space launcher equipped with an auxiliary propulsion system, and auxiliary propulsion system equipping such a launcher
The two-stage space launcher with a Navier main engine and integrated auxiliary propulsion system addresses the need for multiple propulsion systems by sharing components, reducing mass and cost while providing efficient acceleration, precision maneuvers, and attitude control.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- LATITUDE
- Filing Date
- 2024-12-18
- Publication Date
- 2026-06-19
AI Technical Summary
Existing rocket stages require multiple propulsion systems, leading to additional costs and complexity, as they separate during flight, necessitating a need for acceleration, low-power precision maneuvers, and attitude control during orbital phases.
A space launcher with a two-stage design incorporating a Navier main engine and an auxiliary propulsion system (APS) with auxiliary propulsion units (APU) and reaction control thrusters (RCS) sharing common tanks and supply lines, providing acceleration, precision maneuvers, and attitude control.
Minimizes mass and cost by integrating a single propulsion system that meets acceleration, precision maneuvering, and attitude control needs, while ensuring efficient and reliable performance throughout the mission.
Smart Images
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Abstract
Description
Title of the invention: space launcher equipped with an auxiliary propulsion system, and auxiliary propulsion system equipping such a launcher. SCOPE OF THE INVENTION
[0001] The present invention relates to a space launcher equipped with an auxiliary propulsion system. It also relates to an auxiliary propulsion system equipping a space launcher. STATE OF THE ART
[0002] A rocket stage generally has a single propulsion system to perform its mission. Once the propellants are burned, the stage is separated to allow another, lighter upper stage to continue the mission, resulting in additional costs.
[0003] The present applicant has developed a second stage that includes two different propulsion systems to avoid having an additional stage that would separate during flight. The majority of the propulsion phase is delivered by a Navier Mk2-Vacuum main engine to place the second stage into an elliptical orbit. Then, instead of separating a third stage to complete the mission, an auxiliary propulsion system is used to perform the final orbital maneuvers for the customer. At the end of its mission, the auxiliary propulsion system can be used to deorbit the stage.
[0004] The need for an auxiliary propulsion system on the second stage of the space launcher arose from three needs: - A need for acceleration during the stage separation phase to push the second-stage propellant to the bottom of the tanks in order to ignite the main engine. Furthermore, providing thrust during the stage separation phase aids in stage separation maneuvers by reducing their duration and thus optimizing the overall performance of the launch vehicle. - a need for a restartable, low-power, high-precision propulsion system to provide small pulses for orbital maneuvers for which the second-stage main engine is not suitable. The requirements for in-orbit maneuvering and precision are met by the auxiliary power unit. - A need for a launcher attitude control system during the second-stage flight phases and orbital phases. Attitude control requirements are met by the auxiliary propulsion system through the use of its restartable, low-power, high-precision RCS thrusters.
[0005] The aim of the present invention is to provide a new propulsion system for a space launcher that meets these three needs, while also helping to minimize the mass and cost of the launcher by providing a single, common technical solution rather than independent systems to meet each of the three needs. Description of the invention
[0006] This objective is achieved with a space launcher comprising a first stage equipped with a first propulsion system dedicated to the intra-atmospheric flight phase of said launcher and a second stage intended to receive a payload, comprising a Navier main engine and an auxiliary propulsion system (APS) integrating two auxiliary propulsion units (APU) and a set of reaction control thrusters (RCS) responsible for attitude control of said second stage during the extra-atmospheric flight phase of said launcher.
[0007] The auxiliary propulsion system (APS) and the reaction control thruster assembly (RCS) can advantageously share common tanks and supply lines.
[0008] In a preferred embodiment of the invention, the auxiliary propulsion system (APS) is fixed on a lower skirt of the second stage around the Navier main engine.
[0009] The two auxiliary propulsion units are preferably located symmetrically with respect to a longitudinal axis of the launcher, on each side of the Navier main engine.
[0010] The reaction control thruster (RCS) assembly may advantageously comprise two sub-assemblies of three thrusters on each side of said launcher, each sub-assembly of thrusters being located near one of the auxiliary propulsion units (APUs) which are preferably oriented towards the center of gravity of the second stage.
