CA3060449C - Capture device and capture method for capturing uncooperative satellites in space - Google Patents

Abstract

Abstract A capture device (10, 10') for capturing satellites in space is disclosed. The capture device comprises two legs (11, 12) each with a first end (11a, 12a) and a second end (11b, 12b). A connecting bracket (13) connects the respective first ends of the two legs to one another. A gripping device (14) is arranged on the connecting bracket for gripping a satellite currently to be captured. By means of a common fastening foot or a fastening foot in each case (15, 16) on the respective second end of each of the legs, the respective leg can be or becomes fastened to a capturing spacecraft (1). The legs are connected to the connecting bracket and to the fastening foot or fastening feet in each case so as to be swivellable, wherein the respective (swivelling) axes (AI, A2, A3, A4) are all parallel to one another A spacecraft (1) with at least one, but preferably three capture devices (10, 10') and a capture method for capturing a satellite in space are also disclosed. (Figure 1) CA 3060449 2019-10-28

Description

Capture device device and capture method for capturing uncooperative satellites in space Description The present invention relates to a capture device, a spacecraft and a capture method each for the (in particular robotic) capture of uncooperative satellites in space.
A capture of uncooperative satellites in space, i.e. which cannot be moved in a targeted manner by means of remote control, means gripping and holding firm the respective satellite by means of a suitable device of a spacecraft (which may itself be a satellite). The satellite to be captured (which is also referred to as the "target satellite") is thus coupled to the spacecraft. The latter is then able for example to carry out repairs and/or maintenance operations such as in particular re-fuelling and/or a payload exchange or also to suitably transfer the captured satellite into a currently more advantageous orbit.
Many satellites do not have an interface provided explicitly for such coupling. Instead, specific holding means can conventionally be introduced into the nozzle of an apogee engine, or the payload adapter ring (also referred to as the "launch-adapter-ring") of the satellite can be held by means of pincer-like grippers, which are guided by robot arms: A payload adapter produces the stable mechanical connection between the rocket and the satellite at the launch. As a rule, it comprises two components, one on the rocket and one on the satellite, which at the launch are connected together. After the launch, this connection is released and the satellite is thus separated from the rocket. The satellite-side component of the payload adapter is the payload adapter ring. Techniques for holding the payload adapter ring by means of grippers are described in

-2-documents capturable at http://www.satelliteevolutiongroup.com/articles/orbitalatk.
pdf or http://hq.wvrtc.com/ICRA2015/posters/ratti.pdf.
High-precision positioning of the respective tool and a correspondingly expensively controlled movement mechanism are required in each case for this, in particular because the contact of the tool with the satellite in zero gravity can have a great effect on the position and orientation of the satellite and because the respective elements engage at least partially in an internal region of the satellite, for example in a radially interior region of the payload adapter ring, which can lead to damage to the sensitive material and in particular damage to the proper functioning of the target satellite.
The problem underlying the present invention is to provide a technique, with which capture of uncooperative satellites can be simplified.
The problem is solved by a capture device, a spacecraft and a capture method as described throughout the description and claims. Advantageous embodiments are disclosed in the description and the figures.
A capture device according to the invention is used, when it is attached to a spacecraft (possibly together with at least one further capture device according to the invention), to capture satellites in space (robotically), i.e., to grip and hold the latter.
The capture device comprises two legs, which each comprise a first end and a second end; the respective first ends are connected to one another by a connecting bracket. A
gripping device for gripping a satellite currently to be captured (for example at an element arranged thereon such Date Recue/Date Received 2021-05-31

- 3 -as in particular a payload adapter ring) is arranged on the connecting bracket. At the respective second end of each of the legs, a fastening foot (one in common or one each) is arranged, by means of which the respective leg is or can be fastened to a capturing spacecraft. The connections of the first ends to the connecting bracket and of the second ends to the fastening foot or the respective fastening feet are constituted so as to be swivellable about respective axes which run (in pairs) parallel to one another (i.e. two of the axes in each case are parallel to one another). In particular, the mentioned swivellable connections thus form links; at least one or each of the links preferably has precisely one degree of freedom. In particular, at least one or each of the links can preferably be constituted as a hinge.
In a state fastened to the spacecraft, therefore, the capture device forms at least a part of a frame, which is variable on account of the swivelability about axes parallel to one another; in the case of a plurality of fastening feet, such a frame can also comprise a section of the surface of the spacecraft. In particular, sensitive positioning of the gripping device arranged on the connecting bracket can easily be brought about with the frame arrangement, by means of which a subsequent sensitive change in the position and orientation of the satellite currently to be captured can be minimised. The effect of the frame arrangement is also that the respective angles mutually influence one another. The gripping device can thus be brought into a desired position with particularly little drive and control effort. In particular, the capture device (especially in the fastened state) preferably comprises at least two degrees of freedom, so that the gripping device can be moved precisely in a region which lies in a plane.

