Patent Publication Number: US-2023143280-A1

Title: Space traffic management system, space information recorder, space traffic management device, space traffic management method, collision avoidance assist business device, space object business device, mega-constellation business device, rocket launch assist business device, space situational awareness business device, debris removal business device, rocket launch business device, and oadr

Description:
TECHNICAL FIELD 
     The present disclosure relates to a space traffic management system, a space information recorder, a space traffic management device, a space traffic management method, a collision avoidance assist business device, a space object business device, a mega-constellation business device, a rocket launch assist business device, a space situational awareness business device, a debris removal business device, a rocket launch business device, and an OADR. 
     BACKGROUND ART 
     In recent years, construction of a large-scale satellite constellation consisting of several hundred to several thousand satellites, or a so-called mega constellation, has started, and a risk of satellite collision on an orbit is increasing. In addition, space debris such as satellites that have become uncontrollable due to failure, and rocket wreckage, are increasing. 
     With this rapid increase of space objects such as satellites and space debris in outer space, there is an increasing need in space traffic management (STM) to create international rules for avoiding collisions of space objects. 
     Patent Literature 1 discloses a technique of forming a satellite constellation consisting of a plurality of satellites on the same circular orbit. 
     Conventionally, a framework exists with which the U.S. Combined Space Operations Center (CSpOC) continuously monitors space objects and issues an alarm when approach of space objects to each other or collision of space objects against each other is anticipated. In response to this alarm, manned space stations and commercial communication satellites carry out avoidance operation when it is determined to be necessary. However, in recent years, projects have been announced in the United States to transfer the framework of issuing alarms to private satellites, to a private business operator, and a new framework has been in need. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2017-114159 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     A framework is not available that allows mega-constellation business operators to avoid collisions with each other so that flight safety is ensured at an unsteady operation stage such as orbit insertion and orbital disposal. Thus, collision avoidance operations might be insufficient in the future. 
     Patent Literature 1 does not describe a framework that allows mega-constellation business operators to avoid collisions with each other so that flight safety is ensured. 
     The present disclosure has as its objective to effectively assist avoidance of collision of a space object and an individual satellite of a mega-constellation satellite group with each other. 
     Solution to Problem 
     In a space traffic management system according to the present disclosure in which space traffic management devices individually mounted in a mega-constellation business device and in each business device of a plurality of business devices are connected to each other via a communication line, the mega-constellation business device managing a mega-constellation consisting of 100 or more satellites, 
     the space traffic management device mounted in the mega-constellation business device 
     specifies one to a plurality of representative satellites from a mega-constellation satellite group flying on orbits having a same nominal orbital altitude, has quasi-real-time high-accuracy orbital information of the representative satellite and orbital information relative values of constituent satellites other than the representative satellite, relative to the representative satellite, and shares the quasi-real-time high-accuracy orbital information of the representative satellite and the orbital information relative values of the constituent satellites relative to the representative satellite, with the space traffic management devices mounted in the plurality of business devices. 
     Advantageous Effects of Invention 
     With a space traffic management system according to the present disclosure, a business device other than a mega-constellation business device can conduct analysis of a danger involving a mega-constellation on its own, and can effectively assist avoidance of a space object and an individual satellite of a mega-constellation satellite group with each other. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    presents an example in which a plurality of satellites cooperate with each other to realize a global communication service around the entire Earth. 
         FIG.  2    presents an example in which a plurality of satellites having the same single orbital plane realize an Earth observation service. 
         FIG.  3    presents an example of a satellite constellation having a plurality of orbital planes intersecting in vicinities of polar regions. 
         FIG.  4    presents an example of a satellite constellation having a plurality of orbital planes intersecting outside of the polar regions. 
         FIG.  5    is a configuration diagram of a satellite constellation forming system. 
         FIG.  6    is a configuration diagram of a satellite of the satellite constellation forming system. 
         FIG.  7    is a configuration diagram of a ground facility of the satellite constellation forming system. 
         FIG.  8    presents a function configuration example of the satellite constellation forming system. 
         FIG.  9    presents a hardware configuration example of a space traffic management device of a collision avoidance assist business device according to Embodiment 1. 
         FIG.  10    presents a hardware configuration example of a space traffic management device of a mega-constellation business device according to Embodiment 1. 
         FIG.  11    presents a diagram illustrating status quo of mega-constellation satellite groups and danger regions during rocket launch. 
         FIG.  12    presents an example of orbital prediction information according to Embodiment 1. 
         FIG.  13    presents an example of a space information recorder of the mega-constellation business device according to Embodiment 1. 
         FIG.  14    presents an overall configuration example of a space traffic management system according to Embodiment 1. 
         FIG.  15    is a diagram illustrating an example of a configuration of the space traffic management system according to Embodiment 1. 
         FIG.  16    presents a detailed configuration example of the mega-constellation business device according to Embodiment 1. 
         FIG.  17    is a diagram illustrating a relative azimuth angle of an orbital plane according to Embodiment 1. 
         FIG.  18    is a diagram illustrating a relative elevation angle within an orbital plane according to Embodiment 1. 
         FIG.  19    is a diagram illustrating a relative elevation angle between orbital planes according to Embodiment 1. 
         FIG.  20    is a diagram illustrating a relative elevation angle within an orbital plane according to Embodiment 1. 
         FIG.  21    presents a detailed configuration example of a rocket launch business device which is an example of a second business device according to Embodiment 1. 
         FIG.  22    presents a hardware configuration example of a space traffic management device of a collision avoidance assist business device according to a modification of Embodiment 1. 
         FIG.  23    presents a hardware configuration example of a space traffic management device of a mega-constellation business device according to a modification of Embodiment 1. 
         FIG.  24    presents a function configuration example of an OADR according to Embodiment 2. 
         FIG.  25    presents a function configuration example of the OADR according to Embodiment 2. 
         FIG.  26    presents a function configuration example of the OADR according to Embodiment 2. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present disclosure will now be described below with referring to drawings. In the drawings, the same or equivalent portion is denoted by the same reference sign. In description of the embodiments, where appropriate, the same or equivalent portion will not be described, or will be described only briefly. Further, in the drawings below, a relationship in size among configurations may differ from what it actually is. Further, in description of the embodiments, sometimes a direction or position such as “upper”, “lower”, “left”, “right”, “forward”, “backward”, “front”, and “rear” is indicated. These notations are merely given for descriptive convenience and do not limit a layout and orientation of a configuration such as a device, an appliance, and a component. 
     Embodiment 1 
     An example of a satellite constellation which is a prerequisite for a space traffic management system according to the embodiment below will be described. 
       FIG.  1    is a diagram illustrating an example in which a plurality of satellites cooperate with each other to realize a global communication service around an entire Earth  70 . 
       FIG.  1    illustrates a satellite constellation  20  that realizes the communication service around the entire Earth. 
     Regarding a plurality of satellites flying on the same orbital plane and at the same altitude, a ground communication service range of each satellite overlaps with a communication service range of a following satellite. Hence, with the plurality of such satellites, the plurality of satellites on the same orbital plane can provide a communication service for a particular point on the ground alternately in a time-division manner. If an adjacent orbital plane is formed, the communication service can exhaustively cover the surface of the ground between adjacent orbits. Likewise, if a large number of orbital planes are arranged almost evenly around the Earth, it is possible to provide a global communication service for the ground around the entire Earth. 
       FIG.  2    is a diagram illustrating an example in which a plurality of satellites having the same single orbital plane realize an Earth observation service. 
       FIG.  2    illustrates a satellite constellation  20  that realizes the Earth observation service. In the satellite constellation  20  of  FIG.  2   , satellites each equipped with an Earth observation device, which is an optical sensor or a radio wave sensor such as a synthetic aperture radar, fly on the same orbital plane and at the same altitude. In this manner, with a satellite group  300  in which a ground imaging range of a following satellite overlaps a preceding ground imaging range with a time delay, the plurality of satellites on the orbit sense a ground image of a particular point on the ground alternately in a time-division manner, thereby providing the Earth observation service. 
     In this manner, the satellite constellation  20  is constituted of the satellite group  300  formed of the plurality of satellites having individual orbital planes. In the satellite constellation  20 , the service is provided by cooperation of the satellite group  300 . The satellite constellation  20  specifically refers to a satellite constellation formed of one satellite group run by a communication business service company as illustrated in  FIG.  1   , or by an observation business service company as illustrated in  FIG.  2   . 
       FIG.  3    presents an example of a satellite constellation  20  having a plurality of orbital planes  21  intersecting in vicinities of polar regions.  FIG.  4    presents an example of a satellite constellation  20  having a plurality of orbital planes  21  intersecting outside of the polar regions. 
     In the satellite constellation  20  of  FIG.  3   , orbital inclinations of the individual orbital planes  21  of the plurality of orbital planes are approximately 90 degrees, and the individual orbital planes  21  of the plurality of orbital planes exist on different planes. 
     In the satellite constellation  20  of  FIG.  4   , orbital inclinations of orbital planes  21  of the plurality of orbital planes are not approximately 90 degrees, and the individual orbital planes  21  of the plurality of orbital planes exist on different planes. 
     In the satellite constellation  20  of  FIG.  3   , two arbitrary orbital planes intersect at points in the vicinities of polar regions. In the satellite constellation  20  of  FIG.  4   , two arbitrary orbital planes intersect at points outside of the polar regions. In  FIG.  3   , there is a possibility that collision of satellites  30  occurs in the vicinities of the polar regions. As illustrated in  FIG.  4   , intersections of the plurality of orbital planes having orbital inclinations of more than 90 degrees separate from the polar regions according to the orbital inclinations. Also, depending on a combination of the orbital planes, there is a possibility that the orbital planes intersect at various positions including a vicinity of an equator. Accordingly, a location where collision of the satellites  30  can occur varies. The satellites  30  are also called artificial satellites. 
     Particularly, in recent years, construction of a large-scale satellite constellation consisting of several hundred to several thousand satellites has started, and a risk of satellite collision on the orbit is increasing. In addition, debris such as artificial satellites that have become uncontrollable due to failure. and rocket wreckage, are increasing. The large-scale satellite constellation is also called a mega-constellation. Such debris is also called space debris. 
     In this manner, as the debris increases in outer space and a number of satellites typically represented by mega-constellations increases rapidly, demands for space traffic management (STM) have arisen. 
     Also, to realize orbital transfer of a space object, demands have arisen for post-mission disposal (PMD) that takes place after a mission on the orbit is ended, or for ADR according to which debris such as a failed satellite and a floating upper block of a rocket is subjected to orbital disposal by an external means such as a debris removal satellite. International discussion for STM about such ADR demands has begun. PMD stands for Post Mission Disposal. ADR stands for Active Debris Removal. STM stands for Space Traffic Management. 
     With referring to  FIGS.  5  to  8   , description will be made on an example of a satellite  30  and a ground facility  700  in a satellite constellation forming system  600  which forms the satellite constellation  20 . For example, the satellite constellation forming system  600  is operated by a business operator that runs a satellite constellation business of a mega-constellation business device  41 , an LEO constellation business device, a satellite business device, or the like. LEO stands for Low Earth Orbit. 
     A satellite control scheme using the satellite constellation forming system  600  is also applied to a business device  40  that controls a satellite. For example, this satellite control scheme may be loaded in a business device  40  such as a debris removal business device  45  to manage a debris removal satellite, a rocket launch business device  46  to launch a rocket, and an orbital transfer business device to manage an orbital transfer satellite. 
     The satellite control scheme using the satellite constellation forming system  600  may be loaded in any business device as far as it is a business device of a business operator that manages a space object  60 . 
     Individual devices of the business devices  40  will be described later. 
       FIG.  5    is a configuration diagram of the satellite constellation forming system  600 . 
     The satellite constellation forming system  600  is provided with a computer.  FIG.  5    illustrates a one-computer configuration. In practice, computers are provided to the individual satellites  30  of the plurality of satellites constituting the satellite constellation  20  and to the ground facility  700  which communicates with the satellites  30 . The computers provided to the individual satellites  30  of the plurality of satellites and to the ground facility  700  communicating with the satellites  30  cooperate with each other to implement functions of the satellite constellation forming system  600 . In the following, an example of a configuration of a computer that implements the functions of the satellite constellation forming system  600  will be described. 
     The satellite constellation forming system  600  is provided with the satellites  30  and the ground facility  700 . Each satellite  30  is provided with a satellite communication device  32  to communicate with a communication device  950  of the ground facility  700 .  FIG.  5    illustrates the satellite communication device  32  among configurations provided to the satellite  30 . 
     The satellite constellation forming system  600  is provided with a processor  910  and other hardware devices as well, 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 devices via a signal line and controls the other hardware devices. The hardware of the satellite constellation forming system  600  is the same as hardware of a space traffic management device  100  to be described later with referring to  FIG.  9   . 
     The satellite constellation forming system  600  is provided with a satellite constellation forming unit  11  as a function element. A function of the satellite constellation forming unit  11  is implemented by hardware or software. 
     The satellite constellation forming unit  11  controls formation of the satellite constellation  20  while communicating with the satellites  30 . 
       FIG.  6    is a configuration diagram of the satellite  30  of the satellite constellation forming system  600 . 
     The satellite  30  is provided with a satellite control device  31 , a satellite communication device  32 , a propulsion device  33 , an attitude control device  34 , and a power supply device  35 . The satellite  30  is also provided with other constituent elements that implement various types of functions. With referring to  FIG.  6   , description will be made on the satellite control device  31 , the satellite communication device  32 , the propulsion device  33 , the attitude control device  34 , and the power supply device  35 . The satellite  30  is an example of the space object  60 . 
     The satellite control device  31  is a computer that controls the propulsion device  33  and the attitude control device  34 , and is provided with a processing circuit. Specifically, the satellite control device  31  controls the propulsion device  33  and the attitude control device  34  in accordance with various types of commands transmitted from the ground facility  700 . 
     The satellite communication device  32  is a device that communicates with the ground facility  700 . Specifically, the satellite communication device  32  transmits various types of data concerning its own satellite to the ground facility  700 . The satellite communication device  32  receives various types of commands transmitted from the ground facility  700 . 
     The propulsion device  33  is a device to give propulsion to the satellite  30  and changes a 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) refers to an upper-block propulsion device used for orbit insertion of an artificial satellite, and is also called an apogee motor (when a solid rocket motor is employed) or an apogee engine (when a liquid engine is employed). 
     The chemical propulsion device is a thruster that uses a one-component or two-component fuel. An example of the electric propulsion device is an ion engine or a Hall thruster. Apogee kick motor is a name of a device used for orbital transfer, and is sometimes a kind of chemical propulsion device. 
     The attitude control device  34  is a device to control attitude elements such as an attitude of the satellite  30 , an angular velocity of the satellite  30 , and a Line of Sight. The attitude control device  34  changes the attitude elements into desired directions. Alternatively, the attitude control device  34  maintains the attitude elements in desired directions. The attitude control device  34  is provided with 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 rection wheel, and a control moment gyro. The controller controls the actuator in accordance with measurement data of the attitude sensor or various types of commands from the ground facility  700 . 
     The power supply device  35  is provided with apparatuses such as a solar cell, a battery, and a power control device, and supplies power to the apparatuses mounted in the satellite  30 . 
     The processing circuit provided to the satellite control device  31  will be described. 
     The processing circuit may be dedicated hardware, or may be a processor that runs a program stored in the memory. 
     In the processing circuit, some of its functions may be implemented by dedicated hardware, and its remaining functions may be implemented by software or firmware. That is, the processing circuit can be implemented by hardware, software, or firmware; or a combination of hardware, software, and firmware. 
     The dedicated hardware is specifically a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC, or an FPGA; or a combination of a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC, and an FPGA. 
     ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field Programmable Gate Array. 
       FIG.  7    is a configuration diagram of the ground facility  700  provided to the satellite constellation forming system  600 . 
     The ground facility  700  program-controls a large number of satellites on every orbital plane. The ground facility  700  is an example of a ground device. The ground device is constituted of: a ground station including, for example, a ground antenna device, a communication device connected to the ground antenna device, and an electronic calculator; and a ground facility serving as a server or terminal connected to the ground station via a network. The ground device may include a communication device mounted in a mobile body such as an aircraft, an automotive vehicle, and a mobile terminal. 
     The ground facility  700  forms the satellite constellation  20  through communication with the satellites  30 . The ground facility  700  is provided to the space traffic management device  100 . The ground facility  700  is provided with the processor  910  and other hardware devices such as the memory  921 , the auxiliary storage device  922 , the input interface  930 , the output interface  940 , and the communication device  950 . The processor  910  is connected to the other hardware devices via the signal line and controls the other hardware devices. The hardware of the ground facility  700  is the same as hardware of the space traffic management device  100  to be described later with referring to  FIG.  9   . 
     The ground facility  700  is provided with an orbit control command generation unit  510  and an analytical prediction unit  520 , as function elements. Functions of the orbit control command generation unit  510  and analytical prediction unit  520  are implemented by hardware or software. 
     The communication device  950  transmits and receives a signal that performs tracking control of the satellites  30  of the satellite group  300  constituting the satellite constellation  20 . Also, the communication device  950  transmits an orbit control command  55  to the satellites  30 . 
     The analytical prediction unit  520  analytically predicts orbits of the satellites  30 . 
     The orbit control command generation unit  510  generates the orbit control command  55  to be transmitted to the satellites  30 . 
     The orbit control command generation unit  510  and the analytical prediction unit  520  implement the function of the satellite constellation forming unit  11 . That is, the orbit control command generation unit  510  and the analytical prediction unit  520  are examples of the satellite constellation forming unit  11 . 
