of these. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array.

[0274] The pointing function of the observation satellite 200 will now be explained in more detail. The observation satellite 200 has a pointing function for directing the observation direction toward the space object 110 . For example, the observation satellite 200 is equipped with a reaction wheel. The reaction wheel is a device for controlling the attitude of the observation satellite 200. The reaction wheel controls the attitude of the observation satellite 200, thereby achieving body pointing. For example, the observation device 201 includes a pointing mechanism. The pointing mechanism is a mechanism for changing the line of sight of the observation device 201. For example, a drive mirror or the like is used for the pointing mechanism.

[0275] The observation function of the observation device 201 will now be described. The observation device 201 has a variable resolution function and an autofocus function. The variable resolution function is a function that changes the resolution during observation. The autofocus function is a function for focusing on the space object 110 .

[0276] ***Explanation of Operation*** The operation of the observation system 100, and in particular the operation of the observation satellites 200, corresponds to an observation method.

[0277] An overview of the observation method will be given. The propulsion device 204 changes the flight speed of the observation satellite 200 after the observation satellite 200 starts to orbit either the near side of the Earth 101 or the far side of the Earth 101. This causes the orbital altitude of the observation satellite 200 to change from the altitude of the geostationary orbit 103. The propulsion device 204 changes the flight speed of the observation satellite 200 before the observation satellite 200 starts to orbit the other of the near side of the Earth 101 and the far side of the Earth 101. This causes the orbital altitude of the observation satellite 200 to return to the altitude of the geostationary orbit 103. The observation device 201 optically photographs a space object 110 flying at an altitude different from the orbital altitude of the observation satellite 200 .

[0278] The observation method will be described with reference to FIGS. The four times "00:00", "06:00", "12:00" and "18:00" assigned to the geostationary orbit 103 indicate the time in a specific region of the Earth 101 (for example, Japan). The observation satellite 200 orbits the near side of the Earth 101 during the daytime hours (06:00 to 18:00) in a specific region. In other words, the observation satellite 200 starts orbiting the near side of the Earth 101 at around 6:00 and finishes orbiting the near side of the Earth 101 at around 18:00. The observation satellite 200 orbits the far side of the Earth 101 during the nighttime hours (18:00 to 06:00) in a specific region. In other words, the observation satellite 200 starts orbiting the far side of the Earth 101 at around 18:00 and finishes orbiting the far side of the Earth 101 at around 6:00.

[0279] <Example 1> The first embodiment will be described with reference to FIGS. In the first embodiment, an observation satellite 200 orbits the near side of the Earth 101 .

[0280] After the observation satellite 200 starts orbiting the near side of the Earth 101, the propulsion device 204 increases the flight speed of the observation satellite 200. Specifically, the satellite control device 202 determines whether the observation satellite 200 has started to orbit the near side of the Earth 101. For example, the satellite control device 202 makes this determination by referring to the time. When the observation satellite 200 has started to orbit the near side of the Earth 101, the satellite control device 202 instructs the propulsion device 204 to increase speed. Then, the propulsion device 204 increases the flight speed of the observation satellite 200. As a result, the orbital altitude of the observation satellite 200 increases from the altitude of the geostationary orbit 103 .

[0281] As the orbital altitude of the observation satellite 200 rises from the altitude of the geostationary orbit 103, the ground speed of the observation satellite 200 decreases. In other words, the ground speed of the observation satellite 200 is slower than the ground speed of the space object 110 .

[0282] FIG. 40 shows the state in which a space object 110 that has caught up with an observation satellite 200 is photographed by the observation satellite 200. FIG. 41 shows a space object 110 that has passed an observation satellite 200 being photographed by the observation satellite 200. While the observation satellite 200 orbits the near side of the Earth 101, the observation device 201 photographs the space object 110 flying at an altitude lower than the orbital altitude of the observation satellite 200. In this way, the observation device 201 photographs the space object 110 with direct sunlight. Specifically, while the observation satellite 200 orbits the near side of the Earth 101, the observation device 201 photographs the direction toward the Earth 101. In this way, the observation device 201 photographs the space object 110 that passes the observation satellite 200 while flying in the geostationary orbit 103.

