Rotating arc ultralight compact space remote sensing concave mirror device

Abstract

The invention provides a rotating arc ultra-light compact space remote sensing concave mirror device aiming at the pain points that an earth observation space telescope is difficult to deploy due to a large aperture, high in cost and inconvenient to transport, an integrated double-fan-shaped paraboloid primary mirror is taken as a core, and two fan-shaped sub-mirrors are symmetrically divided based on a complete paraboloid mirror of 10m or above; a stable-shape, high-temperature-resistant and low-temperature-resistant high-performance ceramic material including ultrahigh-modulus silicon carbide is adopted, water-based colloidal forming is used as a core process, and a'thickness gradient + honeycomb 'lightweight design is matched, so that the weight is reduced by more than 40%, and the surface precision reaches lambda / 50; a mainstream rocket fairing is adapted through vertical storage, a mirror body does not need a folding mechanism, a view field is complemented by means of coaxial rotation, fan-shaped scanning equivalent view field distortion generated by rotation of a double-fan-shaped primary mirror is accurately corrected through a ground AI image restoration system, 0.1 m-level and higher ground resolution and wide-view-field collaborative observation is achieved, and the system is simple in structure and convenient to use. The device has the advantages of being sufficient in rigidity, high in reliability and adaptive to the space environment, and meets the requirements of accurate measurement and wide coverage of earth observation.

Description

Technical Field

[0001] This invention belongs to the field of interdisciplinary technology of space optics and spacecraft payloads, and specifically relates to a spiral arc ultralight compact space remote sensing concave mirror device. It adopts an integrated double-fan parabolic primary mirror structure, which takes into account the requirements of large-aperture light collection capability, wide field of view observation and compact launch. It is especially suitable for high-resolution optical observation missions of the earth carried by space platforms. Background Technology

[0002] Earth observation is a core area of ​​space technology applications, and its mission capabilities directly depend on the resolution, coverage efficiency, and reliability of its core payload—the space remote sensing concave mirror. Resolution depends on the mirror's aperture and optical focal length, while coverage efficiency depends on the field of view. The synergistic optimization of these two aspects, along with lightweight structure and launch adaptability, are key technologies currently being developed in the industry.

[0003] Currently, mainstream Earth observation space telescopes are mainly divided into two categories: one is small-to-medium aperture wide-field telescopes (such as the 1-3m aperture payloads carried by the Gaofen series satellites), which adopt a single complete primary mirror design. Although they have the advantages of low launch difficulty and controllable cost, their ground resolution is limited to the 0.5-2m level due to the aperture, making it difficult to meet the needs of fine observation; the other is large-aperture high-resolution telescopes (such as the 6m aperture payloads of the US Keyhole satellite), which achieve 0.1m-level resolution by increasing the primary mirror aperture, but faces three major core technological bottlenecks: 1. Launch challenges of large-aperture mirrors: The fabrication of complete large-aperture parabolic mirrors (e.g., over 6m) requires overcoming the surface shape precision control of ultra-large mirrors (needing to reach λ / 60 or higher), and the mirror body is heavy, placing extremely high demands on the payload capacity of the launch vehicle; at the same time, the diameter limitation of the rocket fairing (the diameter of the fairing of most mainstream domestic launch vehicles is 4.2-5.2m) makes it difficult to launch complete aperture mirrors over 5m directly, requiring the use of complex on-orbit deployment structures (such as the folding parabolic primary mirror of the James Webb Telescope), but the reliability and cost of the deployment mechanism are difficult to control.

[0004] 2. The contradiction between the accuracy and reliability of the segmented mirror splicing: Existing large-aperture instruments mostly use multiple segmented mirrors spliced ​​together (such as the segmented parabolic primary mirror for astronomical observations), which requires complex on-orbit calibration to ensure the surface accuracy. Splicing errors can easily lead to blurred images. Moreover, the movable connection structure between the segmented mirrors is prone to failure in the microgravity and vibration environment of space, making it difficult to meet the high stability requirements of ground observations.

[0005] 3. Complexity and risks of the folding mechanism: To accommodate the size of the rocket fairing, some large-aperture mirrors employ a folding and unfolding design (such as the James...). The Weber Telescope is an example of a telescope, but its deployment mechanism contains a large number of moving parts (such as linear motors and locking components), which not only increases the weight and cost of the system, but also poses a risk of deployment failure, making it difficult to guarantee reliability.

[0006] Furthermore, existing applications of "large-aperture segmented mirrors" are mostly limited to astronomical observation (such as the segmented primary mirror of the Large Ultraviolet-Optical-Infrared Measurement Instrument (LUVOIR) planned by the United States). Their design aims for high-resolution staring observation of deep-space objects in near-Earth orbit, and their optical systems prioritize imaging stability under extremely long exposure times. They do not consider the wide field of view and rapid field-switching requirements for Earth observation, and therefore cannot be directly adapted to Earth observation payloads. Therefore, developing a space telescope structure that balances large-aperture light-gathering capability, wide field of view coverage, low-cost launch, and high-reliability operation has become a key direction for overcoming current technological bottlenecks and is the core research and development background of this invention. Summary of the Invention

[0007] The purpose of this invention is to overcome the technical shortcomings of existing Earth observation space telescopes, such as difficulties in deploying large-aperture telescopes, high costs, and inconvenient transportation. It provides a spiral arc ultra-lightweight and compact device that achieves a fold-free compact structure. It uses an integrated double-fan parabolic primary mirror as the core and combines a "gradient thickness + lightweight honeycomb structure" design to achieve ground resolution of 0.1m or higher, wide field of view coverage, and compatibility with conventional rocket launches, thus meeting the collaborative needs of "precise measurement + wide coverage" for Earth observation.

[0008] The technical solution of this invention is as follows: This invention is based on the innovative concept of "integrated double-fan-shaped parabolic primary mirror + coaxial spiral convergence," using a hollow main shaft collinear with the optical axis of the parabolic surface as the core load-bearing component. The overall device includes an integrated double-fan-shaped parabolic primary mirror system, a coaxial drive system, an optical transmission system, an imaging system, a space environment adaptation system, and a sunshade power generation system. The various components work together to achieve precise optical path control and efficient observation. The specific scheme is as follows: The integrated dual-fan-shaped parabolic primary mirror system is designed with a complete parabolic mirror of 10m or larger diameter as the optical reference. It is radially divided into 8-12 fan-shaped sub-mirrors with the same central angle, and two symmetrical sub-mirrors are selected as the core light-receiving units. The dual-fan-shaped parabolic primary mirrors are made of shape-stable, high- and low-temperature-resistant high-performance ceramic materials, including ultra-high modulus silicon carbide (SiC), and are integrally fabricated using water-based colloidal molding (such as gel casting). The components are seamless, avoiding assembly errors. Furthermore, it can be combined with photopolymerization and laser technology. Auxiliary processes such as machining complete local detail finishing and surface accuracy optimization; the back of the mirror integrates a lightweight honeycomb structure adapted to the fan-shaped contour, achieving a weight reduction of over 40%; to balance rigidity and lightweight, the thickness of the parabolic primary mirror is designed to gradually change radially, with a thickness of 200-250mm in the central area of ​​the fan-shaped region (near the main axis) (to ensure structural rigidity during rotation), and a thickness of 150-180mm in the edge area of ​​the fan-shaped region (to reduce overall weight). The overall surface accuracy is controlled to λ / 60 by computer-controlled optical surface forming processes. The double-fan-shaped parabolic primary mirror is rigidly connected to the hollow main axis through an integrated titanium alloy bracket. During installation, it is ensured that the "double-fan-shaped center, main axis, and original parabolic symmetry axis" are completely collinear, with a coaxiality error ≤0.001mm, avoiding optical path deviation during rotational observation. During launch, a "vertical storage" layout is adopted. The double-fan-shaped parabolic primary mirror is rigidly connected to the hollow main shaft through an integrated titanium alloy bracket and is arranged vertically along the height direction of the rocket fairing. The radial direction (radius 5m) of the fan-shaped primary mirror is completely consistent with the height direction of the fairing (the radial length is less than the height of the fairing by more than ten meters, so there is no spatial conflict). The maximum outer circle diameter of the parabolic primary mirror in the lateral direction (perpendicular to the height direction of the fairing) is determined by the characteristics of the fan-shaped structure and is smaller than the diameter of the fairing after optimization design.

[0009] Coaxial Rotation and Drive System: The core function of the rotating parabolic primary mirror is to complete the field of view coverage of a full parabolic mirror (10m and above) through the continuous rotation of the double-fan-shaped integrated structure, while maintaining the light-gathering efficiency of a large aperture, achieving coordinated observation with high resolution and a wide field of view. The hollow fixed main shaft is integrally wound with high-strength, high-modulus carbon fiber composite material of T800 or higher grade, with an inner diameter of 300-400mm (for the light path to pass through), an outer diameter of 500-600mm, and an axial stiffness ≥10. 5 N / m, radial stiffness ≥8×10 4 N / m, a large-diameter frameless torque motor is nested in the middle section of the main shaft, the motor stator is fixed to the main shaft of the spacecraft platform by high-strength bolts, and the rotor is keyed to the integrated bracket of the parabolic primary mirror; the rated torque of the motor is 500-800N. The system, in conjunction with a high-precision photoelectric encoder, forms a closed-loop control to drive the double-fan-shaped parabolic primary mirror to rotate continuously around the optical axis, achieving wide field-of-view coverage. A metal-rubber vibration damping pad (vibration attenuation rate ≥90%) is installed between the motor and the spindle to prevent motor vibration from being transmitted to the parabolic primary mirror and affecting its surface accuracy.

[0010] Optical and Imaging System Integration: Based on the optical characteristics of parabolic surfaces of 10m and above, a 30-40m focal length (focal ratio f / 3-f / 4) is designed. Ground target reflected light is reflected by the double-fan-shaped parabolic primary mirror and then converged along the optical axis to the secondary mirror at the primary axis. The secondary mirror has a diameter of 500-600mm and can be made of materials such as fused silica or silicon carbide (coated with a high-reflectivity film, reflectivity ≥99.5%). It is fixed by a combination of a retractable carbon fiber support and a piezoelectric ceramic focusing mechanism, balancing launch and storage with on-orbit precision adjustment. The retractable support design uses a multi-section nested T800-grade carbon fiber telescopic arm. In the launch and storage state, the axial length is compressed to 3-4m (adapting to the lateral space constraints of the rocket fairing). After deployment in orbit, it is driven by a micro servo motor (rated torque 50-80N). (m), simultaneously extending to the length corresponding to a focal length of 30-40m, and then locked by an electromagnetic locking mechanism (locking stiffness ≥5×10). 4 The system ensures optical path stability by using a piezoelectric ceramic focusing mechanism integrated at the end of the support, enabling ±20mm axial displacement (displacement accuracy ≤0.01mm). After the support is deployed and locked, it precisely compensates for focus deviations caused by on-orbit temperature changes and attitude adjustments. The imaging system is built into the hollow main shaft and includes a CCD (Charge-Coupled Device) detector or a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor with over 100 million pixels (visible-near-infrared band, spectral resolution 5-10nm), a band-switching filter module (adjustable from 400-1000nm), and a data compression unit (compression ratio 10:1, fidelity ≥98%). The system is rigidly connected to the main shaft via a titanium alloy support, which integrates micro-vibration damping components to further isolate external vibrations. It also records auxiliary data such as the rotation trajectory of the dual-fan-shaped primary mirror and optical path parameters, which are transmitted along with the observed images, providing fundamental support for ground-based AI reconstruction.

[0011] Space environment adapted design: The parabolic primary and secondary mirrors adopt a temperature control scheme of "multi-layer heat insulation components + micro heating elements" to stabilize the mirror body temperature at 20±1℃; the motor windings use polyimide insulation material to achieve vacuum compatibility, and the optical mirrors are equipped with an on-orbit deployable light shield; the main shaft is equipped with fluororubber sealing rings at both ends, combined with the matte black paint treatment on the inner wall, forming a comprehensive protection system of "temperature control + anti-fouling + anti-stray light".

[0012] Sunshade system design: The core function of the sunshade system is to accurately track the sun and block direct solar radiation, keeping the parabolic primary mirror in shadow throughout the entire process, avoiding a huge temperature difference between the sun-facing and shadow-facing sides of the primary mirror, thereby ensuring the stability of the mirror's surface shape accuracy; at the same time, it integrates solar power generation function, working in conjunction with the spacecraft body to meet the dual needs of temperature control and protection and energy supply, and does not interfere with the telescope's pointing towards the ground throughout the entire process. The system mainly consists of a flexible sunshade body, integrated solar panels, a single-axis rotary joint, and a drive control module. The flexible sunshade uses a lightweight aluminized Kapton film as its base and is foldable. Its upper solar side integrates a foldable solar panel, which combines heat insulation and power generation capabilities. The sunshade is rigidly connected to the spacecraft body through a single-axis rotary joint. The joint axis is parallel to the orbital plane. In conjunction with the drive control module and the solar sensor, a closed-loop control is formed, which can drive the sunshade to rotate adaptively around the joint axis to ensure accurate alignment with the sun throughout the entire process and continuously provide shadow coverage for the parabolic primary mirror. During launch, the flexible sunshade and the integrated solar panel are folded and stored together to adapt to the space constraints of the rocket fairing. After entering orbit, it automatically unfolds and takes shape. The independent drive logic of the rotary joint is completely decoupled from the telescope's Earth-pointing direction, eliminating the risk of motion interference.

[0013] This invention includes a launch process and an observation process. The launch process involves: ground-based integration, assembly, and pre-sealing of the parabolic primary mirror, main shaft, and various systems; the primary mirror is then vertically housed within the rocket fairing (the radial direction of the parabolic primary mirror is aligned with the height of the fairing, its lateral diameter is adapted to the fairing body, and a retractable support is used to compress and lock it into its housed state); the flexible sunshade, along with the integrated solar panel, is folded and secured to the end of the sunshade telescopic frame via a locking mechanism. After folding, the overall maximum lateral circumscribed circle diameter is ≤5.2m, fully adapting to the lateral space limitations of mainstream rocket fairings; during launch, shock-absorbing components isolate vibrations, and a heat-insulating and sealed structure protects the mirror body; after orbit insertion, once the spacecraft's attitude stabilizes, the support is unlocked, and the spacecraft is extended to its working length by a micro servo motor and electromagnetically locked. The temperature control system is activated, and the sunshade telescopic frame extends to its working length, automatically unfolding the sunshade and solar panel (unfolding time ≤3 minutes), completing the observation preparation. Observation Procedure: After the spacecraft is aligned with the observation area, the frameless torque motor of the coaxial drive system, in conjunction with the photoelectric encoder, drives the parabolic primary mirror to rotate continuously around the optical axis at a constant speed. By rotating and sweeping across the target area, the dual-fan-shaped light-collecting unit effectively covers the entire observation field of view of the large-aperture mirror, ensuring wide coverage without sacrificing imaging resolution. Ground target light rays are reflected by the parabolic primary mirror to the secondary mirror, and then transmitted to the imaging system within the primary axis. During observation, the piezoelectric ceramic focusing mechanism (±20mm displacement, accuracy ≤0.01mm) compensates for focus deviation in real time. During the remote sensing satellite's on-orbit operation, the sunshade adapts to the single-axis rotation joint. Driven by the sun, the system is always precisely oriented towards the sun, continuously providing complete shadow protection for the satellite body and preventing direct sunlight from affecting equipment stability. Simultaneously, the photovoltaic panels integrated into its solar panel capture solar energy and convert it into electricity, providing stable energy support for the continuous operation of the entire system. Data is collected by a CCD detector or CMOS image sensor with over 100 megapixels, filtered by a 400-1000nm adjustable filter module, processed with a 10:1 compression ratio (fidelity ≥98%), and then transmitted down to the ground via the data transmission system. The parabolic primary mirror continuously rotates to achieve wide field-of-view continuous coverage, with the rotation speed adjustable to adapt to coverage efficiency. After receiving the data on the ground, it is processed by an AI image reconstruction system: based on a pre-stored complete parabolic mirror optical model, combined with the downlink rotation trajectory and optical path parameters, a deep learning algorithm is used to accurately correct the distortion of the equivalent field of view (such as local stretching and field-of-view splicing misalignment) generated by the rotating sweep of the dual-fan-shaped primary mirror, splicing fragmented fields of view, and reconstructing a distortion-free image of the equivalent complete large-aperture mirror with a reconstruction accuracy ≥99%.

