Method and space system for ejecting a stack of satellites

Abstract

A method for ejecting a stack (2) of satellites contained in a launcher (1) is described, where each stage of the stack comprises at least two satellites arranged around a central geometric axis (AA) of the stack, and in which the satellites of one of the stages, with the exception of the first stage, are stacked on the satellites of the previous stage, so as to simultaneously eject the stack of satellites while minimizing the risk of collision, in the long term, between the satellites. A space system for ejecting a stack of satellites for implementing this method is also described. Abstract figure: Figure 1

Description

Title of the invention: Method and system for ejecting a stack of satellites Technical field

[0001] The present disclosure relates to a method for ejecting a stack of satellites comprising several superimposed stages where each stage comprises several satellites. The present disclosure also relates to a space system comprising a launcher and a stack of satellites, suitable for implementing such a method. Prior art

[0002] The massive deployment of satellite constellations requires reducing satellite launch costs and therefore proposing solutions for the simultaneous launch of a set of satellites. In this respect, it is known to stack several satellites in the fairing of a launcher, or even to store in the fairing of a launcher a stack consisting of several columns of satellites. Thus, a single launcher can store three to four columns of satellites, which can comprise for example up to twelve satellites each, or for example 48 satellites per launch.

[0003] However, the process for ejecting stacks of satellites must be implemented while minimizing the risks of collision between the satellites during ejection and then in orbit. Summary

[0004] The present disclosure provides a solution to this problem.

[0005] A method of ejecting a stack of satellites contained in a launcher is proposed, the stack of satellites comprising a plurality of stages, each stage of the stack comprising at least two satellites arranged around a central geometric axis of the stack, and in which the satellites of one of the stages, with the exception of the first stage, are stacked on the satellites of the previous stage, the ejection method being characterized in that it is implemented from an initial configuration in which the satellites of the stack are held integral with each other and integral with the launcher by a holding and releasing device, first quantities of energy being stored in spacing devices arranged between the consecutive stages of the stack and tending to separate two consecutive stages of the stack,the first quantities of energy stored between two consecutive stages being decreasing from the two ends of the stack towards the middle of the stack and the spacing devices between two consecutive stages generating decreasing forces from the two ends of the stack towards the middle of the stack, and in that it comprises: , - an orientation of the launcher in pitch so that the axis of the stack of satellites are inclined relative to an axis tangent to a scrolling orbit of the satellites, called the scrolling axis, - a release of the satellites relative to the launcher and to each other, causing the release of the first quantities of energy stored between the stages of the stack, resulting in the application of forces, along the axis of the stack, on the different stages of satellites, the projections of which on the axis of travel are different for each stage, and - an application, on the satellites of the same stage, during the release of the satellites, of actions in a radial plane, relative to the axis of the stack corresponding to a longitudinal direction, the projections of which on the axis of movement are different for each satellite of the stage, the release of the satellites occurring at a roll angle determined as a function of the first quantities of stored energy and the actions in the radial plane.

[0006] In embodiments, the satellite stack comprises at least one preloaded mechanical spring between all consecutive satellites of the stack, the preload of the springs forming said first stored energy quantities.

[0007] In embodiments, the variation of the first quantities of stored energy and / or of the forces exerted by the spacing devices, between two consecutive stages, from the ends towards the middle of the stack, is implemented by at least one of: - a variation in the stiffness of the springs, - a variation in the preload applied to the springs, and - a variation in the number of springs.

[0008] In embodiments, the method comprises, before the release of the satellites, at least one rotation of the launcher relative to the stacking axis, said rotation giving the satellites of the same stage different speed components along the scrolling axis, during the release of the satellites, the release of the satellites occurring at a first roll angle.

[0009] In embodiments, the method further comprises sending remote commands from a ground station sending: - A remote control for tilting determined in pitch, - A remote control for rotating the launcher around the longitudinal axis at a determined rotation speed, - A remote control for releasing all the satellites at a determined roll angle corresponding to the first angle.

[0010] In embodiments, in the initial configuration, second amounts of energy are also stored between neighboring satellites, arranged face to face in the same stage, tending to separate the neighboring satellites, so that the release of the sa tellites further causes the release of said second quantities of energy and the application, on the satellites of the same stage, of radial forces, the release of the satellites occurring at a second roll angle.