[0283] Before the observation satellite 200 starts orbiting behind the Earth 101, the propulsion device 204 slows down the flight speed of the observation satellite 200. Specifically, the satellite control device 202 determines whether the observation satellite 200 will start orbiting on the far side of the Earth 101. For example, the satellite control device 202 makes this determination by referring to the time. Before the observation satellite 200 starts orbiting on the far side of the Earth 101, the satellite control device 202 instructs the propulsion device 204 to decelerate. Then, the propulsion device 204 reduces the flight speed of the observation satellite 200. As a result, the orbital altitude of the observation satellite 200 descends to the altitude of the geostationary orbit 103 .

[0284] <Example 2> A second embodiment will be described with reference to FIGS. In the second embodiment, an observation satellite 200 orbits on the other side of the Earth 101 .

[0285] After the observation satellite 200 starts orbiting the other side of the Earth 101, the propulsion device 204 slows down the flight speed of the observation satellite 200. Specifically, the satellite control device 202 determines whether the observation satellite 200 has started to orbit behind the Earth 101. For example, the satellite control device 202 makes this determination by referring to the time. When the observation satellite 200 has started to orbit behind the Earth 101, the satellite control device 202 instructs the propulsion device 204 to decelerate. Then, the propulsion device 204 reduces the flight speed of the observation satellite 200. As a result, the orbital altitude of the observation satellite 200 descends from the altitude of the geostationary orbit 103 .

[0286] As the orbital altitude of the observation satellite 200 descends from the altitude of the geostationary orbit 103, the ground speed of the observation satellite 200 increases. In other words, the ground speed of the observation satellite 200 becomes faster than the ground speed of the space object 110 .

[0287] FIG. 45 shows a state in which a space object 110 that has been caught up with an observation satellite 200 is photographed by the observation satellite 200. FIG. 46 shows a state in which a space object 110 that has been overtaken by an observation satellite 200 is photographed by the observation satellite 200. While the observation satellite 200 orbits on the far side of the Earth 101, the observation device 201 photographs the space object 110 flying at an altitude higher than the orbital altitude of the observation satellite 200. In this way, the observation device 201 photographs the space object 110 with direct sunlight. Specifically, while the observation satellite 200 orbits the far side of the Earth 101, the observation device 201 photographs the opposite side of the Earth 101. In this way, the observation device 201 photographs the space object 110 that is overtaken by the observation satellite 200 while flying in the geostationary orbit 103.

[0288] Before the observation satellite 200 starts orbiting the near side of the Earth 101, the propulsion device 204 increases the flight speed of the observation satellite 200. Specifically, the satellite control device 202 determines whether the observation satellite 200 will start orbiting the near side of the Earth 101. For example, the satellite control device 202 makes this determination by referring to the time. Before the observation satellite 200 starts orbiting the near side of the Earth 101, the satellite control device 202 instructs the propulsion device 204 to increase speed. Then, the propulsion device 204 increases the flight speed of the observation satellite 200. As a result, the orbital altitude of the observation satellite 200 increases to the altitude of the geostationary orbit 103 .

[0289] ***Advantages of the First Embodiment*** The observation satellite 200 flies in or near the geostationary orbit 103 . After 6:00, the observation satellite 200 accelerates and increases its orbital altitude. Then, the observation satellite 200 photographs the space object 110 flying in the geostationary orbit 103 and overtaking the observation satellite 200. Also, before 18:00, the observation satellite 200 decelerates and decreases its orbital altitude. When the observation satellite 200 accelerates, the orbital altitude of the observation satellite 200 increases. When the orbital altitude of the observation satellite 200 increases, the ground speed of the observation satellite 200 decreases. Therefore, the observation satellite 200 is overtaken by the space object 110 flying in the geostationary orbit 103. The observation satellite 200 flies at an orbital altitude higher than the altitude of the geostationary orbit 103 between 6:00 and 18:00. The observation satellite 200 receives sunlight reflected from the space object 110 flying in the geostationary orbit 103. This allows the observation satellite 200 to observe the space object 110 under optimal conditions.

