JPH07277294A - Device and method for controlling orbit of three axis controlled geostationary satellite - Google Patents

Abstract

PURPOSE:To reduce the amount of gas jet fuel required to maintain the orbit of a geostationary satellite by utilizing sunlight radiation pressure, the amount of gas jet fuel being the greatest cause of restricting the life of a geostationary satellite on the orbit. CONSTITUTION:A three axis controlled geostationary satellite has sunlight reflectors 1 extended in the geocentric direction of the three axis controlled geostationary satellite and in the opposite direction, shafts 2 extending in the direction in which the center of gravity of the satellite 3 aligns with the geocenter and in the opposite direction to the geocenter from the center of gravity, and a controller for rotating the satellite about the shafts 2. The angle by which the reflectors 1 rotate about the rotating shafts 2 are controlled for sunlight 10 to impinge on the sunlight reflectors 1 only in those seasons when the direction 12 of the sun is perpendicular to the direction 11 of the north-bound node, and thereby thrusts for varying the inclination angle of the orbit can be obtained in front of and behind the north-bound node 7 and the descending node 9, and the amount of gas jet fuel required to maintain the orbit can be reduced on the orbit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to orbit control of a three-axis control geostationary satellite, and more particularly to a method and apparatus for orbit control using solar radiation.

[0002]

2. Description of the Related Art A conventional satellite orbit control system utilizing the solar radiation pressure controls the solar radiation by rotating the solar array paddle and controlling the angle between the solar array paddle and sunlight (sun angle). The pressure was controlled to control the orbit (for example, Japanese Patent Laid-Open No. 4-325399).

[0003]

In the conventional orbital control system utilizing the solar radiation pressure to the solar cell paddle, it is necessary to change the sun angle of the solar cell paddle when performing the orbital control. There was a drawback that it would give a constraint. When applying the conventional method to the orbit control of a three-axis geostationary satellite, it is usually necessary to have a rotation axis perpendicular to the orbit plane because of the need for solar tracking of the solar array paddle and earth orientation of the satellite body. Is. With this control around the axis of rotation perpendicular to the orbital plane, the thrust in the orbital plane to change the orbital eccentricity can be controlled, but the orbital inclination angle that is dominant as the allocation of propellant for orbital control of geostationary satellites It is not possible to obtain thrust in the direction perpendicular to the orbital plane to change the.
The angle between the orbital plane of the satellite and the equatorial plane of the earth is the orbital tilt angle. Controlling this inclination angle is called orbital control or north-south control.

[0004]

In order to solve the above problems, the present invention provides the following means.

A device for controlling the orbit of a three-axis controlled geostationary satellite, which is installed in a three-axis controlled geostationary satellite, passes through the center of gravity of the main body of the geostationary satellite, and extends in the direction of the earth's center and in the direction opposite to the direction of the earth's center. A shaft and a portion of the rotation shaft extending from the center of gravity to the earth center side and to the opposite side of the center of gravity from the earth center;
A track control device for a three-axis controlled geostationary satellite, comprising: first and second solar reflectors attached to each and a reflector angle controller for rotating the rotating shaft.

In the method for controlling the orbit of a three-axis controlled geostationary satellite, the axis of rotation is extended from the center of gravity of the geostationary satellite body in the direction of the earth center and in a direction opposite to the earth center, and the center of gravity on the rotation axis is The first and second solar reflectors at two symmetrical positions, respectively, and when the geostationary satellite is located in the vicinity of an ascending or descending point, the angle of the solar reflector with respect to the sunlight is 45 degrees. Below 0 °, the orbital tilt angle of the geostationary satellite is controlled by utilizing the component of the solar reaction thrust in the direction perpendicular to the orbital plane that is received by the sunlight reflecting plate reflecting the sunlight. Axis control Geostationary satellite orbit control method.

The three-axis control geostationary satellite orbit control method described above, characterized in that the in-orbit direction component of the solar reaction thrust is canceled by a gas jet.

[0008]

According to the present invention, the sunlight reflection pressure is received by the sunlight reflecting plate by reflecting the sunlight by the sunlight reflecting plate, and the component in the direction perpendicular to the orbital plane of the sunlight reaction thrust generated on the sunlight reflecting plate. Is used to control the inclination angle of the orbit. Since the gas jet is not used to generate the thrust in the direction perpendicular to the orbital plane, the present invention contributes to the extension of the life of the satellite.

[0009]

The present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing an orbit control device for a geostationary satellite according to an embodiment of the present invention. According to this embodiment, north-south control, which is orbital plane control of a geostationary satellite, can be performed without using a gas jet. This example is described to illustrate the apparatus and method of the present invention.

The satellite 3 extends the solar reflector 1 in the direction toward the earth and in the opposite direction. The solar reflector 1 is attached to the rotating shaft 2. The rotating shaft 2 is composed of a portion extending from the center of gravity of the satellite 3 toward the earth center and a portion extending from the center of gravity in a direction opposite to the earth center. The angle of the rotary shaft 2 is
Reflector angle control device (provided inside the satellite 3)
Controlled by.

Geostationary satellites typically have one axis pointing to the earth. Therefore, while the satellite 3 is in orbit, the rotary shaft 2 continues to point in the direction of the earth's center, so that the angle 13 formed by the reflector 1 and the sunbeam 10 changes with the orbital motion. A season in which the ascending-point direction vector 11 connecting the ascending-point 7 on the orbit 4 and the earth's center is almost perpendicular to the sun-direction vector 12 is selected, and control is performed only in that season.

