RU186183U1 - Transformable screen made of flexible composite material to protect the spacecraft from small space debris - Google Patents

Abstract

The technical solution of the device relates to transformable space structures, specifically to transformable screens to protect the spacecraft (SC) from small space debris (MKM). The cumulative technical result is the provision of screen protection of the spacecraft from MKM and small meteoroids due to the use of only a two-layer flexible fabric composite screen, which ensures the required weight reduction; rational reverse angle of inclination of the central axis of symmetry of the screen relative to the direction (velocity vector) of the spacecraft’s flight and at the same time rationalizing the dimensions of the screen in the working and traveling (transport) positions due to the principle and scheme of screen transformation. The technical result is provided by a transformable screen to protect the spacecraft from small space debris, which has a centrally axisymmetric power frame, consisting of a power element for mounting on the body of the protected spacecraft, a composite base for installing a system of four main and four telescopic mesh rods with the possibility of their extension from the main mesh rods. In the folded state, the telescopic mesh rods are removed inside the main rods, while in the inner cavity of the power frame the internal flexible composite screen is laid, and the external flexible composite screen is laid on the external surface. In the opened state, the screen over the area covers the midsection (usually it is the end face) of the protected spacecraft and has a rational inverse angle (from 30 to 60 angular degrees) of inclination of its central axis of symmetry relative to the flight speed vector of the protected spacecraft. External and internal flexible screens are made of fabric composite material and in the open state are separated from each other, while the open screen has the shape of a tetrahedral pyramid oriented in the direction of flight of the device with its open base and apex towards the device. Each of the four two-layer composite screen sections with its vertex attached to the composite base, and two other angles to the vertices of telescoping telescopic rods, while the outer and inner screens are attached to opposite telescopic rods that form the edges of the pyramid. Aramid fabrics based on fibers of such brands as CBM, Kevlar, Armos were used as a flexible composite material, and mesh structures made of high-strength and high-modulus carbon fiber from high-strength carbon fibers and an epoxy binder were used to create a power frame. 2 s.p. f-ly, 12 ill.

Description

Technical field

The technical solution of the device relates to transformable space structures, specifically to transformable screens to protect the spacecraft (SC) from small space debris (MKM).

State of the art

In the process of patent search, a number of technical solutions were selected relating to the screens of the spacecraft or satellites from MKM and meteoroids. It should be noted that in a number of solutions the main emphasis is on new materials for protection screens, and in a number of decisions on constructive solutions of transformable screen devices, few solutions have been found where these protection means (materials and transformable screen designs) are considered in detail together.

Solutions for various multilayer, including composite, materials for SC protection screens, but without specifics of transformable shield designs, are presented in the following patent documents: Chinese Patents CN105109709 (A) THERMAL INSULATION / PROTECTION INTEGRATED SPACE DEBRIS PROTECTION STRUCTURE AND APPLICATION THEREOF ( -12-02); CN 206416595 (U) A HETEROGENEOUS INTERCALATION COMPOSITE CONSTRUCTION BOARD FOR PROTECTION OF HYPERVELOCITY PIECE (published 2017-08-18); South Korean patent KR 20150136172 (A) COMPOSITE SHIELDING STRUCTURE FOR SPACECRAFT (published 2015-12-07); Russian patents RU 2457160 SCREEN FOR PROTECTING A SPACE VEHICLE FROM HIGH-SPEED SHOCK IMPACT OF METEOROIDS (Published: July 27, 2012 Bul. No. 21); RU 2623782 SCREEN FOR PROTECTION OF THE SPACE VEHICLE FROM HIGH-SPEED SHOCK EXPOSURE TO PARTICLES OF THE SPACE ENVIRONMENT (Published: June 29, 2017 Bull. No. 19).

Solutions for transformable designs of spacecraft safety screens with little specificity (or even complete lack of information) on the screen materials are presented in the following patent documents: Chinese patent CN 101342947 (A) SPACE FRAGMENT AND MICROMETEOROID IMPACT RESISTANT PROTECTION MECHANISM CAPABLE OF INFLATING AND EXPANDING ON RAILS 2009-01-14); English patent GB 2475926 (B) DEBRIS IMPACT MITIGATION APPARATUS FOR SPACECRAFT (published 2011-10-19); Korean Patent Application US US 2018127115 SPACECRAFT FOR SPACE DEBRIS REMOVAL (published 2018-05-10).

And finally, three technical solutions were found where details and designs and materials of transformable screens are examined with varying degrees.