[0290] After 18:00, the observation satellite 200 decelerates and lowers its orbital altitude. Then, the observation satellite 200 photographs the space object 110 that flies in the geostationary orbit 103 and is overtaken by the observation satellite 200. Then, before 6:00 the next day, the observation satellite 200 increases its speed and raises its orbital altitude. When the observation satellite 200 decelerates, the orbital altitude of the observation satellite 200 descends. When the orbital altitude of the observation satellite 200 decreases, the ground speed of the observation satellite 200 increases. Therefore, the observation satellite 200 overtakes the space object 110 flying in the geostationary orbit 103. The observation satellite 200 flies at an orbital altitude lower than the altitude of the geostationary orbit 103 after 6:00 p.m. and before 6:00 a.m. the next day. The observation satellite 200 receives sunlight reflected from the space object 110 flying in the geostationary orbit 103. This allows the observation satellite 200 to observe the space object 110 under optimal conditions.

[0291] ***Addition to the first embodiment*** The observation satellite 200 may fly in an orbit other than the geostationary orbit 103 or in its vicinity. The space object 110 may fly in an orbit other than the geostationary orbit 103. Also, the space object 110 may fly in an orbit other than a circular orbit.

[0292] Furthermore, from the above-mentioned embodiments 1 to 13, the following SSA business device can be realized.

[0293] SSA operators who obtain information on space objects using surveillance equipment A business device for managing space object information, Equipped with a monitoring device that flies near geostationary orbit, As the monitoring device moves eastward relative to the space object, Between 18:00 Local Sun Time (LST) and 06:00 LST the following morning Above the other side of the Earth, where the sun doesn't shine Activate the monitoring device SSA business equipment.

[0294] SSA operators who obtain information on space objects using surveillance equipment A business device for managing space object information, Equipped with a monitoring device that flies near geostationary orbit, As the monitoring device moves westward relative to the space object, Between 06:00 Local Sun Time (LST) and 18:00 LST Above the sun's surface Activate the monitoring device SSA business equipment.

[0295] SSA operators who obtain information on space objects using surveillance equipment A business device for managing space object information, A monitoring device flying near a geostationary orbit; The monitoring device includes a ground facility for orbital control and monitoring control, While moving eastward relative to the space object, Between 18:00 Local Sun Time (LST) and 06:00 LST the following morning Above the other side of the Earth, where the sun doesn't shine Activate the monitoring device, While moving westward relative to the space object, Between 06:00 Local Sun Time (LST) and 18:00 LST Above the sun's surface Activate the monitoring device, and adjust the average monitoring device orbital period. SSA business equipment.

[0296] SSA operators who obtain information on space objects using surveillance equipment A business device for managing space object information, A monitoring device flying near a geostationary orbit; The monitoring device includes a ground facility for orbital control and monitoring control, While moving eastward relative to the space object, Between 18:00 Local Sun Time (LST) and 06:00 LST the following morning Above the other side of the Earth, where the sun doesn't shine Activate the monitoring device, While moving westward relative to the space object, Between 06:00 Local Sun Time (LST) and 18:00 LST Above the sun's surface Activate the monitoring device, Maintaining an average relative position to the ground equipment SSA business equipment.

[0297] SSA operators who obtain information on space objects using surveillance equipment A business device for managing space object information, A monitoring device equipped with a communication device and flying near a geostationary orbit; a geostationary satellite having a communication device; A ground facility communicating with the geostationary satellite, A command for orbit control and monitoring control of the monitoring device is Transmitting the signal to the monitoring device via the geostationary satellite; The monitoring data acquired by the monitoring device The ground equipment receives the signal via the geostationary satellite. SSA business equipment.