[0011] The auxiliary propulsion system may further include, for each auxiliary propulsion unit, a propellant tank arranged to also supply the reaction control thrusters associated with that auxiliary propulsion unit.
[0012] Propellant tanks, intended to supply the auxiliary propulsion units, are arranged opposite each other in a section between the first and second stages to balance the position of the center of mass of the auxiliary propulsion system on the pitch and yaw axes of said launcher.
[0013] In each reaction control thruster subset, the reaction control thrusters are connected to the propellant tanks by a single shared propellant line.
[0014] In a preferred embodiment, a reaction control propulsion (RCS) subset and its associated auxiliary propulsion unit (APU) are designed as a self-contained unit before being integrated into the launcher.
[0015] Nozzle outlets of the reaction control thrusters (RCS) and the auxiliary propulsion unit (APU) can advantageously be located outside the frame of the second stage.
[0016] For a space launcher in which the auxiliary propulsion system includes auxiliary propulsion system actuators and auxiliary propulsion system sensors, this launcher further includes, during its flight, a power supply system (PDS) to power these actuators and a data acquisition system (DAS) to which these sensors are connected.
[0017] According to another aspect of the invention, an auxiliary propulsion system (APS) is proposed equipping a space launcher according to the invention, this space launcher comprising a first stage equipped with a first propulsion system dedicated to the intra-atmospheric flight phase of said launcher and a second stage intended to receive a payload and comprising a Navier main engine, characterized in that it comprises two auxiliary propulsion units (APUs) and a set of reaction control thrusters (RCS) responsible for attitude control of said second stage during the extra-atmospheric flight phase of said launcher.
[0018] The auxiliary propulsion system according to the invention can be organized into two auxiliary propulsion sub-assemblies, each comprising an auxiliary propulsion unit (APU) and a reaction control thruster (RCS) sub-assembly, these two auxiliary propulsion sub-assemblies being arranged on either side of the Navier main engine.
[0019] The auxiliary propulsion systems implemented in the space launcher according to the invention use green propellants.
[0020] The functions of an APS auxiliary propulsion system according to the invention equipping a two-stage space launcher are as follows: - to provide a specific and nearly constant longitudinal acceleration to the second stage of the launcher, - to provide a velocity differential (Delta V) to the second stage of the launcher with high precision and repeatability, - to provide attitude control to the second stage of the launcher on the three axes of yaw, pitch and roll, - to start its thrusters in microgravity, - restart all its thrusters several times, - maintain nominal performance while firing multiple propulsion systems simultaneously (APU and RCS), - to interface with a ground-based system for filling, pressurizing, draining, venting, or cleaning processes, - to be assembled on the second stage of the launcher, - be powered and controlled by the PDS and DAS of the launcher. DESCRIPTION OF THE FIGURES
[0021] [Fig.1] Fig.1 represents an example of the integration of an auxiliary propulsion system according to the invention in a space launcher;
[0022] [Fig.2] Fig.2 illustrates an example of RCS thruster positioning on a second stage of a space launcher;
[0023] [Fig. 3] [Fig. 3] illustrates different operational states of a propellant tank implemented in an auxiliary propulsion system according to the invention;
[0024] [Fig.4] Fig.4 is a schematic bottom view of an example embodiment of an auxiliary propulsion system according to the invention;
[0025] [Fig. 5] Fig. 5 is a schematic perspective view of a system of piping implemented in an auxiliary propulsion system according to the invention;
[0026] [Fig. 6] Fig. 6 represents mechanical supports equipping a pack of three RCS thrusters in an auxiliary propulsion system according to the invention;
[0027] [Fig.7] Fig.7 schematically illustrates the respective positions of packs of RCS thrusters on each side of a main thruster of a space launcher according to the invention;
[0028] [Fig.8] Fig.8 represents an example of fluidic and electrical integration in a auxiliary propulsion system according to the invention; and
[0029] [Fig.9] Fig.9 is a global synoptic diagram of an example of an embodiment of a auxiliary propulsion system according to the invention.
