PROCESS FOR FITTING A PLURALITY OF SPACE VESSELS UNDER THE CAP OF A LAUNCHER WITHOUT STRUCTURAL DISTRIBUTOR AND ASSEMBLY RESULTING FROM SUCH A PROCESS

The invention relates to the field of astronautics, and more particularly to the launching of spacecraft such as artificial satellites. More particularly, it relates to a method of fitting out a plurality of spaceships under the fairing of a launcher and to an assembly which may result from such a method.

As part of an aggressive policy of optimizing costs and systems, it is necessary to modify and optimize the usual methods of assembling satellites under the fairings of space launchers in order to maximize the space and mass available for them. spaceships.

Usually, the arrangement of satellites within a launcher is done using two solutions:

The first option is the use of a central tubular element placed along the axis of the casing of the launcher, called a distributor. This tube is mechanically linked to the satellites in order to maintain them during launch and flight using mechanical interfaces. The assembly formed by the distributor and mechanical interfaces provides a rigid assembly. In space, after release of this assembly from the launcher, pyrotechnic charges, electromechanical coils, shape memory alloys or paraffin actuators, separate the satellites from the structural distributor. The simplest solution consists in joining together a plurality of satellites on a single stage around a central tube.

FIG. 1 shows a distributor of the prior art (taken from document EP 3081496) which can be housed under the fairing of a Falcon 9 launcher, this distributor allowing more efficient use of the space under the available fairing. This assembly works only for small satellites, arranging them in several layers around a distributor. This assembly comprises 6 stages of 12 2-layer satellites, plus a single-layer stage, comprising 4 satellites. This assembly makes it possible to launch up to 76 satellites. The use of a dispenser therefore makes it possible to maintain

mechanically the satellites to the launcher and control the sequence of satellite releases. However, installing a distributor has significant financial and logistical costs. In addition, the central tube occupies a significant space which is not converted into payload (satellites) and, on average, the distributor constitutes 10 to 14% of the total launched mass.

It is known from the prior art to adapt the shape and type of non-tubular dispenser (see for example US patent 5411226 A) in order to minimize the space occupied by the dispenser. However, although the space occupied is minimized, the mass of the distributor remains substantial and limits the number of satellites that can be launched simultaneously.

The second option is the stacking of satellites along the longitudinal axis of the launcher under the fairing. The disadvantage of this solution is that the mass of the stacked satellites is reflected on the bottom satellite (s), which forces the design and structure of these satellites to be adapted (generally by increasing their mass) so that they can support such mechanical stress. In addition, such an arrangement greatly complicates and increases the risks of the satellite separation sequence. Finally, such an assembly is very often limited to one satellite per level.

The invention aims to allow more efficient use of the volume available under the fairing, of the total mass launched and therefore to increase the number and / or the mass of satellites that can be launched simultaneously.

ABSTRACT

In accordance with the invention, this object is achieved by arranging the satellites under the fairing of a launcher without using a structural distributor.

Thus, an object of the invention is an assembly comprising: at least a first set of a plurality of spacecraft intended to be attached to a launcher in a launch phase, characterized in that the spacecraft are arranged around 'a central axis in the same transverse plane perpendicular to said central axis, said space vessels having ridges along a longitudinal axis and being further arranged in

so that a spacecraft is linked to a neighboring spacecraft by means of a ridge by at least one fixing device located on said stop, so as to ensure the mechanical retention of said vessels between them,

a satellite-launcher adapter to which said spacecraft are attached in a transverse plane. According to particular embodiments of such an assembly:

Said spacecraft are attached to the launcher via a launcher interface part, called a satellite-launcher adapter, adapted according to the number of spacecraft to be assembled.

- Said satellite-launcher adapter is a part having a flat upper part, on the spacecraft side, and a circular or conical lower part, on the launcher side.

Said satellite-launcher adapter is a cylindrical part placed below the spacecraft.

- Said spaceships are mounted directly on the launcher and secured to the launcher and to each other by a strap.

The assembly includes a central mast common to all spaceships to control the sequence of release of the spaceships.

