A thermal control device of a star sensor

Abstract

The utility model discloses a kind of thermal control devices of star sensor, comprising: heat-conducting body and heat insulation boss;Heat-conducting body includes: shell and the tree-shaped microchannel structure filled in shell;Channel of tree-shaped microchannel structure is filled with liquid ammonia;The first installation outer surface of shell is fixedly connected with the bottom mounting surface of star sensor, and the first installation outer surface is filled with heat-conducting silicone grease between bottom mounting surface;Second installation outer surface of shell is provided with at least two heat insulation bosses;Heat insulation boss is fixedly connected with the support of star sensor, and heat insulation material is arranged between heat insulation boss and support;Shell and tree-shaped microchannel structure are all 3D printing molding of aluminium alloy material;Heat insulation boss is titanium alloy material.The utility model decouples the temperature coupling relationship of star sensor and satellite, can maintain the temperature stability required by high-precision star sensor, heat-conducting body can be same 3D printing molding, meet the dual needs of high-function density star sensor to temperature stability and batch manufacturability.

Description

Technical Field

[0001] This utility model relates to the field of satellite structure technology, and in particular to a thermal control device for a star sensor. Background Technology

[0002] With the rapid development of aerospace technology, star sensors, as core components for spacecraft attitude measurement, are experiencing continuously increasing functional density, significantly enhanced mission complexity, and increased uncertainty in their operating environment (such as changes in orbital illumination conditions and fluctuations in satellite platform operating conditions). Against this backdrop, the thermal control requirements for star sensors are becoming increasingly stringent—their internal optical components and detectors require extremely high temperature stability (typically controlled within ±0.5℃). Temperature fluctuations can directly lead to problems such as focal length drift in the optical system and increased detector noise, thereby affecting the accuracy and reliability of attitude measurement.

[0003] Currently, traditional thermal control solutions for star sensors mainly include the following: One method involves directly mounting the star sensor onto the satellite bracket, with heat conducted to the satellite body through structural components, and then dissipated into space by the satellite platform's heat dissipation surfaces (such as radiators); another method uses heat pipes to connect the star sensor to a heat sink mounted on the satellite body, utilizing the heat pipes' high thermal conductivity to assist heat transfer. Because the star sensor is directly coupled with the satellite body for heat transfer, fluctuations in satellite operating conditions (such as orbital sunlight / shadow switching, power changes caused by equipment start-up and shutdown) can lead to significant changes in the satellite body's temperature (measured fluctuations exceeding ±5℃). The star sensor temperature is inevitably affected by this, making it difficult to maintain the temperature stability required for high accuracy, ultimately reducing attitude measurement accuracy. Another thermal control design requires separate application of thermal control materials (such as multi-layer insulation and thermally conductive fillers) during the star sensor assembly stage. This not only involves complex assembly procedures and high labor costs, but also makes standardization and mass production difficult due to differences in satellite platform structures. Utility Model Content

[0004] To address the aforementioned problems in the existing technology, this utility model provides a thermal control device for a star sensor. The technical problem to be solved by this utility model is achieved through the following technical solution:

[0005] A first aspect of this utility model provides a thermal control device for a star sensor, comprising: a heat-conducting body and a heat-insulating boss;

[0006] The heat-conducting body includes: an outer shell and a tree-shaped microchannel structure filled within the outer shell;

[0007] The channels of the tree-shaped microchannel structure are filled with liquid ammonia.

[0008] The first mounting surface of the housing is fixedly connected to the bottom mounting surface of the star sensor, and thermally conductive silicone grease is filled between the first mounting surface and the bottom mounting surface.

[0009] At least two heat-insulating bosses are provided on the second mounting outer surface of the housing;

[0010] The heat-insulating boss is fixedly connected to the bracket of the star sensor, and a heat-insulating material is provided between the heat-insulating boss and the bracket;

[0011] Both the outer shell and the tree-shaped microchannel structure are 3D printed from aluminum alloy material.

