JPS59203000A - Control material for heat - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention relates to the improvement of a thermal control material that controls the heat of a space vehicle such as an artificial satellite. Specifically, the present invention relates to the improvement of a thermal control material that controls the heat of a spacecraft such as an artificial satellite. The present invention provides a thermal control material equipped with a grounding mechanism that grounds the surface.

It is widely known that when a spacecraft such as an artificial satellite flies through outer space, it generates electric charges due to space plasma and cosmic rays. This charging causes electrostatic discharge, which has an unfavorable effect on the operation of the spacecraft. For example, destroying the receiver.

These include deterioration of thermal control materials and malfunctions, and there have been many reports of these incidents actually occurring in orbit. Since most of such electrostatic discharge occurs in the heat control material, it is necessary to prevent the heat control material from being charged.

First, conventional heat control materials will be briefly explained using figures. 1st
The figure is a configuration diagram of a conventional heat control material. In the figure, (1) is a heat control material (for example, silver-deposited Teflon).

(2) is a sheet-like polymer material (e.g. Teflon sheet)
, (3) is a metal film (for example, silver) deposited on the back surface of the polymer material (2), and the polymer material (2) and the metal film (3)
This constitutes the heat control material (1). (4) is a screw that attaches the edge of the heat control material (1) to the structure (5), and this is a grounding mechanism. (5) is the structure of the spacecraft which is made of a conductive material and serves as a reference for electric potential; (6) is the electron incident on the thermal control material (1), which is the main cause of electrification.

In such a configuration, the heat control material (1) is attached to the structure (5).
) and space. Space (2) When electrons (6) from the space plasma enter the thermal control (1), the electrons (6) are captured by the polymer material (2), accumulated inside the polymer material (2), and the potential increases. do. According to data actually observed by artificial satellites, the maximum is -20,0OO
It is known that the absolute potential of V is reached.

In order to reach such a high potential, thermal control material (1
) and the structure (5), a high potential difference is likely to occur, and electrostatic discharge will occur between the two. Therefore.

Attach the above metal film (3) to the structure (
5) to maintain electrical continuity and release the electrons (6) accumulated in the polymer material (2) to the structure (5), thereby increasing the leakage current and thereby reducing the potential difference. .

However, when the area of the heat control material (1) increases.

At the same time, the number of electrons (6) flowing in increases, and a large amount of energy is accumulated, increasing the size of electrostatic discharge. Along with this, the energy of electromagnetic waves generated by electrostatic discharge also increases. This will cause significant interference to the equipment mounted on the spacecraft.Also, the energy of electrostatic discharge generated inside the polymer material (2) toward the metal film (3) (3) will increase. result,
There is a problem in that the material tends to deteriorate and break.

Therefore, it is necessary to conduct grounding at one or more points over an area of about 207 mm, and since the area of the thermal control material (1) is larger than the IR, it is possible to ground at multiple points not only at the edges but also over the entire surface of the thermal control material (1). Something was desired.

The present invention improves these conventional problems and will be explained in detail below with reference to the drawings. FIG. 2 is a sectional view showing the structure of an embodiment of the present invention, and FIG. 3 is a plan view showing the structure of an embodiment of the invention.

In the figure, (1) to (6) are the same as in FIG. 1, and (7) is a metal lattice (for example, a copper foil lattice) formed of metal foil in the form of a lattice, which is attached to the metal film (3). (8) is a lattice point of this metal lattice (7), C9) is a hole drilled at this lattice point so as to penetrate the thermal control material (1) and the metal lattice (7), and 110) is a thermal control Material (1) and metal grid (7
) with a conductive rivet-like ground electrode passing through the head (1
1) is exposed on the surface of the polymer material (2), and the end portion (1) is welded to the lattice point (8) of the metal lattice (7). ) constitutes a grounding mechanism with the pole (lα).

Next, the operation of the present invention will be explained in detail using figures. In FIG. 2, the process in which electrons (6) are accumulated in the polymer material (2) is the same as in FIG. The electrons (2) accumulated in the polymer material (2) in FIG.
5), it flows to the head (11) of the ground electrode f1α on the surface of the polymer material (2). By making the interval between the lattice points (8) of the metal lattice (7) sufficiently small (for example, 4.5 m), it is possible to reduce the area surrounded by each lattice point (8) in the polymer material (2). (for example, 207), the energy accumulated and discharged here can be kept small. Therefore, electromagnetic waves due to electrostatic discharge can be suppressed, and deterioration of the thermal control material (1) can also be suppressed. Furthermore, the discharge flowing from the interior of the polymer material (2) toward the metal film (3) can also be suppressed to a small level as described above. Furthermore, regarding the thermal characteristics of thermal control (1),
The area of the head qυ of the above ground electrode is 004% (head fi
(If the diameter of ll is about 1 m), the influence on sunlight absorption and reflectance is extremely small.

(5) Note that a drill-like tool is not suitable for drilling the holes 191 in the thermal control material (1) and the metal grid (7), and the beam diameter is 0.2 m.
Drill a hole with a pulsed laser of approximately 1.5 m. Further, explosive welding using a laser is also performed to weld the end portion (1) of the ground electrode 11α to the lattice point (8) of the metal lattice (7).

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional heat control material, FIG. 2 is a sectional view showing the structure of an embodiment of the present invention, and FIG. 3 is a plan view showing the structure of an embodiment of the present invention. In the figure, (1) is a thermal control material, (2) is a polymer material, and (3) is a metal film. (4) is a screw, (5) is a structure, (6) is an electron, and (7) is a metal grid. (8) is the grid point, (9) is the hole, and the hole is the ground electrode, 111
) is the head. 0 is the terminal part. In FIG. 9, the same or corresponding parts are designated by the same reference numerals. Agent Masuo Oiwa (6)

Claims (1)

[Claims] In a heat control material in which a metal film is attached to the back side of a sheet-like polymer material, the metal foil is formed in a lattice shape, and the metal lattice attached to the metal film, the polymer material, the metal film, and the a hole that penetrates through the lattice points of the metal lattice, and a conductive rivet-shaped ground electrode that is penetrated through the hole and has one head exposed on the surface of the polymer material and a terminal end welded to the lattice point of the metal lattice. A heat control material characterized by comprising: