Passive grabbing and disposing spacecraft, cubesat and method for small space debris

Abstract

The invention discloses a small space debris-oriented passive capturing and disposing spacecraft, cubesat and method, solves the problems that in the prior art, small space debris cannot be captured, and an existing capturing device performs active capturing, and has the beneficial effects that the space debris is passively captured and thoroughly eliminated. According to the specific scheme, the passive grabbing and handling spacecraft for the small space debris comprises a chip satellite and a capturing assembly, a plurality of solar sails are connected to the peripheral side of the chip satellite, the chip satellite controls the bending state of the solar sails so as to control flight of the spacecraft, and the capturing assembly comprises a folding storage wall plate, a triggering platform and a bistable capturing arm; the folding storage wall plate is connected to the peripheral side of the chip satellite through the hinge, the hinge is a bent hinge and has elasticity, the triggering platform is connected with the chip satellite, and after the bistable capturing arm passes through the triggering platform, the bistable capturing arm is in a straight state when a spacecraft is in a non-working state.

Description

Technical Field

[0001] This invention relates to the field of space debris cleanup technology, and in particular to spacecraft, CubeSats and methods for the passive capture and disposal of small space debris. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, frequent space activities have generated over 100 million pieces of space debris (also known as space junk, which refers to objects generated or left behind by humans during space missions in outer space, including defunct spacecraft and rocket remnants) of varying sizes. This debris occupies valuable orbital space, impacting future space missions and seriously threatening the safety of spacecraft and astronauts in orbit. Cracks have been found on some spacecraft windows, initially estimated to be caused by millimeter-sized space debris, severely threatening the lives of astronauts during their return journey. To address the severe space debris environment, the international community has proposed three approaches: reducing rocket launches, shortening the on-orbit lifespan of launched rockets, and effectively removing space debris. Therefore, effectively cleaning up space debris is urgently needed.

[0004] Currently, major spacefaring nations are conducting related research, hoping to equip service satellites with designed capture systems to capture space debris and deorbit it. Existing capture mechanisms are mainly divided into rigid capture and flexible capture. Rigid capture mechanisms include harpoon-type capture mechanisms and linkage-type capture mechanisms. Harpoon-type capture mechanisms are prone to generating new space debris during the capture process, while linkage-type capture mechanisms have large gaps between the links, making it difficult to capture smaller debris, resulting in a large number of smaller debris in space. On the other hand, flexible capture mechanisms mainly include rope-net-type capture mechanisms and soft capture mechanisms. Rope-net-type capture mechanisms have good shape adaptability, but are prone to collisions between spacecraft and targets during the capture process, while soft capture mechanisms are difficult to adapt to the vacuum environment of space.

[0005] In summary, existing capture mechanisms are mainly designed for capturing larger pieces of space debris, and cannot effectively capture smaller debris. Moreover, they are all active structures, which rely on external factors such as electricity for capture. If the power supply is unavailable, the capture of space debris cannot be successfully achieved. Furthermore, how to dispose of the captured debris is also a problem. Current methods involve loading the debris into a spacecraft and then bringing it back to Earth for unified disposal, which is time-consuming and labor-intensive. Summary of the Invention

[0006] In view of the shortcomings of existing technologies, the purpose of this invention is to provide a spacecraft for passively capturing and disposing of small space debris, which can passively achieve the successful capture of space debris, especially smaller space debris.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: A passive capture and disposal spacecraft for small space debris includes a chip satellite and a capture assembly. The chip satellite has multiple solar sails connected to its periphery, and controls the bending state of the solar sails to control the spacecraft's flight. The capture assembly includes a folding storage panel, a trigger platform, and a bistable capture arm. The folding storage panel is hinged to the periphery of the chip satellite; the hinge is a bent and elastic hinge. The trigger platform is connected to the chip satellite. After passing the trigger platform, both sides of the bistable capture arm contact the folding storage panel and overcome the hinge's elasticity to provide a set pressure to the folding storage panel. When the spacecraft is in a non-operational state, the bistable capture arm is in a straight state. When the trigger platform is subjected to external force, it can apply a force to the center of the bistable capture arm, causing the bistable capture arm to switch to a bending state and grip the space debris. Under the action of the hinge, the folding storage panel moves towards the space debris to achieve capture.

[0008] As described above, in the passive capture and disposal spacecraft for small space debris, the width of the bistable capture arm is adapted to the width of the trigger platform, so that one end of the bistable capture arm is inserted between the trigger platform and the chip satellite. The bistable capture arm is bonded to the trigger platform. The bistable capture arm is made of NiTi alloy that has undergone solution treatment and constraint aging.