[0011] In embodiments, the method comprises sending remote commands from a ground station sending: - A remote control for tilting determined in pitch - A remote control for rolling the launcher at a determined angle corresponding to the second angle - A remote control for releasing all the satellites.

[0012] In embodiments, in the initial configuration, at least a third amount of energy is stored between a wall of the support ring of the stack and the stack of satellites, tending to separate the stack from this support wall.

[0013] In embodiments, the third amount of energy stored between the wall of the support ring and the stack of satellites involves a longitudinal force greater than the maximum longitudinal force between two satellites of consecutive stages and furthermore the third amount of energy stored is greater than the maximum amount of energy stored between two consecutive stages of the stack.

[0014] According to another object, there is described a space system for ejecting a stack of satellites comprising a plurality of stages, comprising a launcher receiving the stack of satellites supported by a ring of the launcher, each stage of the stack comprising at least two satellites arranged around a central geometric axis of the stack, and in which the satellites of one of the stages, with the exception of the first stage, are stacked on the satellites of the previous stage, the launcher comprising a device for holding and releasing the satellites keeping the satellites of the stack secured to each other and secured to the launcher in an initial configuration, characterized in that first quantities of energy are stored in spacing devices arranged between the consecutive stages of the stack and tending to separate two consecutive stages of the stack,the first quantities of energy stored between two consecutive stages being decreasing from the two ends of the stack towards the middle of the stack and the spacing devices between two consecutive stages generating decreasing forces from the two ends of the stack towards the middle of the stack, and in that it comprises: , - a first module for controlling a pitch orientation of the launcher so that the axis of the stack of satellites is inclined relative to an axis tangent to a scrolling orbit of the satellites, called the scrolling axis, - a second module for controlling the release of the satellites relative to the launcher and between them, causing the release of the first quantities of energy stored between the stages of the stack, resulting in the application of forces, along the axis of the stack, on the different stages of satellites, the projections of which on the scrolling axis are different for each stage, and - a third application module, on the satellites of the same stage, during the release of the satellites, of actions in a radial plane, relative to the axis of the stack corresponding to a longitudinal direction, the projections of which on the axis of movement are different for each satellite of the stage, the release of the satellites occurring at a roll angle determined according to the first quantities of stored energy and the actions in the radial plane.

[0015] In embodiments, the satellite stack comprises at least one preloaded mechanical spring between all consecutive satellites of the stack, the preload of the springs forming said first stored energy quantities.

[0016] In embodiments, the variation of the first quantities of stored energy and / or of the forces exerted by the spacing devices, between two consecutive stages, from the ends towards the middle of the stack, is implemented by at least one of: - a variation of the stiffness of the springs, - a variation in the preload applied to the springs, and - a variation in the number of springs.

[0017] In embodiments, the third module controls, before the release of the satellites, at least one rotation of the launcher relative to the stacking axis, said rotation giving the satellites of the same stage different speed components along a scrolling axis of the satellites, during the release of the satellites, the release of the satellites being provided at a first roll angle.

[0018] In embodiments, the third module stores second quantities of energy stored between neighboring satellites, arranged face to face in the same stage, tending to separate the neighboring satellites, so that the release of the satellites further causes the release of said second quantities of energy and the application, on the satellites of the same stage, of radial forces, the release of the satellites being provided at a second angle (see new figure) in roll.

[0019] In embodiments, in the initial configuration, at least a third amount of energy is stored between a wall of the stack support ring and the satellite stack, tending to separate the stack from this wall.

[0020] In embodiments, the third amount of energy stored between the support ring wall and the satellite stack involves a longitudinal force greater than the maximum longitudinal force between two satellites of consecutive stages and moreover the third quantity of stored energy is greater than the maximum quantity of energy stored between two consecutive stages of the stack.

[0021] The proposed ejection method advantageously makes it possible to simultaneously eject a stack of satellites comprising several satellites at each stage while minimizing the risk of collision, in the long term, between the satellites, because it allows all the satellites in the set to have, during ejection, a different speed depending on the axis of movement of the satellites.

