Satellite operation system and residual propellant discharge error control method

Abstract

To provide a satellite operation system and a residual propellant discharge error control method capable of suppressing deviation of an orbit of an artificial satellite from a target orbit in a residual propellant discharge operation.SOLUTION: The satellite operation system includes an orbit estimating means for estimating an orbit of the artificial satellite by using the ranging data, a discharge timing determining means for determining a residual propellant discharge timing based on the estimated orbit, and a plan creating means for creating an operation plan for first executing in-plane control in a visible cycle and then executing out-of-plane control for residual propellant discharge.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a satellite operation system for a satellite and a method for controlling residual propellant discharge error. [Background technology]

[0002] The satellite is controlled by a control device in the ground facility. Specifically, the satellite receives commands from the control device and executes processing according to the received commands. The satellite also sends telemetry to the ground facility at predetermined times.

[0003] When a satellite's operation is terminated, it is preferable to deorbit the satellite or perform a maneuver to change the satellite's orbit in order to prevent the generation of space debris, etc. (See, for example, Patent Document 1). In the following explanation, deorbiting a satellite means leaving its orbit, specifically, changing the orbit of a satellite that has ceased operation to a disposal orbit. The orbit after the change is a disposal orbit (also called a graveyard orbit) that is higher than the orbits of geostationary satellites and quasi-zenith satellites. Hereinafter, the disposal orbit that a satellite will orbit after its operation is terminated will be referred to as the target orbit.

[0004] When a satellite's operation ends and it is deorbited, propellant generally remains in the satellite. It is preferable to discharge the remaining propellant (residual propellant) for reasons such as preventing the fragmentation of the satellite from generating space debris. Hereinafter, control related to the discharge of residual propellant, which is performed while the satellite is orbiting the target orbit, will be referred to as residual propellant discharge operation.

[0005] The ground facility determines whether the propellant has been depleted during the remaining propellant discharge operation. If it is determined that the propellant has been depleted, the control device in the ground facility sends a stop command to the satellite. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2024-502631 Summary of the Invention [Problem to be solved by the invention]

[0007] Typically, during propellant discharge operations, satellites discharge propellant by performing out-of-plane maneuvers (north-south maneuvers), which require large thrust and have minimal impact on the target orbit. Out-of-plane maneuvers adjust the satellite's inclination angle, i.e., perform out-of-plane orbital maneuvers, but do not change the orbit itself. However, when an out-of-plane orbital maneuver is performed, a chain reaction of coupling can occur, potentially resulting in in-plane velocity changes.

[0008] When a change in in-plane velocity occurs, the satellite's orbit may deviate from the target orbit. The deviation of the satellite's orbit from the target orbit may exceed a tolerance. That is, during a propellant discharge operation, the satellite's orbit may deviate from the target orbit beyond a tolerance. While it is desirable for the satellite's orbit to be maintained on the target orbit after the satellite's operation has ended, there is a problem in that the desired state may not be maintained due to the propellant discharge operation.

[0009] In general, whether the remaining propellant discharge operation has ended, i.e., whether the satellite's propellant has been depleted, is determined by the operator based on satellite status information contained in telemetry from the satellite.

[0010] While a satellite is orbiting its target orbit, performing out-of-plane control multiple times at equal time intervals during each orbit is thought to reduce the deviation of the satellite's orbit from the target orbit. While it is preferable to end the remaining propellant discharge operation early, for example, continuing the remaining propellant discharge operation for the entire time the satellite orbits the target orbit, places a heavy burden on the operator. Because the satellite's attitude becomes unstable when the propellant runs out, an emergency command to immediately stop orbit control must be sent from the ground station to the satellite. Therefore, during the remaining propellant discharge operation, the operator must closely monitor the satellite's status (telemetry) so that they can quickly determine if the remaining propellant is depleted.

[0011] If out-of-plane control is performed only during the daytime shift of the operator in order to reduce the burden on the operator, the period until the remaining propellant discharge operation is completed will be longer.

[0012] Furthermore, if residual propellant discharge operations are performed only during the daytime shift, there will be a bias in the location where orbital control is performed as the satellite orbits the target orbit once, which could result in a large deviation from the target orbit after the second visibility cycle, potentially exceeding the allowable error range of the target orbit.

[0013] Furthermore, even when out-of-plane control is performed multiple times at equal time intervals, deviations of the satellite orbit from the target orbit may occur as described above.