[0009] As described above, the passive grasping and disposal spacecraft for small space debris includes a trigger platform comprising multiple support legs, two trigger plates disposed on the inner side of the support legs, one end of the support leg being vertically connected to the chip satellite disposal, three elastic elements being disposed at each support leg, the three elastic elements being separated by the two trigger plates, and the trigger plates being parallel to the chip satellite. There are two bistable capture arms, which are arranged in a cross configuration. One bistable capture arm passes through the space between the two trigger plates, while the other bistable capture arm passes through the space between the trigger plate and the chip satellite.

[0010] As described above, the passive capture and disposal spacecraft for small space debris has four folding storage panels, which are respectively located around the chip satellite. Each folding storage panel is triangular in shape. The length of the folding storage panel near the chip satellite is the same as the length of the side of the chip satellite.

[0011] As described above, in a passive grasp and disposal spacecraft for small space debris, the length of the folding storage panel is less than, equal to, or greater than the height of the solar sail. The solar sail is trapezoidal in shape, with the shorter side of the solar sail connected to the chip satellite. When the spacecraft is not in operation, all the solar sails are on the same plane, and the distance between adjacent solar sails is set.

[0012] As described above, the passive capture and disposal spacecraft for small space debris includes a solar sail comprising an AL layer, a PI layer, and a shape memory NiTi alloy layer arranged sequentially. The shape memory NiTi alloy layer is a hollow, unclosed trapezoidal shape. The AL layer faces the capture assembly. The shape memory NiTi alloy layer is connected to the chip satellite so that the chip satellite can provide current to the shape memory NiTi alloy layer to control the Joule heating of the shape memory NiTi alloy layer, thereby controlling the bending angle of the solar sail. The bending angle of the solar sail is opposite to the capture direction of the capture assembly. The hinge is made of shape memory NiTi alloy.

[0013] As described above, in the passive capture and disposal spacecraft for small space debris, the AL layer and the PI layer are an integral structure, the PI layer and the shape memory NiTi alloy layer are connected, the thickness of the AL layer is 0.0001mm, the thickness of the PI layer is 0.0124mm, and the thickness of the shape memory NiTi alloy layer is 0.05mm. The alloy material is dissolved at a set temperature for a set time, and then aged to obtain a two-way shape memory alloy sheet with a phase transformation temperature of a certain temperature. The processed two-way shape memory alloy sheet is then laser-cut to obtain a shape memory NiTi alloy layer or hinge.

[0014] Secondly, the present invention also provides a cube for cleaning up space debris. The cube has a cavity inside, and a passive grasping and disposal spacecraft for small space debris is installed inside the cavity. The cube has a door and a robotic arm. The end of the robotic arm is equipped with a sensing component and a robotic hand. The robotic hand can grasp the spacecraft. The cube has a control center, which is connected to the robotic arm, the sensing component, and the door.

[0015] As described above, in a CubeSat used for cleaning up space debris, the sensing component is a camera located at the end of the robotic arm, which sends the captured images to the control center.

[0016] Thirdly, the present invention also provides a method for cleaning up space debris using a CubeSat, comprising the following: The spacecraft is in a flattened state before the CubeSat launch and when not in operation. After the CubeSat enters space, the robotic arm at the end of the robotic arm grabs the spacecraft by opening and closing the door. The robotic arm then begins to move. After the sensing components detect space debris, they send information to the control center. The control center controls the robotic arm to move in the direction of the space debris's movement, and makes the spacecraft's trigger platform face the space debris. The robotic arm releases the spacecraft in the path of the space debris's movement. The space debris moves forward and contacts the trigger platform, and applies force to the trigger platform. After being subjected to external force, the trigger platform applies force to the center of the bistable capture arm, so that the bistable capture arm switches to a bent state and grips the space debris. Then, the hinge drives the folding storage panel to move towards the space debris to lock the space debris again. After the spacecraft captures space debris, the chip satellite controls the bending angle of the solar sail to make the spacecraft fly towards the atmosphere. During the spacecraft's flight, air resistance increases sharply, and the space debris and spacecraft heat up rapidly and disintegrate and melt in the high-temperature environment, burning up completely before reaching the ground.

