JP2765498B2 - Microwave plasma thruster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave plasma propulsion device mounted on a spacecraft flying in outer space for attitude and orbit control, and more particularly to a microwave plasma propulsion device accompanied by plasma generation by microwaves. It is about.

[0002]

2. Description of the Related Art In a microwave plasma thruster,
The propellant is ionized by supplying microwave power into the discharge chamber of the thruster head, thereby generating a plasma.

FIG. 3 shows a conventional example. In the conventional example shown in FIG. 3, a satellite bus 10 that is a spacecraft that flies in outer space is used.
0 is a microwave plasma thruster 20
0 is provided. This microwave plasma thruster 200
A thruster head 51 that generates plasma and accelerates the thruster to generate a thrust, a propellant supply unit 52 that stores propellant and supplies the thruster to the thruster head 51, A microwave supply unit 57 that generates a wave and supplies it to the thruster head 51
And a power supply unit 53 for supplying power for accelerating the generated plasma to the thruster head 51.

[0004] Here, depending on the type of plasma propulsion device, for example, an arc jet thruster that does not require power for plasma acceleration to expand the generated plasma with a nozzle is used. Plasma thruster 200
Is the solar battery paddle 5 mounted on the satellite bus 100
6 through the satellite power supply system 54, the power required for microwave generation and plasma acceleration is supplied.

[0005]

The conventional microwave plasma thruster system shown in FIG. 3 generates hundreds to thousands of watts of power required for operation of the thruster by the solar cell paddle 56 of the satellite. Is configured. Therefore, a large-sized solar battery paddle 56 is required, which not only increases the weight of the satellite but also increases disturbances during the attitude control of the satellite, which is a major problem in system design. In addition, when the propulsion device is inactive, power for operating the plasma propulsion device is unnecessary, and therefore, only when the propulsion device is operating,
Having a large solar cell paddle 56 is inefficient.

Furthermore, the efficiency of the microwave amplification amplifier in the microwave supply unit 57 is 30 to 6 at the present stage.
Since it is as low as about 0%, a large amount of heat is generated from the microwave supply system during the operation of the propulsion device, but it is difficult to take measures against the temperature rise based on this, and the effect on the long-term operation of the satellite system is large. All of these problems are growing in proportion to the size of the propulsion system. It may be an obstacle.

On the other hand, Japanese Unexamined Patent Publication No. 61-127439
Japanese Patent Application Laid-Open Publication No. H11-157, discloses that a radiation source is provided in a discharge chamber in a plasma propulsion device so that a power source for generating plasma is not required.

However, providing a radiation source in the discharge chamber is substantially the same as that shown in FIG. 3, and has a disadvantage in that it hinders downsizing of the discharge chamber.

Japanese Patent Application Laid-Open No. 4-76275 discloses a configuration in which a propellant required as an ion source is procured from another satellite in outer space without storing the propellant required as an ion source in the satellite. I have.

However, Japanese Patent Application Laid-Open No. 4-76275
The technique disclosed in Japanese Patent Application Publication No. H11-27139 is intended to solve the problem of the supply of the propellant, and in such a point, the above problem cannot be solved at all.

[0011]

An object of the present invention is to improve the disadvantages of the prior art and to reduce the power consumption of the propulsion device in a plasma propulsion device mounted for attitude and orbit control in a spacecraft flying in outer space. It is an object of the present invention to provide a microwave plasma propulsion device that can reduce the size of a solar cell paddle that exerts an influence, thereby reducing the overall size of the plasma propulsion device main body.

[0012]

According to the first aspect of the present invention, in a microwave plasma propulsion device of a spacecraft for performing a plasma jet propulsion utilizing plasma generated by a microwave, an antenna for receiving microwaves is provided. And generating plasma based on microwaves supplied from the outside via this antenna.

The invention according to claim 2 employs a configuration in which a parabolic antenna is employed as an antenna, a gimbal mechanism for driving the parabolic antenna is provided, and the parabolic antenna can be directed in an arbitrary direction. .

This aims to achieve the above-mentioned object.

[0015]

[Function] Microwave power is transmitted from a power transmission ground station or a power generation satellite launched into outer space, received by a spacecraft via a parabolic antenna, and transmitted to a plasma propulsion device via a waveguide. Supply to discharge chamber. The parabolic antenna is always pointed in a desired direction by the action of the gimbal mechanism.

The propellant is supplied from a propellant supply unit (propellant tank) via a pipe to the discharge chamber of the plasma propulsion device. In practice, the amount of propellant is adjusted by a flow controller provided in the middle of the pipe to an amount suitable for the required thrust.

The thruster head has a discharge chamber for generating plasma, similar to a known plasma propulsion system using a microwave, and a nozzle for ejecting the generated plasma as a jet into space to obtain a thrust. The propellant is efficiently turned into plasma by a resonance phenomenon between a microwave and a magnetic field obtained by a permanent magnet installed in a discharge chamber.

