RU2785868C2 - Method for arrangement of set of spacecrafts under head fairing of launch vehicle without structural distributor and assembly obtained using such a method - Google Patents

Abstract

FIELD: cosmonautics.

SUBSTANCE: invention relates to the field of cosmonautics and, in particular, concerns a method for arrangement of a set of spacecrafts (hereinafter – SC) under head fairing of a launch vehicle (hereinafter – LV) without the use of a structural distributor. For this purpose, spacecrafts with longitudinal ribs are arranged around the central axis of LV. Each SC is connected to the neighboring one by means of a mounting device located on the mentioned rib. Assembly of spacecrafts has a central rack, which is shared by all SC, and which serves for control of a sequence of SC separation. Blocks of several SC form layers stacked on top of each other along the longitudinal axis of LV.

EFFECT: more efficient use of an available volume under head fairing and increase in a number of satellites, which can be launched simultaneously.

5 cl, 6 dwg

Description

The invention relates to the field of astronautics and, in particular, to the launch of spacecraft such as artificial satellites. More specifically, it relates to a method for arranging a plurality of spacecraft under a launch vehicle fairing and to an assembly that can be obtained using such a method.

As part of an active cost and systems optimization policy, it is necessary to change and optimize the usual ways of combining satellites under the nose fairing of launch vehicles in order to maximize the space and mass available for spacecraft.

Typically, two solutions are used to position satellites inside a launch vehicle:

The first option is to use a central tubular element located along the axis of the head fairing of the launch vehicle and called the distributor. This tube is mechanically connected to the satellites to hold them during launch and flight using mechanical interfaces. The block, consisting of a distributor and mechanical interfaces, allows you to get a rigid assembly. In outer space, after separation of this assembly from the launch vehicle, pyrotechnic charges, electromechanical coils, shape memory alloys, or paraffin actuators disconnect the satellites from the constructive distributor. The simplest solution is to mount multiple satellites on the same stage around the central tube.

In FIG. 1 shows a prior art distributor (disclosed in EP 3081496) that can be placed under the fairing of a Falcon 9 launch vehicle, the distributor making better use of the space available under the fairing. This assembly only works for small satellites with multiple layers around the spreader. This assembly contains 6 stages of 12 satellites in 2 layers, plus one stage with one layer containing 4 satellites. This build allows you to launch up to 76 satellites. Thus, the use of a distributor makes it possible to mechanically hold the satellites on the launch vehicle and control the separation sequence of the satellites. However, the installation of the distributor is costly and requires complex logistics. In addition, the central tube occupies a large space that is not used for payload (satellites), and on average the distributor makes up 10-14% of the total mass launched into space.

Known solutions (see, for example, US Pat. No. 5,411,226 A) adapt the shape and type of a non-tubular distributor to minimize the space occupied by the distributor. However, even with space minimization, the mass of the spreader remains significant and limits the number of satellites that can be launched simultaneously.

The second option is to place the satellites one above the other in a set along the longitudinal axis of the launch vehicle under its nose fairing. The disadvantage of this solution is that the mass of the satellites in the set acts on the satellite(s) below, forcing the design and construction of these satellites (typically by increasing their mass) to be able to withstand such a mechanical load. In addition, such an arrangement greatly complicates and increases the risks of the satellite separation sequence. Finally, such a build is very often limited to one companion per level.

The invention is intended to provide more efficient use of the available volume under the nose fairing, the total launch payload and, therefore, increase the number and/or mass of satellites that can be launched simultaneously.

SUMMARY OF THE INVENTION

According to the invention, this problem is solved by arranging the satellites under the head fairing of the launch vehicle without using a constructive distributor.

Thus, the object of the invention is an assembly containing:

- at least one first block from a plurality of spacecraft to be fixed on the launch vehicle in the launch phase, characterized in that the spacecraft are located around the central axis in one transverse plane perpendicular to the said central axis, while the said spacecraft have ribs along the longitudinal axis and, in addition, are located in such a way that one spacecraft is connected to an adjacent spacecraft through one rib using at least one fastening device located on said rib to provide mechanical retention of the said spacecraft between themselves ,

- adapter "satellites - carrier rocket", on which the above-mentioned spacecraft are fixed in the transverse plane.

According to private options for performing such an assembly:

Said spacecraft are fixed to the launch vehicle by a launcher connector called a satellite-to-booster adapter, adaptable depending on the number of spacecraft to be assembled.

- Said satellite-to-launcher adapter is a piece having a flat top on the spacecraft side and a round or conical bottom on the launcher side.