[0298] Communicate with the communication device of the monitoring device The antenna of the communication device of the geostationary satellite is It is an omnidirectional antenna or a fixed antenna that does not have a driving mechanism. SSA business equipment.

[0299] Send commands to monitoring equipment via communications satellite, Ground equipment constituting the SSA business equipment receives monitoring data acquired by the monitoring device via a communications satellite.

[0300] Embodiment 14 In this embodiment, the following will be mainly described with respect to additions or differences from the embodiments 1 to 12. Note that the same configurations as those in the embodiments 1 to 12 are given the same reference numerals, and the description thereof may be omitted.

[0301] ***Configuration Description*** The configuration of the communications satellite 120 will be described with reference to FIG. The communications satellite 120 is equipped with a camera 124 . Camera 124 is a wide-angle camera that points in the same direction as the direction of orientation of first directional antenna 121E or second directional antenna 121W.

[0302] The communication satellite 120 allows visual capture of the observation satellite 110 and other space objects flying in geostationary orbit 103 or in orbit close to geostationary orbit 103. This allows visual confirmation that the environment around the communication satellite 120 is free of interference and noise due to communication. Other space objects are space objects other than space object 109 observed by observation satellite 110.

[0303] The communications satellite 120 is equipped with a camera 124 . However, the camera 124 is a camera having a fisheye lens. Also, the camera 124 is disposed so that the direction from the communication satellite 120 to the Earth 101 is the line of sight vector. The camera 124 equipped with a fisheye lens provides image information in the elevation direction within a 360-degree viewing direction around the line of sight vector. By arranging the camera 124 so that the direction from the communication satellite 120 to the Earth 101 is the line of sight vector, it is possible to visually capture the observation satellite 110 and other space objects flying in the geostationary orbit 103 or in an orbit close to the geostationary orbit 103. Furthermore, it becomes possible to estimate the positions of other space objects in orbit. This makes it possible to visually confirm that the surroundings of the communication satellite 120 are an environment free of communication interference and noise.

[0304] The configuration of the observation satellite 110 will be described with reference to FIG. The observation satellite 110 further includes a camera 117 . Camera 117 is a wide-angle camera pointed at communications satellite 120 .

[0305] The camera 117 allows visual capture of the communication satellite 120 and other space objects flying in orbit around the geostationary orbit 103 or the geostationary orbit 103. This allows visual confirmation that the surroundings of the observation satellite 110 are an environment free of interference and noise due to communications. The observation satellite 110 is equipped with a camera 117 . However, the camera 117 is a camera having a fisheye lens. Also, the camera 117 is disposed so that the direction from the observation satellite 110 to the communication satellite 120 is the line of sight vector.

[0306] A camera 117 equipped with a fisheye lens provides image information in the elevation direction within a 360-degree viewing direction centered on the line-of-sight vector. By arranging the camera 117 so that the direction from the observation satellite 110 to the communication satellite 120 is the line of sight vector, it is possible to visually capture the communication satellite 120 and other space objects flying in the geostationary orbit 103 or in an orbit close to the geostationary orbit 103. Furthermore, it is possible to estimate the positions of other space objects on orbit. Therefore, it is possible to visually confirm that the surroundings of the observation satellite 110 are in an environment free of interference and noise due to communication.

[0307] In FIG. 50, camera 117 having a fisheye lens is referred to as a "camera with fisheye lens."

[0308] The meanings of the descriptions in each figure are as follows: The dashed line represents a geostationary orbit. The dashed line represents the orbit of the observation satellite 110. (Wn) represents a space object flying in a geostationary orbit to the west of the communication satellite 120. (En) represents a space object flying in a geostationary orbit to the east of the communication satellite 120. A specific example of a space object is an artificial satellite. The bold frame centered on the observation satellite 110 indicates the field of view 195 of the fisheye lens camera. The frame within the field of view 195 represents the communication range 196 of the communication device 113 provided on the observation satellite 110 .

[0309] Furthermore, from the above first to fourteenth embodiments, the following observation satellite can be realized.