[0018]

Next, an embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the microwave plasma propulsion device of this embodiment receives microwaves generated by a ground station or a dedicated power generation satellite through an antenna 5 mounted on a satellite bus 41, and generates a plasma. It is supplied to the thruster head 1 in the propulsion unit 40.

That is, in the embodiment shown in FIG. 1, the satellite bus 41, which is a spacecraft that flies in outer space, includes a microwave plasma propulsion device 40 as a propulsion device. The microwave plasma thruster 40 generates a plasma, accelerates the thruster to generate thrust, and a propellant supply unit 2 that stores a propellant and supplies the thruster to the thruster head 1. for thruster head 1, and a power supply unit 3 supplies power for accelerating the plasma generated in the thruster head within 1.

FIG. 2 shows the system configuration of the embodiment shown in FIG. The system configuration shown in FIG. 2 exemplifies a case where a propulsion unit is configured using an arc jet thruster.

As shown in FIG. 2, the discharge chamber 11 of the thruster head 1 composed of an arc jet thruster has a waveguide 5A for supplying microwaves and a pipe 23 for taking in propellant from the propellant supply unit 2. Is connected. The microwave is supplied from a ground station for microwave power transmission (or another power generation satellite launched into space) installed on the ground.
Done by

The spacecraft receives the transmitted microwave power via the parabolic antenna 5. The gimbal mechanism 30 is provided in the parabolic antenna 5 so that the antenna 5 can be directed in a desired direction. Here, reference numeral 30A indicates a rotation drive unit,
Reference numeral 30B denotes an up-and-down rotation drive unit. Reference numeral 30Ba indicates a drive motor for undulating rotation. As a result, microwave power is received with high efficiency and supplied to the discharge chamber 11 of the thruster head 1 via the waveguide 5A.

The thruster head 1 is similar to a known plasma propulsion system using a microwave, and discharges a plasma chamber J and a generated plasma P into a space jet as a plasma jet J. And a nozzle 12 for obtaining thrust. Sign 1
Reference numeral 3 denotes a permanent magnet.

The supply of the propellant for plasma generation to the discharge chamber 11 is performed from a propellant supply unit (propellant tank) 2 upstream of the pipe 23. A flow controller 22 for adjusting the amount of propellant is provided in the middle of the pipe 23. The permanent magnet 13 is provided inside the discharge chamber 11 as described above, and the supplied propellant is efficiently turned into plasma by a resonance phenomenon between the magnetic field and the microwave obtained by the permanent magnet 13.

In this embodiment, an arc jet thruster is described as an example of a plasma thruster, but other types of thrusters such as an ion thruster can be realized. However, in the case of an ion thruster, power for ion acceleration is required in addition to plasma generation.

[0027]

Since the present invention is constructed and functions as described above, according to the present invention, the consumption of the propulsion device in a plasma propulsion device mounted for attitude and orbit control in a spacecraft flying in space is described. since so as to receive power from the universe outside the microwave required for to and the plasma generation so as to eliminate the microwave generation unit significantly affecting the power through an antenna, a microwave power inside the spacecraft Therefore, the power consumption in the satellite can be greatly reduced, and therefore, the size of the solar cell paddle can be reduced, and at the same time, the heat generation from the microwave supply system is significantly reduced. And a microwave plasma thruster, which has never before been excellent in that the overall reliability and durability can be significantly increased. .

In the case of the present invention, a parabolic antenna for receiving microwaves and a gimbal mechanism for driving the antenna are required, but the weight of these devices does not depend much on the power consumption of the propulsion device. Since the weights of the microwave generation unit and the solar cell paddle tend to increase in proportion to the power consumption, the present invention is applied when considering a larger propulsion device and a higher power consumption expected in the future. This has the advantage that the weight of the spacecraft can be significantly reduced.

At the present stage, the efficiency of the microwave generation unit is as low as about 30 to 60%. Therefore, when the power of the propulsion unit is increased, the processing of heat generation becomes a serious problem in the satellite system design. According to the present invention, such a problem does not occur because microwave generation is performed by a dedicated power generation satellite or a ground station.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a microwave plasma thruster showing one embodiment of the present invention.

FIG. 2 is a system configuration diagram showing a microwave plasma thruster in the embodiment shown in FIG.

FIG. 3 is a block diagram showing system functions of a microwave plasma propulsion device in a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thruster head 2 propellant supply unit 3 power supply unit 4 satellite power supply system 5 parabolic antenna 6 solar cell paddle 30 gimbal mechanism 40 plasma thruster 41 satellite bus J plasma jet P plasma

Claims (2)

(57) [Claims] 1. A microwave plasma propulsion device for a spacecraft that performs plasma jet propulsion using plasma generated by a microwave, comprising: an antenna for receiving the microwave; A microwave plasma thruster for generating the plasma based on microwaves. 2. The microwave plasma according to claim 1, wherein said antenna comprises a parabolic antenna, a gimbal mechanism for driving said parabolic antenna is provided, and said parabolic antenna can be pointed in an arbitrary direction. Thruster.