[0030] DEFINITIONS AND ACRONYMS
[0031] APS Auxiliary Propulsion System
[0032] APU Auxiliary Propulsion Unit
[0033] DAS Data Acquisition System
[0034] HDRM Hold Down Release Mechanism (H&R)
[0035] HTP High-Test Peroxide Hydrogen peroxide
[0036] ISP Specific Impulse
[0037] MLI Multi-Layer Insulation Multi-layer insulation
[0038] MMH Monomethylhydrazine
[0039] PDS Power Delivery System
[0040] PLK Propellant Loading Kart
[0041] RCS Reaction Control System
[0042] UDMH Unsymmetrical 1,1-DiMethylHydrazine DETAILED DESCRIPTION
[0043] In a practical embodiment, an auxiliary propulsion system S is arranged in the interstage space of a launcher 1 comprising two stages E1, E2. This auxiliary propulsion system S is attached to the lower skirt 2 of the second stage E2, with reference to Figures 1 and 4. It comprises: - two auxiliary propulsion units APU 13,16 arranged on either side of a central Navier 10 engine equipped with a nozzle extension 11, - two sub-assemblies 80A, 80B of RCS reaction control thrusters, each located near one of the two auxiliary propulsion units 13,16, - two propellant tanks 14,17 connected to each other and to the two auxiliary propulsion units 13,16 and the associated control thrusters, - a helium tank 12 connected to the two propellant tanks 14,17 to ensure their pressurization, - a set of gas and liquid piping and fluid equipment with various functions serving the proper functioning of the propulsion system such as conveying fluids, reducing and regulating gas pressure, ensuring the safety of the system and operators, allowing the emptying of stored fluids, etc.
[0044] The two auxiliary propulsion units APU 13,16 are oriented at an angle with respect to the longitudinal axis of the launcher 1 such that the respective longitudinal axes of these two auxiliary propulsion units 13,16 intersect at the center of mass of the second stage E2.
[0045] With reference to [Fig. 2], the two RCS reaction control thruster subassemblies 8OA, 8OB are located on the periphery of the lower skirt 2, diametrically opposite each other on either side of the Navier main engine 10. In each subassembly 8OA, 8OB, - an RCS 81 or 84 reaction control thruster is dedicated to exerting thrust along the ±Y axis in order to produce a yaw moment around the Z axis, - a pair of RCS reaction control thrusters 82 and 85, or 83 and 86, is dedicated to exerting thrust on the ±Z axis in order to produce a pitching moment around the ±Y axis, - and a pair of RCS reaction control thrusters 82 and 86, or 83 and 85, is dedicated to exerting thrust along the ±Z axis in order to produce a roll torque around the X axis.
[0046] In a practical embodiment illustrated by [Fig.3], the two propellant tanks T implemented in an auxiliary propulsion system according to the invention can have a conventional cylindrical shape closed by hemispheres and have a volume of 35L, with a length of 600 mm and a diameter of 300 mm for its cylindrical part.
[0047] The two propellant tanks 14, 17 must be pressurized by an inert gas, for example helium, which is stored in a separate high-pressure container. The single pressurized gas tank may be spherical or cylindrical in shape as long as its outside diameter does not exceed, for example, 300 mm.
[0048] During the initial charging of the tank T, the liquid propellant occupying a part volume 32a is kept under pressure by helium gas injected through an inlet 30 of the tank T and separated from the propellant by a bladder 34 occupying the remaining volume 31a corresponding to about 20% of the total volume of the tank T.
[0049] After a certain time of use with propellant evacuation through an outlet 33 of the tank T and injection of pressurizing helium gas, the latter then occupies an increasing volume 31b which becomes greater than that occupied by the propellant, until the liquid propellant occupies only a residual volume 32c.
[0050] An auxiliary propulsion system S according to the invention is designed to share tanks and piping in order to minimize their mass and size, as illustrated in [Fig. 5]. Thus, each propellant tank 14, 17 is configured to supply both the auxiliary propulsion unit 13, 16 and the RCS reaction control thrusters 80A, 80B (not visible in [Fig. 5]). The helium tank 12 provides pressurization for both propellant tanks 14, 17. A common piping 50 connects the propellant tanks 14, 17 to the auxiliary propulsion units 13, 16, while lower-flow piping 52 connects these tanks 14, 17 to the RCS reaction control thrusters 8OA, 8OB.
