JP4523974B2 - Artificial satellite - Google Patents

Description

The present invention relates to an artificial satellite that can be mounted on a rocket and launched into outer space to communicate with the ground or perform earth observation.

In the early days of space development, each artificial satellite was a developed product, and all the artificial satellites were designed and developed from the very beginning, and were launched onboard rockets. At that time, improvements were made one after another while looking at the launch results of individual components and parts, and standardization of the satellite itself and some of its components, like ordinary industrial products. I couldn't. In other words, it was one-piece production, which caused a rise in costs and a prolonged development period.

In the late 1970s, communication satellites have been highlighted as the main mission of artificial satellites. With the growing demand for communications and the era of private companies owning satellites, many communications satellites have been launched.

In communication satellites, the system part of the satellite called the bus part is almost common among the demands for artificial satellites, so this bus part is designed as a common part, and the functional part ( Only the mission equipment part) can be designed and developed individually.

The standardization of the bus part of the satellite will greatly reduce the development and manufacturing costs of the satellite and shorten the development period, which will greatly benefit both the satellite manufacturer and its users. I can do it now. This method has been very successful by Hughes Aircraft and others, and this basic concept has now been reached.

Conventionally, as an example of an artificial satellite designed and manufactured individually, a technical test satellite 6 (made in Japan) is known. This is an artificial satellite in which a solar cell panel, an antenna module, and a communication device are mounted on a box-shaped structure made of a mission panel and an access panel made of a honeycomb sandwich panel (see Non-Patent Document 1, for example).

In addition, as a modular artificial satellite, an example is known in which a common device part called a satellite bus part is standardized and only a satellite mission (target function part) is manufactured according to an order (for example, non-patent document). 2).

Further, a module-connected space structure and its attitude control method are known (for example, see Patent Document 1). A modular spacecraft development method is known (for example, see Patent Document 2). A modular spacecraft backbone interface is known (see, for example, Patent Document 3). A modular spacecraft structure is known (for example, see Patent Document 4).
Editor: Masamichi Mobara and Yoshio Toriyama “Introduction to Satellite Design” Baifukan Co., Ltd., issued on June 13, 2002 Fig. 3.6 of Fig. 82 Editor: The Japan Aerospace Society “Aerospace Engineering Handbook” publisher, Maruzen Co., Ltd., issued September 30, 1992, p. 840 Table C1.14 and P.I. 841 Figure C1.22 Claims of JP 2000-264299 A Claims of JP-A-10-226399 Claims of JP-A-10-210057 Claims of JP-A-10-203494

Although there was great success through standardization of the bus part of artificial satellites such as communication satellites by the method described above, the functions and performance of the artificial satellites are considered as general satellites including other earth observation satellites. Standardization is difficult due to the large variety of demands, and since it is a single-product production, its development will take a great deal of cost and development time.

This is because the main load of communication satellites is a repeater, and there is not much difference in function requirements, whereas general satellites use radar or TV broadcasts that use higher power. There are cases where equipment is installed, and there are some satellites equipped with special observation machines that have particularly severe requirements for attitude control systems. In order to develop a satellite having these various functional requirements, the standardized bus developed with the communication satellite as the main target is difficult to use, and cost merit was not received.

In addition, Non-Patent Documents 1 and 2 are structurally complex and large, and cannot be folded compactly, so that they cannot be mounted on a small rocket.

Each of Patent Documents 1 to 4 is a modular structure or a coupling structure between modules, and does not disclose a technical idea of combining a plurality of modules (panels) having different functional elements.

The present invention has been made paying attention to the above circumstances, and the object of the present invention is to be mounted on a rocket and foldable to be compact when launched, and to be expanded in function, performance and capacity according to user requirements.・ Providing artificial satellites that can be reduced, and that can reduce costs and shorten the development period.

