Satellite and operating method for satellite

Abstract

A satellite according to an embodiment of the present invention includes a main body capable of receiving a plurality of mission information from a ground station and controlling the operation of the satellite, and a payload capable of being mounted on the main body to perform a mission. The payload includes an antenna capable of transmitting and receiving radio waves and a memory unit capable of storing a reference number of mission information transmitted from the main body, and may include a controller capable of generating radio waves using the mission information stored in the memory unit and transmitting radio waves to the antenna. Accordingly, the payload according to the embodiments of the present invention can store a plurality of missions to be performed and then sequentially perform a plurality of missions in chronological order. Consequently, the number of communications between the satellite body and the payload can be reduced compared to conventional methods. As a result, a plurality of missions can be performed stably, and the mission completion rate can be increased.

Description

Technology Field

[0001] The present invention relates to a satellite and a method of operating a satellite, and more specifically, to a satellite capable of stably performing a mission and a method of operating a satellite. Background Technology

[0002] A satellite (i.e., an artificial satellite) may include a main body responsible for the overall operation of the satellite and a payload capable of performing a mission. Furthermore, the payload may include a Synthetic Aperture Radar (SAR) capable of photographing the ground to acquire at least one of images and photographs. In other words, the satellite may be a SAR satellite.

[0003] The ground station transmits mission information to the satellite body, and the body transmits the received mission information to the payload. Accordingly, the payload performs the mission. In other words, the body transmits the mission information to be performed to the payload, and the payload executes the mission using the received information. In this case, if there are multiple missions to be performed, the body transmits the mission information to the payload sequentially. That is, after the first mission is completed, the body transmits mission information to the payload for performing the second mission. Then, when the second mission is completed by the payload, the body transmits mission information to the payload for performing the third mission.

[0004] In this way, whenever a mission is completed, the main body transmits information for the next mission to the payload. Additionally, for specific targets or regions, repetitive mission execution may be required at short intervals. Accordingly, it is necessary to perform multiple missions within a single orbit. Consequently, communication between the main body and the payload occurs frequently. However, there is a problem in that the more frequent the communication between the main body and the payload, the higher the probability of mission failure.

[0005] In addition, if an error occurs in the payload for any reason, the payload can only resume operations for mission execution after receiving a separate command from the main body. In other words, if the payload fails to perform a mission for any reason, the payload itself cannot restart the mission. Therefore, there is a problem with a low mission completion rate. Furthermore, since it takes approximately 90 minutes to complete one orbit, if a mission cannot be performed in that orbit, it can only be performed after at least 90 minutes. Consequently, there is a problem where at least 90 minutes are wasted to perform the same mission. Prior art literature

[0006] Korean Registered Patent 10-2520001 The problem to be solved

[0007] The present invention provides a satellite and a method for operating the satellite that can improve the success rate of mission execution.

[0008] The present invention provides a satellite and a method for operating the satellite that can reduce the number of communications between the main body and the payload. means of solving the problem

[0009] A satellite according to an embodiment of the present invention comprises: a main body capable of receiving a plurality of mission information from a ground station and controlling the operation of the satellite; and a payload capable of being mounted on the main body to perform a mission. The payload may include: an antenna capable of transmitting and receiving radio waves; a memory unit capable of storing a reference number of mission information transmitted from the main body; and a controller capable of generating radio waves using the mission information stored in the memory unit and transmitting the radio waves to the antenna.

[0010] The above standard number exceeds 1, and the memory unit can selectively store mission information transmitted from the main body, and the mission information includes the mission start time and the shooting target location, and the memory unit can store mission information among the mission information transmitted from the main body where the mission start time is in the future of the current time.

[0011] The above-mentioned payload includes a transceiver capable of receiving radio waves generated by the controller and transmitting them to the antenna, or receiving a signal transmitted from the antenna; and the controller may include a radio wave generator capable of generating radio waves; a radiation control unit capable of being connected to the radio wave generator to control the operation of the radio wave generator; and a mission execution control unit capable of being connected to the radiation control unit and the memory unit to control the operation of the radiation control unit using the current time and mission information stored in the memory unit.

[0012] The above-described payload includes a power supply unit that can be connected to the main body, controller, transceiver, and antenna so as to supply power transmitted from the main body to the controller, transceiver, and antenna, and the mission execution control unit can identify unexecuted mission information among a plurality of mission information stored in the memory unit and can select mission information including the earliest mission execution time among the identified mission information, and the mission execution control unit can be connected to the memory unit, antenna, and power supply unit so as to supply power to the antenna using the difference between the mission execution time included in the selected mission information and the current time.

[0013] When the difference between the mission start time included in the selected mission information and the current time reaches a first difference, the main body supplies power to the power supply, and when the difference between the mission start time included in the selected mission information and the current time reaches a second difference, the main body controls the operation of the power supply so that power is supplied to the controller, and when the difference between the mission start time included in the selected mission information and the current time reaches a third difference, the mission execution control unit controls the operation of the power supply so that power is supplied to the antenna, and the second difference may be smaller than the first difference, and the third difference may be smaller than the second difference.

[0014] When the difference between the mission execution start time included in the above-mentioned selected mission information and the current time reaches a fourth difference, the mission execution control unit sets the mission information in the above-mentioned selected mission information to the radiation control unit, transceiver, and antenna, and the fourth difference may be smaller than the third difference.

[0015] When the current time reaches the mission start time included in the above-mentioned selected mission information, the radiation control unit can control the operation of the radio wave generator so that the radio wave generator can generate radio waves.

[0016] The above controller includes a mode monitoring unit capable of determining the current mode of the payload; the mode monitoring unit determines whether the payload is in an initialization mode by determining whether power is supplied to the power supply unit, determines whether the payload is in a standby mode by determining whether power is supplied to the controller and the transceiver, determines whether the payload is in a stabilization mode by determining whether power is supplied to the antenna, determines whether the payload is in a ready mode by determining whether the selected mission information is set to the radiation control unit, the transceiver, and the antenna, and determines whether the payload is in an operating mode by determining whether radio waves are generated from the radio wave generation unit.

[0017] If the mode monitoring unit determines that the mode of the payload is an initialization mode, the main body controls the operation of the power supply so that power is supplied to the controller; if the mode monitoring unit determines that the mode of the payload is a standby mode, the mission execution control unit controls the operation of the power supply so that power is supplied to the antenna; if the mode monitoring unit determines that the mode of the payload is a stabilization mode, the mission execution control unit sets the selected mission information to the radiation control unit, the transceiver, and the antenna; and if the mode monitoring unit determines that the mode of the payload is a ready mode, the radiation control unit can determine whether the current time is the mission execution start time included in the selected mission information.

[0018] If the mode monitoring unit determines that the mode of the payload is not an initialization mode, is not a standby mode, is not a stabilization mode, or is not a preparation mode, the above-described mode monitoring unit may operate to re-execute at least one of the following processes: the main body controlling the operation of the power supply to supply power to the power supply according to the remaining time from the current time to the mission start time; the main body controlling the operation of the power supply to supply power to the controller; the mission execution control unit controlling the operation of the power supply to supply power to the antenna; and the mission execution control unit setting mission information to the radiation control unit, transceiver, and antenna.

[0019] A satellite operation method according to an embodiment of the present invention may include: a process of transmitting a plurality of mission information stored in a main body capable of controlling the operation of the satellite to a payload connected to the main body at a time interval; a process of storing the mission information transmitted by the main body in the payload to satisfy a reference number; and a mission execution process of transmitting radio waves using the mission information and receiving reflected radio waves.

[0020] The above standard number exceeds 1, and the mission information includes the mission start time and the shooting target location. When storing the mission information transmitted by the main body in the payload, among the multiple mission information transmitted from the main body, mission information in which the mission start time is a future time from the current time can be stored.