[0310] FIG. 51 is a diagram showing the following observation satellites according to this embodiment. Observing space objects orbiting the Earth and flying near geostationary orbit An observation satellite, Equipped with observation equipment and propulsion equipment, By controlling the propulsion device so as to decelerate the observation satellite, Decreasing the orbital altitude of the observation satellite, As the orbital altitude decreases, the observation satellite By increasing the rotation speed of As the observation satellite moves eastward relative to the space object, Between 18:00 Local Sun Time (LST) and 06:00 LST the following morning Above the other side of the Earth, where the sun doesn't shine Activate the monitoring device Observation satellite.

[0311] FIG. 52 is a diagram showing the following observation satellites according to this embodiment. Observing space objects orbiting the Earth and flying near geostationary orbit An observation satellite, Equipped with observation equipment and propulsion equipment, By operating the propulsion device so as to accelerate the observation satellite, Raise the orbital altitude of observation satellites, As the orbital altitude increases, the observation satellite By slowing down the rotation speed of As the observation satellite moves westward relative to the space object, Between 06:00 Local Sun Time (LST) and 18:00 LST Above the sun's surface Activate the monitoring device Observation satellite.

[0312] Observing space objects orbiting the Earth and flying near geostationary orbit An observation satellite, Equipped with observation equipment and propulsion equipment, by operating the propulsion device to decelerate the observation satellite; Decreasing the orbital altitude of the observation satellite, As the orbital altitude decreases, the observation satellite By increasing the rotation speed of the observation satellite moves eastward relative to the space object; By operating the propulsion device so as to accelerate the observation satellite, Raise the orbital altitude of observation satellites, As the orbital altitude increases, the observation satellite By slowing down the rotation speed of the observation satellite moves westward relative to the space object; Operate the monitoring device at any timing during eastward and westward movement, And adjust the average orbital period Observation satellite.

[0313] Observing space objects orbiting the Earth and flying near geostationary orbit An observation satellite, Equipped with observation equipment and propulsion equipment, by operating the propulsion device to decelerate the observation satellite; Decreasing the orbital altitude of the observation satellite, As the orbital altitude decreases, the observation satellite By increasing the rotation speed of the observation satellite moves eastward relative to the space object; By operating the propulsion device so as to accelerate the observation satellite, Raise the orbital altitude of observation satellites, As the orbital altitude increases, the observation satellite By slowing down the rotation speed of the observation satellite moves westward relative to the space object; Operate the monitoring device at any timing during eastward and westward movement, and maintains an average relative position to the target Observation satellite.

[0314] It is also possible to realize an observation satellite equipped with a camera equipped with a fisheye lens as described below, or a wide-angle camera pointed forward in the direction of travel.

[0315] FIG. 53 is a diagram showing an example of the operation of a camera equipped with a fisheye lens according to this embodiment. An observation satellite, which flies at a lower orbital altitude than geostationary orbit and moves relatively eastward while monitoring space objects near geostationary orbit, is equipped with a fisheye lens camera.If all space objects are flying in geostationary orbit with an orbital inclination of 0 degrees, the image captured will show the space objects lined up in a row in the field of view of the fisheye lens, as shown in Figure 53.

[0316] FIG. 54 is a diagram showing another example of the operation of the camera equipped with the fisheye lens according to the present embodiment. If a space object has an orbital inclination angle other than 0 degrees, the space object will not be aligned in a line in the images captured by the fisheye camera, but will be scattered as shown in Figure 54. If the center of the field of view of the image from the fisheye lens camera is taken as the origin and the horizontal axis is the geostationary orbit plane with an orbital inclination angle of 0 degrees, the angle from the horizontal axis corresponds to the azimuth angle of the space object, and the distance from the center corresponds to the distance between the observation satellite and the space object.

