JPH04278898A - Artificial satellite and method for securing electric power in initial phase - Google Patents

Abstract

PURPOSE:To sufficiently secure the electric power in the initial phase by using a lightweight and simple satellite system. CONSTITUTION:Solar battery paddles 1a and 1b for the exclusive use for the initial phase are installed besides the solar battery paddles 2a and 2b used in the mission phase 9. In launching, the solar battery paddles 1a, 1b, 2a, and 2b are accommodated along the surface of a satellite body 3. In the initial phase 6, the solar battery paddles 1a and 1b are developed, and the operation in the initial phase is carried out. After the sufficient preparation is performed, the solar battery paddles 1a and 1b are separated and removed, and the whole of the satellite is spun up, and fed into a mission orbit 12 in a stable spin state.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-axis attitude control artificial satellite having a solar array paddle that is inserted into a mission orbit in a stable spin state, and a method for securing power during its initial phase.

0002

BACKGROUND OF THE INVENTION Attitude control systems for artificial satellites are broadly classified into spin stabilization systems and three-axis attitude control systems. The former method has the advantage that the configuration of the attitude control system is much simpler than the latter method, but if the entire satellite were to spin, it would have to spin around the principal axis of maximum inertia, which would cause structural problems. There are major restrictions.

[0003] In general, solar battery paddles for artificial satellites are made to be lightweight, so they cannot withstand the load when the satellite is spinning, and they occupy a large space, so they are folded up at the time of launch.

[0004] Conventional artificial satellites with solar array paddles are launched into an initial orbit with the solar array paddle folded, and while spinning in the initial orbit, the initial phase operation for determining orbital parameters is carried out to stabilize the spin. The normal sequence is to enter the mission orbit, stop spinning, enter 3-axis attitude control, and deploy the solar array paddles.

[0005]

[Problems to be Solved by the Invention] The above-mentioned conventional artificial satellites had a problem in that it was difficult to secure power in the initial phase.

[0006] As an example, consider an artificial satellite with two wings of solar battery paddles with a three-panel configuration.The power in the initial phase is as follows, where P is the power generated after the paddles are deployed.
It is expressed as the following formula.

[0007] Initial phase generated power=P×1/3×1/π where 1/
Item 3 is due to the fact that the solar array paddles are folded and only one of the three panels is exposed to sunlight. Furthermore, the term 1/π is due to the fact that the artificial satellite is spinning.

[0008] Therefore, in the initial phase, the generated power is about 1/10 of that after the paddle is deployed, so the situation is extremely poor in terms of power.

[0009] In conventional artificial satellites, devices are turned off only during the initial phase to reduce power consumption, and if necessary, take measures such as using a battery also during the initial phase to survive the initial phase. I've come up with a method.

However, when taking such a method,
Significant restrictions are placed on the functionality of the satellite, and when batteries are used, additional restrictions are placed on the time allotted to the initial phase, which has the disadvantage of placing significant restrictions on the entire satellite system.

[0011] In order to solve these problems, it is conceivable to make the solar battery paddle expandable and retractable even after launch. An example of such a solar cell paddle is a flexible solar cell paddle. However, the mechanism for making solar arrays retractable in orbit is extremely complex, reduces reliability, and increases weight.

[0012] Another possible measure is to perform 3-axis attitude control in the initial phase to deploy the solar array paddles, and then move to the mission orbit while maintaining the 3-axis attitude control. In order to enter the mission orbit, it is necessary to reduce the load on the solar array paddle by using a propulsion system with a complex mechanism such as a two-component kick motor, and a propulsion system with a simple mechanism such as a solid kick motor is required. It becomes unusable. If the satellite is medium-sized, this method will only complicate the satellite system and have drawbacks in terms of weight and reliability.

[0013]

[Means for Solving the Problems] The artificial satellite of the present invention has a satellite main body having a function of transitioning from an initial orbit to a mission orbit in a spin stable state and a three-axis attitude control function, and a The solar battery paddle is provided with a first solar battery paddle that is deployed after launch and separated from the satellite main body, and a second solar battery paddle that is deployed after launch along the outer surface of the satellite main body during launch.