The present invention has been made paying attention to the above circumstances, the purpose of which is provided with a plurality of types of panels each having functional elements required for artificial satellites, each panel having substantially the same shape, and Mechanical, electrical and data interfaces are standardized,
Between each of the panels is configured to be able to transmit power and information,
The panels are configured so that the panels can be pivotably connected to each other by a hinge mechanism .
Each of the connected panels can be folded into a stacked state when mounted on a rocket and launched, and can be deployed in outer space after launch, with the deployed state including panels connected at right angles. The satellite assembly unit is characterized in that each panel is connected in a plane or at a right angle .

The second aspect of the present invention is a communication device, a CPU, a power supply, an attitude control device, and a thermal control, which are specific devices necessary for the artificial satellite distributed on each panel of the artificial satellite assembly unit according to the first aspect. One device selected from the device and the mission device is stored, and the satellite assembly unit is a collection of all or a part of these panels.
A third aspect of the present invention is characterized in that each panel of the satellite assembly unit according to the first or second aspect has a solar cell mounted on the outer surface thereof.

  According to a fourth aspect of the present invention, each panel of the artificial satellite assembly unit according to any one of the first to third aspects is selected according to a function required by the artificial satellite, and the selected panels can be rotated by a hinge mechanism. And satellites connected to each other so that power and information can be transmitted between panels.

According to a fifth aspect of the present invention, a solar cell is mounted on the outer surface of each panel, and electric power generated by the solar cell of each panel is used for equipment in the panel. The artificial satellite according to claim 3 or 4 , wherein the artificial satellite is used for a satellite or sent to another panel.

According to the said structure, since the several panel is connected by the hinge mechanism, it can fold compactly and can be mounted in the narrow space of a rocket. In addition, by mounting a device according to the user's request on a plurality of panels, using the necessary panels, and increasing or decreasing the number of panels, it is possible to flexibly cope with the required functions and accuracy.

Moreover, by mounting the solar cell panel on the outer surface of the panel, the area for receiving sunlight can be increased, and the generated power can be improved.
The specification discloses an invention in which adjacent panels are connected to each other by a heat conductive sheet having flexibility, and the heat conductive sheet is in contact with a device mounted on the panel. According to this invention, the temperature difference of each panel can be made close to zero as much as possible by connecting panels with the heat conductive sheet which has flexibility.

As described above, according to the present invention, an artificial satellite can be mounted on a rocket and folded into a compact configuration when launched, and functions can be expanded / reduced according to user requirements, thereby reducing costs.・ The development period can be shortened.

Hereinafter, an embodiment of the present invention will be described as an example with reference to drawings of an artificial satellite that performs optical observation using a lens.

1 to 9 show the artificial satellite of the first embodiment, FIG. 1 is a perspective view of the artificial satellite before deployment, and FIG. 2 is a perspective view of the artificial satellite after deployment. In the present embodiment, the artificial satellite 1 is configured by connecting nine panels of substantially the same size so as to be foldable by a hinge mechanism described later. Referring to FIG. 2, the deployed artificial satellite 1 is schematically described. A mission device panel 3 is connected to one end of the communication panel 2 in a planar manner. A first CPU panel 4 is connected to the other end of the mission equipment panel 3 at a right angle to the mission equipment panel 3. In the example of the artificial satellite 1 shown here, the mission equipment panel 3 is loaded with a device for optical observation, for example, an optical equipment such as a lens having a long focal length.

The other end of the first CPU panel 4 is connected to the power source panel 5, the first attitude control panel 6, and the second CPU panel 7 in this order in a planar manner. An image sensor / memory panel 8 is connected to the other end of the second CPU panel 7 at a right angle to the second CPU panel 7.