[0051] The auxiliary propulsion subassembly 8A comprises, with reference to [Fig. 6]: - an auxiliary propulsion unit 13 comprising a combustion chamber 63 equipped with a nozzle 64 and receiving the propellant via a pipe 62, - A sub-assembly 80A of three reaction control thrusters 81, 82, 83 which are supplied with propellant via a pipeline 61.
[0052] The two pipes 61,62 are both connected to a common pipe 65 connected to a common propellant tank (not shown).
[0053] With reference to [Fig.7], the Navier main engine 10 equipped with a nozzle 11, is surrounded by two propellant tanks 17 and a helium tank 12 intended to ensure the pressurization of the propellant tank 17, and by two auxiliary propellant sub-assemblies 8A,8B each comprising an auxiliary propulsion unit APU 16,13 and an assembly 8OA,8OB of reaction control propellants RCS.
[0054] The propulsion pack, consisting of an APU and three RCS thrusters on each side of the launcher, must be integrated as a self-contained unit before being integrated into the launcher to simplify the integration processes. The mechanical supports and interfaces must therefore allow for this integration. An example of the support design is shown in [Fig. 6].
[0055] With reference to [Fig.8], the 8A propulsion pack comprising the APU 16 auxiliary propulsion unit, with a thrust of 280N, and the three RCS reaction control thrusters 81, 82, 83 with a thrust of IN each, further includes an electrical connection panel 80. This electrical connection panel 80 includes, on the one hand, connections with the outside of the 8A pack and, on the other hand, connections with the thrusters of the 8A pack.
[0056] The external connections include on the one hand a cable transmitting signals from internal sensors in the 8A pack to the DAS data acquisition system, and on the other hand a cable transmitting actuator control signals from the PDS power supply system.
[0057] The internal connections of the electrical connection panel 80 include control cables for the auxiliary propulsion unit APU 16 and the three RCS reaction control thrusters 81, 82, 83 for their respective propellant supply valves and for their respective electric preheating systems, and sensor signal transmission cables, including temperature and pressure sensors, located on the auxiliary propulsion unit APU and on the three reaction control thrusters.
[0058] The auxiliary propulsion unit 16 and the three reaction control thrusters 81, 82, 83 are supplied with propellant via a propellant inlet port 87.
[0059] In an embodiment illustrated by [Fig.9], an auxiliary propulsion system 9 according to the invention comprises two auxiliary propulsion packs 8.1,8.2 each comprising an auxiliary propulsion unit and its three associated reaction control thrusters.
[0060] To simplify the integration process of the APS auxiliary propulsion system into the launcher, its electrical connections can be grouped into three groups: the propellant distribution group and two propellant packs. Each group has a single connector for the electrical lines to the group's actuators and a single connector for the lines from the group's sensors.
[0061] The connection panel 96 between the APS 90 auxiliary propulsion system and the PLK 97 propellant loading kart is located on the skirt of the second stage of the space launcher. It is completely independent of the other fluidic or electrical connection plates of the launcher.
[0062] A control / command system 91 comprising an on-board computer (OBC) 92, a power supply system (PDS) 93 and a data acquisition system (DAS) 94 is connected via a harness 98 to the connection panel 96.
[0063] This connection panel 96 can be manually handled by an operator (connections and disconnections) and must therefore be designed for safe use against pressure and propellant leaks.
[0064] The design of the connection panel 96 must be oriented towards minimizing the mass and protrusions on the part of the panel which remains on the launcher after disconnection.
[0065] The APS / PLK connection panel must include the following functions: - physical / mechanical connection - High and low pressure gas connection(s) - propellant connection(s) - Prevention of leaks from all the above elements (pressure, gas, propellant...) - Electrical connections for access from the PLK propellant loading kart to the onboard APS actuators and sensors.