[0012] The heat-insulating boss is made of titanium alloy.

[0013] In one embodiment of this utility model, the thickness of the heat-conducting body is 6-8mm;

[0014] The width of the tree-shaped microchannel structure is 0.5-2 mm;

[0015] The height of the heat-insulating boss is 1-3mm.

[0016] In one embodiment of the present invention, the outer surface of the housing, except for the portion of the first mounting outer surface that contacts the bottom mounting surface, and the surface of the heat-insulating boss, except for the portion that contacts the bracket, are all coated with a thermal control coating.

[0017] In one embodiment of this utility model, the heat insulation material is aerogel.

[0018] In one embodiment of this utility model, a thin-film heater and a thermistor temperature sensor are provided on the top of the star sensor;

[0019] The top of the star sensor and the star sensor shield are both covered with multiple layers of heat insulation components.

[0020] In one embodiment of this utility model, the number of heat-insulating bosses is four.

[0021] In one embodiment of this utility model, the thermal control coating is white paint.

[0022] The beneficial effects of this utility model are:

[0023] This invention dissipates heat from the star sensor using a heat-conducting body, while simultaneously insulating the star sensor's support and the satellite using a heat-insulating boss. This reduces the impact of satellite operating temperature fluctuations on the star sensor's temperature. The independent heat conduction (dissipation or absorption) via the heat-conducting body decouples the temperature coupling between the star sensor and the satellite, maintaining the temperature stability required for high-precision star sensor measurements and ultimately improving attitude measurement accuracy. The heat-conducting body can be 3D printed for standardized mass production, allowing for independent pre-assembly and testing, simplifying the thermal control assembly process and meeting the dual requirements of high-function-density star sensors for temperature stability and mass production manufacturability.

[0024] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0025] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 A schematic diagram of the structure of a thermal control device for a star sensor provided in an embodiment of this utility model;

[0028] Figure 2 This is a schematic diagram of the assembly structure of a thermal control device for a star sensor provided in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10-Outer shell; 20-Tree-shaped microchannel structure; 30-Insulating boss; 40-Bottom mounting surface; 50-Bracket. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0032] like Figure 1 As shown, the first aspect of this utility model provides a thermal control device for a star sensor, including: a heat-conducting body and a heat-insulating boss 30.

[0033] The heat-conducting body includes a shell 10 and a tree-shaped microchannel structure 20 filled within the shell 10. The channels of the tree-shaped microchannel structure 20 are filled with liquid ammonia. Liquid ammonia has a thermal conductivity ≥20000 W / mK, which, combined with the thermal conductivity of the tree-shaped microchannel structure 20, further enhances the heat conduction effect. The width of the tree-shaped microchannel structure 20 is 0.5-2 mm.

[0034] The first mounting surface of the housing 10 is fixedly connected to the bottom mounting surface 40 of the star sensor, and thermally conductive silicone grease is filled between the first mounting surface and the bottom mounting surface 40.

[0035] In this embodiment, the tree-shaped microchannel structure 20 branches progressively from the root (near the heat source) to the end, forming multi-level heat conduction channels. This decomposes the heat that would otherwise need to be transferred through a single long path into multiple shorter parallel paths. Heat can be transferred simultaneously along multiple short paths, avoiding heat accumulation along a single long path, thereby accelerating the overall heat conduction process. This shortens the effective heat conduction path and reduces thermal resistance.

[0036] Preferably, the main channel of the tree-shaped microchannel structure 20 is located close to the heat source, responsible for rapidly collecting high-density heat; the branch channels gradually narrow and extend outward, distributing heat to a wider area. This hierarchical diffusion mechanism is similar to a tree canopy dispersing sunlight energy through its branches and leaves, preventing excessively high temperatures in localized areas. It effectively alleviates the temperature gradient caused by heat concentration in traditional single channels, resulting in a more uniform temperature distribution on the device surface or inside, and preventing material performance degradation due to excessive temperature differences. Within a limited installation space, the more branches and the finer the channels, the larger the total surface area per unit volume, and the higher the efficiency of heat transfer to the external medium through the channel walls.