In Japanese patent JPH 07277298 PROTECTIVE DEVICE FOR SPACECRAFT (published 1995-10-24), the emphasis is on the structure, the material is in the background. To avoid collisions with small objects moving in outer space (space debris), a protective shield (made of metal foil or composite material) is placed opposite the direction of movement of the protected spacecraft, with a screen with many parallel openings (in a cellular form) extending in the direction spacecraft to protect the front of the device and capture any object due to its deceleration during its collision and destruction of the walls of the holes. After that, the inhibited object stops completely at the back of the screen and thus prevents its collision with the main body of the protected spacecraft. The screen is positioned so as to freely fold and unfold radially through the supporting structure. There may be many such screens in a complex combination on one protected device.

More detailed structural and material science information is missing in the patent description, that is, the principle of protecting the spacecraft from moving small space objects was patented. The disadvantage of this technical solution is the rigid shape of the protective shield, which limits the size of the area to be protected to 4 m (the fairing diameter of modern launch vehicles).

Chinese patent CN 107697319 (A) HIGH-PERFORMANCE FIBER FABRIC AND FOAM BASED FLEXIBLE PROTECTION STRUCTURE (published 2018-02-16) describes a high-performance fiber fabric and a flexible foam-based protective structure. A flexible protective structure includes a buffer screen, foam filling the screen, and a rear wall; a buffer screen is used to destroy space debris; foam is used to control the amount of compression or the amount of swelling of the protective structure; screens filled with foam are used to decompose clouds of space debris; the back wall is used to capture a cloud of space debris. The buffer screen, foam, filling sieves and the back wall are sequentially glued. A flexible protection structure can be folded and compressed through filling screens and can compensate for the low reliability of conventional protective structures; significantly increased protective ability of a flexible protective structure. The spacecraft itself covers this protective structure deployed in space. In addition to the foam, basalt fibers are used as materials (the first screen is woven from basalt fiber, the number of layers of the buffer screen is at least three), aramid or Kevlar fibers for the inner second screen (two layers of weaving), polyurethane foam and other materials available for Chinese space industry. The compressible or expandable protective structure is folding, has a compact design, is suitable for various working conditions, has a long service life and can work well in difficult working conditions and has a wide range of applications.

The main attention in this patent is given to materials, and about the design of the deployment (transformation) of the information structure is clearly not enough. The disadvantage of this technical solution can be recognized as the complexity of the transformation scheme, and the large specific gravity of the screen, which is associated with an excessive number of layers.

In the patent of the Russian Federation RU 2573684 MULTI-LAYERED TRANSFORMABLE SEALED SHELL (published: 01/27/2016 Bull. No. 3), the emphasis is also on the materials used in the protective shell, and the design and the principle of transformation are in the background. The multilayer transformable sealed shell (MTGO) includes a screen-vacuum thermal insulation (EVTI) with protection against atomic oxygen, anti-meteoroid protection in the form of protective anti-meteoroid screens with inter-screen separators, a reinforcing layer, a sealing layer, a layer that protects against damage from the inside. The anti-meteoroid shield consists of multi-layer anti-meteoroid screens made of aramid fabric. Inter-screen dividers are made with “waffle” non-through perforation. The technical result of the invention is to provide sufficient protection for the multilayer transformable airtight shell from micrometeoroids and technogenic particles through the use of perforated inter-screen separators, the possibility of maximum compression of the MTGO in the transport position and its full restoration in the working position, as well as a decrease in the mass characteristics of the MTGO. The shell of the transformable space module consists of several groups, layers of materials that perform various functions. The objective was to provide sufficient mechanical protection of MTGO from micrometeoroids and technogenic particles through the use of perforated inter-screen separators, as well as to provide the possibility of maximum compression of MTGO in the transport position and its full restoration in the working position, and to reduce the mass characteristics of MTGO. The anti-meteoroid protection consists of multi-layer anti-meteoroid screens made of aramid fabric, the first from the outer to the inner containing at least 40% of the total number of layers or the total surface density of the screens, in the second at least 20%, which are separated by 100 ± 75 mm from each other and inter-screen dividers are made with "waffle" through hole perforation. The main thickness of the MTGO in the working position is formed by inter-screen dividers of the antimeteoroid protection integrated into the MTGO. In the transport position, the MTGO is placed in the allotted payload zone, limited by the inner surface of the fairing, due to the preload (elastic deformation) of the screen separators. Preloading of inter-screen separators is ensured primarily due to their perforation, as well as due to the open-porous structure of the material. As an example, in order to provide a sufficient level of anti-meteoroid protection, it is proposed to use four anti-meteoroid screens spaced by 100 mm thick inter-screen dividers made of perforated polyurethane foam.