[0021] The above-mentioned payload comprises: a controller capable of storing mission information transmitted from the main body in the reference number and generating radio waves; an antenna capable of receiving and transmitting radio waves generated by the controller and receiving radio waves reflected back; a transceiver capable of receiving radio waves generated by the controller and transmitting them to the antenna, or receiving a signal transmitted from the antenna and transmitting it to the controller; and a power supply capable of supplying power to the controller, the antenna, and the transceiver. The mission execution process may include: a process in which the main body supplies power to the power supply; a process in which the main body controls the operation of the power supply to supply power to the controller; a process in which the controller controls the operation of the power supply to supply power to the transceiver; and a process in which the controller controls the operation of the power supply to supply power to the antenna.

[0022] The above mission execution process includes, before the power supply performs the process of supplying power to the antenna, a process in which the controller selects mission information, and the process in which the controller selects mission information includes: a process in which the controller identifies unexecuted mission information among the stored plurality of mission information; and a process in which the controller selects mission information including the earliest mission execution time among the identified mission information; and when the power supply supplies power to the antenna, if the difference between the mission execution start time included in the selected mission information and the current time reaches a preset time difference, the power supply can supply power to the antenna.

[0023] The above mission execution process includes the process of the controller setting the selected mission information to the transceiver and antenna after the power supply supplies power to the antenna; and in setting the selected mission information to the transceiver and antenna by the controller, when the difference between the mission execution start time included in the selected mission information and the current time reaches a preset time difference, the controller may set the selected mission information to the transceiver and antenna.

[0024] The above mission execution process includes: a process in which the controller generates radio waves when the current time reaches the mission execution time of the selected mission information after the controller has set the selected mission information with the transceiver and antenna; and a process in which the antenna receives the radio waves generated by the controller. The process of transmitting radio waves using the mission information includes a process in which the antenna transmits radio waves to a shooting target location, and in receiving the reflected radio waves, the antenna can receive radio waves that are reflected from the shooting target location and return to the antenna.

[0025] The above mission execution process may include: a process of determining whether power is supplied to the power supply between the process in which the main body supplies power to the power supply and the process in which the power supply supplies power to the controller, thereby determining whether the payload is in an initialization mode; a process of determining whether power is supplied to the controller between the process in which the power supply supplies power to the controller and the process in which the power supply supplies power to the antenna, thereby determining whether the payload is in a standby mode; a process of determining whether power is supplied to the antenna between the process in which the power supply supplies power to the antenna and the process in which the controller sets the selected mission information to the transceiver and antenna, thereby determining whether the payload is in a stabilization mode; and a process of determining whether the selected mission information is set to the transceiver and antenna between the process in which the transceiver and antenna set the selected mission information and the process in which the current time has reached the mission execution time of the selected mission information, thereby determining whether the payload is in a ready mode.

[0026] When the power supply is supplying power to the controller, if it is determined that the payload is in initialization mode, power is supplied to the controller; when supplying power to the antenna, if it is determined that the payload is in standby mode, power is supplied to the antenna; when setting the selected mission information with the transceiver and antenna, if it is determined that the payload is in stabilization mode, the selected mission information is set with the transceiver and antenna; and when determining whether the current time has reached the mission execution time of the selected mission information, if it is determined that the payload is in preparation mode, it can determine whether the current time has reached the mission execution time of the selected mission information.

[0027] If it is determined that the mode of the above-mentioned payload is not an initialization mode, is not a standby mode, is not a stabilization mode, or is not a preparation mode, at least one of the following processes may be repeated depending on the remaining time from the current time to the mission start time: the process of the main body supplying power to the power supply, the process of the power supply supplying power to the controller, the process of the power supply supplying power to the antenna, and the process of setting mission information to the transceiver and antenna. Effects of the invention

[0028] A payload according to embodiments of the present invention can store a plurality of missions to be performed and then sequentially perform the plurality of missions in chronological order. Accordingly, the number of communications between the satellite body and the payload can be reduced compared to conventional methods. As a result, a plurality of missions can be performed stably, and the mission completion rate can be increased. In addition, the time interval for sequentially performing a plurality of missions can be minimized. Therefore, the time required to perform a plurality of missions can be shortened.

[0029] In addition, if an action for mission execution could not be performed for any reason, the action can be performed again based on the remaining time until the mission start time. This can improve the mission completion rate or mission success rate. Brief explanation of the drawing

[0030] FIG. 1 is a block diagram showing the configuration of a satellite according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a method in which a memory unit of a payload stores mission information according to an embodiment of the present invention. FIGS. 3 and 4 are flowcharts illustrating a method for determining the mode of a payload in a mode monitoring unit according to an embodiment of the present invention. FIGS. 5 and FIGS. 6 are flowcharts illustrating a method of operation of a payload according to an embodiment of the present invention. Specific details for implementing the invention

[0031] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and these embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. To illustrate embodiments of the present invention, the drawings may be exaggerated, and like reference numerals in the drawings refer to like components.

[0033] FIG. 1 is a block diagram showing the configuration of a satellite according to an embodiment of the present invention.

[0034] The satellite may be an artificial satellite capable of performing a mission while moving along an orbit. Referring to FIG. 1, the satellite may include a main body (100) responsible for the operation and function of the satellite and a payload (200) that can be mounted on the main body (100) to perform a mission. Such a satellite may be capable of performing a mission of transmitting radio waves to the ground to acquire at least one of images and images. That is, the satellite may be a Synthetic Aperture Radar (SAR) satellite. Additionally, the satellite may be a small satellite capable of carrying a Synthetic Aperture Radar (SAR).

[0035] The main body (100) may include a structure (not shown) forming the framework of the satellite, a thruster (110) capable of providing propulsion for movement, an attitude controller (120) capable of adjusting or controlling the direction of orientation, a satellite navigation signal receiver (130) capable of receiving a GPS (Global Positioning System) satellite signal and interpreting the time included in the signal, an onboard clock (140) that receives time information from the satellite navigation signal receiver (130) and provides it as a time standard for the operation of the satellite, a first power supply (150) capable of supplying power to a configuration requiring power, and a communication device (160) capable of communicating with a ground station and a payload (200). Additionally, the satellite may include a main body controller (170) capable of controlling the operation of the thruster (110), the attitude controller (120), the satellite navigation signal receiver (130), the onboard clock (140), the first power supply (150), and the communication device (160).

[0036] The thruster (110), attitude controller (120), satellite navigation signal receiver (130), onboard clock (140), first power supply (150), communication device (160) and main body controller (170) can be installed in the structure.

[0037] The structure is a component forming the framework of the satellite and may be made of metal or composite material. For example, the structure may be made of at least one of a frame and a panel made of metal or composite material.

[0038] The thruster (110) may be a means of providing thrust to enable the satellite to enter an orbit in space, move to a different orbit, adjust its attitude, or change its speed. Such a thruster (110) may be operated by at least one of fuel and electricity.

[0039] The attitude controller (120) may be a means to enable the satellite to orient itself in a desired direction in orbit. That is, the attitude controller (120) may be a means to adjust the satellite's orientation to correct the position to be photographed, or to adjust the satellite's orientation so that the solar panel can receive sunlight. Such an attitude controller (120) may include, for example, a drive unit that provides a driving force to change the attitude of the satellite. Here, the drive unit may include, for example, at least one of a reaction wheel, a magnetic torquer, and a control moment gyroscope.

[0040] A satellite navigation signal receiver (130) can receive signals from GPS satellites and obtain the satellite's orbital position and accurate time information.

[0041] The onboard clock (140) can receive time information from the satellite navigation signal receiver (130) and provide time for operating or operating the satellite. The time provided by the onboard clock (140) can be used, for example, to perform a mission according to a mission execution plan.

[0042] The mission execution plan will be explained again later.