[0022] Indeed, with regard to satellites belonging to consecutive stages of the stack, the release of the satellites is carried out from an initial configuration in which a quantity of energy is stored between each stage, the quantity of energy between two stages being variable along the stack, this therefore results in a different ejection speed for each satellite along the launcher axis.

[0023] Furthermore, with regard to satellites of the same stage, the application of a radial force or a rotation of the assembly providing a radial speed difference, makes it possible to give these satellites a different speed along an axis orthogonal to the launcher.

[0024] According to another advantage, the inclination of the launcher relative to the axis of movement of the satellites, confers distinct individual speeds, according to the axis of movement. Brief description of the drawings

[0025] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0026] [Fig.l] schematically represents a spatial system according to an exemplary embodiment and the conventions used according to the invention. Fig. 2a

[0027] [Fig.2a] schematically represents an example of stored energy quantities between the stages of the satellite stack in the initial configuration according to the invention. Fig. 2b

[0028] [Fig.2b] schematically represents the order of separation of the stages of the satellite stacking induced by the release of the stored energy according to the invention. Fig. 3a

[0029] [Fig.3a] schematically represents examples of velocity vectors, oriented ra dially, of satellites of the same stage during ejection according to the invention. Fig. 3b

[0030] [Fig.3b] schematically represents an example of configuration of the satellites of a same floor. Fig. 3c

[0031] [Fig.3c] schematically represents examples of ortho-radial velocity vectors of satellites of the same stage during ejection according to the invention. Fig. 3d

[0032] [Fig.3d] schematically represents examples of radial velocity vectors of satellites of the same stage during ejection according to the invention. Fig. 4

[0033] [Fig.4] represents an example of separation of the satellites according to the invention. Fig. 5a

[0034] [Fig.5a] represents a simulation of a first example of distribution of the speeds of all the satellites of the stack on the scroll axis after release according to the invention. Fig. 5b

[0035] [Fig.5b] represents a simulation of a second example of distribution of the speeds of all the satellites of the stack on the scroll axis after release according to the invention. Fig. 6

[0036] [Fig.6] schematically represents an example of a device for holding and releasing the stack of satellites according to the invention. Fig. 7

[0037] [Fig.7] schematically represents an example of a method of ejecting a stack of satellites according to the invention. Description of the embodiments

[0038] With reference to the appended figures, a method for ejecting a stack 2 of satellites 20 contained in a launcher 1 will now be described. This method can in particular be implemented for placing a constellation of satellites into orbit around the Earth. These satellites can be placed in a low Earth orbit (or LEO for the English acronym Low Earth Orbit), or in a medium Earth orbit (MEO) or even in a geostationary Earth orbit (GEO). The satellites in the stack can be, but not limited to, telecommunications satellites. The method according to the invention can be controlled by a control device 10 on board the launcher, comprising for example a computer, formed for example by one or more microcontrollers, microprocessors, FPGAs, DSPs, ASICs, etc. The control device can control a device for holding and releasing the stack of satellites.The control device 10 can for example receive instructions from a ground station 3, the station being in communication with the launcher and sending remote controls to the control device for the implementation of the different steps of the method. The control device. may for example comprise a memory (not shown), for example of the magnetic hard disk type, electronic memory, optical disk, etc., storing code instructions executed by the computer for implementing the method according to the invention.

[0039] The figures, in particular 1 and 2a, schematically show a launcher 1 containing a stack 2 of satellites 20. The stack comprises several stages 21 of satellites superimposed on each other in a stacking direction. The first stage of satellites is mounted on a support wall 10 of the launcher 1.

[0040] Referring for example to Figures 3a to 3c, each stage 21 comprises at least two satellites 20 arranged around a central geometric axis AA of the stack, preferably distributed regularly around this axis. Each stage 21 comprises for example between two and five satellites, and Figures 3a, 3c and 3d show an example in which each stage comprises three satellites, and [Fig.3b] an example in which each stage comprises two satellites 20. All the stages comprise for example the same number of satellites.