Assembly in which there are several sets of spacecraft arranged around a central axis in the same transverse plane perpendicular to said central axis, said spacecraft having ridges along a longitudinal axis and further being arranged so that one vessel space is linked to a neighboring spaceship by means of a ridge by at least one fixing device located on said ridge, so as to ensure the mechanical retention of said vessels between them, forming layers stacked along the longitudinal axis of the launcher , the layers being linked together in a transverse plane of said launcher.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics, details and advantages of the invention will emerge on reading the description given with reference to the appended drawings given by way of example and which represent, respectively:

- Figure 1, described above, an assembly of spaceships under the cover according to the prior art;

FIG. 2, an overall view of the assembly of spaceships according to the invention;

Figure 3, a view of a spacecraft;

FIG. 4, a detailed view of an assembly of spaceships according to one embodiment of the invention;

FIG. 5, a simplified sectional view of an assembly of spaceships according to one embodiment of the invention;

FIG. 6, an assembly of spaceships according to one embodiment of the invention;

In what follows, the term “longitudinal direction” (or “longitudinal axis”) will be understood to mean a direction (respectively an axis) parallel to the axis of the fairing, and therefore to the direction of advance of the launcher. The term “transverse plane” is understood to mean a plane perpendicular to the axis of the cover (therefore to the longitudinal axis).

The term “spacecraft” can designate an artificial satellite or any other device intended to evolve in space, such as an interplanetary probe. In the following, the terms “satellite” and “spacecraft” will be used interchangeably.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 represents an elevational view of an assembly 2 of spaceships 20, 21, 22 intended to be fixed under the fairing of a launcher in a launch phase, the fairing being shown in transparency 23. Here the assembly is composed of three satellites with trapezoidal section. In the assembly according to the invention, the satellites are arranged around a central axis Z in the same transverse plane so as to form a layer. The central axis is an axis parallel to the longitudinal axis of the space launcher. The term transverse plane is used here to mean any plane perpendicular to the central axis Z. The satellites are mechanically linked to each other only by means of their edges, along the longitudinal axis of the space launcher. More precisely, the satellites or spacecraft are arranged so that a spacecraft is linked to a neighboring spacecraft of the assembly by means of a ridge by at least one fixing device B (or fixing point) located on said stop, so as to ensure the mechanical retention of said vessels between them. FIG. 2 illustrates three of these fixing points B, located at the top of the edges of the neighboring satellites. In addition, the satellites are mechanically linked to the launcher by means of an interface piece called the satellite-launcher adapter (24, visible in FIG. 3) similar to that shown diagrammatically in FIG. 4 comprising points (or feet) of fixing binding the satellites to this part. The launcher interface being typically circular, the satellite-launcher adapter generally comprises a circular part in order to be fixed to the launcher. In the embodiment of FIG. 2, the satellite / satellite and satellite / launcher attachments are made by pyrotechnic bolts. This type of attachment has the advantage of facilitating the sequence control of release of grouped / separated spaceships. These fixing devices therefore also allow the satellites to be released from one another during the release sequence. Alternatively, in another embodiment, the fixing device (s) B are electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely. In the embodiment of FIG. 2, the satellite / satellite and satellite / launcher attachments are produced by pyrotechnic bolts. This type of attachment has the advantage of facilitating the sequence control of release of grouped / separated spaceships. These fixing devices therefore also allow the satellites to be released from one another during the release sequence. Alternatively, in another embodiment, the fixing device (s) B are electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely. In the embodiment of FIG. 2, the satellite / satellite and satellite / launcher attachments are produced by pyrotechnic bolts. This type of attachment has the advantage of facilitating the sequence control of release of grouped / separated spaceships. These fixing devices therefore also allow the satellites to be released from one another during the release sequence. Alternatively, in another embodiment, the fixing device (s) B are electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely. These fixing devices therefore also allow the satellites to be released from one another during the release sequence. Alternatively, in another embodiment, the fixing device (s) B are electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely. These fixing devices therefore also allow the satellites to be released from one another during the release sequence. Alternatively, in another embodiment, the fixing device (s) B are electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely.

The assembly according to the invention does not use a distributor to hold the spaceships to the launcher during launch. The role of mechanical support along the longitudinal axis of the launcher which was fulfilled

usually by a structural distributor is here made by the connections between the ridges of the satellites along the same axis, here by pyrotechnic bolts. By structural distributor is meant here a structural element having a very high mechanical rigidity and making it possible to resist the forces between the launcher and each of the satellites and between the satellites themselves. This solution therefore allows a considerable saving in storage volume and a gain in launchable useful mass. It is then possible to modify the structure of the satellites to take advantage of this space and this available mass in order to carry more payload which represents the value of the satellites. In addition, not installing a dispenser reduces costs and simplifies the fitting process. The useful mass saved thanks to this assembly is estimated at 5 to 7% of the total useful mass launched (ie approximately 50% of the mass of a conventional distributor). The arrangement shown in Figure 2 is called a "trapezoid" because it is made up of satellites with a trapezoidal section. In another embodiment, the satellites have a rectangular section. However, the use of satellites with a trapezoidal section allows greater use of the space made available by the absence of a distributor than with satellites with a rectangular section. It will therefore preferably be used. In another embodiment, the satellites have a rectangular section. However, the use of satellites with a trapezoidal section allows greater use of the space made available by the absence of a distributor than with satellites with a rectangular section. It will therefore preferably be used. In another embodiment, the satellites have a rectangular section. However, the use of satellites with a trapezoidal section allows greater use of the space made available by the absence of a distributor than with satellites with a rectangular section. It will therefore preferably be used.