[0017] The beneficial effects of the present invention are as follows: 1) The spacecraft structure in this invention is rationally designed, including a chip satellite and a capture assembly. The capture assembly is defined by a bistable capture arm that defines the position of the foldable storage panel. The bistable capture arm is a bistable structural component. After the trigger platform is subjected to a force, the trigger platform applies a force to the center of the bistable capture arm after being subjected to an external force, so that the bistable capture arm switches to a bent state and initially grasps the space debris. Under the action of the hinge, the foldable storage panel moves towards the space debris. The space debris is passively captured by multiple foldable storage panels that wrap around or contact the space debris. The whole process does not require power. The chip satellite is used to control the movement of the solar sail to adjust the flight state of the spacecraft so that after capturing the space debris, the whole spacecraft moves into the atmosphere to completely eliminate the space debris, thus achieving the successful capture and complete elimination of smaller space debris.

[0018] 2) The trigger platform structure in this invention is reasonable. It is supported by a multi-layer trigger plate by a support leg. The moving space debris or space debris with a certain force can contact the trigger plate and overcome the force of the elastic element to press the trigger plate, thereby triggering the action of the bistable capture arm, realizing the change from a flat state to a curled state, and no longer restricting the folding storage wall panel.

[0019] 3) The solar sail structure in this invention is rationally designed, including an AL layer, a PI layer, and a shape memory NiTi alloy layer arranged sequentially. The shape memory NiTi alloy layer is connected to the chip satellite to control the Joule heating of the shape memory NiTi alloy layer, thereby controlling the bending angle of the solar sail. The bending angle of the solar sail is opposite to the capture direction of the capture component, adjusting the solar radiation pressure on the spacecraft, which allows the spacecraft to lower its orbit and move towards the atmosphere. In addition, the rational control of the thickness of each layer effectively controls the overall weight of the solar sail, improves its propulsion efficiency and maneuverability in space, and enables the solar sail of this space debris removal device to work stably and efficiently.

[0020] 4) The present invention provides a CubeSat, which is equipped with a robotic arm. The robotic arm is equipped with a sensing component. After the sensing component detects space debris, the control center controls the movement of the robotic arm so that the robotic arm moves the spacecraft to the path of the space debris. The space debris moves forward and contacts the trigger platform and provides force to the trigger platform, thereby achieving successful capture of the space debris. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is a front view of a spacecraft for passively capturing and disposing of small space debris according to one or more embodiments of the present invention.

[0023] Figure 2 This is the present invention. Figure 1 Enlarged view of point A (a diagram of the trigger platform before it is triggered).

[0024] Figure 3 This is a schematic diagram of the triggering platform in a spacecraft for the passive capture and disposal of small space debris according to one or more embodiments of the present invention.

[0025] Figure 4 This is a frontal schematic diagram of a spacecraft for passively capturing and disposing of small space debris according to one or more embodiments of the present invention.

[0026] Figure 5 This is a rear view of a spacecraft for passively capturing and disposing of small space debris according to one or more embodiments of the present invention.

[0027] Figure 6 This is a schematic diagram of a spacecraft in operation for passively capturing and disposing of small space debris according to one or more embodiments of the present invention.

[0028] Figure 7 This is an enlarged view of the capture component of a passive grasping and disposal spacecraft for small space debris according to one or more embodiments of the present invention when capturing square space debris.

[0029] Figure 8 This is an enlarged view of the capture component of a passive grasping and disposal spacecraft for small space debris according to one or more embodiments of the present invention when capturing sheet-like space debris.

[0030] Figure 9 This is a schematic diagram of the solar sail motion state in a spacecraft for passively capturing and disposing of small space debris, according to one or more embodiments of the present invention. Figure 1 .

[0031] Figure 10 This is a schematic diagram of the solar sail motion state in a spacecraft for passively capturing and disposing of small space debris, according to one or more embodiments of the present invention. Figure 2 .

[0032] Figure 11 This is a schematic diagram of the solar sail motion state in a spacecraft for passively capturing and disposing of small space debris, according to one or more embodiments of the present invention. Figure 3 .

[0033] Figure 12 This is a schematic diagram of the solar sail motion state in a spacecraft for passively capturing and disposing of small space debris, according to one or more embodiments of the present invention. Figure 4 .

[0034] Figure 13 This is a schematic diagram of the solar sail motion state in a spacecraft for passively capturing and disposing of small space debris, according to one or more embodiments of the present invention. Figure 5 .

[0035] Figure 14 This is a dimensional representation of the trigger platform, folding storage panel, and bistable capture rod in a spacecraft for passive capture and disposal of small space debris according to one or more embodiments of the present invention.

[0036] Figure 15 This is a schematic diagram of the working process of a CubeSat used for cleaning up space debris according to one or more embodiments of the present invention.