Further, a second attitude control panel 9 is connected to the other end of the image sensor / memory panel 8 in a planar manner. The image sensor / memory panel 8 and the second attitude control panel 9 are in parallel with the communication panel 2 and the mission equipment panel 3. A third posture control panel 10 is connected to one side of the second posture control panel 9 at a right angle. The first, second, and third attitude control panels 6, 9, and 10 face in three orthogonal directions, and can generate attitude control forces around three axes. Accordingly, the artificial satellite 1 has a substantially U-shape when deployed, and the panels 2 to 10 can be stacked and mounted on the rocket as shown in FIG. 1 by folding them in a zigzag shape and binding them with a binding string 1a. It is like that. The reason why the artificial satellite 1 shown here is substantially U-shaped is that the light passing through the lens of the mission device panel 3 is imaged by the image sensor / memory panel 8 and optically observed. .

Each of the panels 2 to 10 has basically the same shape and the same size, and the first posture control panel 6 will be described as an example as shown in FIGS. That is, the panel main body 11 formed of a light metal material or a lightweight and high-strength composite material such as CFRP has an octagonal shape in which four corners of a square are cut into a triangle shape in plan view. Then, triangular corner panels 12 are coupled to the four corners of the panel body 11.

The panel main body 11 has a flat box shape constituted by a bottom plate 13, a side plate 14 and a cover plate 15 constituting a peripheral wall, and notches 16 are provided on four sides of the side plate 14. Moreover, the corner panel 12 is also a flat box shape comprised by the baseplate 17, the side plate 18 and the cover plate 19 which comprise a surrounding wall. The bottom plate 17 and the lid plate 19 of the corner panel 12 are fixed to the bottom plate 13 and the lid plate 15 of the panel body 11 by bolts 20, respectively, and the corner panel 12 is connected to the panel body 11.

A hinge 21a constituting a hinge mechanism is attached to a corner portion of the bottom plate 17 and the side plate 18 of the corner panel 12, and adjacent panels are rotatably connected by the hinge 21a. The hinge 21a is urged by a biasing spring or the like in a direction in which the mutual connection of the panels is developed. It should be noted that the structure is not limited to the hinge 21a, and any structure may be used as long as it is a hinge mechanism that can rotatably connect adjacent panels. The side plate 18 on the side opposite to the hinge 21a is provided with a latch mechanism 21b so that when the panel is unfolded, the unfolded state is held by the latch mechanism 21b.

A solar cell panel 22 is affixed to the outer surface of the panel main body 11 on which the sunlight rays hit, for example, the outer surfaces of the bottom plate 13 and the cover plate 15. The solar cell panel 22 is electrically connected to a battery 23 installed inside the panel body 11, and the battery 23 is provided with a battery control unit 24.

Further, a controller 25, a LAN card 26, a wireless LAN antenna 27, and a functional element 28 are installed inside the panel body 11. The functional element 28 is electrically connected to the battery 23, and the controller 25 Connected by signal line. When the panel is the first posture control panel 6, the functional element 28 is a posture control device, a device for changing the posture (a device such as a reaction wheel that stores and releases angular momentum), and a communication panel. 2 is a device for communication with the ground, and the panels 2 to 10 are different only in the functional element 28 and other configurations are common.
Moreover, the panel main body 11 of the adjacent panel is connected by the tape-shaped heat conductive sheet 29 which has the flexibility derived | led-out from the notch part 16 through the inside. The heat conductive sheet 29 is bonded to a part of the panel body 11 or an apparatus with an adhesive (not shown). The heat conductive sheet 29 is a high heat conductive sheet and functions to make the temperature difference between the panels as close to “0” as possible. That is, each panel has a temperature difference due to the contact of sunlight, heat radiation from the control device inside the panel body 11, etc., but by connecting the panels to each other by the heat conductive sheet 29, the panel having the higher temperature Therefore, the entire temperature difference can be kept substantially uniform by conducting heat quickly from the lower panel to the lower panel.

Further, when the heat generation or heat input is excessive in the entire artificial satellite 1 and the temperature rises too much, a radiator may be provided in the panel body 11. With this radiator, heat can be released to outer space, and the heat conduction sheet 29 can also dissipate heat.