The dynamic behavior of the assembly must meet the requirements of the launching authorities. More particularly, the frequencies of the first modes of oscillation in a vertical and longitudinal direction must be greater than limit values ​​which depend on the launcher and which are of the order of a few Hz or tens of Hz. Numerical simulations have made it possible to show that , in the embodiment of Figure 2, the first transverse and longitudinal frequency have values ​​in accordance with the specifications.

The rigid assembly formed by the three satellites with trapezoidal section and the satellite-launcher adapter is placed in the center of the launcher fairing. FIG. 3 shows an isolated elevational view of the satellite with a trapezoidal section 22 alone placed on the satellites-launcher adapter 24. The edges 25 of the satellite 22 are those which, joined to the others of the neighboring satellites 20 and 21 (shown in the figure). FIG. 2) by means of fixing devices B allowing the satellites to be held together and allowing the release of these satellites. FIG. 3 illustrates the fixing devices B which are placed on the ridges 25 and distributed along the latter. In the example of Figure 3, given without limitation,

In the embodiment of Figures 2 and 3, the satellites have a cylindrical reinforcement 26 placed at the base of the structure of the satellites, in the extension of the attachment with the satellite-launcher adapter 24 to provide rigidity and a additional maintenance of the satellites to the satellite-launcher adapter. In another embodiment, this cylindrical reinforcement is not installed in the structure of the satellites.

In another embodiment, the satellites are secured to each other in the same way as the assembly illustrated in FIG. 2 but are linked directly (without satellite-launcher adapter 24) to the launcher by means of a strap for example providing in fact an additional maintenance between them. In this case, the satellites are fixed on the circular periphery of the launcher interface. In another embodiment, the number of satellites that make up the assembly may be different from three, both in the embodiment with a satellite-launcher adapter and in that with direct attachment to the launcher. FIG. 4 is a plan view of the assembly according to the invention of a satellite and of the satellite-launcher adapter interface part 24. This part links the launcher 32 to the three satellites (here only one satellite 21 is shown) by means of a fixing foot 33. In this embodiment, the satellite-launcher adapter is a rigid cylindrical metal part placed directly in the middle. below the satellites and between the satellites and the launcher. In another embodiment, the satellites-launcher adapter is a part whose upper part (satellite side) is a simple flat rigid plate making it possible to make the link with the satellites and whose lower part (launcher side) is circular or conical. to link to the launcher. In the the satellites-launcher adapter is a rigid cylindrical metal part placed directly below the satellites and between the satellites and the launcher. In another embodiment, the satellites-launcher adapter is a part whose upper part (satellite side) is a simple flat rigid plate making it possible to make the link with the satellites and whose lower part (launcher side) is circular or conical. to link to the launcher. In the the satellites-launcher adapter is a rigid cylindrical metal part placed directly below the satellites and between the satellites and the launcher. In another embodiment, the satellites-launcher adapter is a part whose upper part (satellite side) is a simple flat rigid plate making it possible to make the link with the satellites and whose lower part (launcher side) is circular or conical. to link to the launcher. In the

embodiment of FIG. 4, the satellite-launcher adapter is a part common to the three satellites. In another embodiment, this interface part is adapted to the number and to the structure of the spaceships that it is desired to assemble.

Figure 5 shows a schematic sectional view of the assembly of spaceships according to the same embodiment as that of Figure 4. As a reminder, the structure of the satellites is trapezoid in order to optimize the space freed by the no distributor. The three satellites 20, 21, 22 are linked by their edges by means of fixing devices B and the reinforcements 26a, 26b, 26c in each satellite are thirds of cylinders making it possible to provide rigidity and additional support for the satellites to the satellite-launcher adapter. The fixing devices B are placed at the top of the edges of neighboring satellites of the same layer and making it possible to secure the satellites together. In addition, a central mast 31 which, unlike a conventional distributor does not perform any structural function and can therefore be much lighter, is installed in the center of the assembly and is connected to all satellites. This mast is connected to all the points of attachment of the satellites to each other and those of the satellites to the satellite-launcher adapter. This mast is a simple non-mechanical interface, which does not hold the satellites together or to the launcher, but which includes the device for releasing the spacecraft. The ends of this mast are pyrotechnic charges make it possible, at the desired moment, to separate the satellites from one another and the satellites from the launcher. In the embodiment of this figure, the points of attachment of the satellites to each other and those of the satellites to the satellites-launcher adapter are pyrotechnic bolts and the mast makes it possible to control the explosion of these bolts. This non-structural mat therefore makes it possible to control the satellite release sequence. It is possible to release several satellites together, or to release them separately one by one.

