JPH0141560B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to improvements in gas jet devices used for attitude control and orbit control of artificial satellites. Generally, an artificial satellite is composed of a plurality of modules. That is, FIG. 1 shows a conventional artificial satellite, and 11 and 12 are modules constituting the satellite, such as a power supply system and a communication system, respectively. A gas jet module 13 including a thruster for attitude control and orbit control is provided between the modules 11 and 12. This gas jet module 13 is composed of a plurality of thrusters 14. The module 12 is also provided with a normally cylindrical adapter 15 that is connected to a launch rocket. By the way, each of the modules 11, 12, 13
It is desirable that there are few interfaces between the two. That is, in the case of FIG. 1, modules 11,
The mechanical and electrical interface of 12 is provided by a gas jet module 13. For example, when testing the modules 11 and 12,
This has the disadvantage that it cannot be performed without the gas jet module 13. Additionally, a solar battery panel is usually provided in the direction of the pitch axis of the satellite. Therefore, if the gas jet module 13 is located in the center, the gas ejected from the thruster 14 may cause chemical changes in the solar cells and cause them to deteriorate during orbital surface control or the like.
This causes problems such as disturbance torque occurring in the panel. Therefore, in order to eliminate the above-mentioned drawbacks, it may be considered to provide a gas jet module at one end of the satellite. FIG. 2 shows one example, in which a plurality of thrusters 14 are provided on an adapter 15. With such a configuration, the interface problem between the modules 11 and 12 and the adverse effect on the solar cell can be eliminated. However, gas jet systems usually must have attitude and orbit control functions. In the above configuration, although attitude control can be performed by the combined injection of the thrusters 14, orbit control is not possible. To make this possible, the configuration of FIG. 2 must have at least a positive (+) sign as shown in FIG.
Thrusters 16, 17 in the negative (-) roll direction R;
A thruster 18 must be provided in the pitch direction P. That is, in-plane control (varying the orbital radius) in orbit control is performed by varying the speed of the satellite in the roll direction. For example, if the thruster 17 increases the speed twice in the +roll direction, the orbital radius increases as shown by the dashed line A in Figure 4a, and the thruster 16 increases the speed twice in the -roll direction. As the speed increases, the radius of the orbit becomes smaller as shown by the dotted line B in Figure 4a. Furthermore, out-of-plane control (controlling the orbital inclination) is performed by generating a velocity vector in the pitch direction. That is, suppose that the trajectory is inclined as shown by D with respect to the normal trajectory C as shown in FIG. 4b. In this case, the velocity vector at point P ₁ is V _C for trajectory C and V _D for trajectory D, and the difference vector between these is ΔV. Therefore, the thruster 18 directed in the -pitch direction may be controlled to offset this. Also, this control
It is sufficient to perform this at either point P ₁ or P ₂ shown in Figure b, which has an appropriate acceleration vector, and it is sufficient to have at least one thruster in the pitch direction. As mentioned above, by providing the gas jet module 13 at one end of the satellite, problems such as interface with other modules can be solved, but it has the disadvantage that orbit control cannot be performed. be. In FIGS. 2 and 3, the same parts as in FIG. 1 are given the same reference numerals. Also, in Figures 4a and 4b, E is the earth. This invention was made based on the above-mentioned circumstances, and a plurality of thrusters are provided at one end of the satellite body, and a combination of the above-mentioned thrusters is fired for attitude control, and the satellite body is rotated in yaw rotation for orbit control. It is an object of the present invention to provide a gas jet device that can eliminate adverse effects on other modules, etc., and can reliably control the attitude and orbit of a satellite by performing a combined injection of the predetermined thrusters while rotated by a predetermined angle. It is. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 5, reference numerals 51 and 52 are modules such as a power supply system and a communication system that constitute the satellite body, and among these, module 52 is provided with a gas jet module 53. This gas jet module 53 is comprised of an adapter 54 and a plurality of thrusters 55-66, as shown in FIG. Of these thrusters, 55, 58, 6
1 and 64 are oriented in the -roll direction, 56 and 60 are oriented in the -pitch direction, 62 and 66 are oriented in the +pitch direction, 59 and 63 are oriented in the -yaw direction, and 57 and 65 are oriented in the +yaw direction. In such a configuration, the satellite normally orbits in the +roll direction as shown by the dotted line in FIG. When performing attitude control in this state, the plurality of thrusters 55,
, 66 are combined and injected. + roll rotation; thrusters 57, 63 - roll rotation; thrusters 59, 65 + pitch rotation; thruster 55 - pitch rotation; thruster 61 + yaw rotation; thruster 58 - yaw rotation; thruster 64. Also, the orbit control of the satellite remains unchanged. Or, it is performed with the satellite's attitude rotated around +yaw or around -yaw. An actuator or a reaction wheel is used as a means for rotating the satellite. For example, when using a reaction wheel, move the wheel to arrow F shown in Figure 5.
By rotating in this direction, the satellite is rotated in the direction of arrow G, and with the satellite rotating near a predetermined position, by rotating the wheel in the opposite direction, the rotation of the satellite is stopped. Here, when performing the above-mentioned in-plane control of the satellite, increasing the speed by increasing the orbit radius is the fifth
For example, in the state shown by the dotted line in the figure, the thruster 5
The deceleration by injecting 8,64 and making the orbit radius small is:
This is done by firing the thrusters 58 and 64 while the satellite's attitude is rotated by 180 degrees around yaw. When out-of-plane control of the satellite is performed, the attitude of the satellite is rotated by 90 degrees in +yaw or -yaw, and in this state, for example, the thrusters 58 and 64 are fired. According to the above configuration, the gas jet module 53 is provided at one end of the satellite, and the gas jet module is configured to eject the gas jet module while the attitude of the satellite is rotated around yaw during orbit control of the satellite. Therefore, it is possible to perform attitude control and orbit control only by the gas jet module 53 provided at one end of the satellite. Further, since there are few electrical and mechanical interfaces between the gas jet module 53 and the other modules 51 and 52, manufacturing and testing of each module can be easily performed. Furthermore, the gas jet module 53 can be easily replaced. Also,
Since there is no solar panel in the direction of thruster injection during out-of-plane control, which is particularly problematic, adverse effects on the solar panel and disturbance torque on the satellite as a whole can be reduced. As described in detail above, according to the present invention, it is possible to provide a gas jet device that can eliminate adverse effects on other modules, etc., and can reliably control the attitude and orbit of a satellite.

[Brief explanation of drawings]

1 to 3 are schematic configuration diagrams shown to explain the conventional gas jet device, FIGS. 4a and 4b are diagrams shown to explain the orbit control of the satellite, and FIG. 5 is a diagram showing the structure of the conventional gas jet device. A schematic configuration diagram showing one embodiment of such a gas jet device, FIG.
It is a diagram showing the main parts of the diagram. 51, 52... Modules constituting the satellite such as power supply system and communication system modules, 53... Gas jet module, 55-66... Thruster.

Claims (1)

[Claims] 1 A plurality of thrusters that inject gas in the roll direction, pitch direction, and yaw direction are installed at one end of the satellite body, and for attitude control, a combination of the above-mentioned thrusters is performed, and for orbit control, the satellite body is rotated in the yaw direction. A gas jet device characterized in that the combination injection of the predetermined thrusters is performed while the thrusters are rotated by a predetermined angle.