[0043] The first power supply (150) may include a solar cell capable of receiving sunlight to produce electricity and a battery capable of storing electricity. The solar cell may be a solar cell panel as a means of receiving sunlight and converting it into electricity or electrical energy.

[0044] A communication device (160) can receive a signal from a ground station that includes at least one of a command, various data, and mission information, and can transmit data to the ground station. The data may include information (mission information) regarding the mission that the payload must perform. Such a communication device (160) may include a communication antenna, a transmitting unit capable of modulating data into a high-frequency signal and transmitting it to the communication antenna, and a receiving unit capable of receiving commands, data, etc. transmitted from the ground station.

[0045] The payload (200) can perform a mission transmitted from the main body (100). The mission according to the embodiment may be to acquire at least one of a ground image and a picture. Accordingly, the payload (200) can perform a mission to acquire at least one of a ground image and a picture by irradiating radio waves toward the ground.

[0046] Referring to FIG. 1, the payload (200) can generate radio waves and may include a controller (210) that can selectively store mission information transmitted from the main body (100) and control the payload (200) according to a mission execution plan.

[0047] Additionally, the payload (200) may include an antenna (230) capable of transmitting or radiating radio waves to the ground and receiving radio waves reflected from the ground, and a transceiver (220) capable of receiving radio waves transmitted by the controller (210) and transmitting them to the antenna, and receiving a signal transmitted by the antenna (230) and transmitting it to the controller (210).

[0048] Additionally, the payload (200) may include a second power supply (250) capable of supplying power delivered from the first power supply (150) of the main body (100) to the components of the payload (200).

[0049] First, the transmitter / receiver (220), antenna (230), and second power supply (250) will be described.

[0050] The transceiver (220) can receive radio waves transmitted by the controller (210), and can amplify the received radio waves and transmit them to the antenna (230). Additionally, the signal transmitted by the antenna (230) can be received by the transceiver (220), and the transceiver (220) can transmit the signal to the controller (210).

[0051] The antenna (230) can transmit radio waves transmitted from the transceiver (220) to the ground. That is, the antenna (230) can transmit radio waves to the target location for shooting. In addition, the antenna (230) can receive radio waves reflected from the ground. In addition, the antenna (230) can convert the received radio waves into electrical signals and transmit them to the transceiver (220). Such an antenna (230) may include a phase array antenna in the form of a linear or flat panel.

[0052] The second power supply (250) can supply or apply power to the components of the body (200). That is, the first power supply (150) of the main body (100) can supply power or electricity to the second power supply (250). Then, the main body (100) can control the operation of the second power supply (250) to supply power to the controller (210), and subsequently, the controller (210) can control the operation of the second power supply (250) to supply power to the transceiver (220) and antenna (230).

[0053] The controller (210) can store a mission transmitted from the main body (100) and can control the operation of the transceiver (220) and antenna (230) according to the mission execution plan.

[0054] The mission to be performed by the payload (200) may be to acquire at least one of an image and a photograph of a target location. And, the ground station may transmit a signal containing information about the mission (hereinafter, mission information) to the satellite. That is, the ground station may transmit a signal containing mission information to the satellite. The mission information may include the time of start of the mission and the target location.

[0055] The satellite and the ground station can exchange signals through the communication device (160). That is, mission information can be transmitted to the satellite through communication between the satellite's communication device (160) and the ground station. Mission information transmitted from the ground station can be received by the receiver of the main body (100). Then, the receiver of the main body (100) can transmit the mission information to the payload (200).

[0056] The ground station can transmit multiple mission information to the receiver of the satellite body (100). The receiver of the main body (100) can transmit the mission information to the controller (210) of the payload (200). At this time, the main body (100) can transmit multiple mission information to the controller (210) of the payload (200) with a time difference. The controller (210) of the payload (200) can selectively store the mission information transmitted from the main body (100).

[0058] The controller (210) may include a radio wave generating unit (215) capable of generating radio waves, a memory unit (211) capable of selectively storing mission information transmitted from the main body (100), a radiation control unit (216) capable of controlling the operation of the radio wave generating unit (215), and a mission execution control unit (212) capable of controlling the operation of at least one of a transceiver (220), an antenna (230), and a radiation control unit (216) so as to perform a mission according to the time order included in the mission information.

[0059] Additionally, the controller (210) may include a signal processing unit (213) capable of processing a signal transmitted from a transceiver (220) and a mode monitoring unit (214) capable of determining the current mode or state of the payload (200).

[0060] The radio wave generating unit (215) can generate radio waves. That is, the radio wave generating unit (215) can generate microwaves. In addition, the radio wave generating unit (215) can generate radio waves of a preset frequency band and can generate radio waves of a preset waveform. At this time, at least one of the frequency and the waveform may be determined by at least one of the shooting target location and the distance between the satellite and the shooting target location. The radio wave generating unit (215) as described above may be named a waveform generating unit.

[0061] The radio waves generated by the radio wave generation unit (215) can be transmitted to the transceiver (220), and the transceiver (220) can transmit the radio waves to the antenna (230). Accordingly, the antenna (230) can transmit the radio waves to the target location for shooting.

[0062] The radiation control unit (216) can control the operation of the radio wave generation unit (215). For example, when the current time reaches the time to start the mission, the radiation control unit (216) can operate the radio wave generation unit to generate radio waves from the radio wave generation unit (215). Such a radiation control unit (216) may include, for example, an FPGA (Field Programmable Gate Array).

[0064] FIG. 2 is a flowchart illustrating a method in which a memory unit of a payload stores mission information according to an embodiment of the present invention.

[0065] The memory unit (211) can receive and store mission information. At this time, the memory unit (211) can optionally store mission information. That is, the memory unit (211) can store mission information when the first condition and the second condition are satisfied.

[0066] The first condition is that the number of mission information stored in the memory unit (211) satisfies the standard number. The standard number may be multiple (more than 1), for example, 5 or more. More specifically, the standard number may be selected from a range of 5 to 100. As another example, the standard number may be selected from a range of 15 to 25. The standard number is not limited to the examples described above and may be varied to multiple numbers exceeding 1.

[0067] The second condition is that the mission start time is in the future relative to the current time. In other words, it is a condition where the mission start time included in the mission information has not passed the current time. Here, time can be explained as a point in time.

[0068] The satellite moves along an orbit, and the mission may be to take pictures in a specific section of the orbit. For example, the mission may be to take pictures of the Korean Peninsula. That is, the target location for photography included in the mission information may be a location within the Korean Peninsula. Accordingly, the satellite can take pictures of the target location when it is located within a predetermined section on the orbit. For convenience of explanation, the section on the orbit where the satellite moves in which the target location can be photographed is referred to as the 'mission execution section' below. The ground station can transmit the mission execution section to the satellite body (100), and the satellite body (100) can store the mission execution section.

[0069] The ground station can transmit multiple missions to the main body (100) before the satellite reaches the mission execution section. Accordingly, multiple missions can be stored in the main body (100) before the satellite reaches the mission execution section. More specifically, multiple missions can be stored in the main body (100) when the distance between the current position of the satellite in orbit and the mission execution section becomes a first distance.

[0070] Additionally, before the satellite reaches the mission execution section, the main body can transmit multiple mission information to the memory unit (211) of the payload (200), and the memory unit (211) can selectively store multiple mission information. At this time, when the distance between the current satellite position in orbit and the mission execution section becomes close to a predetermined distance, the main body (100) can start transmitting mission information to the memory unit (211), and the memory unit (211) can selectively store mission information. More specifically, when the distance between the current satellite position in orbit and the mission execution section becomes a second distance, the main body can start transmitting mission information to the memory unit (211), and the memory unit (211) can selectively store mission information.

[0071] Here, the distance between the satellite and the mission section may refer to the distance between the starting position of the mission section and the satellite based on the direction in which the satellite moves. Also, the first distance may be shorter than the second distance.