[0317] Figures 55 and 56 plot information about space objects on a graph with distance on the horizontal axis and azimuth on the vertical axis. If information about a space object is plotted on a graph with distance on the horizontal axis and azimuth on the vertical axis, the information will be concentrated near azimuth angles of 0 degrees and 180 degrees, as shown in Figure 55. Analyzing this graph, as shown in Figure 56, we can see that space objects near an azimuth angle of 0 degrees are eastward, and space objects near an azimuth angle of 180 degrees are westward, and that the deviation in azimuth angle varies due to the orbital inclination being other than 0 degrees.

[0318] Fig. 57 is a diagram showing an example of the operation of a camera equipped with a fisheye lens according to the present embodiment. Fig. 58 is a graph corresponding to Fig. 57. If the observation satellite moves eastward and takes multiple images after a time delay, space objects in the west will move away while roughly maintaining their relative distribution, and space objects in the east will move closer while roughly maintaining their relative distribution, and after the observation satellite has overtaken them, they will move westward. Strictly speaking, the azimuth angle of a space object flying in an orbit with an inclination of θ degrees will fluctuate by ±θ degrees over the course of a year, but the fluctuation between multiple images taken in a short period of time is very small.

[0319] FIG. 59 is a graph corresponding to an example of the operation of a camera equipped with a fisheye lens according to this embodiment. Next, the case where a space object is moving will be described. As mentioned above, in images taken multiple times with a time difference, eastern space objects should generally maintain their relative distribution while becoming closer in distance; however, if the orbital altitude of the space object is different from that of a geostationary orbit, or if the space object moves by operating a propulsion device, then the relative distribution will deviate.

[0320] FIG. 60 is a graph corresponding to an example of the operation of a camera equipped with a fisheye lens according to this embodiment. If the relative relationship is maintained, the position of the space object can be predicted in advance, and if the actual measured value deviates from this, it is determined that the space object is a moving object. If the approach speed in the east is slower than predicted, i.e., if the distance is farther than predicted, it is estimated that the space object's orbital altitude is lower than geostationary orbit, and is estimated to be at an altitude between the orbital altitude of the observation satellite and that of geostationary orbit. Furthermore, if there is a deviation in the azimuth direction, it is clear that there is movement outside the orbital plane; however, since it is usually difficult for an artificial satellite to achieve large out-of-plane movement in a short period of time, in this case it is estimated that the debris is near geostationary orbit and has an out-of-plane velocity component that has crossed. Needless to say, similar analysis can be performed even with a wide-angle camera that does not have a fisheye lens.

[0321] In the above first to fourteenth embodiments, each system, such as the satellite constellation forming system and the space traffic management system, and each unit of each device have been described as an independent functional block. However, the configuration of each system and each device does not have to be as in the above-mentioned embodiments. The functional blocks of each system and each device may have any configuration as long as they can realize the functions described in the above-mentioned embodiments. Furthermore, each system and each device may be a single device or a system composed of multiple devices. In addition, a combination of multiple parts of the first to fourteenth embodiments may be implemented. Alternatively, one part of these embodiments may be implemented. In addition, any combination of these embodiments may be implemented, either as a whole or in part. That is, in the first to fourteenth embodiments, any combination of the embodiments is possible, or any component of each embodiment may be modified, or any component of each embodiment may be omitted.

[0322] It should be noted that the above-described embodiment is essentially a preferred example, and is not intended to limit the scope of the present disclosure, the scope of application of the present disclosure, and the scope of use of the present disclosure. The above-described embodiment can be modified in various ways as necessary. [Explanation of symbols]