[0014] Preferably, in the integrated double-fan-shaped parabolic primary mirror system, the 10m diameter complete parabolic mirror is radially divided into 10 fan-shaped sub-mirrors with a central angle of 36°. Two symmetrically distributed sub-mirrors are selected as the core light-gathering unit. This number of divisions can balance the light-gathering efficiency (equivalent to 1 / 5 of the light-gathering area of ​​the complete 10m mirror) and the structural compactness.

[0015] Preferably, the ultra-high modulus silicon carbide (SiC) material of the double-fan-shaped parabolic primary mirror meets the requirements of elastic modulus ≥ 400 GPa and fracture toughness ≥ 4.5 MPa. m¹ / ², the overall molding is achieved using water-based colloidal molding (such as gel casting), combined with auxiliary processes such as photopolymerization and laser processing to improve local precision; the lightweight honeycomb structure on the back of the mirror adopts a regular hexagonal honeycomb hole design, combined with a radial thickness gradient design, which reduces the weight by more than 40% compared with traditional equal-thickness SiC mirrors.

[0016] Preferably, the frameless torque motor in the coaxial drive system adopts a permanent magnet synchronous design with a motor efficiency of ≥90%, a rated speed of 150rpm, and a temperature rise of ≤50K, making it suitable for the vacuum environment of space. The metal rubber damping pad between the motor and the spindle is made of titanium alloy wire with a porosity of 35% and a vibration attenuation rate of ≥95% in the frequency range of 10-1000Hz, effectively isolating the influence of motor operation vibration on the surface shape of the mirror.

[0017] Preferably, the secondary mirror in the optical light guide system is made of fused silica material through ultra-precision grinding and polishing, and the mirror surface is coated with a multi-layer dielectric high-reflectivity film, with a reflectivity of ≥99.8% in the 400-1000nm wavelength band; the retractable bracket is a multi-section nested T800 grade or higher carbon fiber telescopic arm, with an axial length of 3.5m in the launch and storage state, a length of 35m after on-orbit deployment, a deployment repeatability accuracy of ≤0.02mm, and a natural frequency of ≥100Hz after electromagnetic locking to avoid resonance during on-orbit operation.

[0018] Preferably, after receiving data on the ground, the data is processed by an AI image restoration system: based on a pre-stored complete parabolic mirror optical model, combined with the downlink rotation trajectory and optical path parameters, a deep learning algorithm is preferably used to accurately correct the equivalent field-of-view distortion (such as local stretching and field-of-view stitching misalignment) caused by the rotation and sweeping of the dual-fan-shaped primary mirror, stitching together the fragmented field of view, and restoring the equivalent complete large-aperture mirror without distortion. When this preferred scheme is used, the image restoration accuracy is ≥99%.

[0019] Compared with the prior art, the significant advantages of the present invention are as follows: The launch compatibility problem of large-aperture mirrors has been solved: the dual-fan parabolic primary mirror adopts a vertical storage layout, which can be adapted to the mainstream rocket fairing size without the need for a folding mechanism, thus avoiding the risk of failure when the folding mechanism is deployed.

[0020] High surface accuracy and excellent imaging quality: The dual-fan parabolic primary mirror adopts a one-piece molding process with no segmentation splicing error. The surface accuracy is stable at λ / 60. With temperature control and vibration reduction design, the ground resolution can reach 0.1m level or even higher, meeting the needs of fine-grained Earth observation.

[0021] Ultralight and efficient with sufficient rigidity: The parabolic primary mirror features a "gradual thickness + honeycomb lightweight" design, which reduces weight by more than 40% compared to traditional equal-thickness split mirrors. At the same time, the thickened area in the middle ensures structural rigidity, with deformation ≤0.01mm in the microgravity environment of space, eliminating the need for complex optical compensation.

[0022] High reliability and simple control: The dual-fan parabolic primary mirror is driven to rotate by a single frameless torque motor, reducing the number of control nodes by 80% compared to a multi-mirror array. There are no moving or unfolding parts, and the failure rate is reduced by more than 60%.