[0072] The memory unit (211) can store mission information when both the first condition and the second condition described above are satisfied. And, if at least one of the first and second conditions is not satisfied, the memory unit (211) does not store mission information. Additionally, when the number of mission information stored in the memory unit (211) reaches a reference number, the memory unit (211) may no longer store mission information.

[0073] Referring to FIG. 2, a method (S100) for storing mission information in a standard number in a memory unit (211) is described.

[0074] When the distance between the satellite moving along the orbit and the mission execution section becomes a second distance, the main body (100) can transmit mission information to the memory unit (211). Accordingly, the mission information transmitted from the main body (100) can be received by the memory unit (211) (S110). When mission information is received by the memory unit (211), the memory unit (211) determines whether the number of mission information stored in the memory unit (211) satisfies a reference number (S120). If the number of mission information stored in the memory unit (211) does not satisfy the reference number (S120 --> No), the memory unit (211) determines whether the mission execution start time included in the received mission information is in the future of the current time (S130). If the mission execution start time included in the received mission information is in the future of the current time (S130 --> Yes), the memory unit (211) stores the received mission information (S160).

[0075] Meanwhile, if the number of mission information stored in the memory unit (211) is equal to the standard number (S120-->Yes), the memory unit (211) does not store the received mission information. Additionally, if the number of mission information stored in the memory unit (211) is less than the standard number (S120-->No), but the mission execution start time included in the received mission information is the current time or a past time of the current time, the memory unit (211) does not store the mission information (S150).

[0076] As described above, mission information may include the mission start time and the target location for shooting. The target location for shooting may be a location where shooting is possible when the satellite is positioned within the mission execution section. The memory unit (211) may store multiple mission information. At this time, the mission start time and the target location for shooting to be performed at the mission start time may be stored in the memory unit (211) in a linked (or matched) manner. Accordingly, mission information may be listed or sorted in the memory unit (211) according to the order of mission start times. Accordingly, the target location for shooting can be photographed according to the order of mission start times stored in the memory unit (211).

[0077] Mission information listed or arranged according to the mission start time may signify a mission execution plan. Therefore, photographing target locations in the order of mission start times may imply executing the mission in accordance with the mission execution plan.

[0078] In addition, the number of missions stored in the memory unit (211) is multiple as described above. Furthermore, the missions have a predetermined time difference between the start times of mission execution. The embodiment of the present invention performs multiple missions stored in the memory unit and executes them sequentially according to the start times of mission execution. In other words, multiple missions can be executed continuously according to the start times of mission execution. That is, the satellite according to the embodiment of the present invention can perform missions continuously.

[0080] The mission execution control unit (212) can select the mission information with the earliest mission execution start time among the multiple mission information stored in the memory unit (211). That is, the mission execution control unit (212) can identify mission information that has not yet been completed among the mission information stored in the memory unit (211), and can select mission information that includes the mission execution start time closest to the current time among the identified mission information. Of course, if there is only one unexecuted mission information stored in the memory unit (211) instead of multiple, the mission execution control unit (212) can select the remaining unexecuted mission information.

[0081] The mission execution control unit (212) can control the operation of the second power supply (250) to supply power to the transceiver (220) and the antenna (230). Additionally, the mission execution control unit (212) can control the operation of at least one of the memory unit (211), the signal processing unit (213), and the mode monitoring unit (214). Furthermore, the mission execution control unit (212) can control the operation of the radiation control unit (216) so that the radio wave generator (215) can generate radio waves, and can control the operation of the antenna (230) so that the antenna (230) becomes a receiving mode. Also, the mission execution control unit (212) can input mission information to the radiation control unit (216), the transceiver (220), and the antenna (230) to set it, or delete the set mission information. Such a mission execution control unit may include an MCU (Micro Controller Unit).

[0082] The mission execution control unit (212) can supply or apply power to each of the transceiver (220) and the antenna (230). More specifically, the main body controller (170) can control the operation of the first power supply (150) to supply or apply power to the second power supply (250) of the payload (200). When power is supplied to the second power supply (250), the main body controller (170) can control the operation of the second power supply (250) to supply power to the controller (210). Subsequently, the mission execution control unit (212) of the controller (210) can control the operation of the second power supply (250) to supply power to each of the transceiver (220) and the antenna (230). The mission execution control unit (212) can control whether power is supplied to the transceiver (220) and antenna (230) according to the current time. At this time, power may be supplied to the transceiver (220) immediately after power is supplied to the controller (210), and power may be supplied to the antenna (230) after a predetermined time has elapsed.

[0083] The method of applying power to the configuration of the payload (200) is described in more detail below. As described above, the mission execution control unit (212) can select mission information that includes the mission execution time closest to the current time among multiple mission information stored in the memory unit (211) that has not yet been executed. Then, when the time difference between the mission execution start time of the selected mission information and the current time reaches a first difference (first time difference), the main body controller (170) supplies power to the second power supply unit (250) of the payload (200). Subsequently, when the time difference between the mission execution start time and the current time reaches a second difference (second time difference), the main body controller (170) controls the operation of the second power supply unit (250) to supply power to the controller (210). When power is supplied to the controller (210), the mission execution control unit (212) controls the operation of the second power supply (250) and supplies power to the transceiver (220). That is, power can be supplied to the transceiver (220) immediately after power is supplied to the controller (210). Then, when the time difference between the mission execution start time of the selected mission information and the current time reaches a third difference (third time difference), the mission execution control unit (212) can control the operation of the second power supply (250) so that power is supplied to the antenna (230). After power is supplied to the antenna (230), the mission execution control unit (212) can input or set mission information to the radiation control unit (216), the transceiver (220), and the antenna (230). That is, when the time difference between the start time of the mission of the selected mission information and the current time reaches the fourth difference, the mission execution control unit (212) can input or set the mission information to the radiation control unit (216), the transceiver (220), and the antenna (230). Accordingly, the payload (200) can be prepared to perform the mission.

[0084] As described above, mission information can be input or set in the radiation control unit (216). Accordingly, when the current time reaches the start time of the mission execution of the selected mission information, the radiation control unit (216) can operate the radio wave generator (215) to generate radio waves. As a result, the radio wave generator (215) can generate radio waves. The radio waves generated by the radio wave generator (215) can be transmitted to the antenna (230), and the antenna (230) can transmit the radio waves to the target location for shooting. Additionally, radio waves reflected back from the ground can be received by the antenna (230).

[0085] The antenna (230) converts the received radio waves into electrical signals and transmits them to the transceiver (220). Afterward, the transceiver (220) can amplify the signal and then transmit it to the signal processing unit (213) of the controller (210). Afterward, the signal processing unit (213) can perform signal processing, such as converting the signal to conform to a protocol, and then transmit it to the main body (100). The signal received by the main body (100) can be transmitted to the ground station. The ground station can then use the received signal to generate at least one of an image and a video of the target location.

[0086] The first to fourth differences may differ from each other. Also, the second difference may be smaller than the first difference, the third difference may be smaller than the second difference, and the fourth difference may be smaller than the third difference.

[0088] The mode monitoring unit (214) can monitor or determine what mode or state the payload is currently in.

[0089] First, the modes of the payload (200) are described. The state in which power is supplied to the second power supply (250) of the payload (200) is defined as "Initialization Mode," and the state in which power is supplied to the controller (210) and transceiver (220) of the payload (200) is defined as "Standby Mode." Additionally, the state in which power is supplied to the antenna (230) is defined as "Stabilization Mode," and the state in which mission information is input and set in the radiation control unit (216), transceiver (220), and antenna (230) is defined as "Ready Mode." Furthermore, the state in which the radio wave generator (215) generates radio waves at the time the mission begins is defined as "Operation Mode."

[0090] FIGS. 3 and 4 are flowcharts illustrating a method for determining the mode of a payload in a mode monitoring unit according to an embodiment of the present invention.

[0091] Hereinafter, a method for determining the mode of a payload in a mode monitoring unit according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

[0092] When the time difference between the start time of the mission and the current time becomes the first difference, the first power supply (150) of the main body (100) supplies power to the second power supply (250). Subsequently, the mode monitoring unit (214) can determine whether the payload (200) is currently in an initialization mode (S212). To this end, the mode monitoring unit (214) can transmit a first mode confirmation signal to the second power supply (250) (S21). Accordingly, the first mode confirmation signal can be received by the second power supply (250). When the first mode confirmation signal is received while power is supplied to the second power supply (250), the second power supply (250) can transmit a first response signal to the mode monitoring unit (214). Accordingly, the first response signal can be received by the mode monitoring unit (214). However, when the mode monitoring unit (214) transmits a first mode confirmation signal while power is not supplied to the second power supply (250), the second power supply (250) may not be able to transmit a first response signal.

[0093] If the first response signal is received within the first mode verification reference time from the time the first mode verification signal is transmitted (S22 --> Yes), the mode monitoring unit (214) determines that power is supplied to the second power supply (250) and determines that the mode of the payload (200) is "initialization mode" (S23). However, if the first response signal is not received within the first mode verification reference time from the time the first mode verification signal is transmitted (S22 --> No), the mode monitoring unit (214) determines that power is not supplied to the second power supply (250) and determines that the mode of the payload (200) is not "initialization mode" (S24).

[0094] In determining whether the initialization mode is active, the determination may be made using other methods, not limited to the example described above. For example, when the mode monitoring unit (214) transmits a first mode confirmation signal while power is not supplied to the second power supply (250), a signal different from the first response signal may be received by the mode monitoring unit (214). Accordingly, if a signal is received by the mode monitoring unit (214) within the first mode confirmation reference time but the signal is different from the first response signal, the mode monitoring unit (214) may determine that the mode of the payload (200) is not an "initialization mode."

[0095] When the mode monitoring unit (214) confirms that the mode of the payload (200) is in the initialization mode, the main body (100) controls the operation of the second power supply (250) to supply power to the controller (210). Subsequently, the mission execution control unit (212) of the controller (210) can supply power to the transceiver (220). That is, when the time difference between the mission start time and the current time becomes the second difference, the main body (100) controls the operation of the second power supply (250) to supply power to the controller (210). Then, when power is supplied to the controller (210), the mission execution control unit (212) controls the operation of the second power supply (250) to supply power to the transceiver (220). Next, the mode monitoring unit (214) can determine whether the payload (200) is currently in standby mode (S313). To this end, the mode monitoring unit (214) may transmit a second mode confirmation signal to, for example, the transceiver (220) (S31). When the second mode confirmation signal is received while power is supplied to the transceiver (220), the transceiver (220) may transmit a second response signal to the mode monitoring unit (214). Accordingly, the second response signal may be received by the mode monitoring unit (214). However, if the mode monitoring unit (214) transmits the second mode confirmation signal while power is not supplied to the transceiver (220), the transceiver (220) may not be able to transmit the second response signal.

[0096] If a second response signal is received from the transceiver (220) within the second mode verification reference time from the time the second mode verification signal is transmitted (S32-->Yes), the mode monitoring unit (214) determines that power is supplied to the controller (210) and the transceiver (220), and determines that the mode of the payload (200) is "standby mode" (S33). That is, if a second response signal is received by the mode monitoring unit (214) within the second mode verification reference time from the time the second mode verification signal is transmitted, the mode monitoring unit (214) determines that the mode of the payload (200) is "standby mode". However, if the second response signal is not received within the second mode confirmation reference time from the time the second mode confirmation signal is transmitted (S32-->No), the mode monitoring unit (214) determines that power is not supplied to at least one of the controller (210) and the transceiver (220), and can determine that the mode of the payload (200) is not "standby mode" but "initialization mode" (S34).

[0097] In determining whether a standby mode exists, the determination may be made in a different way, not limited to the example described above. For example, when the mode monitoring unit (214) transmits a second mode confirmation signal while power is not supplied to the transceiver (220), a signal different from the second response signal may be received by the mode monitoring unit (214). Accordingly, if a signal is received by the mode monitoring unit (214) within the second mode confirmation reference time but the signal is different from the second response signal, the mode monitoring unit (214) may determine that the mode of the payload (200) is not "standby mode" but "initialization mode."

[0098] When the mode monitoring unit (214) determines that the mode of the payload (200) is in standby mode, the mission execution control unit (212) can supply power to the antenna (230). That is, when the time difference between the mission start time and the current time becomes a third difference, the mission execution control unit (212) can control the operation of the second power supply (250) so that power is supplied to the antenna (230).

[0099] When the second power supply (250) is operated to supply power to the antenna (230), the mode monitoring unit (214) can determine whether the payload (200) is currently in a stabilization mode (S413). To this end, the mode monitoring unit (214) can transmit a third mode confirmation signal to the antenna (230) (S41). When the third mode confirmation signal is received while power is supplied to the antenna (230), the antenna (230) can transmit a third response signal to the mode monitoring unit (214). Accordingly, the third response signal can be received by the mode monitoring unit (214). However, if the mode monitoring unit (214) transmits the third mode confirmation signal while power is not supplied to the antenna (230), the antenna (230) may not be able to transmit the third response signal.

[0100] If the third response signal is received within the third mode verification reference time from the time the third mode verification signal is transmitted (S42-->Yes), the mode monitoring unit (214) determines that power is supplied to the antenna (230) and can determine that the mode of the payload (200) is "stabilization mode" (S43). However, if the third response signal is not received within the third mode verification reference time from the time the third mode verification signal is transmitted, the mode monitoring unit (214) can determine that the mode of the payload (200) is not "stabilization mode" but "standby mode" (S44).

[0101] In determining whether a stabilization mode exists, the above example is not limited to other methods. For example, when the mode monitoring unit (214) transmits a third mode confirmation signal while power is not supplied to the antenna (230), a signal different from the third response signal may be received by the mode monitoring unit (214). Accordingly, if a signal is received by the mode monitoring unit (214) within the third mode confirmation reference time but the signal is different from the third response signal, the mode monitoring unit (214) may determine that the mode of the payload (200) is not "stabilization mode" but "standby mode" (S44).

[0102] When the mode monitoring unit (214) determines that the mode of the payload (200) is in a stabilization mode, the mission execution control unit (212) sets the mission information by inputting it into the radiation control unit (216), the transceiver (220), and the antenna (230). That is, when the time difference between the mission execution start time and the current time becomes the fourth difference, the mission execution control unit (212) can set the mission information by inputting it into the radiation control unit (216), the transceiver (220), and the antenna (230).

[0103] When the mission execution control unit (212) is operated to set mission information in the radiation control unit (216), transceiver (220), and antenna (230), the mode monitoring unit (214) can determine whether the payload (200) is currently in a ready mode (S513). To this end, the mode monitoring unit (214) can transmit a fourth mode confirmation signal to the radiation control unit (216), transceiver (220), and antenna (230) (S51). When the fourth mode confirmation signal is received while mission information is set in each of the radiation control unit (216), transceiver (220), and antenna (230), the radiation control unit (216), transceiver (220), and antenna (230) can transmit a fourth response signal to the mode monitoring unit (214). Accordingly, three fourth response signals can be received by the mode monitoring unit (214). That is, the fourth response signal transmitted by the radiation control unit (216), the fourth response signal transmitted by the transceiver (220), and the fourth response signal transmitted by the antenna (230) can be received by the mode monitoring unit (214). However, if the mode monitoring unit (214) transmits a fourth mode confirmation signal while mission information is not set in at least one of the radiation control unit (216), transceiver (220), and antenna (230), at least one of the radiation control unit (216), transceiver (220), and antenna (230) for which mission information is not set may not be able to transmit the fourth response signal.