- 4 -The spacecraft according to the invention comprises at least one capture device according to the invention according to one of the embodiments disclosed in this specification, which is fastened with its fastening foot or its fastening feet to a further component such as for example a base plate of the spacecraft. The legs preferably extend parallel to one another.
According to a preferred embodiment, a spacecraft according to the invention comprises two, three or more capture devices according to the invention, which are arranged rotationally symmetrical to one another about an axis; the axis can preferably lie perpendicular to a surface on which the capture devices are arranged. The gripping device of at least one of the capture devices with such embodiments can preferably be swivelled radially with respect to the mentioned axis (i.e. along a plane containing the axis optionally towards the axis or away from the axis), in particular by swivelling the legs of the respective capture device relative to their respective fastening foot. In this way, the capture device on a spacecraft can be adapted to different elements of satellites currently to be captured, with which the respective satellites can be gripped, for example to different diameters of given payload adapter rings.
According to an advantageous embodiment of the present invention, the spacecraft itself is a satellite. A
satellite to be captured may in each particular case be uncooperative; it is preferably position-controlled in each case, i.e. stabilised with regard to its orientation.
The two legs of a capture device according to the invention preferably have the same leg length; such a leg length is understood in this specification to mean a respective distance of a swivelling axis at the first end to a swivelling axis at the second end of the respective leg. In

- 5 -embodiments in which the second ends of the legs are connected to a common fastening foot, the swivelling axes at the second ends of the legs also preferably have the same distance from one another as the swivelling axes at the first ends from one another; in embodiments in which the second ends are connected to different fastening feet, the latter can preferably be fastened correspondingly to a spacecraft (i.e. so that the distance of the second ends from one another is equal to that of the first ends from one another). With such embodiments, the four associated links then form together the corners of a parallelogram. In such embodiments, the at least one capture device fastened to a spacecraft according to the invention is then preferably fastened in such a state, which is subsequently referred to as the "parallelogram state" of the respective capture device.
In such embodiments, swivelling of the legs relative to the foot or the feet (or swivelling of the capture device as a whole relative to the spacecraft, in particular on a surface thereof) only changes the characteristics of the respective parallelogram, but not the basic fact that the four links form the corners of a parallelogram. An (abstract, straight) connection of the links to the first two ends of the legs to one another thus remains parallel to an (abstract, straight) connection of the links to the second two ends of the legs. It thus emerges that an alignment (i.e. respective angles) of the connecting bracket with respect to a surface of the spacecraft also remains (remain) constant with swivelling, which thus also applies to the gripping device, in particular for a contact surface that may be present and/or a clamping finger of the gripping device, which are described below.
In particular, the gripping device does not then have to be adapted to changed angles when swivelling of the legs takes place, but rather it retains its orientation with respect

- 6 -to the satellite to be captured (or with respect to an element of the satellite, for example its payload adapter ring). On the one hand, this facilitates the control of the capture device, on the other hand it enables a methodical, cautious approach of the gripping device towards the satellite (e.g. its payload adapter ring).
The legs of a capture device according to the invention can for example each have a leg length which lies in the range from 35 cm to 65 cm, in particular from 40 cm to 60 cm.
With a capture device according to the invention, a distance of the swivelling axes at the first ends from one another can lie for example in a range from 20 cm to 50 cm, in particular from 30 cm to 45 cm.
According to advantageous embodiments of the present invention with a plurality of fastening feet, the latter have the same foot height; the latter denotes in this specification a distance between a contact surface of the respective fastening foot, which when fastened to a spacecraft lies adjacent to a surface thereof, and the respective swivelling axis, about which the respective fastening foot can be swivelled relative to the connected leg. Such variants of embodiment are particularly suitable for fastening to a flat surface of the spacecraft.
The gripping device of a capture device according to the invention can preferably comprise a contact surface, which is designed, during capture (preferably with flat contact), to be placed on a surface of a satellite currently to be captured, said surface facing the capturing spacecraft.
Such a contact surface is preferably flat.
Embodiments are particularly preferred wherein the legs have the same leg length and comprise such a contact surface. The contact surface then preferably runs in a plane parallel to the plane that is produced through the