[0014] An object of the present invention is to provide a satellite operation system and a method for controlling residual propellant discharge error that can suppress deviation of a satellite's orbit from a target orbit during residual propellant discharge operations. [Means for solving the problem]

[0015] A satellite operation system according to the present disclosure is a satellite operation system that controls residual propellant discharge operations after changing the orbit of a satellite to a discard orbit, and includes an orbit estimation means that estimates the orbit of the satellite using ranging data, a discharge timing determination means that determines the timing of residual propellant discharge based on the estimated orbit, and a planning means that creates an operation plan that first performs in-plane control in a visibility cycle and then performs out-of-plane control for residual propellant discharge.

[0016] The residual propellant discharge error control method according to the present disclosure is a residual propellant discharge error control method for controlling the operation of residual propellant discharge after changing the orbit of a satellite to a discard orbit, in which the orbit of the satellite is estimated using ranging data, the timing of residual propellant discharge is determined based on the estimated orbit, and an operational plan is created in which in-plane control is first performed in the visibility cycle, and then out-of-plane control is performed to discharge residual propellant.

[0017] The residual propellant discharge error control program according to the present disclosure is a residual propellant discharge error control program that controls the residual propellant discharge operation after changing the orbit of a satellite to a discard orbit, and causes a computer to execute the following processes: a process of estimating the orbit of the satellite using ranging data; a process of determining the timing of residual propellant discharge based on the estimated orbit; and a process of creating an operation plan that first performs in-plane control in the visibility cycle and then performs out-of-plane control for residual propellant discharge. [Effects of the Invention]

[0018] According to the present invention, deviation of the satellite orbit from the target orbit during residual propellant discharge operations can be suppressed. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is an explanatory diagram for explaining the remaining propellant discharge operation by the satellite operation system. [Figure 2] FIG. 10 is an explanatory diagram showing an example of a remaining propellant discharge operation schedule. [Figure 3] FIG. 10 is an explanatory diagram showing a detailed example of a remaining propellant discharge operation schedule. [Figure 4] FIG. 10 is an explanatory diagram showing an example of corrective maneuver planning using an eccentricity vector. [Figure 5] FIG. 1 is a block diagram showing an example of the configuration of a satellite operation system. [Figure 6] 10 is a flowchart showing the operation of the satellite operation ground facility in the non-visibility cycle. [Figure 7] 1 is a flowchart showing the operation of a satellite operating ground facility during a visibility cycle. [Figure 8] FIG. 1 is a block diagram illustrating an example of the configuration of an information processing system. [Figure 9] FIG. 1 is a block diagram showing the main parts of a satellite operation system. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment will be described with reference to the drawings.

[0021] FIG. 1 is an explanatory diagram for explaining the residual propellant discharge operation by the satellite operation system of the present disclosure. In FIG. 1, horizontal arrows represent the orbital change of a satellite 10 due to in-plane control. The satellite 10 is driven by thrusters 11 as a propulsion system. Vertical arrows represent the residual propellant discharge due to out-of-plane control. Note that a quasi-zenith satellite is used as an example of the satellite 10. The satellite operation system is also sometimes referred to as a ground station.

[0022] The satellite operation system according to the present disclosure performs de-orbiting to inject the satellite 10 into a target orbit.

[0023] In the present disclosure, when the satellite 10 is orbiting the target orbit, the satellite operation system first causes the satellite 10 to perform a maneuver (hereinafter referred to as a correction maneuver) using in-plane control during a visibility (radio wave reception possible) period (visibility cycle). Then, the satellite operation system causes the satellite 10 to perform a remaining propellant discharge using out-of-plane control.

[0024] In addition, the satellite operation system uses the eccentricity vector to predict coupling in order to improve the accuracy of the correction maneuver.

[0025] Generally, in a propellant discharge operation, the satellite 10 discharges propellant by repeatedly performing out-of-plane orbital control, which has little impact on the target orbit. When the propellant runs out, the satellite's attitude becomes unstable. Therefore, the satellite operation system immediately transmits an emergency command to the satellite 10 to stop orbital control. Therefore, during the propellant discharge operation, the operator of the satellite operation system closely monitors the satellite's status (telemetry) so that they can quickly determine whether the satellite is running out of propellant.

[0026] Fig. 2 is an explanatory diagram showing an example of a remaining propellant discharge operation schedule, and Fig. 3 is an explanatory diagram showing a detailed example of a remaining propellant discharge operation schedule.