       FIG.  8    is a diagram illustrating a function configuration example of the satellite constellation forming system  600 . 
     The satellite  30  is further provided with a satellite constellation forming unit  11   b  which forms the satellite constellation  20 . The satellite constellation forming units  11   b  of the individual satellites  30  of the plurality of satellites and the satellite constellation forming unit  11  provided to the ground facility  700  cooperate with each other to implement the functions of the satellite constellation forming system  600 . Alternatively, the satellite constellation forming unit  11   b  of the satellite  30  may be provided to the satellite control device  31 . 
     Description of Configurations 
     A space traffic management system  500  according to the present embodiment is provided with a collision avoidance assist business device  43  and a plurality of mega-constellation business devices  41 . The collision avoidance assist business device  43  assists avoidance of collision of space objects with each other in outer space. The mega-constellation business devices  41  manage mega-constellations which are satellite constellations each consisting of 100 or more satellites. 
     The space traffic management device  100  according to the present embodiment is mounted in the collision avoidance assist business device  43  and in each of the plurality of mega-constellation business devices  41 , and is provided with a database  211  and a server  212 . A space traffic management device  100  may be mounted in a space insurance business device of a space insurance business operator which runs a space insurance business. 
     In the space traffic management system  500 , the space traffic management devices  100  individually mounted in the collision avoidance assist business device  43 , the plurality of mega-constellation business devices  41 , and the space insurance business device are connected to each other via a communication line. 
       FIG.  9    is a diagram illustrating a hardware configuration example of the space traffic management device  100  of the collision avoidance assist business device  43  according to the present embodiment. 
       FIG.  10    is a diagram illustrating a hardware configuration example of the space traffic management device  100  of the mega-constellation business device  41  according to the present embodiment. 
     In the present embodiment, the space traffic management devices  100  are individually mounted in the mega-constellation business devices  41 , a space object business device  42 , the collision avoidance assist business device  43 , a space object management business device  44 , the debris removal business device  45 , the rocket launch business device  46 , a Space Situational Awareness (SSA) business device  47 , and a rocket launch assist business device  48 . 
     The mega-constellation business device  41  manages the satellite constellation consisting of a plurality of satellites. Specifically, the mega-constellation business device  41  is a computer of a mega-constellation business operator which runs a large-scale satellite constellation business, that is, a mega-constellation business. The mega-constellation business device  41  is an example of a satellite constellation business device that manages a satellite constellation consisting of, for example, 100 or more satellites. 
     The collision avoidance assist business device  43  assists avoidance of collision of space objects with each other in outer space. Specifically, the collision avoidance assist business device  43  is a computer of a collision avoidance assist business operator which assists avoidance of collision of space objects with each other in outer space. 
     The business devices  40  include the individual business devices described above. Each business device  40  provides information concerning the space object  60  such as an artificial satellite managed by each device, and debris. The business device  40  is a computer of a business operator which collects information concerning the space object  60  such as the artificial satellite and debris. 
     For example, the LEO constellation business device is a computer of an LEO constellation business operator which runs a low-Earth-orbit constellation business, that is, an LEO constellation business. 
     The satellite business device is a computer of a satellite business operator which deals with one to several satellites. The orbital transfer business device is a computer of an orbital transfer business operator which issues a space object intrusion alarm about a satellite. 
     The debris removal business device  45  is a computer of a debris removal business operator which runs a business of collecting debris. 
     The rocket launch business device  46  is a computer of a rocket launch business operator which runs a rocket launch business. 
     The rocket launch assist business device  48  is a computer of the rocket launch business operator which runs the rocket launch business. 
     The SSA business device is a computer of an SSA business operator which runs an SSA business, that is a space situational awareness business. The SSA business device is also called a space situational awareness business device. 
     The space object business device  42  is a business device that manages an unsteady-operation space object. 
     The space object management business device  44  is a business device that manages a deorbiting space object in an orbital descent process. 
     A space traffic management device  100  may be mounted in a ground facility  701  provided to each business device  40 . A space traffic management device  100  may be mounted in the satellite constellation forming system  600 . 
     The space traffic management device  100  is provided with a processor  910 , and is provided with and other hardware devices as well, 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 devices via a signal line and controls the other hardware devices. 
     The processor  910  is an example of a server. The memory  921  and the auxiliary storage device  922  are examples of the database  211 . The server  212  may be provided with other hardware devices such as an input interface  930 , an output interface  940 , a communication device  950 , and a storage apparatus. The server  212  implements individual functions of the mega-constellation business device  41 , the space object business device  42 , the collision avoidance assist business device  43 , the space object management business device  44 , the debris removal business device  45 , the rocket launch business device  46 , the SSA business device  47 , and the rocket launch assist business device  48 . 
     As illustrated in  FIG.  9   , the space traffic management device  100  of the collision avoidance assist business device  43  is provided with an orbital analysis unit  431 , an announcement unit  432 , and a storage unit  140 , as examples of function elements that implement a collision avoidance assist function. A space information recorder  101  is stored in the storage unit  140 . 
     As illustrated in  FIG.  10   , the space traffic management device  100  of the mega-constellation business device  41  is provided with a collision analysis unit  411 , a countermeasure formulating unit  412 , and a storage unit  140 , as examples of function elements that implement a mega-constellation management function. A space information recorder  101  is stored in the storage unit  140 . 
     In the following, a hardware configuration of the space traffic management device  100  will be described with referring to  FIG.  9   , using the space traffic management device  100  of the collision avoidance assist business device  43  as an example. Note that the space traffic management device  100  of another business device  40  has the same hardware configuration. 
     To simplify the description, a configuration having the same function is denoted by the same reference sign. However, each of the mega-constellation business device  41 , the collision avoidance assist business device  43 , and the space insurance business device individually has a hardware configuration and a function configuration individually. 
     Functions of the orbital analysis unit  431  and announcement unit  432  are implemented by software. The storage unit  140  is provided to the memory  921 . Alternatively, the storage unit  140  may be provided to the auxiliary storage device  922 . Also, the storage unit  140  may be provided to the memory  921  and the auxiliary storage device  922  dividedly. 
       FIG.  9    describes the space traffic management device  100  as a device that implements a function of collision avoidance assistance. However, the space traffic management device  100  has various functions other than the function of collision avoidance assistance. 
     The processor  910  is a device that runs a space traffic management program. The space traffic management program is a program that implements the functions of various constituent elements of the space traffic management device  100  and space traffic management system  500 . 
     The processor  910  is an Integrated Circuit (IC) that performs computation processing. Specific examples of the processor  910  are a Central Processing Unit (CPU), a Digital Signal Processor (DSP), and a Graphics Processing Unit (GPU). 
     The memory  921  is a storage device that stores data temporarily. A specific example of the memory  921  is a Static Random-Access Memory (SRAM) or a Dynamic Random-Access Memory (DRAM). 
     The auxiliary storage device  922  is a storage device that keeps data. A specific example of the auxiliary storage device  922  is an HDD. Alternatively, the auxiliary storage device  922  may be a portable storage medium such as an SD (registered trademark) memory card, a CF, a NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) Disc, and a DVD. HDD stands for Hard Disk Drive. SD (registered trademark) stands for Secure Digital. CF stands for CompactFlash (registered trademark). DVD stands for Digital Versatile Disk. 
     The input interface  930  is a port to be connected to an input device such as a mouse, a keyboard, and a touch panel. The input interface  930  is specifically a Universal Serial Bus (USB) terminal. Alternatively, the input interface  930  may be a port to be connected to a Local Area Network (LAN). 
     The output interface  940  is a port to which a cable of a display apparatus  941  such as a display is to be connected. The output interface  940  is specifically a USB terminal or a High-Definition Multimedia Interface (HDMI, registered trademark) terminal. The display is specifically a Liquid Crystal Display (LCD). 
     The communication device  950  has a receiver and a transmitter. The communication device  950  is specifically a communication chip or a Network Interface Card (NIC). In the present embodiment, the space traffic management devices  100  of the mega-constellation business devices  41 , space insurance business device, and collision avoidance assist business device  43  communicate with each other via the communication line. 
     The space traffic management program is read by the processor  910  and run by the processor  910 . Not only the space traffic management program but also an Operating System (OS) is stored in the memory  921 . The processor  910  runs the space traffic management program while running the OS. The space traffic management program and the OS may be stored in the auxiliary storage device  922 . The space traffic management program and the OS which are stored in the auxiliary storage device  922  are loaded into the memory  921  and run by the processor  910 . Part or a whole of the space traffic management program may be built in the OS. 
     The space traffic management device  100  may be provided with a plurality of processors that substitute for the processor  910 . The plurality of processors share running of the program. Each processor is a device that runs the program, just as the processor  910  does. 
     Data, information, signal values, and variable values which are used, processed, or outputted by the program are stored in the memory  921 , the auxiliary storage device  922 , or a register or cache memory in the processor  910 . 