[0023] Lower overall cost: The one-piece molding process eliminates the cost of precision equipment and processes for split mirror splicing and calibration; the absence of complex mechanisms such as folding and multi-mirror drive reduces the cost of component processing and assembly; the lightweight design reduces the load requirements of the launch vehicle and simplifies launch planning; fewer control nodes and a lower failure rate further reduce on-orbit maintenance and subsequent operation and maintenance costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the on-orbit observation of the spiral arc ultralight compact space remote sensing concave mirror device of the present invention.

[0025] Figure 2 This is a schematic diagram of the overall structure of the spiral arc ultralight compact space remote sensing concave mirror device of the present invention installed on the main body of a remote sensing satellite.

[0026] Figure 3 for Figure 2 The front sectional view of the structure shown.

[0027] Figure 4 for Figure 2 Top view of the structure shown.

[0028] Figure 5 This is a schematic diagram of the back of the parabolic primary mirror of the spiral arc ultralight compact concave mirror device for space remote sensing of the present invention.

[0029] In the diagram: 1-Earth; 2-Main body of remote sensing satellite; 3-Sunshade bracket; 4-Sunshade pivot; 5-Sunshade telescopic frame; 6-Sunshade; 7-Solar panel; 201-Parabolic primary mirror; 202-Frameless motor; 203-Parabolic primary mirror bracket; 204-Hollow main shaft; 205-Telescopic rod; 206-Secondary mirror; 207-Imaging system. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. However, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments based on the present invention fall within the scope of protection of the present invention.

[0031] Figure 1 The invention visually presents the in-orbit observation configuration of the ultra-lightweight and compact concave mirror device for space remote sensing. The Earth 1 on the left is the object of observation, and the remote sensing satellite body 2 on the right is equipped with a parabolic primary mirror 201 and a sunshade 6. The assembly relationship between the sunshade support 3, the sunshade pivot 4, the sunshade telescopic frame 5, the sunshade 6, the solar power panel 7, and the core optical components is shown. The spatial correspondence of "Sun → Sunshade 6" and "Parabolic Primary Mirror 201 → Earth 1" is clearly demonstrated. Figure 2 This is a schematic diagram of the overall structure of the spiral arc ultralight compact space remote sensing concave mirror device of the present invention installed on the main body of a remote sensing satellite, showing the assembly relationship of the core components of the spiral arc ultralight compact space remote sensing concave mirror device of the present invention; Figure 3 for Figure 2 The front sectional view shows that the internal optical path of the parabolic primary mirror 201, frameless motor 202, parabolic primary mirror support 203, hollow main shaft 204, telescopic rod 205, secondary mirror 206, and imaging system 207 is as follows: ground target reflected light → parabolic primary mirror 201 reflection → secondary mirror 206 reflection → imaging system 207. Figure 4 for Figure 2 The top view shows the double-fan symmetrical layout of the parabolic primary mirror 201 (the central angle of each fan is 36°, totaling 72°, and the two fan-shaped primary mirrors are integrally formed). Figure 5 This is a schematic diagram of the back of the parabolic primary mirror of the spiral arc ultralight compact concave mirror device for space remote sensing of the present invention, clearly showing the regular hexagonal honeycomb lightweight structure on the back of the parabolic primary mirror 201.

[0032] This invention relates to a spiral arc ultralight compact concave mirror device for space remote sensing. A hollow main shaft 204 serves as the core load-bearing component. All functional modules are precisely assembled around the hollow main shaft 204. The overall device must meet the requirements of being housed within a rocket fairing with a diameter ≤ 5.2m during launch and operating stably after deployment in orbit. The specific implementation process is as follows: like Figure 3 As shown, the hollow spindle 204 is integrally wound with T800 or higher carbon fiber composite material. Its inner diameter is set to 300mm (for the optical path to pass through) and its outer diameter is set to 400mm. A frameless motor 202 is nested in the middle section of the hollow spindle 204. The frameless motor 202 adopts a permanent magnet synchronous design with a motor efficiency of ≥90%, a rated speed of 150rpm, and a temperature rise of ≤50K, making it suitable for the vacuum environment of space. The stator of the frameless motor 202 is fixed to the remote sensing satellite body 2 with high-strength bolts. The rotor is connected to the parabolic primary mirror bracket 203 by a key. A metal rubber shock-absorbing pad made of titanium alloy wire is installed between the frameless motor 202 and the hollow spindle 204. The porosity of the shock-absorbing pad is 35%, and the vibration attenuation rate is ≥95% in the frequency range of 10-1000Hz, which can effectively isolate the influence of motor operation vibration on the surface shape of the parabolic primary mirror 201.