[0037] Both the outer shell 10 and the tree-shaped microchannel structure 20 are 3D printed from aluminum alloy, enabling mass production with annotations. 3D printing improves the production efficiency of satellite components.

[0038] Preferably, the outer shell 10 is made of aluminum alloy 6061 (thermal conductivity ≥170W / mk) with a surface flatness ≤0.1mm. The outer shell 10 itself has a thickness of 1-3mm, and the thermally conductive body has a thickness of 6-8mm. The relatively thick thermally conductive body greatly improves the thermal conductivity.

[0039] At least two heat-insulating protrusions 30 are provided on the second mounting outer surface of the housing 10. The heat-insulating protrusions 30 are fixedly connected to the bracket 50 of the star sensor, and heat-insulating material is provided between the heat-insulating protrusions 30 and the bracket 50. The heat-insulating protrusions 30 are made of titanium alloy. The thermal conductivity of the titanium alloy is ≤1W / mK, and the height of the heat-insulating protrusions 30 is 1-3mm. The heat-insulating material is aerogel.

[0040] Preferably, the number of heat-insulating bosses 30 is four.

[0041] In this embodiment, the star sensor is thermally isolated from the satellite bracket 50 and the satellite body by the heat-insulating boss 30, which effectively blocks the transmission path of temperature fluctuations caused by satellite operating conditions (such as orbital sunshine / shadow switching, equipment power changes, etc.) to the star sensor, decouples the temperature coupling relationship between the star sensor and the satellite body, and significantly reduces the star sensor temperature drift problem caused by changes in the temperature of the satellite body.

[0042] In this embodiment, the thermally insulating boss 30 significantly reduces the temperature interference of the star sensor caused by temperature changes (above ±5°C) on the satellite body, decoupling the temperature coupling between the star sensor and the satellite body. Independent thermal control of the star sensor is achieved through the thermally conductive body, ensuring its temperature depends only on its own thermal balance requirements and is no longer affected by temperature fluctuations on the satellite body. This further decoupling of the temperature coupling between the star sensor and the satellite body fundamentally solves the thermal conflict problem between the satellite platform and the star sensor, avoiding a decrease in attitude measurement accuracy due to changes in satellite operating conditions and improving the reliability of the star sensor in complex space environments.

[0043] Here, through the efficient directional heat conduction of the heat-conducting body (such as the tree-shaped microchannel structure 20 accelerating heat transfer) and the heat insulation of the heat-insulating boss 30, the internal optical components and detector of the star sensor are always in the optimal operating temperature range (such as ±0.5℃ temperature control accuracy), thereby significantly improving the attitude measurement accuracy and long-term stability of the star sensor.

[0044] Meanwhile, the thermally conductive body utilizes 3D printing integrated molding technology, which can precisely control the geometric parameters of the internal microchannel structure (such as tree-like branch layout) and the thermal insulation boss 30. This eliminates the need for separate thermal insulation layers or thermally conductive fillers during the final assembly stage, significantly reducing the time and complexity of thermal control assembly. Furthermore, the standardized design of the thermally conductive body allows for independent pre-assembly and testing, enabling mass production of the thermal control module. This solves the problem of standardizing thermal control solutions due to differences in satellite platforms in traditional approaches, meeting the manufacturability requirements of high-functionality star sensors for mass production.

[0045] Furthermore, the outer surface of the housing 10, except for the portion where the first mounting outer surface contacts the bottom mounting surface 40 and the portion where the second mounting outer surface contacts the bracket 50, is coated with a thermal control coating. The thermal control coating is white paint.