     The term “unit” in each unit of the space traffic management device may be replaced by “process”, “procedure”, “means”, “phase”, or “stage”. The term “process” in an orbital analysis process and in an alarming process may be replaced by “program”, “program product”, or “computer-readable recording medium recorded with a program”. The terms “process”, “procedure”, “means”, “phase”, and “stage” are replaceable with one another. 
     The space traffic management program causes the computer to execute processes, procedures, means, phases, or stages corresponding to the individual units in the space traffic management system, with the “units” being replaced by “processes”, “procedures”, “means”, “phases”, or “stages”. A space traffic management method is a method that is carried out by the space traffic management device  100  running the space traffic management program. 
     The space traffic management program may be provided as being stored in a computer-readable recording medium. Each program may be provided in the form of a program product. 
     Description of Function 
     Representative Satellite (Star Mark Satellite) According to Present Embodiment 
       FIG.  11    presents a diagram illustrating status quo of mega-constellation satellite groups and danger regions during rocket launch. 
     A function outline of the rocket launch assist business device  48  according to the present embodiment will be described with referring to  FIG.  11   . 
     A plurality of mega-constellation business operators advocate a project of deploying many, several hundred to several ten-thousand satellites as if to exhaustively cover the sky. At the present stage, a mega-constellation business operator A has already announced a deployment project involving about 42,000 satellites, a mega-constellation business operator B has announced a deployment project involving about 3,000 satellites, and a mega-constellation business operator C has announced a deployment project involving about 600 satellites. 
     When launching a rocket to an altitude of 1,000 km or more, the rocket must pass through altitude regions where satellite groups of a large number of mega-constellation business operators fly. Then, an optimum launch timing with which no collision occurs in all the altitude regions must be found out. 
     For example, in order to launch a rocket to an altitude of 1,300 km or more, the rocket must clear all of a plurality of altitude regions where about 50,000 satellites fly. In order to clear all of the plurality of altitude regions where about 50,000 satellites fly, orbital information of the satellite groups of the individual mega-constellation business operators must be grasped accurately. 
     In a mega-constellation satellite group, when a satellite group consisting of up to several thousand satellites flies on the same orbit, if the orbit is a polar orbit having an orbital inclination of almost 90° as illustrated in  FIG.  3   , a satellite density is high in polar regions where all orbital planes meet. Therefore, in the polar regions, strict passing timing control must be performed for ensuring flight safety. 
     Meanwhile, if the orbit is an inclined orbit having an orbital inclination far from 90° as illustrated in  FIG.  4   , a collision risk exists at an orbital-plane intersection in a middle-latitude region. Therefore, to ensure flight safety by shifting a satellite passing timing at every lattice intersection, strict passing timing control must be performed. 
     In order to realize such strict passing timing control, the individual satellite groups fly while constantly operating the propulsion devices. 
     A procedure of ensuring flight safety requires performing danger analysis first of all, such as approach analysis and collision analysis. To perform high-accuracy danger analysis, high-accuracy orbital information of a space object is indispensable. 
     As described above, however, in mega-constellation satellite groups, the individual satellite groups fly while constantly operating the propulsion devices, in order to realize strict passing timing control. Hence, accurate position information cannot be grasped unless the orbital information is updated in each satellite group in a real-time manner. It is therefore rational to consider that only the mega-constellation business operators which manage individual mega-constellation satellite groups can manage real-time high-accuracy orbital information of several hundred to several ten-thousand satellites. 
     When performing rocket launch in this situation, it is difficult for the rocket launch business operator to collect every piece of real-time high-accuracy orbital information of about 50,000 satellites possessed by the plurality of mega-constellation business operators, and to perform danger analysis. 
     On the contrary, it is easy to collect high-accuracy orbital information of about one to ten representative satellites of each mega-constellation. High-accuracy orbital information of a total of no more than about 100 satellites of a plurality of mega-constellation business operators can be shared among the mega-constellation business operators. It is possible to collect quasi-real-time, if not real-time, high-accuracy orbital information of about 100 satellites by updating the information at a high frequency. 
     The large number of satellite groups flying on the same altitude are under strict passing timing control, as described above. If real-time high-accuracy orbital information of the representative satellite can be grasped, high-accuracy information can be shared by performing relative value management of orbital information of the other satellites. 
     In view of this, after an epoch and high-accuracy orbital elements of the representative satellite are information-updated at a high frequency, the mega-constellation business operator discloses phase differences within orbital planes of the other satellites with respect to the representative satellite, and relative angles of the orbital planes, to the public, as relative values relative to the representative satellite. Because of this information, even if the representative satellite operates its propulsion device and the orbital information changes accordingly, the relative values of the other satellites as a result of strict timing control for collision prevention in an own system are maintained. As a result, quasi-real-time high-accuracy orbital information can be grasped about all the satellites of the mega-constellation satellite group. 
     Many mega-constellation business operators are, so to speak, in the same boat. For each mega-constellation business operator, if another mega-constellation business operator exists both at a higher altitude than its own system and at a lower altitude than its own system, a contradictory situation occurs. 
     In the example of  FIG.  11   , for each of the mega-constellation business operators A, B, and C, a satellite group of another business operator exists at a higher altitude than its own satellite group, and a satellite group of another business operator exists at a lower altitude than its own satellite group. Hence, in launching a rocket of its own system, the rocket will pass through a flight altitude region of another mega-constellation satellite group. Therefore, a framework of disclosing quasi-real-time high-accuracy orbital information of its own satellite, in launch of another mega-constellation satellite, when this another mega-constellation satellite passes through the flight region of its own satellite group, applies each mega-constellation business operator. It would be impossible to refuse this framework. 
     Therefore, which is the offender and which is the casualty cannot be one-sidedly determined with respect to a responsibility for avoiding collision in launching a rocket and with respect to an accountability for an accident when collision should occur. The positions of the business operator A, the business operator B, and the business operator C can be reversed anytime. Hence, without a framework where a plurality of mega-constellation business operators can coexist and prosper together, it is difficult to guarantee sustainability of mega-constellation businesses. 
       FIG.  12    is a diagram illustrating an example of orbit prediction information  51  according to the present embodiment. 
     For example, a business device  40  stores, to a storage unit, orbit prediction information  51  in which prediction values of an orbit of a space object  60  are set. For example, the business device  40  may acquire prediction values of orbits of a plurality of space objects  60  from another business device  40  utilized by a management business operator which manages the plurality of space objects  60 , and may store the acquired prediction values as orbit prediction information  51 . Alternatively, the business device  40  may acquire, from the management business operator, orbit prediction information  51  in which prediction values of orbits of a plurality of space objects  60  are set, and may store the acquired orbit prediction information  51  to the storage unit. 
     The management business operator is a business operator that manages the space object  60  such as a satellite constellation, various types of satellites, a rocket, and debris, which fly in space. 
     Information such as a space object Identifier (ID)  511 , a predicted epoch  512 , predicted orbital elements  513 , and predicted errors  514  are set in the orbit prediction information  51 . 
     The space object ID  511  is an identifier that identifies the space object  60 . In  FIG.  11   , a satellite ID and a debris ID are set as the space object ID  511 . The space object is specifically an object such as a rocket to be launched to outer space, an artificial satellite, a space base, a debris collection satellite, a planetary space probe, and a satellite or rocket that turned into debris after a mission is completed. 
     The predicted epoch  512  is an epoch predicted for an orbit of each of the plurality of space objects. 
     The predicted orbital elements  513  are orbital elements that identify an orbit of each of the plurality of space objects. The predicted orbital elements  513  are orbital elements predicted for the orbit of each of the plurality of space objects. In  FIG.  12   , Keplerian six orbital elements are set as the predicted orbital elements  513 . 
     The predicted errors  514  are errors predicted for the orbit of each of the plurality of space objects. A traveling-direction error and an orthogonal-direction error are set in the predicted errors  514 . Error amounts involved in performance values are explicitly indicated in the predicted errors  514 . 
     In the orbit prediction information  51  according to the present embodiment, the predicted epoch  512  and the predicted orbital elements  513  are set concerning the space object  60 . A time and position coordinates of the space object  60  in the near future can be obtained from the predicted epoch  512  and the predicted orbital elements  513 . For example, the time and position coordinates of the space object  60  in the near future may be set in the orbit prediction information  51 . 
     In this manner, the orbit prediction information  51  is provided with orbital information of the space object, including the epoch and the orbital elements or the time and the position coordinates, to explicitly indicate predicted values of the space object  60  in the near future. The orbit prediction information  51  may have a configuration other than the configuration of  FIG.  12    as far as it is information explicitly indicating the predicted values of the space object  60  in the near future. 
     Also, regarding the predicted values of rocket orbital information included in the space object information of the rocket, the predicted values of the rocket in the near future are explicitly indicated by the same configuration as that of the orbit prediction information  51 . 
     In  FIG.  12   , assume that satellites A, B, . . . , and F having satellite IDs of A, B, . . . , and F are satellites of a mega-constellation satellite group  301 . 