[0033] like Figure 4 As shown, the parabolic primary mirror 201 is made of shape-stable, high- and low-temperature-resistant high-performance ceramic materials, including ultra-high modulus silicon carbide (SiC), and is integrally fabricated using a water-based colloidal molding process (such as gel casting). After the mirror body is formed, the edge contours can be refined by laser processing, and local microstructure optimization can be completed by combining photopolymerization. Taking a complete 10m diameter parabolic mirror as the optical reference, it is radially divided into 10 fan-shaped sub-mirrors with a central angle of 36°. Two symmetrical sub-mirrors are selected as the core light-receiving units. Through continuous rotation of the dual-fan-shaped integrated structure, the field of view coverage of the complete 10m-class parabolic mirror is completed. Figure 5 As shown, the parabolic primary mirror 201 integrates a regular hexagonal honeycomb lightweight structure on its back, achieving a weight reduction of 40% or more; Figure 3 As shown, the thickness of the parabolic primary mirror 201 is gradually varied radially. The thickness of the central area of ​​the fan-shaped region (near the hollow main shaft 204) is 220mm, and the thickness of the edge area of ​​the fan-shaped region is 160mm. The overall mirror surface accuracy is controlled within λ / 60 by computer-controlled optical surface forming process. The parabolic primary mirror 201 is rigidly connected to the parabolic primary mirror bracket 203. During installation, it is strictly ensured that the "double fan-shaped center of the parabolic primary mirror 201, the axis of the hollow main shaft 204, and the original parabolic symmetry axis" are completely collinear, with a coaxiality error ≤0.001mm, to avoid optical path deviation during rotation observation.

[0034] The telescopic boom 205 is a multi-section nested T800-grade carbon fiber telescopic arm. One end is connected to the hollow main shaft 204, and the other end is fitted with a secondary mirror 206. The secondary mirror 206 is made of fused silica material through ultra-precision grinding and polishing, and the mirror surface is coated with a multi-layer dielectric reflective film, achieving a reflectivity of ≥99.8% in the 400-1000nm wavelength band. The upper end of the telescopic boom 205 integrates a piezoelectric ceramic focusing mechanism, which can achieve ±20mm axial displacement with a displacement accuracy of ≤0.01mm. In the launch and retraction state, the axial length of the telescopic boom 205 is compressed to 3.5m. After being deployed on the track, it is driven by a micro servo motor to extend to the corresponding length. After deployment, it is locked by an electromagnetic locking mechanism with a locking stiffness ≥5×10. 4 N / m, natural frequency ≥100Hz, to avoid resonance during on-orbit operation.

[0035] The imaging system 207 is built into the hollow main shaft 204 and includes a CCD detector or CMOS image sensor with over 100 million pixels, a band-switching filter module, and a data compression unit (compression ratio 10:1, fidelity ≥98%). The imaging system 207 is rigidly connected to the hollow main shaft 204 via a titanium alloy bracket, which integrates micro-vibration damping components. In the space environment adaptation system, the parabolic primary mirror 201 and secondary mirror 206 are wrapped with multi-layer heat insulation components, and micro-heating pads are attached to their surfaces to stabilize the mirror temperature at 20±1℃. The windings of the frameless motor 202 use polyimide insulation material to achieve vacuum compatibility. Fluororubber sealing rings are set at both ends of the hollow main shaft 204, and the inner wall is treated with matte black paint.

[0036] The sunshade bracket 3 adopts a one-piece titanium alloy structure and is rigidly connected to the remote sensing satellite body 2 by high-strength bolts. Its installation position is on the solar-facing side of the parabolic primary mirror 201, with reserved clearance for installation with the solar panel 7 (to avoid interference with the primary mirror's rotation trajectory). The sunshade rotating shaft 4 (single-axis rotation joint) is nested at the top of the sunshade bracket 3, with the joint axis parallel to the track surface. The rotor is keyed to the sunshade telescopic frame 5. A metal rubber shock-absorbing pad (vibration attenuation rate ≥95%) is installed between the rotating shaft and the bracket to prevent on-orbit vibration from affecting the sunshade alignment accuracy. 6. Flexible aluminized Kapton film is used as the substrate, and the upper part of the solar side integrates the solar power panel 7. The sunshade 6 and the solar power panel 7 adopt an integrated foldable design: during launch, it is folded radially and fixed to the end of the sunshade telescopic frame 5 by a locking mechanism to ensure that the overall maximum lateral outer circle diameter is ≤5.2m, which is suitable for the vertical storage layout of the rocket fairing; after entering orbit, the sunshade telescopic frame 5 extends to the working length, which drives the sunshade 6 and the solar power panel 7 to automatically unfold. Through the closed-loop control of the single-axis rotary joint, it is precisely aligned with the sun direction.

[0037] Before launch, the integrated assembly and sealing pretreatment of each component are completed. The parabolic primary mirror 201 is rigidly connected to the frameless motor 202 and the hollow main shaft 204 through the parabolic primary mirror bracket 203. The whole is arranged vertically along the height direction of the rocket fairing. The telescopic rod 205 is compressed to a 3.5m storage state. The sunshade telescopic frame 5, together with the folded sunshade 6, is locked to the solar power panel 7 to ensure that the maximum lateral outer circle diameter of the device is smaller than the fairing diameter. During the launch, each shock absorption component isolates vibration, and the heat insulation and sealing structure protects the parabolic primary mirror 201, secondary mirror 206 and sunshade 6.

[0038] After entering orbit and stabilizing the attitude of the remote sensing satellite body 2, the telescopic rod 205 and the sunshade telescopic frame 5 are unlocked simultaneously: the telescopic rod 205 is extended to the working length by a micro servo motor and electromagnetically locked; the sunshade telescopic frame 5 extends to the working length, simultaneously driving the sunshade 6 and solar power panel 7 to automatically unfold and take shape. The sunshade rotating shaft 4, in conjunction with the drive control module and the sun sensor, forms a closed-loop control, driving the sunshade 6 to adaptively rotate around the joint axis to achieve precise alignment with the sun; then the temperature control system is activated to stabilize the mirror temperature at 20±1℃, and the solar power panel 7 is simultaneously activated to supply power, completing the observation preparation.