[0027] The orbital period of an operational satellite 10 (in this embodiment, a quasi-zenith satellite) is synchronized with the rotation of the Earth. Therefore, the satellite 10 is visible 24 hours a day from a ground station. However, when the orbital altitude is increased by deorbiting, the orbital period deviates from the rotation of the Earth. Therefore, when operated only by domestic stations, periods of visibility and periods of invisibility from ground stations alternate every few days. In this embodiment, the remaining propellant discharge operation is carried out during the visibility period of several days. The remaining propellant discharge operation is carried out continuously for multiple visibility cycles until the remaining propellant is depleted.

[0028] Normally, during orbit control of the satellite 10, slight thrust may be generated in directions other than the injection direction due to reasons such as alignment errors of the thrusters 11. As a result, during orbit control in the out-of-plane direction during residual propellant discharge operations, velocity changes occur not only in the out-of-plane direction but also in the in-plane direction (this is called coupling). Therefore, even when orbit control in the out-of-plane direction, which has little effect on the target orbit, is performed multiple times during residual propellant discharge operations, deviations from the target orbit accumulate due to the coupling component in the in-plane direction.

[0029] Assuming that the in-plane coupling component occurs in the same direction each time, performing multiple out-of-plane maneuvers at evenly spaced intervals throughout one orbit can minimize deviation from the target orbit after deorbit. However, during the propellant discharge operation, the operator must closely monitor the satellite's status to quickly determine if it will be depleted. Therefore, continuing the propellant discharge operation throughout one orbit increases the burden on the operator. If the propellant discharge operation is performed only during the daytime shift to reduce the operator's burden, the location of orbit control within one orbit will be biased. As a result, deviation from the target orbit increases from the second visibility cycle onwards, exceeding the specified tolerance range.

[0030] Therefore, in this embodiment, the satellite operation system first causes the satellite 10 to perform a correction maneuver (in-plane control) in each visibility cycle to correct the deviation from the target orbit due to the coupling of the out-of-plane control performed in the immediately preceding visibility cycle. As a result, it becomes possible to keep the deviation from the target orbit within the error range for one cycle in every visibility cycle, and to prevent deviation from the target orbit from exceeding the allowable error range.

[0031] In the example shown in Figures 2 and 3, a corrective maneuver is performed prior to the residual propellant discharge during the second visibility cycle (2024 / 1 / 9 to 2024 / 01 / 11). The corrective maneuver and residual propellant discharge are performed during the daytime hours of the visibility cycle to reduce the burden on operators. Figure 2 also shows that a corrective maneuver is performed prior to the residual propellant discharge during the third visibility cycle (2024 / 1 / 17 to 2024 / 01 / 19), similar to the second visibility cycle.

[0032] Furthermore, it is preferable that the satellite operation system utilizes an eccentricity vector to improve the accuracy of the correction maneuver. Figure 4 is an explanatory diagram showing an example of corrective maneuver planning using an eccentricity vector.

[0033] The satellite operation system predicts the coupling that will occur during the out-of-plane control of the remaining propellant discharge based on past performance, etc. The satellite operation system plots the change in the eccentricity vector based on the predicted amount of coupling. When the allowable error range of the target orbit is also plotted on the eccentricity vector (e.g., on a screen), the satellite operation system determines the target of the correction maneuver to be performed before the remaining propellant discharge so that the position of the satellite 10 that changes due to the predicted coupling will be within the allowable error range of the target orbit. In this way, the satellite operation system can plan a correction maneuver that will not deviate from the allowable error range of the target orbit, regardless of which burn (out-of-plane control) during the visibility cycle in which the remaining propellant is depleted.

[0034] For example, the satellite operation system determines a target for in-plane control (for example, corrective maneuver #1 in the example shown in FIG. 4) so ​​that the orbit of satellite 10 does not deviate from the allowable error range of the target orbit due to a later out-of-plane control (for example, residual propellant discharge #2 in the example shown in FIG. 4). Specifically, the satellite operation system predicts a coupling amount, which is a change in in-plane velocity that occurs when the out-of-plane control is performed, and predicts a change in the eccentricity vector based on the coupling amount. Then, it determines a target for the in-plane control so that the end point of the eccentricity vector when the later out-of-plane control is performed does not deviate from the allowable error range of the target orbit.

[0035] The target of the correction maneuver corresponds to the position of the satellite 10 after undergoing in-plane control.

[0036] Fig. 5 is a block diagram showing an example of the configuration of a satellite operation system. In Fig. 5, satellite operation ground facility 100 corresponds to the satellite operation system. Satellite operation ground facility 100 transmits commands to satellite 10 via tracking control station 200. In addition, satellite operation ground facility 100 receives telemetry and ranging data from satellite 10 via tracking control station 200.