The disadvantage of this technical solution is the lack of sophistication of the transformation scheme, and the large proportion of the screen, which is associated with an excessive number of layers.

As a result of the analysis, it was concluded that none of the many technical solutions found-analogues can be considered as the closest analogue (prototype) in the totality of the essential features of the design and materials of the transformed spacecraft shield from MKM.

Utility Model Disclosure

The total technical result of the utility model is to provide spacecraft screen protection from MKM and small meteoroids through the use of only a two-layer flexible woven composite screen, which ensures the required weight reduction; a rational inverse angle of inclination of the central axis of symmetry of the screen relative to the direction (velocity vector) of the spacecraft’s flight and at the same time rationalizing the dimensions of the screen in the working and traveling (transport) positions due to the principle and scheme of screen transformation.

The technical result is provided by a transformable screen to protect the spacecraft from small space debris, which has a centrally axisymmetric power frame, consisting of a power element for mounting on the body of the protected spacecraft, a composite base for installing a system of four main and four telescopic mesh rods with the possibility of their extension from the main mesh rods. In the folded state, the telescopic mesh rods are removed inside the main rods, while in the inner cavity of the power frame the internal flexible composite screen is laid, and the external flexible composite screen is laid on the external surface. In the opened state, the screen over the area covers the midsection (usually it is the end face) of the protected spacecraft and has a rational inverse angle (from 30 to 60 angular degrees) of inclination of its central axis of symmetry relative to the flight speed vector of the protected spacecraft. External and internal flexible screens are made of fabric composite material and in the open state are separated from each other, while the open screen has the shape of a tetrahedral pyramid oriented in the direction of flight of the device with its open base and apex towards the device. Each of the four two-layer composite screen sections with its vertex attached to the composite base, and two other angles to the vertices of telescoping telescopic rods, while the outer and inner screens are attached to opposite telescopic rods that form the edges of the pyramid.

Aramid fabrics based on fibers of such brands as CBM, Kevlar, Armos were used as a flexible composite material, and mesh structures made of high-strength and high-modulus carbon fiber from high-strength carbon fibers and an epoxy binder were used to create a power frame.

List of figures

FIG. 1 - deployed protective screen attached to the spacecraft (the spacecraft shown conditionally);

FIG. 2 - deployed protective screen (without spacecraft);

FIG. 3 - expanded two-layer flexible segment of the screen (one of four);

FIG. 4 - the main mesh support rod (one of four);

FIG. 5 - telescopically extendable mesh support rod (one of four);

FIG. 6 - power structure for mounting the screen on the spacecraft;

FIG. 7 - power frame of the screen in the folded position;

FIG. 8 - power frame of the screen in an intermediate position;

FIG. 9 - power frame of the screen in the expanded position;

FIG. 10 - screen folded;

FIG. 11 is a screen in an intermediate position of the deployment of the main rods to the extension of the telescopic rods;

FIG. 12 - screen in an intermediate position with the deployed main rods and with a partial extension of the telescopic rods from the main rods.

Utility Model Implementation

Taking into account the accumulated international experience in developing passive micrometeoroid protection systems, it is rational to use screens (or trap screens) made of flexible composite material (CM) designed to protect spacecraft from the damaging effects of MKM objects moving at speeds from 2 km / s and having a size of up to 10 mm and up to 7 km / s with a size of up to 2 mm. The use of such a screen is necessary to ensure guaranteed coverage and reliable operation of important spacecraft elements located in geostationary orbit.

The following materials have found application in passive protection systems from micrometeoroids: aramid fabrics like Kevlar, Nextel bulk weaving fabrics, carbon plastics, organoplastics, and felts based on carbon or aramid fibers. In the production of these materials and composites, organic, carbon and ceramic fibrous fillers are mainly used. The most famous among organic aramid fibers are fibers based on liquid crystal polyamides: Kevlar (USA), Twaron (Holland), Terlon (Russia) and their copolymers: CBM (Russia), Armos (Russia), Technora (Japan). Nextel three-dimensional weaving fabrics based on ceramic alumina fibers with additives of silicon dioxide and boron dioxide are widely used in micrometeoroid protection systems. As the main material of the micrometeoroid protection, it is necessary to use carbon fiber from high-strength carbon fibers and an epoxy binder for rigid force structures and layers of aramid fabric for trapping micrometeoroids and MKM.