- Said adapter "satellites - launch vehicle" is a cylindrical piece located under the spacecraft.

- The said space vehicles are installed directly on the launch vehicle and are connected to the launch vehicle and to each other by means of a clamp.

- The assembly contains a central rack shared by all spacecraft, serving to control the spacecraft separation sequence.

- An assembly in which there are several blocks of spacecraft located around a central axis in one transverse plane perpendicular to said central axis, while said spacecraft have ribs along the longitudinal axis and, in addition, are located in such a way that one spacecraft is connected to an adjacent spacecraft through one rib using at least one fastening device located on said rib to provide mechanical retention between the said spacecraft forming layers stacked on top of each other along the longitudinal axis of the launch vehicle, while the layers are connected with each other in the transverse plane of said launch vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, details and advantages of the invention will become more apparent from the description with reference to the accompanying drawings, which are presented by way of example and in which:

Fig. 1 (described above) - the assembly of spacecraft under the head fairing according to the prior art.

Fig. 2 is a general view of the spacecraft assembly according to the invention.

Fig. 3 - view of the spacecraft.

Fig. 4 is a detail view of a spacecraft assembly according to one embodiment of the invention.

Fig. 5 is a simplified sectional view of a spacecraft assembly according to an embodiment of the invention.

Fig. 6 shows the assembly of spacecraft according to one embodiment of the invention.

In the following text of the description, "longitudinal direction" (or "longitudinal axis") is to be understood as a direction (or axis) parallel to the axis of the head fairing and therefore to the direction of flight of the launch vehicle. By "transverse plane" is meant a plane perpendicular to the axis of the head fairing (i.e. to the longitudinal axis).

The term "spacecraft" means an artificial satellite or any other vehicle designed to fly in outer space, such as an interplanetary probe. In the following text of the description, the terms "satellite" and "spacecraft" will be used interchangeably.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 2 is a frontal view of an assembly 2 of spacecraft 20, 21, 22 to be secured under the nose fairing of the launch vehicle in the launch phase, with the nose fairing 23 shown transparently. In this case, the assembly consists of three satellites with a trapezoidal section. In the claimed assembly, the satellites are located around the central Z axis in a given transverse plane, forming one layer. The central axis is an axis parallel to the longitudinal axis of the launch vehicle. In this case, the transverse plane is any plane perpendicular to the central axis Z. The satellites are mechanically connected to each other only by means of their ribs (faces) along the longitudinal axis of the launch vehicle. In particular, the satellites or spacecraft are located in such a way that one spacecraft is connected to an adjacent spacecraft of the block through one rib using at least one attachment device (or attachment point) located on said rib, in order to provide mechanical retention of the mentioned devices to each other. In FIG. 2 shows three of these attachment points B located at the top of the edges of adjacent satellites. In addition, the satellites are mechanically connected to the launch vehicle through an interface (connection) piece called the satellite-to-booster adapter (24, shown in FIG. 3) and similar to the interface piece shown schematically in FIG. 4 and containing attachment points (or legs) connecting satellites to this part. Because the launcher interface is typically circular, the satellite-to-booster adapter typically includes a round portion for attaching to the launcher. In the embodiment shown in FIG. 2, the satellite/satellite and satellite/booster mounts are made in the form of pyrotechnic bolts. This type of attachment has the advantage of facilitating the control of the separation sequence of the grouped/separable spacecraft. In addition, these attachment devices allow the satellites to be separated during a separation sequence. In an alternative embodiment, the attachment device or devices B are electromechanical coils, shape memory alloys, paraffin actuators, or other remotely activated separable bonding mechanisms.

The claimed assembly does not use a distributor to hold the spacecraft on the launch vehicle during launch. The role of mechanical retention along the longitudinal axis of the launch vehicle, which was usually assigned to the structural distributor, in this case is performed by the connections between the ribs of the satellites along the same axis, in this case, pyrotechnic bolts. In this case, a structural distributor should be understood as a structural element that has a very high mechanical rigidity and withstands the action of forces between the launch vehicle and each of the satellites and between the satellites themselves. Thus, this solution provides a significant gain in storage volume and payload mass launched. In doing so, satellites can be redesigned to take advantage of that space and that mass and take on more payload, which determines the value of satellites. In addition, eliminating the need to install a distributor reduces costs and simplifies the layout. The useful mass saved with this assembly can be estimated at 5-7% of the total launched useful mass (that is, approximately 50% of the mass of a classic distributor). The arrangement shown in Fig. 2 is called a "trapezoid" because it is formed by satellites with a trapezoidal cross section. In another embodiment, the satellites have a rectangular cross section. However, the use of satellites with a trapezoidal cross-section makes better use of the space freed up by eliminating the distributor than in the case of satellites with a rectangular cross-section. Therefore, it is he who is preferred.