[0037] The satellite operation ground facility 100 includes a satellite control unit 110, an orbit determination unit 120, an orbit planning unit 130, a visibility analysis unit 140, a coupling prediction unit 150, and an eccentricity vector drawing unit 160.

[0038] The satellite control unit 110 has a function to send commands to the satellite 10 in response to instructions from the operator and a function to present the operator with the status of the satellite 10 received as telemetry. The orbit determination unit 120 estimates the satellite's orbit using ranging data and creates orbit determination values. The orbit planning unit 130 creates an orbit control plan based on the orbit determination values ​​and creates orbit control commands.

[0039] The visibility analysis unit 140 analyzes visibility based on the orbit maneuver plan and orbit determination values. That is, the visibility analysis unit 140 determines whether it is a visible cycle or an invisible cycle (invisible period). The coupling prediction unit 150 predicts coupling based on the orbit maneuver plan and orbit determination values. The eccentricity vector drawing unit 160 has a function of drawing changes in the eccentricity vector based on the orbit maneuver plan, orbit determination values, and coupling amount.

[0040] Next, the operation of the satellite operation ground facility 100 will be described with reference to the flowcharts of Figures 6 and 7. Figure 6 is a flowchart showing the operation of the satellite operation ground facility 100 in an invisible cycle. Figure 7 is a flowchart showing the operation of the satellite operation ground facility 100 in a visible cycle. Figures 6 and 7 are also flowcharts showing a method for controlling residual propellant discharge error.

[0041] 6, in the invisible cycle, the orbit determination unit 120 estimates the orbit of the artificial satellite 10 using ranging data acquired in the visible cycle (step S101). Data representing the estimated orbit is set as the orbit determination value.

[0042] The visibility analysis unit 140 checks visibility based on the orbit determination value. That is, the visibility analysis unit 140 determines the visibility period. Specifically, the visibility analysis unit 140 determines the time period of the visibility period. Then, the visibility analysis unit 140 determines the timing of the remaining propellant discharge (the timing of performing orbital maneuver) during the day shift (step S102).

[0043] The coupling prediction unit 150 predicts the amount of coupling that occurs during the out-of-plane control of the residual propellant discharge from past performance and the like (step S103).

[0044] The eccentricity vector drawing unit 160 receives the orbit determination value and the predicted coupling amount, and draws the change in the eccentricity vector based on the orbit determination value and the coupling amount, as illustrated in FIG. 4 (step S104).

[0045] Furthermore, when the allowable error range of the target orbit is expressed together with the eccentricity vector (see FIG. 4), the eccentricity vector drawing unit 160 determines a target for a correction maneuver to be performed immediately before the remaining propellant is discharged so that the predicted change due to coupling falls within the allowable error range of the target orbit (step S105).

[0046] The trajectory planning unit 130 formulates an orbit control plan for correction maneuvers and residual propellant discharge, and generates an orbit control command (step S106).

[0047] As shown in FIG. 7, in the visibility cycle, the satellite control unit 110 transmits to the satellite 10 orbit control commands for the correction maneuvers and the remaining propellant discharge operations that were planned during the non-visibility period (step S201).

[0048] When the visibility period begins, as illustrated in FIG. 3, the satellite 10 first performs a correction maneuver (in-plane control) in accordance with the orbit control command (step S202).

[0049] After performing the correction maneuver, the satellite 10 performs a remaining propellant discharge operation (out-of-plane control) during the daytime shift in accordance with the orbit control command (step S203).

[0050] The operator monitors the status (telemetry) of the satellite 10 and determines whether it is depleted (step S204). For example, the operator determines whether it is depleted by using the telemetry received from the satellite 10 by the satellite control unit 110. The satellite control unit 110 has a display unit or the like that can display the status of the satellite 10.

[0051] If the operator determines that the propellant has been depleted, the satellite control unit 110, in accordance with the operator's instructions, immediately transmits an emergency command to the satellite 10 to stop orbital control, and then transmits a stop signal command to the satellite 10 (step S205).

[0052] If the operator determines that the propellant is not depleted, the satellite control unit 110 continues the ranging operation until the end of the visibility cycle (step S206). The ranging operation is a process of receiving ranging data from the artificial satellite 10 and storing the ranging data.