[0041] In addition, all the satellites of the same stage, and preferably all the satellites of the stack, are for example identical. According to a non-limiting example, shown schematically in [Fig. 6], each satellite 20 may comprise two opposite ends intended to be in contact with respective ends of neighboring satellites of the same stage of the stack, each end comprising a half-support foot 22, 22' extending over half the height of the satellite, considered in the direction AA of the stack. The half-support feet 22, 22' of the two opposite ends of the same satellite extend over respectively two different halves of the height of the satellite, so that a half-support foot of one end of a satellite rests on a half-support foot of the neighboring satellite.A stage 21 of satellites can thus be formed where each satellite 20 comprises a half-support foot resting on that of a neighboring satellite, and another half-support foot on which that of a neighboring satellite rests. The support feet of the satellites of the different stages are further aligned so that the satellites are stacked on top of each other by their support feet.

[0042] In embodiments, and as shown in the example of [Fig.6], each satellite may comprise, in addition to the half-support feet 22, 22' which are superimposed on those of the neighboring satellites, at least one complementary support foot 23, extending a portion of the periphery of the satellite located between the two ends, these support feet extending over the entire height of the satellite and being stacked on the complementary support foot 23 of the satellite of the lower stage.

[0043] In addition, the satellites are held together with each other and with the launcher by a holding and releasing device 4, in an initial configuration adopted throughout the launch of the launcher and until the ejection of the satellites. The holding and releasing device 4 is configured to allow simultaneous release of all the satellites from the stack 2. According to a non-limiting example, and still with reference to [Fig. 6], the holding and releasing device 4 may comprise a plurality of arms 40 distributed around the stack 2 of satellites, where each arm is connected on the one hand, to the launcher and on the other hand, at least to the stage 21 of the stack furthest from the support wall of the launcher. Alternatively, each arm may be connected to all the stages of the stack.Each arm 40 can for example be connected to the launcher by a pivot connection 41 around an axis tangential to the central axis AA of the stack, so as to move the arm away from the stack by rotation when the satellites are released.

[0044] In addition, the holding and releasing device 4 is configured to apply an axial compressive force in the direction of the stack, on the stack of satellites. The holding device comprises, for example, arms applying an axial compressive force. The compressive force makes it possible to hold the stack during the vibrations caused during launch. To return to the example described above, the arms 40 of the holding and releasing device may also comprise a device (not shown) for tensioning the arms, allowing the application of this axial compressive force.

[0045] Furthermore, as described in more detail below, the satellite stack stores axial energy tending to move the satellite stages away from each other. This separation energy is stored as long as the holding device exerts its action. With reference to FIGS. 2a and 2b, in the initial configuration in which the satellites are held integral with each other and integral with the launcher, first quantities of energy are stored in spacing devices 50 schematically represented, arranged between the consecutive stages of the stack, the quantities of stored energy tending to separate two consecutive stages 21 of the stack. The spacing devices 50 generate a force tending to separate the stages of the stack, this force generating stored energy due to the initial stacked configuration in which the satellites are held.

[0046] The spacing devices 50 are for example preloaded mechanical springs, i.e. compressed relative to their rest position, between two consecutive stages 21 of the stack, the preloading of the springs generating the storage of elastic potential energy tending to separate the stages 21 when the stack is released. Alternatively, other spacing devices may be used such as magnets exerting an electromagnetic force tending to separate the stages. The spacing devices may for example be in the form of jacks linear, each comprising a spring, for example.

[0047] As shown schematically in [Fig.2a], the quantities of energy stored between two stages 21 of the stack are not all identical depending on the pairs of stages considered. More precisely, the quantity of energy stored between two consecutive stages 21 of the stack decreases from the ends of the stack towards the middle of the stack, the ends and the middle being considered along the axis AA of the stack 2. On the other hand, the quantities of energy stored can be symmetrical with respect to the middle of the stack considered along the axis XX, that is to say that the same quantity of energy can be stored between the first two stages and the last two stages, then the same quantity of energy, lower, can be stored between stages 2 and 3 on the one hand, and between stages n-2 and n-1 on the other hand, where n designates the last stage of the stack, and so on.

[0048] The forces generated by the spacing devices between two consecutive stages of the stack also decrease from the two ends of the stack towards the middle of the stack.

[0049] The spacing devices thus provide decreasing energies and decreasing forces. The stored energies are adjusted to reach determined final speeds which correspond to the final gaps between each curve of [Fig.4]. The forces are adjusted to sequence the separation, as shown in [Fig.4], where the curves separate two by two as they go along.

[0050] In the case where the spacing devices 50 are mechanical springs, the variation of stored energy from one pair of stages to another can be obtained by at least one of: - a variation of the stiffness of the springs, - a variation in the preload applied to the springs which can also example to appear in the form of identical springs, and - a variation in the number of springs which may also, for example, be in the form of identical springs.

[0051] For example, the variation between two quantities of energy stored between two pairs of stages can be obtained by using springs 50 of different stiffnesses, with potentially the same preload applied to the springs, or by using a set of springs 50 all identical, i.e. of identical stiffness, but by varying the number of springs interposed between different pairs of stages, and / or by varying the preload of springs interposed between different pairs of stages.

[0052] As shown schematically in [Fig.2b], this variable distribution of the stored energy and the forces generated by the spacing devices 50 within the stack 2 makes it possible to induce, during the simultaneous release of all the stages 21, a kinematics of separation of the stages with differentiated speeds, where more The greater the energy stored between two stages, the greater the speed at which the stages separate. In fact, the stages furthest from the center of the stack are separated first, and the stages closest to the center of the stack are separated last.

[0053] Furthermore, and as illustrated in [Fig. 4], which represents the components along the X axis of the speeds of the different stages of the stack, this variable distribution of the stored energy also gives the satellite stages different speeds. With reference to [Fig. 1], when the stack of satellites is inclined relative to an X axis tangent to the orbit of the satellites, designated by the satellite scroll axis, the components of the speeds of the satellite stages along the X axis of scroll are differentiated. Obtaining different speeds along the scroll axis upon ejection of the satellites makes it possible to avoid long-term risks of collision of the satellites with each other.

[0054] Consequently, and with reference to [Fig.7], the method of ejecting the stack comprises a step 100 of orienting the launcher 1, for example from an initial orientation in which the stack 2 of satellites extends in a direction AA substantially radial relative to the Earth or the star around which the satellites are to be put into orbit, to tilt the stack of satellites relative to the X axis of movement. The pitch inclination angle may for example be between 10° and 80°, for example equal to 45°. In the case of axial and lateral ejection with springs, the choice of this angle will make it possible to deduce the energy to be stored in the axial springs and that to be stored in transverse springs. The choice of this angle therefore results from a compromise for the dimensioning of the ejection system. The launcher can be oriented, for example, using thrusters.This step of orienting the launcher 1 may for example comprise the reception by the control device 10 of the launcher of a pitch inclination remote control of the inclination angle value mentioned above transmitted by a ground station 3.

[0055] A rotation of the launcher 110 around its axis AA can possibly be commanded before or after the orientation 100.

[0056] Once the launcher is correctly oriented, the method may comprise the simultaneous release 200 of the satellites, this release being carried out by the holding and release device 40. Using the example provided previously of the holding and release device, all the arms 40 may separate simultaneously from the stack to allow the release of the satellites, and the release of the quantities of energy stored between two consecutive stages of the stack. This release step 200 may comprise the reception by the control device 10 of the launcher of a release remote control transmitted by the ground station 3.

[0057] In embodiments, an amount of energy may also be stored between the base of the stack 2 and the support wall 11 of the launcher, which may for example be a support ring, on which the stack is mounted, this amount of energy tending to separate the stack of satellites from the wall of the launcher. As previously for the first amounts of energy contained between the satellite stages, this amount of energy may be stored in the form of a spacing device 51, for example a preloaded mechanical spring, a linear actuator or a magnetic device tending to separate the stack of satellites from the launcher.The amount of energy stored between the base of the stack and the support wall of the launcher is preferably strictly greater than the maximum amount of energy stored between two stages of the stack, so as to prevent the satellite stage closest to the wall of the launcher from hitting this wall upon release, under the effect of the release of the energy stored between this stage and the upper stage.

[0058] Furthermore, and with reference to [Fig.3a], so that the components of the speeds, in projection along the axis of travel, of the satellites are not only different from one stage to another, but also between two satellites of the same stage, the ejection method comprises an application 300, on the satellites of the same stage, during the release 200 of the satellites, of actions in a radial plane relative to the axis AA of the stack, the projections of which on the axis X of travel of the satellites are different for all the satellites of the same stage. The actions in the radial plane can for example be exerted by the rotation of the launcher. The actions in the radial plane can for example be exerted by the transverse springs between satellites of the same stage, exerting determined forces and energy levels.

[0059] The actions exerted on the satellites of the same stage are for example the same in absolute value, but different projections on the X axis of scrolling can be obtained, by releasing the satellites with a determined orientation in roll of the stack. This orientation is a function in particular of the way in which the radial actions are applied to the satellites. In particular the actions exerted by means of rotation around the AA axis, as shown in [Fig.3c] differ from the actions exerted by means of transverse springs as shown in [Fig.3d], which implies choices of different orientations during release. The transverse springs of [Fig.3d] in fact separate the satellites in radial directions, while rotation around the AA axis separates the satellites in ortho-radial directions as shown in [Fig.3c].

[0060] For example, and as shown schematically in [Fig.3b], in the case where a stage comprises two satellites, and where the actions exerted on the satellites extend radially, the release must occur for a roll orientation of the stack such that the position of the two satellites is not symmetrical with respect to the X axis of scrolling.

[0061] In the configuration example given in [Fig.3b], which would not allow different components to be generated along the scrolling axis X and where the ejection method generates radial velocities, we see that when the position of the two satellites is symmetrical with respect to the scrolling axis X, since the action performed on the satellites is radial, the resultant along the X axis would be zero for the two satellites.

[0062] Similarly, in the case of three satellites, and as shown in [Fig.3d], two of the three satellites must not have a symmetrical position with respect to the X axis, because otherwise the resultants of the radial velocities generated on these satellites along the X axis would be equal. Consequently, the release 200 of the satellites is implemented at a determined roll angle, depending on the radial actions exerted and the stored axial energies.

[0063] With reference to [Fig.3c], in embodiments, the method comprises a step 110 of rotating the launcher 1 around the satellite stacking axis AA, before releasing the satellites, and the satellites 200 are released while the launcher is rotating. The step 110 of rotating the launcher around the axis AA may comprise the control device 110 receiving a rotation remote control sent by the ground station 3.

[0064] When the launcher is mobile in rotation around its axis AA, the distance between the center of gravity of the satellite and the axis of rotation implies an orthoradial linear speed. The rotation speed of the launcher can for example be between 2 and 10° / s, for example between 3 and 57s. In addition, the release of the satellites 200 is carried out at the determined roll angle mentioned above, so that the components of the speeds of the satellites of the same stage projected along the X axis of movement are different.

[0065] Alternatively, and as shown schematically in [Fig.3d], in embodiments, the speeds generated in a radial plane on the satellites of the same stage may result from the release of quantities of energy stored between the satellites 20 of the same stage 21, for example by spacing devices 52 arranged between each pair of neighboring satellites 20 of a stage, and tending to separate these satellites. For example, the forces exerted by the spacing devices are all identical for the same stage, so that the resultant of the forces on a given satellite by the forces induced between this satellite and its neighbors is radial. For example, the spacing devices may be prestressed springs 52 arranged between each pair of neighboring satellites 20. Alternatively, the spacing devices may be hydraulic cylinders or magnetic devices configured to separate the springs.

[0066] The first quantities of energy stored between two consecutive stages, and the second quantities of energy stored between neighboring satellites of the same stage make it possible to induce velocity components, in projection along the scrolling axis, which are different between several stages and between the satellites of the same stage. With reference to Figures 5a and 5b, which represent on the abscissa the stages of satellites considered, and on the ordinate the speed of each satellite along the scrolling axis X, these respective quantities of energy can be adapted according to the desired speed differences between the satellites. In these figures, the satellites of the same tower T are represented by the same figure, that is to say the sets of satellites superimposed on each other within the stack. The number of towers therefore corresponds to the number of satellites of the same stage.In the particular example of the figures, the stack comprises three satellites per floor and we have noted T1, T2, T3 the towers formed respectively by each stack of satellites.