[0037] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0038] Among them: 1. Solar sail, 2. Folding storage panel, 3. Bistable capture arm, 4. Hinge, 5. Trigger platform, 6. Chip satellite, 7. Support leg, 8. Trigger plate, 9. Compression spring, 10. PI layer, 11. AL layer, 12. Space debris, 13. CubeSat, 14. Spacecraft, 15. Robotic arm, 16. Spacecraft in non-operational state, 17. Spacecraft in operational state, 18. Shape memory NiTi alloy layer. Detailed Implementation

[0039] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. As described in the background section, smaller space debris cannot be captured in the prior art, and existing capture devices are all active capture devices. In order to solve the above technical problems, this invention proposes a spacecraft for passive capture and disposal of small space debris.

[0041] Example 1 In a typical embodiment of the present invention, reference is made to Figure 1 , Figure 4 and Figure 5As shown, the passive capture and disposal spacecraft for small space debris includes a chip satellite 6 and a capture assembly. The capture assembly includes a folding storage panel 2, a trigger platform 5, and a bistable capture arm 3. The capture assembly is installed around the chip satellite 6. A solar sail 1 is also installed around the chip satellite 6, and the chip satellite 6 controls the flight of the solar sail 1. There are multiple folding storage panels 2, which are located around the chip satellite 6. The positions of the folding storage panels 2 correspond to the positions of the solar sail 1. The folding storage panels 1 are connected to the chip satellite by hinges 4, such as NiTi hyperelastic alloy hinges. Around 6, the hinge 4 is folded and has super elasticity, which can ensure that the foldable storage wall panel 2 can switch from folded state to flat state under the action of external force. The bistable capture arm 3 is connected to the trigger platform 5. The bistable capture arm 3 passes through the trigger platform 5. The two sides of the bistable capture arm 3 contact the corresponding foldable storage wall panel 2. The bistable capture arm overcomes the force of the hinge and keeps in a straight state. Because the chip satellite 6 is square, there are 2 bistable capture arms. The 2 bistable capture arms 3 are arranged in a cross. The bistable capture arm 3 has two stable states, namely a straight state and a fully curled state.

[0042] The hinge 4 passes through the slot reserved in the solar sail 1. One end of the hinge 4 is connected to the chip satellite 6, and the other end is connected to the folding storage wall panel. The trigger platform 5 is located in the center of the back of the chip satellite 6. One layer of bistable capture arm 3 is bonded to the lower trigger plate 8 or the chip satellite 6 with epoxy glue. The other layer of bistable capture arm 3 is bonded to both the upper and lower trigger plates 8.

[0043] It is easy to understand that the bistable capture arm 3 is made of NiTi alloy that has undergone solution treatment and constraint aging. Of course, other alloys that have undergone solution treatment and constraint aging can also be used. The bistable capture arm has a set width, and its width d1 is slightly smaller than the width of the trigger plate 8. When the bistable capture arm 3 is in the unfolded state, it must overcome the hinge force so that the folding storage panel is in a flat state.

[0044] Two bistable capture arms 3 are provided. One bistable capture arm 3 is set through the space between the two trigger plates 8, and the other bistable capture arm is set through the space between the trigger plate 8 and the chip satellite 6.

[0045] refer to Figure 2 and Figure 3 As shown, the trigger platform 5 includes four support legs 7 and two trigger plates 8. The trigger plates 8 are parallel to the chip satellite 6. The support legs 7 are recessed towards the center of the trigger platform 5. The recesses are equipped with three elastic elements such as compression springs 9. The two trigger plates 8 are separated from the compression springs 9 along the support legs 7. The trigger plates 8 are all square plates. The two trigger plates 8 are separated by the compression springs 9 in the middle. The trigger plates 8 and the compression springs 9 are fixedly connected.

[0046] In this embodiment, the folding storage panel 2 is triangular in shape, and one side of the folding storage panel 2 has the same length as one side of the chip satellite 6. (Refer to...) Figure 6 As shown, the four folding storage panels 2 form a tetrahedral structure after folding, thus creating a space to enclose the debris and prevent it from escaping between adjacent folding storage panels 2. Of course, the shape of the folding storage panels 2 can also be other shapes, as long as multiple folding storage panels 2 form an enclosing space to contain the space debris after folding. Furthermore, the bistable capture arm 3 can reliably grasp debris of different shapes. (Reference) Figure 7 As shown, for regularly shaped fragments, the closing amplitude of each bistable capture arm 3 is similar, forming a uniform grip; subsequently, the folded storage panel 3 is further pressed inward to complete the locking. (Reference) Figure 8 As shown, for irregular debris, although the retraction range of the four bistable capture arms 3 is different, they can all retract to the position where the space debris is stopped; thereafter, the folding storage panel 2 is pressed inward under the constraint of the bistable capture arms 3. Although it is not completely closed, it is still in a stable and fully compressed state, thereby achieving a firm capture and fixation.