     A representative satellite  331  is at least one satellite selected from the mega-constellation satellite group  301  which flies at the same orbital altitude. In  FIG.  12   , assume that the satellite A is the representative satellite  331 . 
     Constituent satellites  332  are satellites other than the representative satellite  331  in the mega-constellation satellite group  301 . Hence, in  FIG.  12   , the satellites B, . . . , and F are the constituent satellites  332 . 
     In the present embodiment, the orbit prediction information  51  of the mega-constellation satellite group  301  is formed of the predicted values of the orbit of the representative satellite  331  and the predicted values of the orbits of the constituent satellites  332  other than the representative satellite  331 . The predicted values of the orbit of the representative satellite  331  are real-time high-accuracy orbital information. The predicted values of the orbits of the constituent satellites  332  other than the representative satellite  331  are relative values relative to the predicted values of the orbit of the representative satellite  331 . The predicted values of the orbits of the constituent satellites  332  are relative values relative to the predicted value of the orbit of the representative satellite  331 , and are referred to as quasi-real-time high-accuracy orbital information as well. 
     In  FIG.  12   , the orbit prediction information  51  of the satellites B, . . . , and F other than the satellite A which is the representative satellite  331  are expressed as relative values relative to the orbit prediction information of the representative satellite  331 . 
       FIG.  13    is a diagram illustrating an example of the space information recorder  101  of the mega-constellation business device  41  according to the present embodiment. 
     The space information recorder  101  of the mega-constellation business device  41  records orbital information of satellites constituting a mega-constellation. The orbital information includes predicted orbital information and performance orbital information. A specific example of the predicted orbital information of the space information recorder  101  has the same configuration as that of the orbit prediction information  51  of  FIG.  12   . 
     The space information recorder  101  is provided with public orbital information associated with a satellite group ID that identifies the mega-constellation satellite group  301 , and real-time high-accuracy orbital information associated with a satellite ID that identifies an individual satellite included in the satellite group. 
     The public orbital information is orbital information that can be disclosed to the other business devices. Constituent satellite information such as a number of satellites constituting the satellite group and satellite IDs of the satellites, an upper limit and lower limit of an orbital altitude of the satellite group, and an upper limit and lower limit of an orbital inclination of the satellite group are set in the public orbital information. 
     The predicted orbital information and the performance orbital information are set in the real-time high-accuracy orbital information to be associated with the satellite ID. The predicted orbital information and the performance orbital information are set in a real-time manner and accurately. 
     In the present embodiment, the orbit prediction information  51  of the mega-constellation satellite group  301  is formed of the predicted values of the orbit of the representative satellite  331  and the predicted values of the orbits of the constituent satellites  332  other than the representative satellite  331 . The predicted values of the orbits of the constituent satellites  332  other than the representative satellite  331  are relative values relative to the predicted values of the orbit of the representative satellite  331 . 
     The representative satellite  331  is at least one satellite selected from the mega-constellation satellite group  301  which flies at the same orbital altitude. 
     The constituent satellites  332  are satellites other than the representative satellite  331  in the mega-constellation satellite group  301 . 
     In  FIG.  13   , as an example, a satellite  30 _ 1  is treated as the representative satellite  331 . The constituent satellites  332  other than the satellite  30 _ 1  are a satellite  30 _ 2 , . . . , and a satellite  30 _ n . Note that n is a natural number expressing a number of satellites constituting the mega-constellation satellite group  301 . 
     At this time, the predicted orbital information of the satellite  30 _ 2 , . . . , and the satellite  30 _ n  other than the representative satellite  331  may be expressed as relative values relative to the predicted orbital information of the representative satellite  331 . 
     As described above, with the space traffic management device  100  according to the present embodiment, if real-time high-accuracy orbital information of the representative satellite  331  can be grasped, relative value management of orbital information of the other satellites can be performed, so that an effect of sharing high-accuracy information sharing can be achieved. 
     Also, with the space traffic management device  100  according to the present embodiment, a single business operator can grasp quasi-real-time high-accuracy orbital information about all the satellites managed by a plurality of the mega-constellation business operators. Hence, the space traffic management device according to the present embodiment provides an effect of ensuring flight safety. 
     Description of Operations 
     Function of Space Traffic Management System  500   
     Function configuration examples of the space traffic management system  500  according to the present embodiment will be described with referring to  FIGS.  14  to  17   . Hardware configurations of the individual space traffic management devices  100  have been described above. 
       FIG.  14    is a diagram illustrating an overall configuration example of the space traffic management system  500  according to the present embodiment. 
       FIG.  15    is a diagram illustrating a detailed configuration example of the rocket launch business device  46  according to the present embodiment. 
       FIG.  16    is a diagram illustrating a detailed configuration example of the mega-constellation business device  41  according to the present embodiment. 
     The plurality of space traffic management devices  100  provided to the space traffic management system  500  are connected to each other via a communication line  200 . The space traffic management devices  100  are individually provided to the plurality of mega-constellation business devices  41 , the space object business device  42 , the collision avoidance assist business device  43 , the space object management business device  44 , the debris removal business device  45 , the rocket launch business device  46 , the SSA business device  47 , and the rocket launch assist business device  48 . Although not illustrated in  FIG.  14   , the space object management business device  44  and the rocket launch assist business device  48  are also connected to each other via the communication line  200 , just as the other business devices  40  are. 
     There may be a plurality of business devices  40 . Alternatively, there may be one business device  40 . 
     Mega-Constellation Business Device  41   
     The space traffic management device  100  of the mega-constellation business device  41  is provided with the space information recorder  101 , a danger alarm device  102 , a danger analysis device  103  to perform orbital analysis of a space object, a danger avoidance action assist device  104 , and a danger avoidance action implementation plan information  105 . 
     The space traffic management device  100  mounted in the mega-constellation business device  41  specifies one to a plurality of representative satellites  331  from the mega-constellation satellite group flying on orbits having the same nominal orbital altitude. The space traffic management device  100  has quasi-real-time high-accuracy orbital information of the representative satellite  331 , and orbital information relative values of the constituent satellites  332 , other than the representative satellite  331 , relative to the representative satellite  331 . The space traffic management device  100  shares the quasi-real-time high-accuracy orbital information of the representative satellite  331 , and the orbital information relative values of the constituent satellites  332  relative to the representative satellite  331 , with the other space traffic management devices  100  mounted in the plurality of business devices  40 . 
     In the space information recorder  101 , one to a plurality of representative satellites  331  are specified from the mega-constellation satellite group flying on orbits having the same nominal orbital altitude. The space information recorder  101  records the quasi-real-time high-accuracy orbital information of the representative satellite  331  and the orbital information relative values of the constituent satellites  332  relative to the representative satellite  331 . These pieces of information are shared with the space information recorders  101  mounted in the other business devices  40 , in a common format via the communication line  200 . 
     The space information recorder  101  of the mega-constellation business device  41  records orbital information of satellites constituting a mega-constellation. 
     The space information recorder  101  is provided with public orbital information associated with a satellite group ID that identifies a satellite group, and the quasi-real-time high-accuracy orbital information associated with a satellite ID that identifies the representative satellite  331 . Further, the space information recorder  101  is provided with relative orbital information associated with the satellite ID that identifies the constituent satellite  332 . 
     The public orbital information is orbital information that can be disclosed to the other business devices. Constituent satellite information such as a number of satellites constituting the satellite group and satellite IDs of the satellites, an upper limit and lower limit of an orbital altitude of the satellite group, and an upper limit and lower limit of an orbital inclination of the satellite group are set in the public orbital information. 
     The quasi-real-time high-accuracy orbital information is predicted orbital information per satellite constituting the satellite group. A specific example of the predicted orbital information is the orbit prediction information  51  of  FIG.  12   . 
       FIG.  17    is a diagram illustrating a relative azimuth angle of an orbital plane according to the present embodiment. 
       FIG.  18    is a diagram illustrating a relative elevation angle within an orbital plane according to the present embodiment. 
       FIG.  19    is a diagram illustrating a relative elevation angle between orbital planes according to the present embodiment. 
     In the relative orbital information of the constituent satellite  332  of  FIG.  16   , a representative satellite ID as a reference, a relative azimuth angle of an orbital plane, a relative elevation angle within an orbital plane, and a relative elevation angle between orbital planes are set as orbital information relative values. 
     A danger alarm device  102  announces danger of approach or collision of a space object. The danger alarm device  102  is provided with orbital information associated with a space object ID that identifies a space object. Also, the danger alarm device  102  is provided with public condition information that sets a public condition of the orbital information. 
     A danger analysis device  103  performs orbital analysis of a space object. For example, the danger analysis device  103  is an example of a collision analysis unit that analyzes collision of an unsteady-operation space object with an individual satellite which constitutes a mega-constellation satellite group. For example, the server  212  provided to the space traffic management device  100  of the mega-constellation business device  41  analyzes collision of an unsteady-operation space object with an individual satellite which constitutes a mega-constellation satellite group. 