[0067] In the embodiment shown in [Fig.5a], the quantities of energy between the satellites of the same stage can be dimensioned so as to confer a speed differential AViat between these satellites, and the quantities of energy between two stages of satellites can be dimensioned so as to confer a speed differential AVax greater than n times AViat, where n designates the number of satellites per stage.

[0068] In the example shown in [Fig.5b], the quantities of energy between two satellite stages can be dimensioned so as to confer a speed differential AVax and dimension the quantities of energy between the satellites of the same stage to confer a speed differential greater than N times AVax where N denotes the number of stages in the stack.

[0069] The choice of speed distributions can advantageously be a function of the desired dimensioning for the spacing devices 50, 51 and where appropriate 52 and of the method of applying forces in the radial plane between the satellites of the same stage.

[0070] Numerical references: 1: launcher 10: control device 11: support wall 2: stacking of satellites 20: satellite 21: satellite stage 22, 22': half support feet 23: additional support feet 3: ground station 4: holding and releasing device 40: arms 41: pivot link 50: spacer device between two floors 51: spacing device between the launcher and the stack 52: separation device between two satellites 100: pitcher orientation in pitch 110: Launcher rotation 200: release of satellites 300: application of actions on satellites.

Claims

1. Claims A method of ejecting a stack (2) of satellites (20) contained in a launcher (1), the stack of satellites comprising a plurality of stages (21), each stage of the stack comprising at least two satellites (20) arranged around a central geometric axis (AA) of the stack, and in which the satellites of one of the stages, with the exception of the first stage, are stacked on the satellites of the previous stage, the ejection method being characterized in that it is implemented from an initial configuration in which the satellites of the stack are held together with each other and with the launcher by a holding and releasing device (4), first quantities of energy being stored in spacing devices (50) arranged between the consecutive stages of the stack and tending to separate two consecutive stages of the stack,the first quantities of energy stored between two consecutive stages being decreasing from the two ends of the stack towards the middle of the stack and the spacing devices between two consecutive stages generating decreasing forces from the two ends of the stack towards the middle of the stack, and in that it comprises:, - an orientation (100) of the launcher in pitch so that the axis (AA) of the stack of satellites is inclined relative to an axis tangent to a scrolling orbit of the satellites, called scrolling axis, - a release (200) of the satellites relative to the launcher and between them, causing the release of the first quantities of energy stored between the stages of the stack, resulting in the application of forces, along the axis of the stack, on the different stages of satellites, the projections of which on the axis of movement are different for each stage, and - an application (300), on the satellites (20) of the same stage (21), during the release of the satellites, of actions in a radial plane, relative to the axis of the stack corresponding to a longitudinal direction, the projections of which on the axis of movement are different for each satellite of the stage, the release of the satellites occurring at a roll angle determined as a function of the first quantities of energy stored and actions in the radial plane.

2. An ejection method according to claim 1, wherein the stack (2) of satellites (20) comprises at least one preloaded mechanical spring (50) between all consecutive satellites of the stack, the preload of the springs forming said first stored energy quantities.

3. An ejection method according to claim 1, wherein the variation of the first quantities of stored energy and / or of the forces exerted by the spacing devices, between two consecutive stages, from the ends towards the middle of the stack, is implemented by at least one of: - a variation of the stiffness of the springs (50), - a variation of the preload applied to the springs (50), and - a variation of the number of springs (50).

4. Ejection method according to one of the preceding claims, comprising, before the release of the satellites, at least one rotation (110) of the launcher (1) relative to the stacking axis (AA), said rotation giving the satellites (20) of the same stage (21) different speed components along the scrolling axis, during the release of the satellites, the release of the satellites occurring at a first roll angle.

5. Ejection method, according to the preceding claim, comprising sending remote controls from a ground station sending: - A remote control of determined pitch inclination, - A remote control of rotation of the launcher around the longitudinal axis at a determined rotation speed, - A remote control of release of all the satellites at a determined roll angle corresponding to the first angle.

6. Ejection method according to one of claims 1 to 4, in which, in the initial configuration, second quantities of energy are also stored between the neighboring satellites, arranged face to face in the same stage, tending to separate the neighboring satellites, so that the release of the satellites further causes the release of said second quantities of energy and the application, on the satellites of the same stage, radial forces, the release of the satellites occurring at a second angle in roll.