[0053] In this embodiment, a correction maneuver is first performed in each visibility cycle, thereby correcting any deviation from the target trajectory due to the coupling of the out-of-plane control performed in the immediately preceding visibility cycle. As a result, it is possible to keep the deviation from the target trajectory within the error range for one cycle in any visibility cycle. Therefore, it is possible to prevent deviation from the target trajectory's allowable error range. In addition, the remaining propellant discharge operation is controlled to be performed during the day shift, thereby reducing the burden on the operator.

[0054] Furthermore, the satellite operation system predicts coupling using the eccentricity vector, so that even if propellant is depleted in any burn during the visibility cycle, it can plan a corrective maneuver with high accuracy so that the target orbit does not deviate from the allowable error range.

[0055] At present, there is little accumulated data on the deorbit operation of the Quasi-Zenith Satellite System. In the future, by accumulating data and increasing information on the targets and coupling of correction maneuvers, it is expected that more appropriate parameters (for example, methods for predicting coupling, and the relationship between the time period for residual propellant discharge operations and the optimal correction maneuvers) can be determined.

[0056] The above-described embodiment can be configured by hardware, but can also be realized by a computer program.

[0057] 8 includes a processor 701 such as a CPU (Central Processing Unit), a program memory 702, and a storage medium 703 for storing data. A semiconductor storage element, a magnetic storage medium such as a hard disk, or the like can be used as the storage medium 703. The information processing system may also include multiple processors 701.

[0058] In the information processing system, a program memory 702 stores a program (residual propellant discharge error control program) for realizing the functions of each block shown in the above embodiment.

[0059] The processor 701 executes processing in accordance with the program stored in the program memory 702, thereby realizing the functions of the satellite operation ground facility 100 shown in the above embodiment.

[0060] For example, the processor 701 executes processing in accordance with a program for realizing the functions of each block in the satellite operating ground facility 100 shown in FIG. 5, thereby realizing the functions of the satellite operating ground facility 100.

[0061] At least the program memory 702 is a non-transitory computer-readable medium. However, the program may be stored in various types of transitory computer-readable medium. The program is supplied to the transitory computer-readable medium, for example, via a wired or wireless communication path, i.e., via an electrical signal, an optical signal, or an electromagnetic wave.

[0062] Fig. 9 is a block diagram showing the main components of a satellite operation system. The satellite operation system 20 shown in Fig. 9 includes an orbit estimation means 21 (implemented by the orbit determination unit 120 in this embodiment) that estimates the orbit of the artificial satellite using ranging data, a release timing determination means 22 (implemented by the visibility analysis unit 140 in this embodiment) that determines the timing of releasing residual propellant based on the estimated orbit, and a plan creation means 23 (implemented by the orbit planning unit 130 in this embodiment) that creates an operation plan in which in-plane control is first performed in the visibility cycle and then out-of-plane control for releasing residual propellant.

[0063] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes.

[0064] (Supplementary Note 1) A satellite operation system that controls residual propellant discharge operations after changing the orbit of a satellite to a disposal orbit, an orbit estimation means for estimating the orbit of the artificial satellite using ranging data; a discharge timing determination means for determining the timing of the discharge of residual propellant based on the estimated orbit; a planning means for creating an operational plan for first performing in-plane control in the visible cycle and then performing out-of-plane control for residual propellant discharge; A satellite operation system comprising:

[0065] (Appendix 2) Controlling the residual propellant discharge operation of the Quasi-Zenith Satellite A satellite operating system as described in Appendix 1.

[0066] (Note 3) A target determination unit (implemented by the eccentricity vector drawing unit 160 in this embodiment) is provided to determine a target position for in-plane control so that the orbit of the satellite does not deviate from the allowable error range of the target orbit due to the out-of-plane control that is subsequently executed. 1. A satellite operating system as described in Appendix 1 or Appendix 2.

[0067] (Supplementary Note 4) The target determination means Coupling prediction means (implemented by a coupling prediction unit 150 in the embodiment) for predicting a coupling amount, which is a change in velocity in an in-plane direction that occurs when out-of-plane control is performed; an eccentricity vector prediction means (implemented by the eccentricity vector drawing unit 160 in the embodiment) for predicting a change in the eccentricity vector based on the coupling amount; Determine the target position for the in-plane control so that the end point of the eccentricity vector when the out-of-plane control is executed later does not deviate from the tolerance range of the target trajectory. A satellite operating system as described in Appendix 3.

[0068] (Appendix 5) The plan creation means creates an operation plan in which in-plane control and out-of-plane control are performed during the day shift. 1. A satellite operating system as described in Appendix 1 or Appendix 2.