[0047] Specifically, the folding storage panel 2 is an isosceles triangle with a base of 30mm and a height of 55mm, the bistable capture arm is a rectangle with a length of 45mm and a width of 10mm, and the trigger platform 5 is a square of 10mm × 10mm. The size of the trigger platform 5 can also be other sizes, such as a side length d2 of 40mm.

[0048] It should be explained that when spacecraft 14 is not in operation, it is in a flattened state, and the entire spacecraft is in a state of static equilibrium. The folding storage panel 2 is constrained by the bistable capture arm 3, and both the bistable capture arm 3 and the folding storage panel 2 are subjected to the reaction force from the hinge 4. Under the action of the compression spring 9, the trigger plate 8 forms a state in balance with the above-mentioned constraint force in a set position, thereby keeping the spacecraft stationary. When the space debris 12 impacts the trigger platform 5, the trigger plate 8 transfers the impact energy to the bistable capture arm 2, causing it to cross the energy barrier and jump from the original energy trough to another stable energy trough. This is manifested as a rapid change from a flat state to a curled state. The bistable capture arm 2 therefore automatically curls up. After losing the constraint of the bistable capture arm 2, the folding storage panel 2 will return to its initial folded form, retract inward, and press against the curled bistable capture arm 2, thereby entering the working state and completing the stable capture of the space debris 12. Subsequently, under the control of ChipSatellite 6 and Solar Sail 1, the spacecraft deorbited and ultimately destroyed Space Debris 12.

[0049] The solar sail 1 mainly consists of three layers: an AL layer (aluminum layer) 11, a PI layer 10 (polyimide layer), and a shape memory NiTi alloy layer 18 connected in sequence. The solar sail 1 is square in shape and has a size of 10cm × 10cm. The shape memory NiTi alloy layer 18 is positioned away from the capture component, which allows the bending direction of the solar sail to be different from the position of the capture component, thus avoiding interference between the two. The shape memory NiTi alloy layer 18 is an unclosed hollow trapezoid that fits the edge of the sail to form a circuit with the chip, ensuring that the chip satellite provides current to the shape memory NiTi alloy layer to generate Joule heat, thereby realizing the control of the shape memory NiTi alloy layer. The AL layer 11 and the intermediate PI layer 10 are integrated. The PI layer and the upper NiTi layer are connected by existing surface treatment and bonding technologies. A slotted through hole of a set size is provided at the fixed position of the solar sail 1 and the chip satellite 6 (to pass through the NiTi alloy hinge). The NiTi alloy hinge achieves bending of 0° to 90° within a set temperature range through a heat treatment process.

[0050] Specifically, the superelastic NiTi alloy hinge requires solution treatment of NiTi alloy at 850℃ for 3 hours, followed by constrained aging treatment at 450℃ for 5 hours to achieve a 60° bending state memory and superelasticity. After solution treatment at 850℃ for 3 hours, NiTi alloy undergoes constrained aging treatment at 450℃ for 5 hours, and finally stress-free constrained aging treatment at 400℃ for 4 hours to obtain a two-way shape memory alloy sheet with a phase transformation temperature of 55℃. The processed NiTi alloy sheet is then laser-cut to obtain an unclosed hollow trapezoidal NiTi shape memory alloy sheet and a U-shaped NiTi shape memory alloy hinge. The port of the unclosed hollow trapezoidal NiTi shape memory alloy end chip satellite symmetrically bonded on the solar sail 1 is then connected.

[0051] In Solar Sail 1, the Al (Al) layer is positioned close to the capture assembly. The Al layer is a material layer composed of aluminum, possessing high reflectivity to achieve greater light pressure. The Al layer (11) is 0.0001 mm thick, and the NiTi layer is 0.05 mm thick. The relatively soft Al layer (11) facilitates the bending of Solar Sail 1. The PI (Polyimide) layer, with its high temperature resistance, chemical corrosion resistance, and excellent insulation properties, serves as a protective and structural support. The PI layer (10) is 0.0124 mm thick, and the NiTi layer is 0.05 mm thick. Precise control of the thickness of each layer achieves multiple technical effects. The excellent conductivity of the Al layer ensures the device's charge is maintained in the space environment. The balance prevents static electricity buildup from interfering with equipment operation. The PI layer, with its high-temperature resistance, ensures the structural stability of solar sail 1 when facing extreme temperature changes such as direct sunlight. Its chemical corrosion resistance further enhances its adaptability to the complex space environment, while providing necessary structural support for the entire solar sail 1. The specific thickness parameters of each layer (AL layer 0.0001mm, PI layer 0.0124mm, NiTi layer 0.05mm) effectively control the overall weight of solar sail 1 while meeting material performance requirements, ensuring smooth bending of the solar sail, and improving its propulsion efficiency and maneuverability in space. This enables the solar sail 1 of spacecraft 14 to operate stably and efficiently.