An example of the preferred implementation of the utility model

The structural layout diagram (CCF) of the screen (or trap) made of flexible CM and its individual elements are shown in FIG. 1-12. The screen (Fig. 1, 2) is designed to protect spacecraft with a cross section of 3 × 3 m ² from the destructive effects of small space debris (MKM) moving at speeds from 2 km / s and having a size of up to 10 mm and up to 7 km / s with sizes up to 2 mm. To guarantee the protection of the spacecraft from the effects of MKM, the transverse screen size was chosen 4.5 × 4.5 m ² . A screen of this size cannot be deployed (Fig. 1) into outer space, since the internal diameter of the payload fairing of modern domestic launch vehicles Proton-M, Angara is 4.1 m. Therefore, the screen design is made transforming, operational in geostationary orbit. At the same time, various types of CMs are widely used to reduce the weight of the screen design. So, to create support rods (Fig. 4, 5) of the power frame (Fig. 7) it is advisable to use mesh structures made of high-strength and high-modulus carbon fiber.

To create a reliable and weight-effective protective structure, it is promising to use a two-layer shell made of flexible CM (there are four two-layer segments (Fig. 3) of such a shell in the screen device). In this case, the first (outer) layer of the shell, whose thickness is from 60 to 80% of the total thickness, serves to mechanically destroy the particle, but will be punctured when exposed. Fine-dispersed fragments of the MCM passing through this layer should be captured by the second (inner) layer, which ensures the integrity of the protected spacecraft. As materials for manufacturing a flexible composite trap, fabrics based on aramid fibers, such as CBM and Kevlar, can be considered.

Also, when creating a CCS screen, the principle of the inverse angle of the screen inclination with respect to the probable direction of influence of the MCM was used. With this screen orientation, the MKM particles falling on it are deflected toward the normal and, thus, are diverted from the protected spacecraft.

In specific quantities, the screen has the following characteristics. Each outer and inner layer of flexible screen segments, in turn, consists of a top layer - EVTI-I screen-vacuum thermal insulation with a thickness of 20 mm, covered with aramid metallized fabric, while EVTI-I is formed from layers of a polyimide film 20 microns thick, separated by fiberglass canvas ; a power layer, which is a fabric bag of 120 layers of SVM brand fabric with a thickness of 24 mm (outer screen) and of 40 layers of SVM brand fabric with a thickness of 8 mm (inner screen) having a plain weave of 15 yarns 58 tex in weft and warp; back layer of EVTI-I 20 mm thick; the distance between the outer and inner layers of the screen is 100 mm. To take into account the solar thermal loads on the open screen, it was assumed that the direction of flight of the screen in a geostationary orbit coincides with its axis of symmetry, and the transverse axis is oriented to the Earth. Under these conditions, the screen will be unevenly illuminated by the Sun, which will cause significant temperature changes on its surface. Using simulation, it was found that the temperature on the outer surface of the screen can vary over a wide range from minus 165 ° С to plus 80 ° С, which is beyond the recommended temperature range for the CBM aramid fabric. However, the use of double-sided thermal insulation from EVTI-I allows to reduce fluctuations in the temperature of the fabric to acceptable values and at the end of the first turn of the trap around the Earth, it is in the range from plus 6 to plus 12 ° C. The temperature distribution was obtained in the layers of antimeteoroid protection. The meteoroid protection gradually cools, but its temperature does not drop below minus 25 ° C, which is acceptable for aramid tissues. Analysis of the temperature state of the mesh support rods showed that the temperature drops in them reach about 150 ° C, but neither the level itself, nor the temperature gradients were critical and unacceptable.

To deploy the trap screen from the transport folded position (Fig. 10), 4 main (Fig. 4) and telescopically extendable (Fig. 5) mesh support rods with a total length of 6 m are used, having a base section of 200 × 100 mm ² . The open screen has the shape of a tetrahedral pyramid (Fig. 1, 2) with sides of each face 6.3, 5.0 and 5.0 m, oriented in the direction of flight with its open base area of 6.3 × 6.3 m. In the formed mouthpiece trap screens should get MKM elements.

The screen-trap includes the following elements (Fig. 2) with the position numbers: 1 - telescopically extendable rod; 2 - the main core; 3 - power element; 4 - the inner layer of the flexible screen; 5 - the outer layer of the flexible screen.