7. Ejection method according to the preceding claim, comprising sending remote controls from a ground station sending: - A remote control of determined pitch inclination - A remote control of roll orientation of the launcher at a determined angle corresponding to the second angle - A remote control of release of all the satellites.

8. An ejection method according to one of the preceding claims, wherein in the initial configuration, at least a third quantity of energy is stored between a wall of the support ring of the stack and the stack of satellites, tending to separate the stack from this support wall.

9. Method according to the preceding claim, in which the third quantity of energy stored between the wall of the support ring and the stack of satellites involves a longitudinal force greater than the maximum longitudinal force between two satellites of consecutive stages and furthermore the third quantity of energy stored is greater than the maximum quantity of energy stored between two consecutive stages of the stack.

10. Space system for ejecting a stack (2) of satellites (20) comprising a plurality of stages (21), comprising a launcher (1) receiving the stack (2) of satellites supported by a ring of the launcher, each stage of the stack comprising at least two satellites (20) arranged around a central geometric axis (AA) of the stack, and in which the satellites of one of the stages, with the exception of the first stage, are stacked on the satellites of the previous stage, the launcher comprising a device (4) for holding and releasing the satellites keeping the satellites of the stack secured to each other and secured to the launcher in an initial configuration, characterized in that first quantities of energy are stored in spacing devices (50) arranged between the consecutive stages of the stack and tending to separate two consecutive stages of the stack,the first quantities of energy stored between two consecutive stages being decreasing from the two ends of the stack towards the middle of the stack and the devices, spacing between two consecutive floors generating decreasing forces from the two ends of the stack towards the middle of the stack, and in that it includes: - a first module for controlling a pitch orientation of the launcher so that the axis of the stack of satellites is inclined relative to an axis tangent to a scrolling orbit of the satellites, called the scrolling axis, - a second module for controlling the release of the satellites relative to the launcher and between them, causing the release of the first quantities of energy stored between the stages of the stack, resulting in the application of forces, along the axis of the stack, on the different stages of satellites, the projections of which on the axis of travel are different for each stage, and - a third application module, on the satellites of the same stage, during the release of the satellites, of actions in a radial plane, relative to the axis of the stack corresponding to a longitudinal direction, the projections of which on the axis of movement are different for each satellite of the stage, the release of the satellites occurring at a roll angle determined according to the first quantities of stored energy and the actions in the radial plane.

11. A space ejection system according to claim 10, wherein the stack (2) of satellites (20) comprises at least one preloaded mechanical spring (50) between all consecutive satellites of the stack, the preload of the springs forming said first stored energy quantities.

12. Spatial ejection system according to one of claims 10 or 11, in which the variation of the first quantities of stored energy and / or of the forces exerted by the spacing devices, between two consecutive stages, from the ends towards the middle of the stack, is implemented by at least one of: - a variation in the stiffness of the springs, - a variation in the preload applied to the springs, and - a variation in the number of springs.

13. Space ejection system according to one of claims 10 or 11, in which the third module controls, before the release of the satellites, at least one rotation of the launcher relative to the stacking axis (AA), said rotation giving the satellites of the same stage different speed components along an axis (X) of movement of the satellites, during the release of the satellites, the release of the satellites being provided at a first roll angle.

14. Space ejection system according to one of claims 10 to 12, in which the third module stores second quantities of energy stored between the neighboring satellites, arranged face to face in the same stage, tending to separate the neighboring satellites, so that the release of the satellites further causes the release of said second quantities of energy and the application, on the satellites of the same stage, of radial forces, the release of the satellites being provided at a second roll angle.

15. Space ejection system according to one of claims 10 to 14, wherein in the initial configuration, at least a third quantity of energy is stored between a wall (11) of the support ring of the stack and the stack of satellites, tending to separate the stack from this wall (11).

16. Space ejection system according to one of claims 10 to 15, in which the third quantity of energy stored between the wall of the support ring and the stack of satellites involves a longitudinal force greater than the maximum longitudinal force between two satellites of consecutive stages and furthermore the third quantity of energy stored is greater than the maximum quantity of energy stored between two consecutive stages of the stack.

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