[0104] If three fourth response signals are received within the fourth mode verification reference time from the time the fourth mode verification signal is transmitted (S52-->Yes), the mode monitoring unit (214) determines that mission information is set in the radiation control unit (216), transceiver (220), and antenna (230), and determines that the mode of the payload (200) is "Ready Mode" (S53). However, if at least one of the three fourth response signals is not received within the fourth mode verification reference time from the time the fourth mode verification signal is transmitted (S52-->No), the mode monitoring unit (214) determines that mission information is not set in at least one of the radiation control unit (216), transceiver (220), and antenna (230), and determines that the mode of the payload (200) is "Stabilization Mode" rather than "Ready Mode" (S54).

[0105] In determining whether it is in a ready mode, it may be determined in a different way, not limited to the example described above. For example, when mission information is not set in at least one of the radiation control unit (216), the transceiver (220), and the antenna (230), if the mode monitoring unit (214) transmits a fourth mode confirmation signal, a signal different from the fourth response signal may be received by the mode monitoring unit (214). Accordingly, if three signals are received by the mode monitoring unit (214) within the fourth mode confirmation reference time but the signals are different from the fourth response signal, the mode monitoring unit (214) may determine that the mode of the payload (200) is not "ready mode" but "stabilization mode" (S54).

[0106] After the mode monitoring unit (214) determines that the mode of the payload (200) is in the ready mode, when the current time becomes the time to start the mission, the radiation control unit (216) can operate the radio wave generating unit (215) so that radio waves are generated in the radio wave generating unit (215). Then, the radio waves generated by the radio wave generating unit (215) can be transmitted to the antenna (230) via the transceiver (220), and the antenna (230) can transmit the radio waves to the target location for shooting.

[0107] When the radiation control unit (216) operates to generate radio waves from the radio wave generation unit (215), the mode monitoring unit (214) can determine whether the payload (200) is currently in an operating mode (S613). To explain this in more detail,

[0108] The radio waves generated by the radio wave generation unit (215) are transmitted to the antenna (230), and at least some of the radio waves transmitted to the antenna (230) can be received by the mode monitoring unit (214). However, if radio waves are not generated by the radio wave generation unit (215), radio waves cannot be transmitted to the antenna (230), so radio waves are not received by the mode monitoring unit (214).

[0109] If a radio wave is received by the mode monitoring unit (214) within the fifth mode verification standard time from the time the radiation control unit (216) transmits a radio wave generation command signal to the radio wave generation unit (215) (S62-->Yes), the mode monitoring unit (214) determines that the mode of the payload (200) is "Operation Mode" (S63). However, if a radio wave is not received by the mode monitoring unit (214) within the fifth mode verification standard time from the time the radiation control unit (216) transmits a radio wave generation command signal to the radio wave generation unit (215) (S62-->No), the mode monitoring unit (214) may determine that the mode of the payload (200) is not "Operation Mode" but "Prep Mode" (S64).

[0110] At least one of the first mode verification standard time, second mode verification standard time, third mode verification standard time, fourth mode verification standard time and fifth mode verification standard time may be different from or the same from each other.

[0111] Also, the method for determining the mode of the payload (200) is not limited to the example described above, and various techniques may be used.

[0113] FIGS. 5 and 6 are flowcharts illustrating a method of operation of a payload according to an embodiment of the present invention. Hereinafter, a method for the payload to perform a mission will be described with reference to FIGS. 1, FIGS. 5, and FIGS. In this case, any content that overlaps with what has been described previously will be briefly explained or omitted. In addition, since the method of storing mission information in the memory unit and the method of determining the mode of the payload in the mode monitoring unit have been described previously, the description thereof will be omitted.

[0114] When the distance between the satellite and the mission execution section in orbit becomes a second distance, the main body (100) transmits multiple mission information to the memory unit (211). Accordingly, the memory unit (211) selectively stores multiple mission information and stores a standard number, for example, 20 mission information.

[0115] The first power supply (150) of the main body (100) supplies power to the second power supply (250) of the payload (200) (S211). That is, when the time difference between the mission start time and the current time reaches the first difference, the main body controller (170) supplies power to the second power supply (250). In addition, the mission execution control unit (212) selects the mission information whose mission start time is closest to the current time among the multiple mission information stored in the memory unit (211) that has not yet been executed (S211). At this time, the first mission has not yet been executed after a reference number of mission information has been stored in the memory unit (211). Accordingly, the mission information with the earliest mission start time can be selected among the multiple mission information stored in the memory unit (211). Afterward, the mode monitoring unit (214) determines whether the current mode of the payload (200) is an initialization mode (S212).

[0116] If the mode monitoring unit (214) determines that the current mode of the payload (200) is an initialization mode (S212 --> yes), it can determine whether the current time is the time to supply power to the controller (210) (S311). That is, it can determine whether the difference between the mission start time of the selected mission information and the current time is a second difference, thereby determining whether it is the time to supply power to the transceiver (220) (S311). Then, if it is determined that the current time is the time to supply power to the controller (210) (S311 --> yes), the main body controller (170) can control the second power supply unit (250) to supply power to the controller (210) (S312). When power is supplied to the controller (210), the mission execution control unit (212) of the controller (210) can supply power to the transceiver (220). And, the mode monitoring unit (214) can determine whether the current mode of the payload (200) is standby mode (S313).

[0117] If the mode monitoring unit (214) determines that the current mode of the payload (200) is standby mode (S313 --> yes), it can determine whether the current time is the time to supply power to the antenna (230) (S411). That is, it can determine whether the time to supply power to the antenna (230) is the time to determine whether the difference between the mission start time of the selected mission information and the current time is a third difference (S411). Then, if it is determined that the current time is the time to supply power to the antenna (230) (S411 --> yes), the mission execution control unit (212) can control the second power supply (250) to supply power to the antenna (230) (S412). Subsequently, the mode monitoring unit (214) can determine whether the current mode of the payload (200) is stabilization mode (S413).

[0118] When the mode monitoring unit (214) determines that the current mode of the payload (200) is a stabilization mode, it determines whether the current time is the time to set mission information to the radiation control unit (216), transceiver (220), and antenna (230) (S511). That is, it determines whether the difference between the mission start time of the selected mission information and the current time is a fourth difference, and determines whether the time to set mission information to the radiation control unit (216), transceiver (220), and antenna (230) (S511). Then, if it is determined that the current time is the time to supply mission information to the radiation control unit (216), transceiver (220), and antenna (230) (S511-->Yes), the mission execution control unit (212) inputs and sets mission information to the radiation control unit (216), transceiver (220), and antenna (230) (S512). Next, the mode monitoring unit (214) determines whether the current mode of the payload (200) is a ready mode (S513).

[0119] When the mode monitoring unit (214) determines that the current mode of the payload (200) is the ready mode (S513-->Yes), the radiation control unit (216) determines whether the current time is the time to start the mission (S611). Then, when the current time is the time to start the mission, the radiation control unit (216) operates the radio wave generator (215) so that radio waves are generated from the radio wave generator (215) (S612). Accordingly, the radio wave generator (215) can generate radio waves and transmit the generated radio waves to the transceiver (220). Then, the transceiver (220) can amplify the radio waves and transmit them to the antenna (230), and the antenna (230) can transmit the radio waves received from the transceiver (220). Accordingly, the antenna (230) can transmit radio waves to the target location for shooting. Next, the mode monitoring unit (214) determines whether the current mode of the payload (200) is an operating mode (S613).

[0120] If the mode monitoring unit (214) determines that the current mode of the payload (200) is the operating mode (S613-->Yes), the mission execution control unit (212) can determine that the mission execution is successful (S711).