The power element 3, which serves to mount the screen on the spacecraft’s body, is made of aluminum alloy, the overall size of about 300 mm. There is also a composite base (not shown in the figures) for attaching the system of support rods 2 to the power element 3.

The screen for protecting the spacecraft from the MKM is put into orbit in the folded state (Fig. 10). The length of the folded screen is 3 m, the width (midsection) is 1.43 m, the design weight does not exceed 1780 kg (the area of the outer segment is 15 m ² , the thickness is 10 mm; the area of the inner segment is 14.5 m ² , the thickness is 32 mm; the weight of the composite power structure is 148 kg). The basis of the screen is its power frame (Fig. 7), in the inner cavity of which a second (inner 4) flexible layer of the screen is laid, and on the outer surface the first (outer 5) flexible layer of the screen is laid. In the folded state, the telescopically extendable support mesh rods 1 are retracted inside the main support rods 2. Each of the four two-layer flexible screens with its apex is attached to the composite base, and two other angles to the vertices of the telescopically extendable rods. The outer 5 and inner 4 layers of the flexible screen are attached to opposite telescopic rods 1, forming the edges of the pyramid, which allows you to create a two-layer composite shell.

When developing the disclosure (transformation) scheme (Fig. 8, 9, 11, 12) of the screen, the following tasks were set: - the disclosure system of power elements should be simple, reliable and have a minimum number of movable joints; - a system for fixing the power structure in the open position should be provided; - to open the trap should be used electric or piezoelectric actuators; - the deployment system should provide reliable, without creases and folds, the expansion of flexible composite screens; - dynamic loads in the power elements during deployment of the trap should be minimal.

To ensure the deployment of a flexible composite screen, a two-stage disclosure of the main power elements is provided. The first stage of the opening of the trap (Fig. 11) is the deviation of all four main support rods 2 at an angle of 60 degrees, around the transverse axis associated with the composite base. To rotate the rods, it is planned to use an electric drive. The rotation time of the rod 2 is about 2000 seconds. The view of the trap after deployment of the main support rods is shown in FIG. 11. The second stage of deployment of the trap (Fig. 12, 2) involves the extension of the telescopic rods 1 and the tension of the flexible composite screen. To extend the telescopic rods 1 is planned to use an electric drive. The extension time of the rod 1 is about 1500 seconds. In FIG. 12 is a view of the screen after extending the telescopic rods 1 to half their length. The view of the screen after the telescopic rods 1 are fully extended is shown in FIG. 2. In the opened state, the screen over the area covers the midsection (usually this is the end) of the protected spacecraft and has a rational inverse angle (30 to 60 angular degrees) of the inclination of its central axis of symmetry relative to the flight speed vector of the protected spacecraft. As the simulation showed, it is this range of angles that provides the maximum possible protection of the spacecraft with the proposed screen from MKM and small meteoroids. The reverse angle of the screen is also regulated by an electric drive.

The proposed utility model was developed in the framework of the agreement 14.574.21.0146 dated September 26, 2017 (unique identification number of the project RFMEFI57417X0146) between the Ministry of Education and Science of the Russian Federation (State customer) and MSTU im. N.E. Bauman (Contractor).

Claims (3)

1. A transformable screen to protect the spacecraft from small space debris, characterized by the presence of an axisymmetric power frame, consisting of a power element for attaching to the body of the protected spacecraft, a composite base for installing a system of four main and four telescopic mesh rods with the possibility of their extension from the main mesh rods; when folded, the telescopic mesh rods are removed inside the main rods, while the internal flexible composite screen is laid in the internal cavity of the power frame, and the external flexible composite screen is laid on the external surface; in the opened state, the screen covers the midship of the spacecraft to be protected by area and has a reciprocal angle of 30 to 60 degrees of inclination of its central axis of symmetry with respect to the flight speed vector of the spacecraft being protected; external and internal flexible screens are made of fabric composite material and in the open state are separated from each other, while the open screen has the shape of a tetrahedral pyramid oriented in the direction of flight of the device with its open base and apex towards the device; each of the four two-layer composite screen sections with its vertex is attached to the composite base, and the other two corners are attached to the vertices of telescoping telescopic rods, while the outer and inner screens are attached to opposite telescopic rods that form the edges of the pyramid. 2. The screen according to claim 1, characterized in that aramid fabrics based on fibers of such brands as CBM, Kevlar, Armos are used as flexible composite material. 3. The screen according to claim 1, characterized in that mesh structures of high-strength and high-modulus carbon fiber from high-strength carbon fibers and an epoxy binder are used to create a power frame.

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