- 7 -swivelling axes at the first ends of the legs (to the connecting bracket). In a parallelogram state of the capture device as mentioned above, the contact surface is then not tilted during swivelling, but rather retains its angle with respect to a facing surface of the satellite.
The requirement for compensatory movements can thus be avoided, movement mechanisms required for this can be dispensed with and the control can be simplified.
According to an advantageous embodiment, the gripping device comprises a clamping finger, which is designed to engage around an element arranged on the satellite currently to be captured (for example a radially external projection on a payload adapter ring of the satellite) or to engage in a groove on the element (for example the payload adapter ring of the satellite).
In particular, such a clamping finger can be mobile relative to a contact surface which may also be present.
The clamping finger can thus be designed to press the element against the contact surface and thus fix it to the gripping device. In such embodiments, the clamping finger preferably comprises a clamping surface facing the contact surface, the distance whereof from the contact surface being variable; a maximum distance can amount for example to at most 16 cm or at most 14 cm. A capture device according to the invention of such an embodiment preferably comprises an electric motor for moving the clamping finger relative to the contact surface.
In an advantageous embodiment of a spacecraft according to the invention, which comprises (as mentioned above) a plurality of capture devices according to the invention arranged rotationally symmetrical about an axis, at least one of the capture devices preferably comprises a clamping finger as described above. The clamping finger is preferably facing the axis, i.e. points towards the axis.

- 8 -In particular, all the capture devices fastened to the spacecraft can be designed in this way.
A payload adapter ring of the satellite, for example, can thus be gripped radially from the exterior. It is thus possible in each case to prevent internal structures such as for example a multilayer insulation material (multilayer-insulation-material, MLI) from being damaged by the capture.
The design makes it possible in particular for the satellite (e.g. at its payload adapter ring) firstly to be mutually prefixed by means of the respective clamping fingers and only then to be clamped between the respective fingers and the respective contact surfaces. Such a so-called "capture before contact" means an especially cautious and at the same time secure gripping, with which damage to the satellite, disruption of its functionality and/or a change in its position relative to the orbit can be avoided.
The capture device according to the invention preferably comprises at least one control device, with which respective swivelling of the legs relative to the respective fastening feet and/or a respective gripping action of the gripping device can be adjusted in an automated manner. The legs and the connecting bracket together then thus form with the control device a robot arm, which is designed to guide and/or to operate the gripping device in an automated manner.
A capture device according to the invention can comprise at least one sensor device, which is configured to detect a respective distance of the gripping device from the respective satellite to be captured. Such a sensor device can comprise a laser device and/or a camera. In particular, the at least one sensor device can be configured, in

- 9 -corresponding embodiments with a contact surface and clamping fingers, to detect whether an element arranged on the satellite is made contact with in a predefined manner both by a contact surface and by the clamping finger.
In embodiments with both at least one sensor device and at least one control device as mentioned above, the latter can preferably be designed to control swivelling of the legs relative to the fastening foot or to the respective fastening feet and/or a gripping state of the gripping device on the basis of sensor data detected by the sensor device.
According to advantageous variants of embodiment of a capture device according to the invention, a connection of one of the legs to the fastening foot (one in common or one each) is constituted as a link, which comprises a motor for swivelling the leg and the fastening foot relative to one another. Alternatively or in addition, a connection of one (other) of the legs can be constituted as a purely passive link, i.e. does not have its own swivelling drive. Such a passive link in the fastened state thus follows suit, for example on account of swivelling of the other leg. Finally, a respective connection of one or both legs to the connecting bracket can be constituted in each case as a purely passive link.
In particular, swivelling of a capture device according to the invention or an approach of the gripping device towards a satellite to be captured or towards an element thereof (e.g. towards a payload adapter ring of the satellite) can thus take place, whereby only one suitable motor is operated and controlled, whereas the other swivellable connections adopt the corresponding swivelling. This means little control effort and - on account of avoiding further motors - a low mass of the capture device.