The dynamic behavior of the assembly must comply with the requirements of the authorities responsible for launching. In particular, the frequencies of the first oscillation modes in the vertical and longitudinal directions must exceed the limit values, which depend on the launch vehicle and are of the order of several Hz or several tens of Hz. The digital models made it possible to establish that in the embodiment shown in FIG. 2, the first transverse and longitudinal frequencies have values that meet the specifications.

A rigid assembly formed by three satellites with a trapezoidal section and an adapter "satellites - launch vehicle" is located in the center of the head fairing of the launch vehicle. In FIG. 3 shows a separate frontal view of a single trapezoidal satellite 22 mounted on a satellite-to-booster adapter 24. FIG. Ribs 25 of satellite 22, connected to other ribs of neighboring satellites 20 and 21 (shown in FIG. 2) by attachment devices B, hold the satellites together and separate the satellites. In FIG. 3 shows attachment devices B located on ribs 25 and distributed along these ribs. In the non-limiting example shown in FIG. 3, the connection between the two satellites is made by two attachment devices B located along the ribs 25, while the connection of the satellite to the booster adapter is made by two attachment devices B.

In the embodiment shown in FIG. 2 and 3, the satellites have a cylindrical reinforcement 26 installed at the base of the satellite structure in continuation of the attachment with the satellite-to-booster adapter 24, providing additional rigidity and retention of the satellites on the satellite-to-booster adapter. In another embodiment, the satellite design lacks a cylindrical mount.

In yet another embodiment, the satellites are connected to each other in the same manner as in the assembly shown in FIG. 2, but are connected directly (without the satellite-to-booster adapter 24) to the launch vehicle by a yoke, for example, providing essentially additional retention between them. In this case, the satellites are fixed on the circumferential contour of the launch vehicle interface. In yet another embodiment, the number of satellites forming an assembly may be different from three in both the satellite-to-booster adapter and the direct mount embodiment. In FIG. 4 is a plan view of the claimed satellite assembly and the interface piece of the satellite-to-launcher adapter 24. This piece connects the booster 32 to three satellites (only one satellite 21 is shown in the figure) via a mounting leg 33. In this embodiment, the satellite-to-booster adapter is a rigid cylindrical metal piece located directly below the satellites and between the satellites and launch vehicle. In yet another embodiment, the satellite-to-booster adapter is a piece whose top (satellite side) is a simple, flat, rigid plate for connection to the satellites, and the bottom (booster side) is round or conical. to ensure connection with the launch vehicle. In the embodiment shown in FIG. 4, the satellite-to-booster adapter is a part common to three satellites. In another embodiment, this connecting piece is adapted to the number and design of the spacecraft to be combined into an assembly.

In FIG. 5 is a schematic sectional view of a spacecraft assembly according to the same embodiment as in FIG. 4. It may be recalled that the design of the satellites is trapezoidal in order to optimize the space freed up by eliminating the distributor. The three satellites 20, 21, 22 are connected at their ribs by attachment devices B, and the reinforcements 26a, 26b, 26c in each satellite represent a third of a cylinder and provide additional rigidity and retention of the satellites on the satellite-to-launcher adapter. Mounting devices B are located at the top of the edges of neighboring satellites of this layer and allow you to connect the satellites to each other. In addition, a central rack 31 is installed in the center of the assembly and connected to the satellites, which, unlike a conventional distributor, does not provide any structural function and can therefore be much lighter. This rack is connected to all attachment points of the satellites between themselves and the attachment points of the satellites on the adapter "satellites - launch vehicle". This rack is a simple non-mechanical interface that does not hold the satellites together or on the launch vehicle, but which contains the spacecraft separation devices. The ends of this rack contain pyrotechnic charges, which, at the right moment, disconnect the satellites from each other and separate the satellites from the launch vehicle. In the embodiment shown in this figure, the attachment points of the satellites between themselves and the attachment points of the satellites on the adapter "satellites - launch vehicle" are pyrotechnic bolts, and the rack allows you to control the undermining of these bolts. Thus, this non-constructive rack allows you to control the sequence of separation of the satellites. This allows you to separate several satellites at once or release them separately one by one.