[0121] Radio waves reflected from the shooting target location can be received by an antenna (230), and the antenna (230) can convert the received radio waves into an electrical signal. The signal converted by the antenna (230) can be received by a transceiver (220). The transceiver (220) can amplify the signal and then transmit it to a signal processing unit (213) of a controller (210). The signal processing unit (213) can process the received signal and transmit it to the main body (100), and the main body (100) can transmit the signal to a ground station. The ground station can use the received signal to generate at least one of an image and a picture of the shooting target location.

[0122] Additionally, if it is determined that the current mode of the payload (200) is an operating mode, the mission execution control unit (212) can process the mission as completed. That is, the mission execution control unit (212) can process the completion of the mission for the selected mission information among the multiple mission information stored in the memory unit (211).

[0123] And, the mission execution control unit (212) can delete mission information set in the radiation control unit (216), transceiver (220), and antenna (230). Accordingly, the payload (200) can be switched to a stabilization mode (S712).

[0124] Next, the mission execution control unit (212) checks the memory unit (211) to determine whether there is other mission information to be performed (S811). If there is other mission information to be performed (S811 --> yes), the mission execution control unit (212) can select the mission information to be performed (S911). That is, among the multiple mission information stored in the memory unit (211), the mission information that has not been completed and includes the earliest mission start time is selected. Afterward, steps S511 through S811 are performed in the same manner. Additionally, steps S511 through S811 are repeated as many times as there is other mission information to be performed. Accordingly, multiple missions can be performed according to the plan.

[0125] If there is no other mission information to be performed (S811 --> No), the mission execution control unit (212) switches or transitions the mode of the payload (200) to standby mode (S900). That is, the mission execution control unit (212) stops the power supply to the antenna (230) using the second power supply (250). Accordingly, the mode of the payload (200) can be switched to standby mode.

[0126] When the mode of the payload (200) is switched to standby mode, the main body (100) can stop supplying power to the second power supply (250) and the controller (210).

[0128] Meanwhile, if the mode monitoring unit (214) determines that the current mode of the payload is not an initialization mode (S212 --> No), the mission execution control unit (212) determines whether the difference between the mission execution start time of the selected mission information and the current time is greater than or equal to the first remaining time (S213). At this time, if it is determined that it is greater than or equal to the first remaining time (S213 --> Yes), the mission execution control unit (212) transmits the determination result to the main body controller (170). Accordingly, the main body controller (170) controls the operation of the first power supply (150) again to re-supply power to the second power supply (250) (S213). However, if it is determined that the difference between the mission execution start time of the selected mission information and the current time is less than the first remaining time (S213 --> No), the mission execution control unit (212) may determine that the mission execution has failed (S614). That is, the mission execution control unit (212) determines that the mission cannot be performed. That is, the mission execution control unit (212) determines that the success or failure of the selected mission information is a failure.

[0129] Additionally, if the mode monitoring unit (214) determines that the current mode of the payload is not a standby mode (S313 --> No), the mission execution control unit (212) determines whether the difference between the mission execution start time of the selected mission information and the current time is greater than or equal to the second remaining time (S314). At this time, if it is determined that it is greater than or equal to the second remaining time (S314 --> Yes), the mission execution control unit (212) transmits the determination result to the main body controller (170). Accordingly, the main body controller (170) controls the operation of the second power supply (250) again to re-supply power to the controller (210) (S213). However, if it is determined that the difference between the mission execution start time of the selected mission information and the current time is less than the second remaining time (S314 --> No), the mission execution control unit (212) may determine that the mission has failed (S614). That is, the mission execution control unit (212) determines whether the selected mission information is successful or not as a failure.

[0130] As another example, if the mode monitoring unit (214) determines that the current mode of the payload is not a stabilization mode (S413 --> No), the mission execution control unit (212) determines whether the difference between the mission execution start time of the selected mission information and the current time is greater than or equal to the third remaining time (S414). At this time, if it is determined that it is greater than or equal to the third remaining time (S414 --> Yes), the mission execution control unit (212) operates the second power supply (250) to re-supply power to the antenna (230) (S412). However, if it is determined that the difference between the mission execution start time of the selected mission information and the current time is less than the third remaining time (S414 --> No), the mission execution control unit (212) may determine that the mission execution has failed (S614). That is, the mission execution control unit (212) determines that the success or failure of the selected mission information is a failure.

[0131] As another example, if the mode monitoring unit (214) determines that the current mode of the payload is not the ready mode (S513-->No), the mission execution control unit (212) determines whether the difference between the mission execution start time of the selected mission information and the current time is greater than or equal to the fourth remaining time (S514). At this time, if it is determined that it is greater than or equal to the fourth remaining time (S514-->Yes), the mission execution control unit (212) sets the mission information by re-entering it into the radiation control unit (216), transceiver (220), and antenna (230) (S612). However, if it is determined that the difference between the mission execution start time of the selected mission information and the current time is less than the fourth remaining time (S514-->No), the mission execution control unit (212) may determine that the mission execution has failed (S614). That is, the mission execution control unit (212) determines the success or failure of the selected mission information as a failure.

[0132] And, if the mode monitoring unit (214) determines that the current mode of the payload is not an operating mode (S613-->No), the mission execution control unit (212) may determine that the mission execution has failed (S614). That is, the mission execution control unit (212) determines that the success or failure of the selected mission information has failed.

[0133] Additionally, if the success or failure of the selected mission information is determined to be a failure (S614), the mission execution control unit (212) may process the mission execution as completed. That is, the mission execution control unit (212) may process the completion of execution for the selected mission information among the multiple mission information stored in the memory unit (211). Here, completion of execution does not mean success or failure of the mission execution, but may mean that the operation for mission execution has been completed regardless of success or failure.

[0135] As such, the payload according to the embodiments of the present invention can store a plurality of missions to be performed and then sequentially perform the plurality of missions in chronological order. That is, a plurality of missions can be performed continuously using a memory unit. Accordingly, the number of communications between the satellite body and the payload can be reduced compared to conventional methods. Consequently, a plurality of missions can be performed stably, and the mission completion rate can be increased. In addition, the time interval between performing a plurality of missions sequentially can be minimized. Therefore, the time required to perform a plurality of missions can be shortened.

[0136] In addition, if an action for mission execution could not be performed for any reason, the action can be performed again based on the remaining time until the mission start time. This can improve the mission completion rate or mission success rate. Explanation of the symbols

[0137] 100: Main body 200: Payload 210: Controller 211: Memory section 212: Mission Execution Control Unit 213: Signal Processing Unit 214: Mode Monitoring Unit 215: Propagation Generation Unit 220: Transmitter / Receiver 230: Antenna