[0323] 11,11b Satellite constellation formation unit, 20 Satellite constellation, 21 Orbital plane, 30 Satellite, 31 Debris collection satellite, 32 Satellite communication equipment, 33 Propulsion equipment, 34 Attitude control device, 40 Business equipment, 41 Mega constellation business equipment, 42 LEO constellation business equipment, 43 Satellite business equipment, 44 Orbital transfer business equipment, 45 Debris removal business equipment, 46 Rocket launch business equipment, 47 SSA business equipment, 51 Orbit control command, 52 Capture command, 60 Space object, 70 Earth, 100 Satellite constellation formation system, 200 Space traffic management equipment, 110 Satellite constellation formation unit, 120 Space traffic management unit, 140 Memory unit, 300 Satellite group, 310 Satellite control device, 500 Ground equipment, 501 Space traffic management rules, 510 Orbit control command transmission unit, 515 Rule information, 525 Dense area identification information, 520 analysis and prediction unit, 600 satellite constellation formation system, 800 space traffic management system, 910 processor, 921 memory, 922 auxiliary storage device, 930 input interface, 940 output interface, 950 communication device, 61 public orbit information, 62 private orbit information, 63 real-time high-precision orbit information, 101 space information recorder, 102 danger warning device, 103 danger analysis device, 104 danger avoidance action support device, 105 danger avoidance action implementation plan information, 100 observation system, 101 Earth, 102 Sun, 103 geostationary orbit, 110 space object, 200 observation satellite, 201 observation device, 202 satellite control device, 203 communication device, 204 propulsion device, 205 attitude control device, 206 power supply device.

Claims

1. An artificial satellite orbiting the Earth and flying near a geostationary orbit, or an observation satellite that observes space objects such as debris, Equipped with observation equipment and propulsion equipment, Decreasing the orbital altitude of the observation satellite by controlling the propulsion device so as to decelerate the observation satellite; As the orbital altitude decreases, the orbital speed of the observation satellite increases relative to the rotation speed of the Earth, and the observation satellite moves eastward relative to the space object, and the observation device is operated in the sky above the other side of the Earth, which is the side not exposed to sunlight, between 18:00 Local Sun Time (LST) and 06:00 LST the next morning. Observation satellite.

2. An artificial satellite orbiting the Earth and flying near a geostationary orbit, or an observation satellite that observes space objects such as debris, Equipped with observation equipment and propulsion equipment, Raising the orbital altitude of the observation satellite by operating the propulsion device so as to increase the speed of the observation satellite; As the orbital altitude increases, the orbital speed of the observation satellite decreases relative to the rotation speed of the Earth, and the observation satellite moves westward relative to the space object, and the observation device is operated above the front side of the Earth, which is the side exposed to sunlight, between Local Sun Time (LST) 06:00 and LST 18:

00. Observation satellite.

3. An artificial satellite orbiting the Earth and flying near a geostationary orbit, or an observation satellite that observes space objects such as debris, Equipped with observation equipment and propulsion equipment, operating the propulsion device to decelerate the observation satellite, thereby decreasing the orbital altitude of the observation satellite; the orbital speed of the observation satellite increases relative to the rotation speed of the Earth as the orbital altitude decreases, causing the observation satellite to move eastward relative to the space object; Raising the orbital altitude of the observation satellite by operating the propulsion device so as to increase the speed of the observation satellite; the orbital speed of the observation satellite decreases relative to the rotation speed of the Earth as the orbital altitude increases, causing the observation satellite to move westward relative to the space object; Operate the observation device at any timing during eastward and westward movement; And adjust the average orbital period Observation satellite.

4. An artificial satellite orbiting the Earth and flying near a geostationary orbit, or an observation satellite that observes space objects such as debris, Equipped with observation equipment and propulsion equipment, operating the propulsion device to decelerate the observation satellite, thereby decreasing the orbital altitude of the observation satellite; the orbital speed of the observation satellite increases relative to the rotation speed of the Earth as the orbital altitude decreases, causing the observation satellite to move eastward relative to the space object; Raising the orbital altitude of the observation satellite by operating the propulsion device so as to increase the speed of the observation satellite; the orbital speed of the observation satellite decreases relative to the rotation speed of the Earth as the orbital altitude increases, causing the observation satellite to move westward relative to the space object; Operate the observation device at any timing during eastward and westward movement; and maintains an average relative position to the target Observation satellite.

5. 5. The observation satellite according to claim 1, further comprising a camera equipped with a fisheye lens or a wide-angle camera directed forward in the direction of travel.

Images