On the other hand, if the generation of heat is small and the temperature of the entire satellite 1 is too low, a heater may be used as in the conventional satellite, and the heat of the heater may be conducted by the heat conductive sheet 29. . Thus, by connecting the panels with each other by the heat conductive sheet 29, it is not necessary to provide a heater for each panel, and the number of heaters and their controllers can be reduced.

Further, a power connector 30 and a flexible cord 31 are built in the corner panel 12, and electrical connection between the panels is connected via the power connector 30 and the flexible cord 31 of the corner panel 12. The power generated by the solar cells in each panel is used to charge the batteries in the panel in addition to being used by the devices in the panel, but the surplus power is insufficient for power through this electrical connection. Sent to another panel.

Here, the heat conduction confirmation test of the heat conductive sheet 29 and adhesive performed by the present inventor will be described. The heat conductive sheet 29 has a product name: PGS graphite sheet (manufactured by Panasonic), heat conductivity: 800 W / mK, and a thickness of 0.15 mm. The adhesive has a product name: 6030HK (manufactured by Techno Alpha) and a thermal conductivity of 60 W / mK.

In order to minimize the temperature difference between the panels, the situation where the heat transfer sheet has to transport the most heat (worst condition) is that three panels are connected at right angles, the surface of one panel being This is a case where sunlight is incident at right angles and no sunlight is incident on the other panel.

In such a configuration, the amount of heat Q that must be transported by the heat conductive sheet is the worst case,
Q = WsS
= 1358 × 0.3 × 0.3 = 120 [W] (Equation (1)). Ws is the solar constant, and S is the area of the panel. The heat transfer between panels is
• Heat flow through the heat transfer sheet • Heat flow through the adhesive. When the temperature difference necessary for transporting 120 W of the formula (1) in each heat flow was evaluated, the results shown in Table 1 and Table 2 were obtained.

As can be seen from Tables 1 and 2, the temperature difference between the panels is about 5 ° C, assuming that heat flows to the adjacent panels in the order of the panel body → adhesive → thermal conductive sheet → adhesive → panel body. Can be realized.

FIG. 10 shows a second embodiment relating to the application method of the heat conductive sheet, and the same components as those in the first embodiment are given the same reference numerals and the description thereof is omitted. In the present embodiment, an aluminum honeycomb panel 33 is provided in a space other than the mounted device 32 installed inside the panel body 11, and a heat conductive sheet 29 is bonded to the upper surface of the mounted device 32.

The aluminum honeycomb panel 33 can prevent temperature unevenness in the thickness direction of the panel body 11. Further, by passing the inside of the panel body 11 through the heat conductive sheet 29 in a state where the heat conductive sheet 29 is bonded to the upper surface of the mounted device 32, the heat generated from the mounted device 32 is adjacent to the panel by the heat conductive sheet 29. Heat conduction, and the temperature difference can be reduced.

The artificial satellite 1 shown in the first and second embodiments is mounted on a rocket 34 as shown in FIG. 11 in a compactly folded state as shown in FIG. The rocket 34 shown in FIG. 11 is provided with a main engine 36 and a thrust-enhanced fixed fuel rocket motor 37 at the lower part of the rocket body 35. Various fuel tanks 38 and a second stage engine 39 are provided in the middle of the rocket body 35. On the upper part of the rocket body 35, a load connection structure 40 is provided in a state of being surrounded by a nose fairing 41. Then, the artificial satellite 1 is mounted in the upper space 42 of the mounted object connection structure 40. Alternatively, as shown in FIG. 11, when a rocket is sufficiently large, a very large artificial satellite can be launched, and then mounted on the side of the load connection structure 40 as the second or third. The artificial satellite 1 is split into the nose fairing 41 by the repulsive force of a spring or the like, and then released into space after the combustion of the rocket engine, and the artificial satellite 1 is deployed as shown in FIG. Yes.