[0039] During observation, after the remote sensing satellite body 2 is aligned with the observation area, the frameless motor 202, in conjunction with the photoelectric encoder, drives the parabolic primary mirror 201 to rotate continuously around the hollow main shaft 204 at a fixed speed. The rated torque of the frameless motor 202 is 650 N. m, which can meet the requirements of rotation drive; the light from the ground target is reflected by the parabolic primary mirror 201 to the secondary mirror 206, and then reflected again and transmitted to the imaging system 207 in the hollow main shaft 204; during the observation, the piezoelectric ceramic focusing mechanism compensates for the focus deviation caused by on-orbit temperature changes, attitude adjustment and equipment operation in real time with a displacement range of ±20mm and a displacement accuracy of ≤0.01mm; the sunshade shaft 4 continuously drives the sunshade 6 to always face the sun, providing continuous shadow protection for the remote sensing satellite body 2, avoiding direct sunlight from affecting the stability of the equipment, while the solar power generation panel 7 on the solar surface of the sunshade 6 synchronously captures solar energy and converts it into electrical energy, providing stable energy support for the continuous operation of the entire system.

[0040] Data is acquired by the CCD detector or CMOS image sensor within the imaging system 207. After wavelength selection by the band-switching filter module, the data is processed by the data compression unit and transmitted to the ground via the data transmission system. The parabolic primary mirror 201 continuously rotates to achieve wide field-of-view continuous coverage, and the rotation speed can be adjusted as needed to adapt to the coverage efficiency. After receiving the data on the ground, it is processed by the AI ​​image restoration system: based on the pre-stored complete parabolic mirror optical model, combined with the downlink rotation trajectory and optical path parameters, a deep learning algorithm is used to accurately correct the distortion of the equivalent field of view (such as local stretching and field of view stitching misalignment) generated by the rotation and sweeping of the dual-fan-shaped primary mirror, stitching together the fragmented field of view, and restoring the equivalent complete large-aperture mirror image without distortion, with a restoration accuracy of ≥99%.

[0041] Optionally, the diameter of the parabolic primary mirror 1 can be adjusted to 6-12m to adapt to different aperture and field of view requirements, and its core assembly logic is the same as described above.

[0042] Optionally, the spindle 4 can be made of M55J grade carbon fiber composite material, which can increase the axial stiffness to ≥1.2×10⁻⁶. 5 N / m, suitable for observation tasks with higher requirements for structural rigidity.

[0043] Optionally, the focusing mechanism can adopt a ball screw drive, combined with a servo motor drive, and the displacement range can be extended to ±30mm to adapt to a wider range of focus deviation compensation requirements.

[0044] Alternatively, the sunshade can be designed in various ways, such as flexible folding, rigid modular or eccentric telescopic design: the flexible version is suitable for compact storage, the rigid version enhances heat insulation and anti-fragmentation performance, and the eccentric telescopic version can precisely optimize the field of view avoidance effect.

[0045] Optionally, a retractable lightweight carbon fiber light shield is added to the side of the parabolic primary mirror 201. During launch, it is stored inside the primary mirror bracket 203 and extends in orbit by a micro-drive mechanism to block stray light, reduce interference, and ensure clear imaging and surface accuracy.