FIG. 6 shows an assembly 40 of three "trapezoidal" satellites 41, 42, 43 - a satellite 43 is not shown for reasons of visibility - linked to the launcher by a cylindrical satellite-launcher adapter 44 with a non-structural central mast. 31 serving as a common interface to the three satellites comprising a device for releasing the spaceships. In the embodiment of FIG. 6, the connection between the neighboring satellites is made by 4 fixing points by pyrotechnic bolts and the satellites / satellite-launcher adapter connection is made using two fixing points (here again pyrotechnic bolts). In addition, as in the embodiment of Figure 3, the structure of the satellites comprises two thirds of cylinder 26a, 26b which serve to promote the transition of the satellite / satellite-launcher adapter efforts. In another embodiment, the number of satellite / satellite and satellite / satellite-launcher adapter links may be different from that of the embodiment of FIG. 6.

In another embodiment, the release device is not produced by pyrotechnic bolts but by electromechanical coils, shape memory alloys, paraffin actuators or other detachable link mechanisms that can be activated remotely.

In another embodiment, the non-mechanical interface common to all spacecraft and which comprises a device for releasing the vessels is not a mast but is produced by cables connected to each other and fixed at the level of the satellite adapter. - launcher and connecting all the fixing points of the satellites to each other and of the satellites to the satellites-launcher adapter. The advantage of a mast is that it is less likely to move around when throwing.

In another embodiment, stacks are made along the launcher longitudinal axis of several layers of sets of multiple spacecraft linked together only along the longitudinal axis of the launcher, without the use of a structural distributor and linked to the launcher. launcher interface in a transverse plane of the launcher. This assembly has the advantage of being able to produce N stacks of n satellites while controlling, for each assembly, the launch sequence of the n satellites. In this embodiment, fixing points (pyrotechnic bolts for example) or continuous fixing in a circular arc by satellite, in the transverse plane will be used between each stack in order to be able to separate the stacks one by one. It is evident that in this case

adapted to withstand the stress of the mass of the satellites stacked above.

In one embodiment, the assembly sequence of a plurality of spacecraft 20, 21, 22 under the fairing of a launcher 23 comprises:

■ Fit the satellite-launcher adapter 24 on the launcher and under the fairing;

■ Install the 1 st set of satellites 2, one by one, in this way;

-Fix a satellite on the satellite-launcher adapter;

-Then another and link it to the satellite already fixed along the launcher longitudinal axis;

-Then another, etc ... until having fixed all the satellites and having linked them together along the launcher longitudinal axis so as to form an integral assembly;

■ Install the non-mechanical interface 31 common to all spacecraft comprising a vessel release device.

In another embodiment, the assembly sequence is identical to that previously illustrated but the installation of the non-mechanical interface is carried out after having fixed a first satellite on the satellite-launcher adapter.

In another embodiment, the installation of the non-mechanical interface can be done before the arrangement of a first set of satellites under the launcher fairing (and after having linked them together along the launcher longitudinal axis).

CLAIMS

1. Assembly comprising:

-at least a first set (2) of a plurality of spacecraft (20, 21, 22) intended to be attached to a launcher (23) in a launch phase, characterized in that the spacecraft are arranged around 'a central axis (Z) in the same transverse plane perpendicular to said central axis, said spacecraft having ridges along a longitudinal axis and being further arranged so that a spacecraft is linked to a spacecraft adjacent to it 'together by means of a ridge by at least one fixing device (B) located on said ridge, so as to ensure the mechanical retention of said vessels between them,

-a satellite-launcher adapter (24) to which said spacecraft are attached in a transverse plane.

2. Assembly of spaceships according to the preceding claim, in which the satellite-launcher adapter is a part having a flat upper part, on the spacecraft side, and a circular or conical lower part, on the launcher side.

3. The assembly of spacecraft according to the preceding claim, wherein the satellite-launcher adapter is a cylindrical part placed below the spacecraft.

4. The assembly of spaceships according to any one of the preceding claims, comprising a central mat (31) common to all the spaceships making it possible to control the sequence of release of the spaceships.

5. A spacecraft assembly according to any preceding claim, wherein there are several sets of spacecraft, forming layers stacked along the longitudinal axis of the vessel.

RECTIFIED SHEET (RULE 91) ISA / EP

launcher, the layers being linked together in a transverse plane of said launcher.

RECTIFIED SHEET (RULE 91) ISA / EP