In the above embodiment, a plurality of rectangular panels are rotatably connected by a hinge mechanism, mounted on a rocket and foldable at the time of launch, and configured to be deployable in outer space after launch. The shape and the number of the panels are merely examples, and are not limited. The form of the unfolded state also changes depending on the increase / decrease of the number of panels and the manner of connection. Which function panel is used and the device mounted on the panel can be changed as appropriate according to the user's request, and is not limited to the above-described embodiment.

According to this embodiment, the following effects can be obtained.
(A) Improvement of low cost and reliability By mass-producing panels having basic functions, it is possible to reduce the cost and improve the reliability of a single panel.

(B) Simplification of development Each panel has a common mechanical, electrical, and data interface even though it has different functions. Can be shared. In particular, standardization of inspection equipment contributes to cost and development time reduction.

(C) The common interface for promoting the entry of small-scale companies into development work can also be said inside the panel. The interface with which the on-board equipment unit (functional element 28) contacts in the artificial satellite is standardized in the present invention, so the conditions for developing the functional element 28 are standardized in advance, making it easy to set a design target. In the development of conventional artificial satellites, there are a wide variety of functional elements 28, and in order to form an interface with each other, all devices are often developed at the same time. It was difficult to tackle only powerful big companies.

However, if the internal interface is determined to some extent, it is easy for a company specialized in individual technology to develop the functional element 28.

(D) Increasing the degree of freedom of the shape In the conventional small artificial satellite, it is difficult to mount the deployment structure, and the artificial satellite having the purpose of requiring a long focal length as in the present embodiment is manufactured. It was difficult. However, since the shape of the artificial satellite body can be widened by deploying the panel, it is possible to achieve a mission that is geometrically limited in conventional small satellites.

The artificial satellite of the 1st Embodiment of this invention is shown, and the perspective view before expansion | deployment. The artificial satellite of the embodiment is shown and the perspective view of the unfolded state. The schematic plan view of the panel of the embodiment. The perspective view which shows the folding form of the panel of the embodiment. The perspective view which shows the same embodiment and shows the internal structure of a panel. The exploded perspective view of a panel which shows the embodiment. The perspective view of the corner panel which shows the same embodiment. The perspective view of the corner panel which shows the same embodiment. The perspective view which shows the same embodiment and shows the internal structure of a corner panel. The 2nd Embodiment of this invention is shown, (a) is a schematic top view, (b) is a vertical side view. The figure of the state where the satellite is mounted on the rocket.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Artificial satellite 2-10 ... Panel 11 ... Panel main body 12 ... Corner panel 21a ... Hinge (hinge mechanism)
22 ... solar cell panel 23 ... battery 25 ... controller 29 ... heat conduction sheet

Claims (5)

Equipped with multiple types of panels each equipped with the functional elements necessary for satellites, each panel has approximately the same shape, and mechanical, electrical, and data interfaces are shared,
Between each of the panels is configured to be able to transmit power and information,
The panels are configured so that the panels can be pivotably connected to each other by a hinge mechanism .
Each of the connected panels can be folded into a stacked state when mounted on a rocket and launched, and can be deployed in outer space after launch, with the deployed state including panels connected at right angles. The satellite assembly unit characterized in that each panel is connected in a plane or at a right angle . Each panel is distributed and contains one device selected from communication devices, CPUs, power supplies, attitude control devices, thermal control devices, and mission devices, which are specific devices required for the satellite, The artificial satellite assembly unit according to claim 1, wherein the artificial satellite assembly unit is an aggregate of all or a part of these panels. The satellite assembly unit according to claim 1 or 2, wherein each panel has a solar cell mounted on an outer surface thereof. According to the function required by the satellite, each panel of the satellite assembly unit according to any one of claims 1 to 3 is selected, the selected panels are connected to each other by a hinge mechanism, and An artificial satellite characterized in that the panels are connected to each other so that power and information can be transmitted. Each panel has a solar cell mounted on its outer surface, and the power generated by the solar cell of each panel is used for equipment in the panel, used for charging the battery in the panel, or The artificial satellite according to claim 3 or 4 , wherein the satellite is sent to another panel.

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