The method for securing power in the initial phase of an artificial satellite according to the present invention includes a first step in which the first and second solar battery paddles are launched into an initial orbit along the outer surface of the satellite body; a second step of deploying the first solar cell paddle through three-orbit attitude control in and a fourth step of performing three-axis attitude control in the mission orbit and deploying the second solar array paddle.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the artificial satellite of the present invention in its initial phase.

In FIG. 1, 1a and 1b are solar battery paddles dedicated to the initial phase. In this embodiment, the solar battery paddles 1a and 1b are expanded in the initial phase, and the solar battery surfaces are directed toward the sun to secure the necessary power in the initial phase.

[0018] After the initial phase is completed and immediately before insertion from the initial orbit to the mission orbit, the solar battery paddles 1a, 1b
is separated from the satellite body 3 and jettisoned. This separation/dumping mechanism has a simple structure using explosive bolts, springs, etc., and can be realized with high reliability.

2a and 2b are solar battery paddles that are deployed and used during the mission phase.

FIG. 2 is a diagram for explaining the sequence from launch to mission phase of the embodiment shown in FIG.

At time 5 immediately after being inserted into the initial orbit 11 from the earth 10, the solar array paddles 1a, 1b, 2a,
2b is stored along the outer surface of the satellite main body 3.

At time 6 of the initial phase, solar cells 1a and 1b are deployed under three-axis attitude control. Since sufficient power is secured from point 6 onwards, the initial phase operation can be performed with sufficient time.

At time 7, when the preparations for insertion into the mission orbit are complete, the solar array paddles 1a and 1b are separated and jettisoned, the entire satellite is spun up around the spin axis 4, and solid kick is performed in a stable spin state. It is inserted into the mission orbit 12 by a motor or the like (time point 8).

After entering the mission orbit 12, a transition is made to a three-axis attitude control state, and the solar battery paddles 2a and 2b are deployed (time point 9).

A comparison of the weight of this embodiment with a conventional artificial satellite using deployable/retractable flexible solar battery paddles is as follows.

[0026] For example, when constructing a solar cell paddle that generates power of about 500 W, the weight of each flexible solar cell paddle is about 25 kg, and the total weight of the two wings is about 50 kg. On the other hand, in the case of a simple solar battery paddle as in this embodiment, each wing weighs 14 kg as the solar battery paddles 2a and 2b used after entering the mission orbit.
, the total weight of the two wings is 28 kg. The weight of the disposable solar array paddles 1a and 1b for the initial phase will depend on the power consumption in the initial phase, but it is thought that it is sufficient to expect about half the power consumption in the normal mission phase, so we estimated the weight to be 20 kg. Even so, the total weight of the satellite is lighter in this embodiment.

[0027]

[Effects of the Invention] As explained above, the present invention has a solar battery paddle exclusively for the initial phase, secures the necessary amount of power in the initial phase, and then disconnects this solar battery paddle to prevent the satellite system from being damaged. It is uncomplicated, lightweight, and has the effect of simply securing sufficient power in the initial phase.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the artificial satellite of the present invention in an initial phase.

FIG. 2 is a diagram for explaining the sequence from launch to mission phase of the embodiment shown in FIG. 1;

[Explanation of symbols]

1a, 1b, 2a, 2b solar battery paddle 3
Satellite body 4 Spin axis 10 Earth 11 Initial orbit 12 Mission orbit

Claims (2)

[Claims] Claim 1: A satellite body having a function of transitioning from an initial orbit to a mission orbit in a spin stable state and a three-axis attitude control function, and a satellite body that is deployed along the outer surface of the satellite body at the time of launch and separated from the satellite body. An artificial satellite comprising a first solar battery paddle and a second solar battery paddle that is deployed along the outer surface of the satellite body during launch and after launch. 2. A first step in which the first and second solar battery paddles are launched into an initial orbit along the outer surface of the satellite body, and a three-orbit attitude control is performed in the initial orbit to control the first solar battery paddle. a second step of deploying a paddle; a third step of separating and spinning up the first solar cell paddle to transfer from the initial orbit to the mission orbit in a spin stable state; and a three-axis attitude in the mission orbit. and a fourth step of controlling and deploying the second solar array paddle.