[0069] (Supplementary Note 6) The orbit estimation means acquires ranging data after in-plane control and out-of-plane control are performed in a visibility cycle. 1. A satellite operating system as described in Appendix 1 or Appendix 2.

[0070] (Appendix 7) A residual propellant discharge error control method for controlling residual propellant discharge operation after changing the orbit of an artificial satellite to a discard orbit, comprising: estimating an orbit of said satellite using the ranging data; The timing of the remaining propellant release is determined based on the estimated orbit. Develop an operational plan to first implement in-plane control during the visible cycle, followed by out-of-plane control for residual propellant discharge. Residual propellant discharge error control method.

[0071] (Appendix 8) A residual propellant discharge error control program for controlling residual propellant discharge operations after changing the orbit of a satellite to a disposal orbit, On the computer, a process of estimating the orbit of the satellite using the ranging data; A process of determining the timing of the remaining propellant discharge based on the estimated trajectory; A process for creating an operational plan to first perform in-plane control in the visible cycle and then perform out-of-plane control for residual propellant discharge. A residual propellant discharge error control program for executing the above.

[0072] Some or all of the configurations described in Supplementary Notes 2 to 6, which are directly or indirectly dependent on Supplementary Note 1, may be made dependent on Supplementary Notes 7 and 8 in accordance with the same dependency relationships as Supplementary Notes 2 to 6. Furthermore, not limited to Supplementary Notes 1, 7, and 8, some or all of the configurations described as the above Supplements may be made dependent on various hardware, software, various recording means for recording software, or systems, provided that they do not deviate from the above-described embodiments. [Explanation of symbols]

[0073] 10 satellite 11 Thruster 20 Satellite Operation System 21 Trajectory estimation means 22 Discharge timing determination means 23 Planning Tools 100 Satellite operation ground equipment 110 Satellite Control Department 120 Orbit determination part 130 Trajectory Planning Department 140 Visual analysis section 150 Coupling Prediction Section 160 Eccentricity Vector Drawing Section 200 Tracking and Control Station 701 processor 702 program memory 703 Storage medium

Claims

1. A satellite operation system that controls a residual propellant discharge operation after changing the orbit of an artificial satellite to a disposal orbit, an orbit estimation means for estimating the orbit of the artificial satellite using ranging data; a discharge timing determination means for determining the timing of the discharge of residual propellant based on the estimated orbit; a planning means for creating an operational plan for first performing in-plane control in the visible cycle and then performing out-of-plane control for residual propellant discharge; A satellite operation system comprising:

2. Controlling the residual propellant discharge operation of the Quasi-Zenith Satellite 2. The satellite operating system according to claim 1.

3. and a target determining means for determining a target position for in-plane control so that the orbit of the satellite does not deviate from the allowable error range of the target orbit by the out-of-plane control that is subsequently executed.

3. A satellite operation system according to claim 1 or 2.

4. The target determination means a coupling prediction means for predicting a coupling amount, which is a change in velocity in an in-plane direction that occurs when out-of-plane control is performed; an eccentricity vector prediction means for predicting a change in the eccentricity vector based on the amount of coupling; Determine the target position for the in-plane control so that the end point of the eccentricity vector when the out-of-plane control is executed later does not deviate from the tolerance range of the target trajectory.

4. The satellite operation system according to claim 3.

5. The plan creation means creates an operation plan in which in-plane control and out-of-plane control are performed during the day shift.

3. A satellite operation system according to claim 1 or 2.

6. The orbit estimation means acquires ranging data after in-plane control and out-of-plane control are performed in a visibility cycle.

3. A satellite operation system according to claim 1 or 2.

7. A residual propellant discharge error control method for controlling a residual propellant discharge operation after changing the orbit of an artificial satellite to a disposal orbit, comprising: estimating an orbit of said satellite using the ranging data; The timing of the remaining propellant release is determined based on the estimated orbit. Develop an operational plan to first implement in-plane control during the visible cycle, followed by out-of-plane control for residual propellant discharge. Residual propellant discharge error control method.

8. A residual propellant discharge error control program for controlling a residual propellant discharge operation after changing the orbit of an artificial satellite to a disposal orbit, On the computer, a process of estimating the orbit of the satellite using the ranging data; A process of determining the timing of the remaining propellant discharge based on the estimated trajectory; A process for creating an operational plan to first perform in-plane control in the visible cycle and then perform out-of-plane control for residual propellant discharge. A residual propellant discharge error control program for executing the above.

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