[0052] Solar sail 1 has 4 segments, namely , , and Each solar sail 1 is trapezoidal in shape, that is, the AL layer (aluminum layer), PI layer (polyimide layer), and NiTi layer are all trapezoidal. When the solar sail 1 is deployed, all solar sails 1 are on the same plane, and the distance between adjacent solar sails 1 is set. The components are placed closer to the center on the shorter side of each solar sail.

[0053] In this embodiment, spacecraft 14 can accommodate space debris of different sizes and shapes within a certain range. One corner of the folding storage panel 2 points towards the long side of the solar sail 1, and the length of the folding storage panel 2 is set to be less than, equal to, or greater than the height of the solar sail 1. The dimensions of the folding storage panel 2, the trigger platform 5, and the bistable capture arm 3 can all be adjusted according to mission requirements, effectively covering space debris sizes within the range of 0.1–10 mm. (Reference) Figure 15 As shown, the length h of the folding storage panel 2 can be 55mm, 63mm, 75mm, or 90mm.

[0054] The spacecraft provided in this embodiment is a passive spacecraft. After the space debris 12 hits the trigger platform 5, the trigger platform 5 absorbs the impact energy from the space debris 12, breaking the original balance of the spacecraft 14. The bistable capture arm 3 is then triggered and quickly completes the passive capture of the space debris. After confirming that the space debris 12 has been securely captured, the spacecraft, under the control of the chip satellite 6, references... Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 As shown, the shape memory NiTi alloy layer in solar sail 1 drives the solar sail 1 to bend and deform, thereby adjusting the incident light angle and changing the magnitude and direction of the light pressure, thus achieving active adjustment of the spacecraft's attitude and orbit. Spacecraft 14, carrying space debris 12, gradually decreases its orbital altitude. After entering the dense atmosphere, air resistance increases sharply, causing the space debris and spacecraft 14 to rapidly heat up and disintegrate and melt under high heat, completely burning up before reaching the Earth's surface. Thus, the entire space debris cleanup process is successfully completed.

[0055] Taking a representative 3cm aluminum fragment as an example, its mass is approximately 15–40g. In this embodiment, a mass m of 20g is used as the median for analysis. Under the guidance and buffering effect of the CubeSat or other cleanup carrier, the relative velocity of space debris entering the capture port is generally controlled at 0.1–0.5m / s, with 0.3m / s being a commonly used design value.

[0056] When space debris travels at a speed of 0.3 m / s Its kinetic energy upon contact with the trigger platform for:

[0057] The instantaneous impulse exerted by space debris on the trigger surface for:

[0058] By combining the mechanical buffer stroke of the trigger platform and the typical contact time of 5 ms, the average force can be obtained as approximately 1.2 N, and the peak force can reach 2.4–5 N.

[0059] The trigger threshold force is designed to be 0.3–0.5 N. This threshold is far lower than the peak force that debris can actually exert, meaning that once space debris comes into contact with the triggering platform, the triggering device can be reliably activated. At the same time, this threshold is higher than the loads generated by orbital micro-vibrations, gas molecule collisions, and other non-contact disturbances, effectively preventing false triggering.

[0060] This embodiment uses four solar sails, each with an area of ​​[area missing]. The diameter is 0.0025 m², and the total deployed area is 0.01 m². This deployment configuration features high drag, high frontal area, and stable aerodynamic attitude.

[0061] Assuming the spacecraft's mass is 1.0 kg, the mass of the captured debris... Given a weight of 0.02 kg and a drag coefficient of Cd = 2.2 for the solar sail, the system's ballistic coefficient is... for:

[0062] Compared to the ballistic coefficient of a typical 1U CubeSat (50–150 kg / m²), the spacecraft's coefficient can be reduced by approximately 5–15 times, significantly increasing atmospheric drag.