FIG. 2 shows the arrow A in FIG. 1 when the satellite is at the ascending node 7. The rotation axis 2 is controlled by the reflector angle control device so that the angle 13 formed by the sun reflector and the sun direction is 45 ° or less, and the sun reflector 1 is fixed at that angle. If mirror surfaces close to a reflectance of 1 are used on both surfaces of the solar reflector 1, the reaction thrust 14 of the solar radiation is generated in a direction substantially perpendicular to the solar reflector 1. The orbital surface vertical component 15 of the reaction thrust 14 is used for orbital surface control.

FIG. 3 shows the arrow B at the orbit position 8 which is the midpoint between the ascending intersection 7 and the descending intersection 9, and FIG. 4 shows the arrow C at the descending intersection 9.

At the orbital position 8 shown in FIG. 3, the solar ray direction 10 is perpendicular to the plane of the drawing and the in-plane direction of the solar reflector 1, so that the solar reflector 1 does not generate a reaction thrust.

At the descending point position 9 shown in FIG. 4, the component 15 of the solar reaction thrust in the direction perpendicular to the orbital plane acts in the opposite direction to that in FIG. 2, and the orbital inclination angle is increased in both FIGS. Thrust is generated in the direction. Since the in-orbit direction component 16 of the solar reaction thrust 14 generated in FIGS. 2 and 4 is an unnecessary component that acts in the direction of changing the orbital radius, it must be canceled by a gas jet. However, since the component 15 of the reaction thrust in the direction perpendicular to the raceway surface is larger than the component 16 in the direction of the raceway surface, the gas jet propellant can be saved as compared with the case where the device of the present embodiment is not used.

[0016]

As described above with reference to the embodiments, the present invention has a solar reflector extending in the direction of the center of the earth and the opposite direction, and the rotation axis of the solar reflector is in the orbital plane. Therefore, the reaction thrust of the solar radiation can be generated in the direction perpendicular to the orbital plane, and the orbital inclination angle can be controlled.
The reaction thrust of the in-orbit component that occurs at that time is an unnecessary thrust and must be canceled by a gas jet, but it is effective by setting it so that the angle between the sunlight and the solar reflector is 45 ° or less. The thrust component that can be used for is larger than the unnecessary thrust component, which has the effect of reducing the propellant charge of the gas jet.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a view on arrow C in FIG.

[Explanation of symbols]

 1 Solar reflector 2 Solar reflector Rotation axis 3 Satellite body 4 Geostationary satellite orbit 5 Earth 6 Sun 7 Ascending point 8 Intermediate position between ascending and descending points 9 descending point 10 Sunbeam direction 11 Ascending direction vector 12 Solar Direction vector 13 Angle between reflector and sun 14 Solar reaction thrust 15 Vertical component of reaction thrust in orbital plane 16 Inward orbital component of reaction thrust

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[Procedure amendment]

[Submission date] May 20, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

In the conventional orbit control method using the solar radiation pressure to the solar cell paddle, it is necessary to change the sun angle of the solar cell paddle when performing the orbit control, and the generated power is reduced. There was a drawback that it would give a constraint. In addition, when applying the conventional method to the orbit control of a three-axis geostationary satellite, it is usually necessary to have a rotation axis perpendicular to the orbit plane because of the need for solar tracking of the solar array paddle and earth orientation of the satellite body. Is. With this control around the axis of rotation perpendicular to the orbital plane, the thrust in the orbital plane to change the orbital eccentricity can be controlled, but the orbital inclination angle which is the dominant propellant allocation for geostationary satellite orbital control can be controlled. It is not possible to obtain thrust in the direction perpendicular to the orbital plane to change the.
The angle formed by the orbital plane of the satellite and the equatorial plane of the earth is the orbital inclination angle. Controlling this inclination angle is called orbital control or north-south control.

Claims (3)

[Claims] 1. A device provided in a three-axis controlled geostationary satellite for controlling the orbit of the three-axis controlled geostationary satellite, which extends through the center of gravity of the main body of the geostationary satellite in the direction of the earth center and in the direction opposite to the earth center. A rotating shaft, and a portion of the rotating shaft extending from the center of gravity to the earth center side and to the opposite side of the center of gravity from the earth center,
A track control device for a three-axis controlled geostationary satellite, comprising: first and second solar reflectors attached to each and a reflector angle controller for rotating the rotating shaft. 2. A method for controlling the orbit of a three-axis controlled geostationary satellite, wherein a rotation axis is extended from a center of gravity of the geostationary satellite body in a direction toward the earth center and in a direction opposite to the earth center, and the center of gravity on the rotation axis. Angles of the solar reflector with respect to sunlight when the geostationary satellite is located near an ascending or descending point, with the first and second solar reflectors attached at two positions symmetric with respect to each other. Is set to 45 ° or less, and the orbital tilt angle of the geostationary satellite is controlled by utilizing the component of the solar reaction thrust that is received by the sunlight reflecting plate to reflect the sunlight. Three-axis control geostationary satellite orbit control method. 3. The three-axis control geostationary satellite orbit control method according to claim 2, wherein the in-orbit direction component of the solar reaction thrust is canceled by a gas jet.