- 10 -According to advantageous embodiments, a capture device according to the invention is designed, in a state fastened to the surface of the capturing spacecraft, optionally to be placed on the surface (for example such that the legs run parallel to the surface) or to be erected so as to project away from a surface. The legs can thus each be swivelled correspondingly far. This enables advantageous transport or an advantageous launch or flight phase of the spacecraft with a folded-down capture device on the one hand and a suitable use in the erected state of the capture device on the other hand.
The capture method according to the invention is used to capture a satellite in space by means of a spacecraft according to the invention according to one of the embodiments disclosed in this specification. The capture method comprises an approach of the spacecraft towards the satellite to be captured and swivelling of the legs of the at least one capture device or at least one of the capture devices, which is/are fastened to the spacecraft, into a gripping position in which the gripping device and a predetermined structure of the satellite to be captured (e.g. a payload adapter ring of the satellite) lie opposite one another (in a predetermined manner). The structure can for example comprise an edge of a projection or a groove in an element of the satellite (e.g. a payload adapter ring), which in the gripping position can lie opposite a clamping finger of the gripping device in corresponding embodiments, so that the clamping finger can engage around the projection or be introduced into the groove. Alternatively or additionally, the structure can comprise a surface of the satellite (which is preferably flat and/or facing away from the satellite). In corresponding embodiments, a contact surface of the gripping device can then lie opposite such a surface in the gripping position.

- 11 -Finally, the capture method comprises gripping of the element with the gripping device of the at least one capture device. The gripping can for example (in corresponding embodiments) comprise a movement of a clamping finger towards an axis, around which a plurality of capture devices can be arranged in a rotationally symmetrical manner (so that the clamping finger is for example introduced into a groove and/or placed around a projection), and/or the movement of a/the clamping finger towards a contact surface (the satellite then preferably being drawn along).
The gripping preferably does not take place until at least two or three capture devices are each in a respective gripping position. The aforementioned "capture before contact" can thus be implemented.
According to advantageous embodiments of a capture method according to the invention, at least one of the capture devices as described above can be designed optionally to be folded down or erected projecting away from the surface.
The capture method can then comprise erecting the legs in a direction projecting away from a surface of the spacecraft and/or folding down the legs (possibly of the same or another of the capture devices) to the surface (for example so that the legs run parallel to the surface).
Preferred examples of embodiment of the invention are explained in detail below with the aid of drawings. It goes without saying that individual elements and components can also be combined in different ways than those represented.
Reference numbers for elements corresponding to one another are used to include all the figures, and may not be described again for each figure.
In the figures, diagrammatically:

- 12 -Figure 1: shows an exemplary embodiment of a capture device according to the invention in a perspective view;
Figure 2: shows the capture device according to figure 1 in another perspective and in another state of the gripping device;
Figure 3: shows the capture device according to figure 1 in a state folded down on the surface of a spacecraft;
Figure 4: shows a part of a spacecraft according to the invention; and Figure 5: shows a detail view of an exemplary capture device according to the invention when holding a captured satellite.
Figure 1 represents, in a perspective view, an example of embodiment of a capture device 10 according to the invention for capturing satellites in space. The capture device comprises two legs 11, 12. A respective first end lla, 12a of the legs is connected to a connecting bracket

13 so as to be swivellable about a respective axis AI, A2, said connecting bracket thus connecting first ends 11a, 12a of the two legs 11, 12 to one another. The respective connection of the legs to the connecting bracket is in each case constituted as a hinge (in particular with precisely one degree of freedom).
A gripping device 14 for gripping a satellite currently to be captured is arranged on connecting bracket 13, which gripping device is described below in detail with respect to figure 2. A sensor device 17 also arranged on connecting bracket 13 is configured to control a gripping procedure carried out by gripping device 14 in each case, which for example can comprise determining a respective distance of gripping device 14 from the satellite to be captured.
In the example of embodiment shown, a fastening foot 15, 16 is arranged in each case on respective second end 11h, 12h, by means of which fastening foot capture device 10 is or can be fastened to a surface of a spacecraft (not represented in figure 1). A respective connection of second ends 11b, 12b of the legs to the respective fastening foot is also constituted as a hinge, so that legs 11, 12 can each be swivelled about an axis A3 and respectively A4 relative to the fastening feet. In alternative (not represented) variants of embodiment, both second ends can be connected to a common fastening foot in each case in a swivellable manner (in particular by means of a respective hinge).
Axes Au A2, A3 and A4 are parallel to one another (in pairs). As shown in figures 2 and 3 (from a different perspective from that in figure 1), capture device 10, in a state fastened to a surface 20 of a spacecraft, forms together with a section of the surface a frame, which is variable, i.e. swivellable as a whole, on account of the parallelism of axes Au A2, A3 and A4. The gripping device can thus easily be guided into an advantageous position.
As also represented in figure 2, gripping device 14 in particular comprises a contact surface 14a and a clamping finger 14b, the distance whereof from contact surface 14a -as denoted by a corresponding double arrow - is variable.
In the example shown, contact surface 14a extends parallel to surface 20, and it is designed or provided to be placed during capture on a surface of a satellite currently to be captured that is facing the capturing spacecraft. Clamping finger 14b is designed to engage around a projection (for example a shoulder) on a surface of the satellite currently to be captured and/or to engage in a groove in the surface