     A danger avoidance action assist device  104  formulates role division of an avoidance action against a space object. For example, the danger avoidance action assist device  104  is an example of a countermeasure formulating unit that formulates a collision avoidance countermeasure when collision of a mega-constellation with an unsteady-operation space object is predicted. For example, the server  212  provided to the space traffic management device  100  of the mega-constellation business device  41  formulates a collision avoidance countermeasure when collision is predicted. 
     An avoidance action plan formulated by the danger avoidance action assist device  104  is set in a danger avoidance action implementation plan information  105 . 
     Predicted orbital information and performance orbital information may be set in the quasi-real-time high-accuracy orbital information to be associated with the satellite ID. The predicted orbital information and the performance orbital information are set in a real-time manner and accurately. 
     Also, unsteady orbital information may be set in the space information recorder  101  of the mega-constellation business device  41 . Predicted orbital information about a space object that performs unsteady operation in an own mega-constellation is set in the unsteady orbital information. An epoch, orbital elements, and predicted errors are set in the predicted orbital information, just as in  FIG.  12   . 
     Space Traffic Management Method 
     In the space traffic management system  500  according to the present embodiment, a space traffic management method of avoiding collision of a satellite constituting a mega-constellation with a space object will be described. 
       FIG.  20    is a flowchart of the space traffic management method according to the present embodiment. 
     Example 1 of Space Traffic Management Method 
     A space traffic management system  500  conducts a space traffic management method of ensuring flight safety by connecting space traffic management devices individually mounted in business devices which are a mega-constellation business device  41 , a first business device that manages a space object, and a second business device, via a communication line. 
     Step S 101   
     A space traffic management device  100  mounted in the mega-constellation business device  41  has the configuration described above, and shares information with the space traffic management device  100  mounted in the second business device. 
     Step S 102   
     The second business device includes a space information recorder  101 , a danger analysis device  103 , and a danger avoidance action assist device  104 . The second business device records the quasi-real-time high-accuracy orbital information of a representative satellite  331 , orbital information relative values of the constituent satellites relative to the representative satellite  331 , and the information of the space object, to the space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from the space traffic management device  100  mounted in the mega-constellation business device. The information of the space object is acquired from the space traffic management device  100  mounted in the first business device. 
     Step S 103   
     The danger analysis device  103  derives collision avoidance information including a timing or a condition at which or under which collision does not occur with any one of the satellites constituting the plurality of mega-constellation satellite groups. 
     Step S 104   
     The danger avoidance action assist device  104  notifies the first business device of the collision avoidance information. 
     Specifically, the mega-constellation business device  41  includes a plurality of mega-constellation business devices each of which manages a mega-constellation. The first business device is a space object business device  42  of an unsteady-operation space object. The second business device is a collision avoidance assist business device  43 . 
     A rocket launch business device  46  of  FIG.  15    is an example of the first business device. 
       FIG.  21    is a diagram illustrating a detailed configuration example of a rocket launch assist business device  48  which is an example of the second business device according to the present embodiment. 
     The collision avoidance assist business device  43  records the quasi-real-time high-accuracy orbital information of the representative satellite  331 , the orbital information relative values of constituent satellites  332  relative to the representative satellite  331 , and planned orbital information being information of the space object, to the space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from the space traffic management devices  100  mounted in individual ones of the plurality of mega-constellation business devices  41 . The planned orbital information is acquired from the space traffic management device  100  mounted in the space object business device  42 . 
       FIG.  21    illustrates the rocket launch assist business device  48  as an example of the second business device. Rocket launch plan orbital information is set in  FIG.  21   . When the second business device is the collision avoidance assist business device  43  of Example 1, a space object ID of the unsteady-operation space object and planned orbital information (unsteady orbital information) of an unsteady-operation space object are set. 
     The danger analysis device  103  derives, as collision avoidance information, a timing and an orbital condition at which and under which collision does not occur with any one of the satellites constituting the plurality of mega-constellation satellite groups. 
     The danger avoidance action assist device  104  notifies the space object business device  42  of the timing and the orbital condition. 
     Example 2 of Space Traffic Management Method 
     In Example 2, the first business device is a rocket launch business device  46 . The second business device is a rocket launch assist business device  48  which assists rocket launch. 
     The rocket launch assist business device  48  records the quasi-real-time high-accuracy orbital information of a representative satellite  331 , the orbital information relative values of constituent satellites  332  relative to the representative satellite  331 , and rocket launch plan orbital information being information of the space object, to a space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from space traffic management devices  100  mounted in individual ones of the plurality of mega-constellation business devices  41 . The rocket launch plan orbital information is acquired from a space traffic management device  100  mounted in the rocket launch business device  46 . 
     A danger analysis device  103  derives, as collision avoidance information, a rocket launch timing at which collision does not occur with any one of the satellites constituting the plurality of mega-constellation satellite groups. In rocket launch, the rocket launch timing must be a timing that enables avoidance of collision with all mega-constellations which the rocket passes through during a launch process. 
     A danger avoidance action assist device  104  notifies the rocket launch business device  46  of the rocket launch timing. 
     Example 3 of Space Traffic Management Method 
     In Example 3, the first business device is a space object management business device  44  for deorbiting in an orbital descent process. The second business device is a collision avoidance assist business device  43 . 
     The collision avoidance assist business device  43  records the quasi-real-time high-accuracy orbital information of a representative satellite  331 , the orbital information relative values of constituent satellites  332  relative to the representative satellite  331 , and planned orbital information of the space object, being information of the space object, during the orbital descent process, to a space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from space traffic management devices  100  mounted in individual ones of a plurality of mega-constellation business devices  41 . The planned orbital information is acquired from a space traffic management device  100  mounted in the space object management business device  44 . 
       FIG.  21    illustrates a rocket launch assist business device  48  as an example of the second business device. Rocket launch plan orbital information is set in  FIG.  21   . When the second business device is the collision avoidance assist business device  43  of Example 3, a space object ID of the space object in the orbital descent process and planned orbital information of the space object in the orbital descent process are set. 
     A danger analysis device  103  derives, as collision avoidance information, a timing and an orbital condition at which and under which collision does not occur with any one of the satellites constituting the plurality of mega-constellation satellite groups. 
     A danger avoidance action assist device  104  notifies the space object management business device  44  of the timing and the orbital condition. 
     If the space object in the deorbit process does not have an orbital control function, a collision avoidance assist business device must guide a timing to avoid collision with all of the plurality of mega-constellations. 
     Example 4 of Space Traffic Management Method 
     In Example 4, the first business device is a space object management business device  44  or a debris removal business device  45 , the space object management business device  44  being capable of performing active orbital descent operation and being for an orbital descent process. The second business device is a space situational awareness business device  47  (SSA business device) which runs a space situational awareness business, or a collision avoidance assist business device  43 . 
     The SSA business device  47  or the collision avoidance assist business device  43  records quasi-real-time high-accuracy orbital information of a representative satellite  331 , orbital information relative values of constituent satellites  332  relative to the representative satellite  331 , and orbital-descent planned orbital information of a space object, or of a debris removal satellite, to a space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from a space traffic management device  100  mounted in a mega-constellation business device  41 . The orbital-descent planned orbital information is information of the space object, and is acquired from a space traffic management device  100  mounted in the space object management business device  44  or the debris removal business device  45 . 
       FIG.  21    illustrates the rocket launch assist business device  48  as an example of the second business device. Rocket launch plan orbital information is set in  FIG.  21   . When the second business device is the SSA business device  47  or collision avoidance assist business device  43  of Example 4, a space object ID of the space object or debris removal satellite in the orbital descent process and orbital-descent planned orbital information of the space object or debris removal satellite are set. 
     A danger analysis device  103  derives, as collision avoidance information, a timing and an orbital condition at which and under which collision does not occur with any one of the satellites constituting the mega-constellation satellite group. 
     A danger avoidance action assist device  104  notifies the space object management business device  44  or the debris removal business device  45  of the timing and the orbital condition. 
     The space object that can perform active orbital descent operation, or the debris removal satellite should only pass through mega-constellation altitude zones sequentially. Therefore, a constraint condition “a plurality of mega-constellations” is not necessary. 
     Example 5 of Space Traffic Management Method 
     In Example 5, a space traffic management system  500  is provided with a mega-constellation business device  41 , and a debris removal business device  45  or a rocket launch business device  46 . The space traffic management system  500  performs a space traffic management method of ensuring flight safety by connecting space traffic management devices  100  individually mounted in business devices  40  via a communication line  200 . 