[0063] In the common low Earth orbit environment of 400–500 km, conventional CubeSats without drag-enhancing devices typically require 10–25 years to naturally deorbit. However, when the ballistic coefficient is reduced to the order of 10 kg / m², based on existing engineering verification results and aerodynamic drag models, the spacecraft in this embodiment can reach a reentry altitude of 120 km within approximately 0.5–2 years, achieving complete deorbiting. Therefore, this spacecraft requires no propellant and can achieve effective deorbiting solely through drag-enhancing structures.

[0064] Simultaneously, solar sails provide drag while also exhibiting radiation pressure characteristics. (Based on solar radiation pressure...) :

[0065] If the solar sail area is 0.01m², then the solar radiation thrust is... for:

[0066] The acceleration provided by the 1kg system is 9.07 × 10⁻⁶. -8 The velocity change is approximately 0.26 m / s² over a year. Although the value is small, it plays a supporting role in reducing orbital altitude and maintaining the force-induced attitude, complementing the drag mechanism.

[0067] Once the spacecraft descends to an altitude below 120 km, it will enter a region of rapidly increasing atmospheric density. The reentry heat flux density at this point... Reachable:

[0068] The space debris captured in this embodiment is no larger than 5 cm in size and typically weighs less than 100 g. According to existing reentry physics models, all objects smaller than 10 cm in size and less than 0.5 kg in mass will completely melt during reentry and cannot maintain structural integrity in any form. Furthermore, the sails in this embodiment are made of a thin-film material with extremely low thickness, which will rapidly ablate in the initial stages of reentry; the spacecraft body, due to its miniaturization and dispersed components, will also melt, break up, and vaporize entirely in the peak heat flux region of reentry, thus disappearing completely.

[0069] Example 2 A CubeSat used for cleaning up space debris, reference Figure 15 As shown, CubeSat 13 has an internal cavity containing multiple spacecraft as described in Embodiment 1. CubeSat 13 has a door that can be opened. Once opened, the CubeSat has a robotic arm 15 with a robotic hand at its end. The robotic hand can grasp spacecraft (by grasping a chip satellite), and the trigger platform 5 is positioned away from CubeSat 13. CubeSat 13 has a control center (the control center of an existing satellite). The control center is connected to the robotic arm 15 and the door, respectively. The control center controls the opening of the robotic arm 15 and the door.

[0070] The robotic arm 15 is equipped with a sensor such as a camera at its end. The camera is positioned higher than the spacecraft 14 to avoid interference from the spacecraft. The camera can detect whether there is space debris 12 at the front end of the robotic arm. The camera sends the captured images to the control center, which determines the size of the space debris 12 (whether it is within the grasping range). The control center can also determine the direction of movement of the space debris 12 through image analysis (existing technology), obtain the positional information between the space debris 12, and control the robotic arm to bring the non-operational spacecraft 16 to the front of the space debris 12 (on the path of the space debris's movement) and prepare for capture.

[0071] It is easy to understand that spacecraft 14 is in a flattened state before launch and in its non-operational state. Before launch, multiple spacecraft are stacked and stored in an orderly manner inside a satellite such as CubeSat 13. After the CubeSat enters its predetermined orbit, its robotic arm 15 begins to search for and capture space debris 12 using spacecraft. When the CubeSat control center determines that the size of space debris 12 requires a capture range, the robotic arm 15 moves in the direction of space debris 12's movement and aligns the trigger platform of spacecraft 14 with space debris 12. That is, the spacecraft is released (at zero speed) on the path of space debris 12's movement (within 10mm of the distance between the spacecraft and the space debris). Space debris 12 continues to move forward, thus providing force to the trigger platform. This achieves passive capture of space debris. After capture, the spacecraft becomes spacecraft 17 in its operational state.

[0072] Of course, in other examples, after the spacecraft is released, the robotic arm can also push the space debris 12 to guide the space debris, so that the space debris has a set speed, thereby facilitating the effective triggering of the space debris on the spacecraft.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A spacecraft for passively capturing and disposing of small space debris, characterized in that, The system includes a chip satellite and a capture assembly. The chip satellite has multiple solar sails connected to its periphery. The chip satellite controls the bending state of the solar sails to control the spacecraft's flight. The capture assembly includes a folding storage panel, a trigger platform, and a bistable capture arm. The folding storage panel is connected to the periphery of the chip satellite via hinges. The hinges are bent and elastic. The trigger platform is connected to the chip satellite. After passing the trigger platform, both sides of the bistable capture arm contact the folding storage panel and overcome the elasticity of the hinges to provide a set pressure to the folding storage panel. When the spacecraft is in a non-operational state, the bistable capture arm is in a straight state. When the trigger platform is subjected to external force, it can apply a force to the center of the bistable capture arm, causing the bistable capture arm to switch to a bending state and grip the space debris. Driven by the hinges, the folding storage panel moves towards the space debris to achieve capture of the space debris.

2. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The width of the bistable acquisition arm is adapted to the width of the triggering platform, so that one end of the bistable acquisition arm is inserted between the triggering platform and the chip satellite; The bistable capture arm is bonded to the trigger platform. The bistable capture arm is made of NiTi alloy that has undergone solution treatment and constraint aging.

3. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The triggering platform includes multiple support legs, two trigger plates are set inside the support legs, one end of the support leg is perpendicularly connected to the chip satellite, three elastic elements are set at each support leg, the three elastic elements are separated by the two trigger plates, and the trigger plates and the chip satellite are parallel to each other; There are two bistable capture arms, which are arranged in a cross configuration. One bistable capture arm passes through the space between the two trigger plates, while the other bistable capture arm passes through the space between the trigger plate and the chip satellite.

4. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The folding storage wall panel is provided in four places, and the four folding storage wall panels are respectively located around the chip satellite. Each folding storage wall panel is triangular in shape. The length of the folding storage panel near the chip satellite is the same as the length of the side of the chip satellite.

5. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The length of the folding storage panel is less than, equal to, or greater than the height of the solar sail; The solar sail is trapezoidal in shape, with the shorter side of the solar sail connected to the chip satellite. When the spacecraft is not in operation, all the solar sails are on the same plane, and the distance between adjacent solar sails is set.

6. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The solar sail comprises an AL layer, a PI layer, and a shape memory NiTi alloy layer arranged sequentially. The shape memory NiTi alloy layer is a hollow, unclosed trapezoidal shape. The AL layer faces the capture component. The shape memory NiTi alloy layer is connected to the chip satellite so that the chip satellite can provide current to the shape memory NiTi alloy layer to control the Joule heating of the shape memory NiTi alloy layer, thereby controlling the bending angle of the solar sail. The bending angle of the solar sail is opposite to the capture direction of the capture component. The hinge is made of shape memory NiTi alloy.

7. The passive grasping and disposal spacecraft for small space debris according to claim 1, characterized in that, The AL layer and the PI layer are an integral structure, and the PI layer is connected to the shape memory NiTi alloy layer. The thickness of the AL layer is 0.0001 mm, the thickness of the PI layer is 0.0124 mm, and the thickness of the shape memory NiTi alloy layer is 0.05 mm. The alloy material is dissolved at a set temperature for a set time, and then aged to obtain a two-way shape memory alloy sheet with a phase transformation temperature of a certain temperature. The processed two-way shape memory alloy sheet is then laser-cut to obtain a shape memory NiTi alloy layer or hinge.

8. A CubeSat for cleaning up space debris, characterized in that, The CubeSat has an internal cavity containing a passive grasping and disposal spacecraft for small space debris as described in any one of claims 1-7. The CubeSat has a door and a robotic arm with a sensor and a manipulator at the end of the robotic arm. The manipulator can grasp the spacecraft. The CubeSat has a control center connected to the robotic arm, the sensor, and the door.

9. A CubeSat for cleaning up space debris according to claim 8, characterized in that, The sensing component is a camera installed at the end of the robotic arm, which sends the captured images to the control center.

10. A method for operating a CubeSat for cleaning up space debris, as described in any one of claims 8 or 9, characterized in that... Includes the following: The spacecraft is in a flattened state before the CubeSat launch and when not in operation. After the CubeSat enters space, the robotic arm at the end of the robotic arm grabs the spacecraft by opening and closing the door. The robotic arm then begins to move. After the sensing components detect space debris, they send information to the control center. The control center controls the robotic arm to move in the direction of the space debris's movement, and makes the spacecraft's trigger platform face the space debris. The robotic arm releases the spacecraft in the path of the space debris's movement. The space debris moves forward and contacts the trigger platform, and applies force to the trigger platform. After being subjected to external force, the trigger platform applies force to the center of the bistable capture arm, so that the bistable capture arm switches to a bent state and grips the space debris. Then, the hinge drives the folding storage panel to move towards the space debris to lock the space debris again. After the spacecraft captures space debris, the chip satellite controls the bending angle of the solar sail to make the spacecraft fly towards the atmosphere. During the spacecraft's flight, air resistance increases sharply, and the space debris and spacecraft heat up rapidly and disintegrate and melt in the high-temperature environment, burning up completely before reaching the ground.

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