[0046] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A spin arc ultra-light compact space remote sensing concave mirror device, characterized in that: The hollow main shaft which is collinear with the parabolic optical axis is used as the core bearing component. The overall device includes an integrated double-fan parabolic primary mirror system, a coaxial driving system, an optical transmission system, an imaging system, a space environment adaptation system, and a sun-shading power generation system. The specific scheme is as follows: The integrated double-fan parabolic primary mirror system design: a complete parabolic mirror with a diameter of 10 m or more is used as the optical reference, which is evenly divided into 8-12 fan-shaped sub-mirrors with the same central angle along the radial direction, and the symmetrical two of them are selected as the core light collecting unit. The double-fan parabolic primary mirror is made of high-performance ceramic materials including ultra-high modulus silicon carbide, which is stable in shape and resistant to high and low temperature, and is integrally prepared by water-based colloidal forming process. The mirror body is integrated with a honeycomb lightweight structure adapted to the fan-shaped profile. The double-fan parabolic primary mirror is rigidly connected to the hollow main shaft through a titanium alloy integrated support. During installation, the double-fan central angle, the main shaft axis, and the original parabolic axis are completely collinear, and the coaxiality error is less than or equal to 0.001 mm. Coaxial rotation and driving system: the core function of the rotating parabolic primary mirror is to complete the field coverage of the complete parabolic mirror with a diameter of 10 m or more through the continuous rotation of the double-fan integrated structure, while maintaining the large-aperture light collection efficiency, realizing the collaborative observation of high resolution and wide field of view; the hollow fixed main shaft is integrally wrapped by high-strength and high-modulus carbon fiber composite material with a level of T800 or above, with an inner diameter of 300-400 mm, an outer diameter of 500-600 mm, an axial stiffness of ≥10 5 N / m, and a radial stiffness of ≥8×10 4 N / m; a large-diameter frameless torque motor is nested in the middle section of the main shaft, the motor stator is fixed to the main shaft on the spacecraft platform through high-strength bolts, and the rotor is key-connected with the integrated support of the parabolic primary mirror; the motor has a rated torque of 500-800 N m, and forms a closed-loop control with a high-precision photoelectric encoder to drive the double-fan parabolic primary mirror to rotate continuously around the optical axis; a metal rubber shock-absorbing pad is installed between the motor and the main shaft; Optical and imaging system integration: based on the optical characteristics of a parabolic mirror with a diameter of 10 m or more, a focal length of 30-40 m is designed. The reflected light of the ground target is reflected by the double-fan parabolic primary mirror and converges to the secondary mirror at the main shaft axis. The secondary mirror has a diameter of 500-600 mm and is fixed by a retractable carbon fiber support and a piezoelectric ceramic focusing mechanism, which takes into account the launch storage and on-orbit precision adjustment. The retractable support design uses a multi-section nested T800 carbon fiber telescopic arm. The axial length is compressed to 3-4 m in the launch storage state. After deployment on orbit, it is driven by a micro servo motor and extended to a length corresponding to a focal length of 30-40 m. After deployment, it is locked by an electromagnetic locking mechanism. The piezoelectric ceramic focusing mechanism is integrated at the end of the support. After the support is deployed and locked, it accurately compensates for the focal point deviation caused by temperature changes and attitude adjustments on orbit. The imaging system is built into the hollow main shaft. The system is rigidly connected to the main shaft through a titanium alloy support. The support is integrated with a micro shock absorption component. It records auxiliary data such as the rotation trajectory of the double-fan primary mirror and the optical path parameters, which are transmitted with the observation image to provide a basis for AI restoration on the ground. Space environment adaptation design: The parabolic primary mirror and the secondary mirror use a temperature control scheme with multiple layers of thermal insulation components and micro heating sheets to stabilize the mirror temperature at 20±1℃. The motor winding uses polyimide insulation material to achieve vacuum compatibility. The optical mirror is equipped with an on-orbit deployable sunshade. Fluorine rubber sealing rings are provided at both ends of the main shaft, and the inner wall is treated with matt black paint to eliminate light. Sunshade system design: It mainly consists of a flexible sunshade body, an integrated solar panel, a single-axis rotary joint, and a drive control module. The flexible sunshade uses lightweight aluminum-coated Kapton film as the substrate and has foldable characteristics. The solar side upper end region is integrated with a foldable solar cell panel, which takes into account the heat insulation and power generation capacity. The sunshade is rigidly connected to the spacecraft body through a single-axis rotary joint. The joint axis is parallel to the orbital plane, and it forms a closed-loop control with the drive control module and the sun sensor to ensure that the sunshade rotates around the joint axis to accurately align with the sun throughout the process, providing continuous shadow coverage for the parabolic primary mirror.

2. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: To balance rigidity and lightweight, the thickness of the parabolic primary mirror gradually changes along the radial direction, with a thickness of 200-250 mm near the hub and a thickness of 150-180 mm at the edge of the sector. The full-mirror type precision is controlled at λ / 60 through computer-controlled optical surface forming process.

3. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: The secondary mirror material can be fused quartz or silicon carbide, coated with a high-reflection film.

4. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: The piezoelectric ceramic focusing mechanism is integrated at the end of the support, which can achieve ±20 mm axial displacement with a displacement accuracy of ≤0.01 mm. After the support is expanded and locked, the focal point deviation caused by changes in on-orbit temperature and attitude adjustment can be accurately compensated.

5. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: The imaging system is built into the hollow spindle, including a 100 million pixel CCD detector or CMOS image sensor, a waveband switching filter module, and a data compression unit. The spectral resolution is 5-10 nm, the waveband switching filter module has a selection adjustment range of 400-1000 nm, the data compression unit has a compression ratio of 10:1, and the fidelity is ≥98%.

6. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: In the integrated dual-fan parabolic primary mirror system, a 10m diameter complete parabolic mirror is divided into 10 sector sub-mirrors with a central angle of 36° along the radial direction, and two symmetrically distributed sub-mirrors are selected as the core light collecting units.

7. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: The frameless torque motor in the coaxial drive system adopts a permanent magnet synchronous design, with a motor efficiency of ≥90%, a rated speed of 150 rpm, and a temperature rise of ≤50K, suitable for space vacuum environment. The metal rubber damping pad between the motor and the spindle is woven with titanium alloy wire, with a porosity of 35%, a vibration attenuation rate of ≥95% in the frequency range of 10-1000 Hz, and effectively isolates the influence of motor operation vibration on the mirror body type.

8. The Spin Arc Ultra-Light Compact Space Remote Sensing Concave Mirror Device, according to claim 1, wherein: Based on the pre-stored optical model of the complete parabolic mirror, combined with the downlink rotation trajectory and optical path parameters, the deep learning algorithm is used to accurately correct the distortion of the fan-shaped scanning equivalent field of view generated by the dual-fan primary mirror rotation scanning, splice the fragmented field of view, and restore the distortionless image of the equivalent complete large aperture mirror.

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