     A space traffic management device  100  mounted in the mega-constellation business device  41  specifies one to a plurality of representative satellites  331  from the mega-constellation satellite group flying on orbits having the same nominal orbital altitude. The space traffic management device  100  has quasi-real-time high-accuracy orbital information of the representative satellite  331 , and orbital information relative values of constituent satellites  332 , other than the representative satellite  331 , relative to the representative satellite  331 . The space traffic management device  100  shares the quasi-real-time high-accuracy orbital information of the representative satellite  331  and the orbital information relative values of the constituent satellites  332  relative to the representative satellite  331 , with the space traffic management device  100  mounted in the debris removal business device  45  or rocket launch business device  46 . 
     The debris removal business device  45  or the rocket launch business device  46  is provided with a space information recorder  101  and a danger analysis device  103 . The debris removal business device  45  or the rocket launch business device  46  records quasi-real-time high-accuracy orbital information of the representative satellite  331 , orbital information relative values of the constituent satellites  332  relative to the representative satellite  331 , and orbital-descent planned orbital information of a debris removal satellite, or planned orbital information for rocket launch, to a space information recorder  101 . The quasi-real-time high-accuracy orbital information and the orbital information relative values are acquired from the space traffic management device  100  mounted in the mega-constellation business device  41 . 
     A danger analysis device  103  derives a timing and an orbital condition at which and under which collision does not occur with any one of the satellites constituting the mega-constellation satellite groups. 
     In this manner, in Example 5, the debris removal business operator or the rocket launch business operator can perform danger analysis independently, and can perform orbital descent or rocket launch while avoiding collision. 
     In the present embodiment, the following business devices have been described. 
     A collision avoidance assist business device employed in a space traffic management method is a rocket launch assist device, a space situational awareness business device, or a space management device such as a space port, or a business device that supervises space traffic management, and ensures flight safety by the space traffic management method. 
     A space object business device of an unsteady-operation space object, employed in a space traffic management method is a satellite business device for an orbital descent process, a debris removal satellite for an orbital descent process, or a rocket launch business operator, and ensures flight safety by the space traffic management method. 
     A mega-constellation business device ensures flight safety by the space traffic management method described above. 
     A rocket launch assist business device ensures flight safety by the space traffic management method described above. 
     A collision avoidance assist business device ensures flight safety by the space traffic management method described above. 
     A space situational awareness business device (SSA business device) ensures flight safety by the space traffic management method described above. 
     A debris removal business device ensures flight safety by the space traffic management method described above. 
     A rocket launch business device ensures flight safety by the space traffic management method described above. 
     A space object business device ensures flight safety by the space traffic management method described above. 
     A space object management business device ensures flight safety by the space traffic management method described above. 
     Description on Effect of Present Embodiment 
     With the space traffic management method according to the present embodiment, quasi-real-time high-accuracy orbital information can be handled even by a business operator other than a mega-constellation business operator. Therefore, with the space traffic management method according to the present embodiment, analysis of danger including a mega-constellation can be performed by a business operator on its own, such as a rocket launch assist business operator, a collision avoidance assist business operator, an SSA business operator, a debris removal business operator, and a rocket launch business operator. 
     Other Configurations 
     In the present embodiment, the functions of the space traffic management device  100  are implemented by software. A modification may be possible in which the functions of the space traffic management device  100  are implemented by hardware. 
       FIGS.  22  and  23    are diagrams each illustrating a configuration of a space traffic management device  100  according to a modification of the present embodiment. 
     The space traffic management device  100  is provided with an electronic circuit  909  in place of a processor  910 . 
     The electronic circuit  909  is a dedicated electronic circuit that implements the functions of the space traffic management device  100 . 
     The electronic circuit  909  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 stands for Gate Array. 
     The functions of the space traffic management device  100  may be implemented by one electronic circuit, or may be distributed among a plurality of electronic circuits and implemented by them. 
     Another modification may be possible in which some of the functions of the space traffic management device  100  are implemented by an electronic circuit and the remaining functions are implemented by software. 
     A processor and an electronic circuit are called processing circuitry as well. That is, the functions of the space traffic management device  100  are implemented by processing circuitry. 
     Embodiment 2 
     In the present embodiment, a difference from Embodiment 1 and an additional point to Embodiment 1 will mainly be described. 
     In the present embodiment, a configuration having the same function as in Embodiment 1 will be denoted by the same reference sign, and its description will be omitted. 
     Due to emergence of mega-constellation business operators, currently, about 50,000 satellites fly at an orbital altitude of 340 km to 1,300 km as if to exhaustively cover the sky. This situation makes it difficult to secure flight safety in rocket launch. A mode will be described in which flight safety in rocket launch is secured by realizing a framework that performs central management of quasi-real-time high-accuracy orbital information of a plurality of mega-constellations. 
     Studies have been in progress on sharing orbital information of a space object among business operators by building a public information system called Open Architecture Data Repository (OADR) so that flight safety of the space object is ensured. 
     The present embodiment will describe a mode of ensuring flight safety of a space object by the public information system called OADR. 
     When setting up an OADR as a public institution under international cooperation, there is a possibility that the OADR is authorized to make an instruction or request to a business operator beyond borders. 
     For example, in central management of orbital information of space objects possessed by business operators around the world, it is rational if the OADR can make an instruction or a request to provide orbital information under a rule based on an international consensus. 
     When a particular country sets up an OADR as a public institution, there is a possibility that the OADR is authorized to make an instruction or request to business operators of the relevant country. 
     There is also a possibility that the OADR forms a framework of disclosing information to business operators of the relevant country unconditionally while disclosing information conditionally to the other business operators. 
     As a public condition, it is possible to set entries such as fee charging, price setting, disclosure item restriction, accuracy restriction of public information, disclosure frequency restriction, and non-disclosure to a specific business operator. 
     For example, a difference of no charging or fee charging, or a difference in an amount of fee for information acquisition may arise between the relevant country and the other countries. How the public condition is set by the OADR will be influential from the viewpoint of framework making for space traffic management or industrial competitive power. 
     It is rational that, regarding space-object confidential information which serves security, the OADR being set up by a country as a public institution possesses the confidential information but keeps the confidential information closed to the outside. Therefore, there is a possibility that the OADR is provided with a database for storing non-public information, in addition to a database for information disclosure. 
     In addition, among pieces of space object information possessed by private business operators, there is information that cannot be disclosed to the public because, for example, the information belongs to a corporate secret. In addition, there is information that is not appropriate for public disclosure, because the information is under constant maneuver control and accordingly an amount of information or an update frequency of the information is enormous. 
     When conducting danger analysis and analysis evaluation related to approach or collision of a space object, it is necessary that orbital information of all space objects be dealt with regardless of whether the space object is confidential or not. For this reason, when the OADR as a public institution conducts danger analysis including confidential information and danger is predicted as a result of analysis evaluation, it is rational to restrict a publication target or a publication content and to conduct conditional disclosure. For example, it is rational to restrict a publication target or a publication content and to conduct conditional disclosure by processing information into disclosable information, and disclosing only orbital information of a risky timeframe to a disclosure target that contributes to danger avoidance. 
     In the future, when the number of on-orbit objects increases and the risk of approach or collision increases, various danger avoidance countermeasures will be needed, such as a means with which a debris removal business operator removes dangerous debris, and a means with which a mega-constellation business operator changes an orbital position or a passing timing so as to avoid collision. If the OADR, being a public institution, can instruct or request a business operator to execute a danger avoidance action, a very large effect can be expected in ensuring flight safety of space. 
     There are space objects managed by an institution, such as an emerging country venture business operator or a university, that is inexperienced in the space business and lacks information that serves danger avoidance. When it is predicted that a space object managed by such an institution which is inexperienced in the space business and lacks information that serves danger avoidance will intrude into an orbital altitude zone where a mega-constellation flies, the OADR intermediates to transmit the relevant information to the business operator in need of the information, so that the danger can be avoided quickly and effectively. 
     In addition, when implementation of a danger avoidance countermeasure, or space insurance, is mediated or introduced to private business operators, it will contribute to promotion and industrialization of space traffic management. 
     The OADR may be realized in the following modes.
     A mode where the OADR is provided with only a public database.   A mode where the OADR possesses a danger analysis means, a collision avoidance assist means, or a space situational awareness (SSA) means to contribute to danger avoidance independently.   A mode where the OADR gives an instruction or a request to a business operator, or performs mediation or introduction to a business operator, thus contributing to danger avoidance through information management.   

     For realizing the OADR, there are various possibilities other than the above-mentioned modes. 
     Note that “the OADR mediates implementation of a space traffic management method” signifies a case where, for example, an entity implementing a space traffic management method includes a plurality of external business devices other than the OADR, and the OADR does not issue a compulsive order but encourages implementation of the method by intermediating among the plurality of business devices. “The OADR mediates implementation of a space traffic management method” is paraphrased as, for example, “the OADR intermediates so that a plurality of external business devices other than the OADR cooperate with each other to implement a space traffic management method”. Alternatively, “mediation” may be replaced with “teaching”. 
     A configuration example of the OADR according the present embodiment will be described below. 
     Configuration Example 1 of OADR 
       FIG.  24    is a diagram illustrating an OADR  800  as Configuration Example 1 according to the present embodiment. 