In FIG. 6 shows an assembly 40 of three "trapezoid" satellites 41, 42, 43 (satellite 43 is not shown to simplify the drawing) connected to the launch vehicle through a cylindrical adapter 44 "satellites - launch vehicle" with a non-structural central rack 31 acting as an interface , common to three satellites and containing a spacecraft compartment device. In the embodiment shown in FIG. 6, the connection between adjacent satellites is made using 4 attachment points through pyrotechnic bolts, and the satellite/satellite-to-launcher adapter connection is made using two attachment points (in this case, also pyrotechnic bolts). In addition, as in the embodiment shown in FIG. 3, the satellite structure includes two-thirds of the cylinder 26a, 26b which assist in transmitting the forces of the satellite/satellite-to-booster adapter. In another embodiment, the number of satellite/satellite connections and satellite/satellite-to-booster adapter may be different from the embodiment shown in FIG. 6.

In yet another embodiment, the separating device is not made in the form of pyrotechnic bolts, but is electromechanical coils, shape memory alloys, paraffin actuators, or other remotely activated separable joint mechanisms.

In another embodiment, the non-mechanical interface, common to all space vehicles and containing a device for separating the vehicles, is not a rack, but is made in the form of cables interconnected and fixed at the level of the satellite-to-carrier adapter, connecting all satellite attachment points between itself and satellites on the adapter "satellites - launch vehicle". The advantage of the strut is that it is less likely to move during launch.

In another embodiment, several layers of blocks from several spacecraft are stacked in sets along the longitudinal axis of the launch vehicle, interconnected only along the longitudinal axis of the launch vehicle without using a structural distributor and connected to the interface of the launch vehicle in the transverse plane of the launch vehicle . This assembly allows you to receive N sets of n satellites and simultaneously control the launch sequence of n satellites for each assembly. In this embodiment, attachment points (eg, pyrotechnic bolts) or one solid circular arc attachment for each satellite in the transverse plane will be applied between each set so that the sets can be separated one by one. Of course, in this case, the construction and design of the satellites in the lower sets must be adapted to support the mass of the satellites in the upper sets.

In an embodiment, the assembly sequence of a plurality of spacecraft 20, 21, 22 under the head fairing of the launch vehicle 23 includes the following operations:

- install the adapter 24 "satellites - launch vehicle" on the launch vehicle and under the head fairing;

- install the 1st block of satellites 2 one after the other as follows:

- one satellite is fixed on the adapter "satellites - launch vehicle";

- then attach another satellite, linking it to the already fixed satellite along the longitudinal axis of the launch vehicle;

- then attach another satellite, etc., until all the satellites are fixed and interconnected along the longitudinal axis of the launch vehicle to obtain a complete assembly;

- install a non-mechanical interface 31, common to all spacecraft and containing the separation device devices.

In yet another embodiment, the assembly sequence is identical to the above sequence, but the non-mechanical interface is installed after the first satellite is attached to the satellite-to-launcher adapter.

In yet another embodiment, installation of the non-mechanical interface may be performed prior to placing the first array of satellites under the nose fairing of the launch vehicle (and after they are connected along the longitudinal axis of the launch vehicle).

Claims (7)

1. Assembly of spacecraft, containing: - at least one first block (2) from a plurality of space vehicles (20, 21, 22) to be fixed on the launch vehicle (23) in the launch phase, characterized in that the space vehicles are located around the central axis (Z) in a predetermined transverse plane perpendicular to said central axis, while said spacecraft have ribs along the longitudinal axis and, in addition, are located in such a way that one spacecraft is connected to an adjacent spacecraft of the block through one rib using at least one attachment device (B) located on said rib to ensure mechanical retention of said spacecraft between themselves, - adapter (24) "satellites - launch vehicle", on which the mentioned space vehicles are fixed in the transverse plane. 2. The spacecraft assembly of the preceding claim, wherein the satellite-to-launcher adapter is a piece having a flat top on the spacecraft side and a round or conical bottom on the launcher side. 3. The spacecraft assembly of the preceding claim, wherein the satellite-to-launcher adapter is a cylindrical piece located under the spacecraft. 4. Spacecraft assembly according to any one of the preceding claims, comprising a central post (31) which is shared by all spacecraft and serves to control the spacecraft separation sequence. 5. Assembly of space vehicles according to any of the previous paragraphs, in which there are several blocks of space vehicles forming layers stacked on top of each other along the longitudinal axis of the launch vehicle, while the layers are interconnected in the transverse plane of the said launch vehicle.

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