To achieve an objective to enable a plurality of management business operators managing space objects flying in space, to share and carry out danger analysis efficiently. In a space traffic management system (500), a plurality of space traffic management devices (100) are connected to each other via a communication line. Each of the plurality of space traffic management devices includes a space information recorder (101), a danger alarm device (102), a danger analysis device (103), a danger avoidance action assist device (104), and a security device (105). The space information recorder includes a space object ID, orbital information, and public condition information; and a business device ID and public condition information. The plurality of space traffic management devices (100) have data format compatibility and share the space object ID and the business device ID, and share orbital information corresponding to the space object ID among business devices that comply with the public condition information.

Orbital debt is removal (ODR) systems under the present approach may use a ground- or surface-based FEL and mirror system with sufficient power and both spatial and temporal resolution to both locate Category II OD (1 cm to 10 cm diameter) in low Earth orbit (LEO, 160 to 2000 km altitude) and remove these objects from orbit. Locating the Category II OD is performed by having, the light beam from an FEL and its beam director scan a volume of space of interest and then observing the light reflected from the OD. Removing the OD may include heating the OD to a sufficiently high temperature to evaporate the OD, changing the orbit of the OD such as to lower the perigee, or both. Megawatt-class MOPA FELs for, inter alia, removing OD, are described.

A method for estimating collision between a satellite in orbit and at least one piece of space debris having a time of closest approach to the satellite is disclosed including: obtaining the reference orbit of the satellite; determining an ephemeris of state transition data representative of the trajectory of the reference orbit; communicating the reference orbit and the ephemeris of state transition data to the satellite. The method includes the steps on board the satellite of: determining the true orbital position of the satellite; propagating the true orbit; calculating a probability of collision between the satellite and the piece of debris.

A method for estimating collision between a satellite in orbit and at least one piece of space debris having a time of closest approach to the satellite is disclosed including: obtaining the reference orbit of the satellite; determining an ephemeris of state transition data representative of the trajectory of the reference orbit; communicating the reference orbit and the ephemeris of state transition data to the satellite. The method includes the steps on board the satellite of: determining the true orbital position of the satellite; propagating the true orbit; calculating a probability of collision between the satellite and the piece of debris.

A space information recorder (100) acquires space object information (500), which is orbit forecast information of a plurality of space objects (60), from a management business device (40) used by a management business operator that manages the plurality of space objects (60), and records the space object information (500). The space object information (500) includes a forecast epoch, a forecast orbital element, and a forecast error of each of the plurality of space objects (60). When it is foreseen that a space object A included in the plurality of space objects (60) will intrude into a range at orbital altitudes of 300 km to 1000 km in which a satellite group of LST 10:00 to 11:00 is present, a time period from intrusion to exit and orbit forecast information are recorded.

Having as its objective to take flight safety measure per satellite group, a space information recorder (101) is mounted in a mega-constellation satellite business device being a business device that manages a satellite constellation of 100 or more satellites, or in a constellation satellite business device being a business device that manages a satellite constellation of 10 or more satellites. The space information recorder (101) is provided with a category of a satellite group ID (112) which identifies a satellite group in which a group of a plurality of satellites having the same nominal orbital altitude cooperate with each other to fulfill a mission. The category of the satellite group ID (112) includes flight safety measure information (115) expressing flight safety measure of the satellite group.

A satellite constellation forming system (600) forms a satellite constellation having a plurality of orbital planes in each of which a plurality of satellites fly at the same average orbital altitude. A satellite constellation forming unit (11) forms a passage region for a space object to pass through before the space object passes through an orbital altitude of the satellite constellation from above the satellite constellation. After the space object has passed through the passage region, the satellite constellation forming unit (11) restores the satellite constellation to a state before the passage region is formed.

A satellite constellation forming system (600) forms a satellite constellation having a plurality of orbital planes in each of which a plurality of satellites fly at the same average orbital altitude. A satellite constellation forming unit (11) forms a passage region for a space object to pass through before the space object passes through an orbital altitude of the satellite constellation from above the satellite constellation. After the space object has passed through the passage region, the satellite constellation forming unit (11) restores the satellite constellation to a state before the passage region is formed.

A satellite constellation forming system (600) forms a satellite constellation which is composed of a satellite group that cooperatively provides a communication service, and has a plurality of orbital planes in each of which a plurality of satellites fly at the same orbital altitude. Each satellite of the satellite group includes inter-satellite communication means and satellite-ground communication means. A satellite constellation forming unit (11) forms the satellite constellation which has ten or more orbital planes with different normal directions, and in which at least one relative angle in an azimuth direction of adjacent orbital planes of the plurality of orbital planes is arranged to be uneven and satellite-ground communication means of satellites flying in orbital planes spaced unevenly have a communication range that achieves complete ground coverage above the equator.

A multi-layer insulation includes a plurality of layers that are laminated on each other. A detection layer that is at least one of the plurality of layers has a piezoelectric film, and a pair of electrode parts installed on both surfaces of the piezoelectric film.