     The OADR  800  as Configuration Example 1 is provided with a space information recorder  101 . 
     The OADR  800  is provided with the space information recorder  101  having a configuration described in Embodiment 1, as a database  810  being a public database. 
     As the OADR  800  is provided with the space information recorder  101 , information can be shared among business operators, achieving an effect of contributing to danger avoidance. 
     Configuration Example 2 of OADR 
       FIG.  25    is a diagram illustrating an OADR  800  as Configuration Example 2 according to the present embodiment. 
     The OADR  800  as Configuration Example 2 is provided with the space traffic management device  100  described in Embodiment 1, and executes the space traffic management method described in Embodiment 1. 
     With the OADR  800  as Configuration Example 2, information is shared among business operators, achieving an effect of contributing to danger avoidance. 
     Configuration Example 3 of OADR 
       FIG.  26    is a diagram illustrating an OADR  800  as Configuration Example 3 according to the present embodiment. 
     The OADR  800  as Configuration Example 3 is provided with the collision avoidance assist business device  43  described in Embodiment 1. 
     With the OADR  800  as Configuration Example 3, as the OADR  800  is provided with the collision avoidance assist business device  43 , the OADR  800  takes an initiative in sharing information among business operators, achieving an effect of danger avoidance. 
     Configuration Example 4 of OADR 
     The OADR  800  illustrated in  FIG.  24    is a public information system to disclose orbital information of a space object. The OADR  800  is provided with the database  810  to store the orbital information of the space object, and a server  820 . 
     The database  810  is provided with a first database  811  to store public information and a second database  812  to store non-public information. 
     The server  820  acquires space object information including non-public information from all or some of business devices which are: a space traffic management device; a space situational awareness business device (SSA business device); a collision avoidance assist business device; a mega-constellation business device; and a debris removal business device, and stores the acquired space object information to the second database  812 . The space traffic management device is provided to, for example, CSpOC. 
     Conventionally, the U.S. CSpOC is not provided with a bi-directional line, and announces a danger alarm uni-directionally. If CSpOC is provided with a space traffic management device, CSpOC can contribute to space traffic management by communication of the space traffic management device with the other business devices via a bi-directional communication line. 
     The server  820  generates conditional public information restricting a publication target and a publication content and stores the generated information to the first database  811 . 
     Then, the server  820  transmits the conditional public information only to a particular business device among the SSA business device, the collision avoidance assist business device, the mega-constellation business device, the debris removal business device, and a space insurance business device which deals with a space insurance. 
     The OADR  800  of Configuration Example 4 mediates implementation of the space traffic management method described in Embodiment 1 while implementing the above functions. 
     There is a possibility that space object confidential information possessed by CSpOC and serving safety security is disclosed only to the OADR. A risk of approach or collision, including the confidential information, must be analyzed and must be predicted. 
     After the information is processed into conditional disclosable information, the conditional public information which serves collision avoidance assist is shared only to a business device related to a collision risk. Hence, even a private business operator can take a collision avoidance action. 
     Among pieces of space object information possessed by the private business operators, regarding space object information that cannot be disclosed to the public, the OADR processes the information into conditional disclosable information likewise, so that the collision avoidance becomes possible. 
     Configuration Example 5 of OADR 
     The OADR  800  illustrated in  FIG.  26    is provided with the collision avoidance assist business device  43 . 
     A database  810  is provided with a first database  811  to store public information and a second database  812  to store non-public information. 
     A server  820  acquires space object information including non-public information from all or some of business devices which are: a space traffic management device; an SSA business device; another collision avoidance assist business device; a mega-constellation business device; a debris removal business device, and a space object business device, and stores the acquired space object information to the second database  812 . The space traffic management device is provided to, for example, CSpOC. 
     Another collision avoidance assist business device is a collision avoidance assist business device other than the collision avoidance assist business device possessed by the OADR  800 . 
     The server  820  generates conditional public information restricting a publication target and a publication content and stores the generated information to the first database  811 . 
     Then, the server  820  transmits the conditional public information only to a particular business device among the SSA business device, another collision avoidance assist business device, the mega-constellation business device, the debris removal business device, the space object business device, and a space insurance business device which deals with a space insurance. 
     When the ORDR serves as the collision avoidance assist business operator as in Configuration Example 5, the same effect as in Configuration Example 4 can be obtained. 
     Configuration Example 6 of OADR 
     An OADR  800  is a public information system to disclose orbital information of a space object, as illustrated in  FIG.  24   . The OADR  800  is provided with a database  810  to store the orbital information of the space object, and a server  820 . The server  820  is also called a space information management server to manage space information. 
     The database  810  is provided with a first database  811  to store public information and a second database  812  to store non-public information. 
     The server  820  being a space information management server performs danger analysis by looking up the first database  811  and the second database  812  to. The server  820  performs identification management of free public information and fee-charged public information of the second database  812 . 
     The space object includes a space object whose orbital information is not disclosed due to security requirement. Meanwhile, when performing analysis of a danger such as approach or collision, danger analysis must be performed to include non-public information. Hence, it is rational to separate databases so as to avoid a risk of information leakage. 
     There is a possibility that free public information and fee-charged public information are mixed in the public information. Therefore, identification management is required when the OADR discloses information to the public. 
     If the OADR separates non-public data from public data by central management and performs identification management of fee-charged public information and free public information, a principle of Need to Know is kept, and appropriate information management can be performed. 
     Configuration Example 7 of OADR 
     A modification of Configuration Example 6 is possible in which a server  820  being a space information management server performs danger analysis by looking up a first database  811  and a second database  812 , and the server  820  performs identification management of unconditional public information and conditioned public information of the second database  812 . 
     When a particular country sets up an OADR as a public institution, it is rational to disclose information to a business operator of a relevant country unconditionally while disclosing information to the other business operators conditionally. As the condition to be set, it is possible to set, for example, fee charging, price setting, disclosure item restriction, accuracy restriction of disclosed information, disclosure frequency restriction, and non-disclosure to a specific business operator. 
     In above Embodiments 1 to 2, individual units in each of the space traffic management system, the space traffic management device, and the business device are described as independent function blocks. However, the space traffic management system, the space traffic management device, and the business device need not have configurations as in the embodiments described above. The function blocks in each of the space traffic management system and the space traffic management device may have any configurations as far as they can implement the functions described in the above embodiments. Also, each of the space traffic management system, the space traffic management device, and the business device may be one device, or may form a system constituted of a plurality of devices. 
     A plurality of parts out of Embodiments 1 to 2 may be practiced as a combination. Alternatively, one part of these embodiments may be practiced. Also, these embodiments may be practiced as a whole or partly as any combination. 
     That is, in Embodiments 1 to 2, any parts out of Embodiments 1 to 2 can be combined arbitrarily, or an arbitrary constituent element can be modified. Also, in Embodiments 1 to 2, an arbitrary constituent element can be omitted. 
     The embodiments described above are essentially preferable exemplifications and are not intended to limit the scope of the present disclosure, the scope of an application product of the present disclosure, and the scope of use of the present disclosure. Various changes can be made to the embodiments described above as necessary. 
     REFERENCE SIGNS LIST 
       20 : satellite constellation;  21 : orbital plane;  211 : database;  212 : server;  30 : satellite;  31 : satellite control device;  32 : satellite communication device;  33 : propulsion device;  34 : attitude control device;  35 : power supply device;  40 : business device;  301 : mega-constellation satellite group;  331 : representative satellite;  332 : constituent satellite;  41 : mega-constellation business device;  411 : collision analysis unit;  412 : countermeasure formulating unit;  431 : orbital analysis unit;  432 : announcement unit;  42 : space object business device;  43 : collision avoidance assist business device;  44 : space object management business device;  45 : debris removal business device;  46 : rocket launch business device;  47 : SSA business device;  48 : rocket launch assist business device;  51 : orbit prediction information;  53 : debris orbit prediction information;  511 : space object ID;  512 : predicted epoch;  513 : predicted orbital element;  514 : predicted error;  60 : space object;  70 : Earth;  100 : space traffic management device;  140 : storage unit;  55 : orbit control command;  61 : public orbital information;  63 : unsteady orbital information;  64 : real-time high-accuracy orbital information;  500 : space traffic management system;  600 : satellite constellation forming system;  11 ,  11   b : satellite constellation forming unit;  300 : satellite group;  700 ,  701 : ground facility;  510 : orbit control command generation unit;  520 : analytical prediction unit;  909 : electronic circuit;  910 : processor;  921 : memory;  922 : auxiliary storage device;  930 : input interface;  940 : output interface;  941 : display apparatus;  950 : communication device;  101 : space information recorder;  102 : danger alarm device;  103 : danger analysis device;  104 : danger avoidance action assist device;  105 : danger avoidance action implementation plan information;  200 : communication line;  800 : OADR;  810 : database;  811 : first database;  812 : second database;  820 : server.