- 14 -of the satellite. By a movement towards the contact surface, the clamping finger can then guide the satellite towards the contact surface and/or press it against the contact surface.
As shown in figure 2, leg length Li of a first leg 11 given by the distance of axes Ai and A3 from one another is equal to leg length L2 of second leg 12 given by the distance of axes A2 and A4 from one another. Capture device 10 could, in a parallelogram state in which links Gl, G2, G3, and G4 represent the corners of a parallelogram, thus be fastened to surface 20 of the spacecraft, as is shown in figure 2.
Like leg lengths Li and length L2, distances G3-G4 and Gi-G2 are identical. As a consequence, when swivelling of capture device 10 takes place, the alignment (determined by respective angles) of swivelling bracket 13 and gripping device 14 arranged thereon remains constant relative to surface 20. In particular, the parallelism of contact surface 14a with respect to surface 20 is also retained with each swivelling action of device 10. The capture device can thus be controlled in a particularly straightforward manner, because compensation for a movement (i.e. swivelling) of the capture device, with which gripping device 14 is guided towards a satellite, is not required.
In the represented example of embodiment, links Gl, G2 and G4 are constituted as passive hinges, which carry out swivelling only as a reaction to swivelling of the link which is also constituted as a hinge, is driven by a motor 18 and is therefore active. The use of passive links and therefore the avoidance of additional motors means both a saving on mass and also a simplification of the control.
Figure 2 shows capture device 10 in an erected state projecting away from surface 20, in which gripping device 14 can advantageously be used for capturing satellites.

- 15 -In contrast, the capture device in figure 3 is shown in a state folded down to surface 20, in which it can advantageously be held for example in a transport procedure, in particular during transport of the spacecraft from the earth into space.
Figure 4 represents a part of a spacecraft 1 according to the invention, to surface 20 whereof three capture devices according to the invention are fastened, only two of which, i.e. capture devices 10 and 10', can be seen in the figure for reasons of clarity. The capture devices are rotationally symmetrical with an angle of 120 about an axis X, which is orthogonal to surface 20 (the rotational symmetry can be seen only partially in the figure on account of the absence of the third capture device and the perspective with the viewing direction parallel to surface 20). The capture devices are fastened in each case to surface 20 in such a way that they can be swivelled radially with respect to axis X (i.e. along a plane containing axis X). A distance of the gripping devices of the capture devices from axis X can thus be changed by swivelling of the capture device. The arrangement can in particular thus be adapted to different diameters of payload adapter rings of satellites currently to be captured.
Clamping fingers 14b, 14b' of capture devices 10, 10' are each facing the axis x, i.e. pointing towards it. The arrangement thus allows capture devices to engage with a satellite to be captured, in particular its payload adapter ring, without having to engage into the interior of the ring. Damage in the sensitive internal region can thus be avoided.
Figure 5 represents a region of an exemplary capture device. Its gripping device 14 comprises a contact surface 14a and a clamping finger 14b, between which, in the state

- 16 -represented, a shoulder 30a of the payload adapter ring 30 of a captured satellite is clamped. The satellite is thus firmly held by gripping device 14. Shoulder 30a is preferably arranged radially outwards relative to a central axis of payload adapter ring 30. In particular, gripping device 14 thus grips the payload adapter ring radially from the exterior.
A capture device 10, 10' for capturing satellites in space is disclosed. The capture device comprises two legs 11, 12 each with a first end 11a, 12a and a second end 11b, 12b. A
connecting bracket 13 connects the respective first ends of the two legs to one another. A gripping device 14 is arranged on the connecting bracket for gripping a satellite currently to be captured. By means of a common fastening foot or a fastening foot in each case 15, 16 on the respective second end of each of the legs, the respective leg can be or becomes fastened to a capturing spacecraft 1.
The legs are connected to the connecting bracket and to the fastening foot or fastening feet in each case so as to be swivellable, wherein the respective (swivelling) axes Au A2, A3, A4 are all parallel to one another A spacecraft 1 with at least one, preferably three capture devices 10, 10' and a capture method for capturing a satellite in space are also disclosed.