[0046] In this embodiment, the portion of the outer surface of the housing 10 where the star sensor needs to be installed is not coated with a thermal control coating, while the other outer surfaces of the housing 10 are coated with a thermal control coating. The surface of the heat-insulating boss 30 that contacts the bracket 50 is not coated with a thermal control coating, while the other surfaces are coated with a thermal control coating. The thermal control white paint requires a solar absorptivity / infrared emissivity < 1. Through the synergistic effect of high reflectivity (reducing heat absorption) and low emissivity (reducing heat dissipation), the white paint can significantly reduce the amplitude of the surface temperature of the housing 10 changing with orbital illumination conditions, providing a more stable external thermal environment for the star sensor, reducing problems such as thermal deformation and optical performance drift caused by temperature fluctuations, and improving the working accuracy and lifespan of the payload.

[0047] Furthermore, a thin-film heater and a thermistor temperature sensor are installed on the top of the star sensor. Both the top of the star sensor and the star sensor's light shield are covered with multiple layers of heat insulation components.

[0048] In this embodiment, the multi-layer heat insulation assembly covers the star sensor's light shield, the top of the star sensor, the thin-film heater, and the thermistor temperature sensor. This multi-layer heat insulation assembly prevents the star sensor from being directly affected by external heat flow, thus avoiding temperature fluctuations. When the thermistor temperature sensor detects that the star sensor's temperature is too low, the thin-film heater starts heating; when the temperature meets the requirements, the thin-film heater stops heating.

[0049] The assembly process of this utility model is as follows: First, the thin-film heater and thermistor temperature sensor are attached to the top of the star sensor. Thermal grease is applied to the bottom mounting surface 40 of the star sensor. The star sensor is then fastened to the outer shell 10 of the thermally conductive body with screws to form an independent thermal control module. Then, aerogel is applied to the mounting interface of the star sensor's bracket 50. The outer shell 10 of the thermally conductive body is then installed on the star sensor's bracket 50 with screws to form structural support and thermal insulation.

[0050] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0055] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A thermal control device for a star sensor, characterized in that, include: Thermally conductive body and thermally insulating boss; The heat-conducting body includes: an outer shell and a tree-shaped microchannel structure filled within the outer shell; The channels of the tree-shaped microchannel structure are filled with liquid ammonia. The first mounting surface of the housing is fixedly connected to the bottom mounting surface of the star sensor, and thermally conductive silicone grease is filled between the first mounting surface and the bottom mounting surface. At least two heat-insulating bosses are provided on the second mounting outer surface of the housing; The heat-insulating boss is fixedly connected to the bracket of the star sensor, and a heat-insulating material is provided between the heat-insulating boss and the bracket; Both the outer shell and the tree-shaped microchannel structure are 3D printed from aluminum alloy material. The heat-insulating boss is made of titanium alloy.

2. The thermal control device of claim 1, wherein the thermal control device is configured to be mounted on a star sensor. The thickness of the heat-conducting body is 6-8mm; The width of the tree-shaped microchannel structure is 0.5-2 mm; The height of the heat-insulating boss is 1-3mm.

3. The thermal control device of claim 1, wherein the thermal control device is a star sensor. The outer surface of the housing, except for the portion of the first mounting outer surface that contacts the bottom mounting surface, and the surface of the heat-insulating boss, except for the portion that contacts the bracket, are all coated with a thermal control coating.

4. The thermal control device of claim 1, wherein the thermal control device is a star sensor. The heat insulation material is aerogel.

5. The thermal control device for a star sensor as described in claim 1, characterized in that, The star sensor is equipped with a thin-film heater and a thermistor temperature sensor on its top. The top of the star sensor and the star sensor shield are both covered with multiple layers of heat insulation components.

6. The thermal control device for a star sensor as described in claim 1, characterized in that, The number of heat-insulating bosses is four.

7. The thermal control device for a star sensor as described in claim 3, characterized in that, The thermal control coating is white paint.

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