Claims

Claim 1 A main body capable of receiving multiple mission information from a ground station and controlling the operation of a satellite; and a payload capable of being mounted on the main body to perform a mission; wherein the payload includes an antenna capable of transmitting and receiving radio waves; and a memory unit capable of storing a reference number of mission information transmitted from the main body, and a controller capable of generating radio waves using the mission information stored in the memory unit and transmitting the radio waves to the antenna; wherein the reference number exceeds 1, the memory unit can selectively store mission information transmitted from the main body, and the mission information includes a mission execution start time and a target location for shooting, and the memory unit stores mission information among the mission information transmitted from the main body where the mission execution start time is in the future of the current time, and the payload includes a transceiver capable of receiving radio waves generated by the controller and transmitting them to the antenna, or receiving a signal transmitted from the antenna; and wherein the controller includes a radio wave generator capable of generating radio waves; and a radiation control unit capable of being connected to the radio wave generator to control the operation of the radio wave generator. A satellite comprising: a mission execution control unit that can be connected to the radiation control unit and the memory unit to control the operation of the radiation control unit using the current time and mission information stored in the memory unit. Claim 2 delete Claim 3 delete Claim 4 In claim 1, the payload includes a power supply that can be connected to the main body, controller, transceiver, and antenna so as to supply power transmitted from the main body to the controller, transceiver, and antenna; the mission execution control unit can identify unexecuted mission information among a plurality of mission information stored in the memory unit and can select mission information including the earliest mission execution time among the identified mission information; and the mission execution control unit can be connected to the memory unit, antenna, and power supply so as to supply power to the antenna using the difference between the mission execution time included in the selected mission information and the current time. Claim 5 In claim 4, when the difference between the mission start time included in the selected mission information and the current time reaches a first difference, the main body supplies power to the power supply; when the difference between the mission start time included in the selected mission information and the current time reaches a second difference, the main body controls the operation of the power supply so that power is supplied to the controller; when the difference between the mission start time included in the selected mission information and the current time reaches a third difference, the mission control unit controls the operation of the power supply so that power is supplied to the antenna; and a satellite in which the second difference is smaller than the first difference and the third difference is smaller than the second difference. Claim 6 In claim 5, when the difference between the mission start time included in the selected mission information and the current time reaches a fourth difference, the mission execution control unit sets the selected mission information to the radiation control unit, transceiver, and antenna, and the satellite in which the fourth difference is smaller than the third difference. Claim 7 In claim 6, when the current time reaches the mission start time included in the selected mission information, the radiation control unit controls the operation of the radio wave generator so that the radio wave generator can generate radio waves. Claim 8 A satellite according to claim 4, wherein the controller comprises a mode monitoring unit capable of determining the current mode of the payload; and the mode monitoring unit determines whether the payload is in an initialization mode by determining whether power is supplied to the power supply, determines whether the payload is in a standby mode by determining whether power is supplied to the controller and the transceiver, determines whether the payload is in a stabilization mode by determining whether power is supplied to the antenna, determines whether the payload is in a ready mode by determining whether the selected mission information is set to the radiation control unit, the transceiver, and the antenna, and determines whether the payload is in an operating mode by determining whether radio waves are generated from the radio wave generator. Claim 9 A satellite according to claim 8, wherein if the mode monitoring unit determines that the mode of the payload is an initialization mode, the main body controls the operation of the power supply so that power is supplied to the controller; if the mode monitoring unit determines that the mode of the payload is a standby mode, the mission execution control unit controls the operation of the power supply so that power is supplied to the antenna; if the mode monitoring unit determines that the mode of the payload is a stabilization mode, the mission execution control unit sets the selected mission information to the radiation control unit, the transceiver, and the antenna; and if the mode monitoring unit determines that the mode of the payload is a ready mode, the radiation control unit determines whether the current time is the mission execution start time included in the selected mission information. Claim 10 A satellite according to claim 9, wherein when the mode monitoring unit determines that the mode of the payload is not an initialization mode, is not a standby mode, is not a stabilization mode, or is not a preparation mode, at least one of the following is re-executed: the main body controlling the operation of the power supply to supply power to the power supply according to the remaining time from the current time to the mission start time; the main body controlling the operation of the power supply to supply power to the controller; the mission execution control unit controlling the operation of the power supply to supply power to the antenna; and the mission execution control unit setting mission information to the radiation control unit, the transceiver, and the antenna. Claim 11 A method for operating a satellite comprising: a process of transmitting a plurality of mission information stored in a main body capable of controlling the operation of the satellite to a payload connected to the main body at a time interval; a process of storing the mission information transmitted by the main body in the payload to satisfy a reference number; and a mission execution process of transmitting radio waves and receiving reflected radio waves using the mission information, wherein the reference number exceeds 1, and the mission information includes a mission execution start time and a target position for shooting, and in storing the mission information transmitted by the main body in the payload, among the plurality of mission information transmitted from the main body, mission information in which the mission execution start time is a future time from the current time is stored, and the payload includes a controller capable of storing the mission information transmitted from the main body in the reference number and generating radio waves; and the controller includes a memory unit capable of storing the mission information in the reference number, a radio wave generating unit capable of generating radio waves, a radiation control unit capable of being connected to the radio wave generating unit to control the operation of the radio wave generating unit, and a mission execution control unit capable of being connected to the radiation control unit and the memory unit to control the operation of the radiation control unit using the current time and the mission information stored in the memory unit. Claim 12 delete Claim 13 In claim 11, the payload comprises: an antenna capable of receiving and transmitting radio waves generated by the controller and receiving radio waves reflected back; a transceiver capable of receiving radio waves generated by the controller and transmitting them to the antenna, or receiving a signal transmitted from the antenna and transmitting it to the controller; and a power supply capable of supplying power to the controller, the antenna, and the transceiver; and the mission execution process comprises: a process in which the main body supplies power to the power supply; a process in which the main body controls the operation of the power supply to supply power to the controller; a process in which the controller controls the operation of the power supply to supply power to the transceiver; and a process in which the controller controls the operation of the power supply to supply power to the antenna. Claim 14 A method of operating a satellite according to claim 13, wherein the mission execution process includes, before the power supply performs the process of supplying power to the antenna, a process in which the controller selects mission information, and the process in which the controller selects mission information includes: a process in which the controller identifies unexecuted mission information among the stored plurality of mission information; and a process in which the controller selects mission information including the earliest mission execution time among the identified mission information; and wherein, when the power supply supplies power to the antenna, if the difference between the mission execution start time included in the selected mission information and the current time reaches a preset time difference, the power supply supplies power to the antenna. Claim 15 In claim 14, the mission execution process comprises the process of the controller setting the selected mission information to the transceiver and antenna after the power supply supplies power to the antenna; and in the process of the controller setting the selected mission information to the transceiver and antenna, when the difference between the mission execution start time included in the selected mission information and the current time reaches a preset time difference, the method of operating a satellite that sets the selected mission information to the transceiver and antenna. Claim 16 In claim 15, the mission execution process comprises: a process in which the controller generates radio waves when the current time reaches the mission execution time of the selected mission information after the controller has set the selected mission information to the transceiver and antenna; and a process in which the antenna receives the radio waves generated by the controller; and a process of transmitting radio waves using the mission information comprises a process in which the antenna transmits radio waves to a target position for shooting, and a method of operating a satellite that receives radio waves reflected from the target position for shooting and returning to the antenna in receiving the reflected radio waves. Claim 17 In claim 16, the mission execution process comprises: a process of determining whether power is supplied to the power supply between the process in which the main body supplies power to the power supply and the process in which the power supply supplies power to the controller, thereby determining whether the payload is in an initialization mode; a process of determining whether power is supplied to the controller between the process in which the power supply supplies power to the controller and the process in which the power supply supplies power to the antenna, thereby determining whether the payload is in a standby mode; a process of determining whether power is supplied to the antenna between the process in which the power supply supplies power to the antenna and the process in which the controller sets the selected mission information to the transceiver and antenna, thereby determining whether the payload is in a stabilization mode; and a process of determining whether the selected mission information is set to the transceiver and antenna between the process in which the transceiver and antenna set the selected mission information and the process in which the current time has reached the mission execution time of the selected mission information, thereby determining whether the payload is in a ready mode. Claim 18 A method of operating a satellite according to claim 17, wherein, when the power supply supplies power to the controller, power is supplied to the controller if it is determined that the payload is in an initialization mode; when the power supply supplies power to the antenna, power is supplied to the antenna if it is determined that the payload is in a standby mode; when the selected mission information is set to the transceiver and antenna, power is set to the transceiver and antenna if it is determined that the payload is in a stabilization mode; and when the current time is determined to have reached the mission execution time of the selected mission information, when the payload is determined to be in a ready mode, power is supplied to the antenna. Claim 19 A method of operating a satellite according to claim 18, wherein if the mode of the payload is determined not to be an initialization mode, is determined not to be a standby mode, is determined not to be a stabilization mode, or is determined not to be a preparation mode, at least one of the following is re-executed according to the remaining time from the current time to the mission start time: the main body supplying power to a power supply, the power supply supplying power to the controller, the power supply supplying power to the antenna, and the power supply setting mission information to the transceiver and the antenna.

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