- 17 -Reference numbers 1 spacecraft 10. 10' capture device 11, 12 leg ha, 12a first end of a leg 11b, 12b second end of a leg 13 connecting bracket 14 gripping device 14a contact surface 14b, 14b' clamping finger 15, 16 fastening foot 17 sensor device

18 motor 20 surface of spacecraft 1 30 payload adapter ring 30a shoulder on payload adapter ring A1, A2, A3, A4 (swivelling) axes LI, L2 leg lengths X axis orthogonal to surface 20, about which capture devices are arranged

Claims (12)

-18-

1. A capture device for capturing satellites in space, wherein the capture device comprises:
- two legs each with a first end and a second end;
- a connecting bracket, which connects the respective first ends of the two legs to one another;
- a gripping device arranged on the connecting bracket for gripping a satellite currently to be captured;
- at least one sensor device, which is configured to control a gripping procedure carried out by the gripping device; and - on the respective second end of each of the legs, a common fastening foot or a fastening foot in each case, by means of which the respective leg is configured to be fastened to a capturing spacecraft;
wherein the legs have the same length (LI, L2) and are connected to the connecting bracket and to the common or respective fastening foot in each case so as to be swivellable about axes (Al, A2, A3, Ad parallel to one another, wherein a connection of one of the legs to the respective fastening foot is constituted as a link (Gfl, which comprises a motor for swivelling, wherein the capture device further comprises a control device configured to control the swivelling based on sensor data detected by the sensor device, wherein the gripping device comprises a contact surface, which is designed so as to be placed, during capture, on a surface of a satellite currently to be captured, the surface of the satellite facing the capturing spacecraft, and wherein the contact surface runs in a plane parallel to a plane defined by the axes (A1, A2) at the first ends of the legs.

2. The capture device according to claim 1, wherein the second ends of the legs - are connected to the same fastening foot, at the same distance from one another as the first two ends also have from one another; or - are connected to a respective fastening foot, wherein the respective fastening feet are designed so as to be fastened to the spacecraft, in such a way that the two second ends of the legs have the same distance from one another as the two first ends.

3. The capture device according to claim 1 or 2, wherein the gripping device comprises a clamping finger, which is designed to at least one of engage around an element arranged on the satellite currently to be captured or to engage in a groove in the element.

4. The capture device according to any one of claims 1 to 3, wherein at least one of - a connection of one of the legs to the respective fastening foot is constituted as a purely passive link (G4); or - a respective connection of one or both legs to the connecting bracket is constituted in each case as a purely passive link (G1, G2).

5. A spacecraft, to which at least one capture device according to any one of claims 1 to 4 is fastened to its fastening feet.

6. The spacecraft according to claim 5, wherein the first ends of the legs are connected by a respective first link (GI, G2) to the connecting bracket and the second ends of the legs are each connected by a respective second link (G2, G4) to the common fastening foot or to a fastening foot in each case, and wherein the first and second links (G1, G2, G3, G4) together form a parallelogram in each swivelling state.

7. The spacecraft according to claim 5 or 6, which comprises two, three or more capture devices in each case according to any one of claims 1 to 4, which are arranged rotationally symmetrical to one another about an axis (X).

8. The spacecraft according to claim 7, wherein at least one of the capture devices is radially swivellable with respect to axis (X); and/or wherein at least one of the capture devices according to claim 1 is constituted with a clamping finger which is facing the axis (X).

9. A capture method for capturing a satellite in space by means of a spacecraft according to any one of claims 5 to 8, wherein the capture method comprises:
- approach of the spacecraft towards the satellite, - swivelling of the legs of at least one capture device of the spacecraft into a gripping position, and using the motor, in which gripping position the gripping device of the at least one capture device and a predetermined structure of the satellite lie opposite one another, and - gripping of an element of the satellite with the gripping device.

10. The capture method according to claim 9, wherein the spacecraft is constituted according to claim 7 and wherein the capture method comprises at least one of swivelling of the legs radially with respect to the axis (X), or the gripping comprises moving a clamping finger of the gripping device by means of an electric motor and towards a contact surface of the gripping device.

11. The capture method according to claim 9 or 10, wherein the gripping does not take place until at least two or three capture devices of the spacecraft are each in a gripping position.

12. The capture method according to claim 10 or 11, wherein the capture method comprises at least one of erecting the legs of at least one of the capture devices in a direction projecting away from a surface of the spacecraft or folding down the legs of at least one of the capture devices to the surface, respectively by swivelling the legs by means of the motor.