[0066] These two propellant packs are supplied with propellant and gas from a propellant supply system 95, which is itself filled via the connection panel 96 by the propellant loading kart PLK 97. The two packs 8.1, 8.2 are also supplied with electrical power from a PDS power supply system 93, which also powers the propellant supply system 95. The PLK 97 propellant loading kart is independent with its own electrical supply so as to be able to interact with the APS system on board the launcher even when the latter and its PDS power supply system are switched off.
[0067] All the filling, emptying and venting ports (for gas and propellant) of the APS auxiliary propulsion system are located on the outer skin of the launcher, on a single fluidic connection plate which serves as an interface between the APS auxiliary propulsion system and the PLK propellant loading kart.
[0068] The routing of the APS pipelines must be designed to limit the differences in pressure losses in the gas and propellant lines (diameter, equipment, length...) to ensure maximum thrust symmetry between the opposing thrusters.
[0069] The APS fluid piping and instrumentation must allow for the simultaneous firing of several APUs and RCS thrusters while maintaining performance nominal values of each booster. The APS shares mechanical interfaces with the main launcher chassis at several mounting points.
[0070] The nozzle outlets of the RCS and APU boosters are located outside the frame of the second stage of the launcher and must be integrated in such a way as to reduce protrusions and aerodynamic effects on the launcher (and the boosters) during atmospheric flight.
[0071] During ground operations, the PLK propellant loading kart is connected to the APS auxiliary propulsion system via a single connection panel which provides the supply of fluids (gas and propellant) and electricity.
[0072] The propellant used in an APS auxiliary propulsion system according to the invention can be a custom premixed bi-propellant. This consists of a combination of an oxidizer (HTP hydrogen peroxide) and an alcohol-based fuel in a single liquid stable at room temperature. Combustion is initiated in the propellant combustion chamber by means of a preheated catalytic bed.
[0073] Of course, the invention is not limited to the embodiment just described, and many other embodiments can be envisaged, without going out of the scope of the invention.
[0074] Thus, the auxiliary propulsion system (APS) according to the invention can be equipped with equipment shelves to accommodate the various fluid and electrical components of the APS in order to facilitate the integration process. The fluid and electrical components are first integrated and tested on the shelves, and then, after validation, this assembly of fluid and electrical components is integrated onto the launch vehicle, following the same logic as the propulsion packs.
Claims
Demands
1. Space launcher (1) comprising a first stage (E1) equipped with a first propulsion system dedicated to the intra-atmospheric flight phase of said launcher (1) and a second stage (E2) intended to receive a payload, comprising a Navier main engine (10) and an auxiliary propulsion system (APS) (S) incorporating two auxiliary propulsion units (APU) (13,16) for carrying out orbital maneuvers and a set of reaction control thrusters (RCS) (8OA,8OB) responsible for attitude control of said second stage (E2) during the extra-atmospheric flight phase of said launcher (1).
2. Space launcher (1) according to the preceding claim, characterized in that the auxiliary propulsion system (APS) (S) and the reaction control thruster (RCS) assembly (8OA,8OB) share common tanks (14,17) and feed lines (50,52).
3. Space launcher (1) according to any one of the preceding claims, characterized in that the auxiliary propulsion system (APS) (S) is fixed on a lower skirt (2) of the second stage (E2) around the Navier main engine (10).
4. Space launcher (1) according to the preceding claim, characterized in that the two auxiliary propulsion units (13,16) are located symmetrically with respect to a longitudinal axis of the launcher (1), on each side of the Navier main engine (10).
5. Space launcher (1) according to the preceding claim, characterized in that the reaction control thruster (RCS) assembly comprises two sub-assemblies (8OA,8OB) of three thrusters (81-83;84-86) on each side of said launcher (1), each sub-assembly of thrusters (8OA,8OB) being located in close proximity to each auxiliary propulsion unit (APU) (13,16).
6. Space launcher (1) according to the preceding claim, characterized in that the propulsion units (APU) (13,16) are each oriented at a predetermined angle with respect to the longitudinal axis of said launcher, the respective longitudinal axes of said auxiliary propulsion units intersecting at the center of mass of the second stage.
7. Space launcher (1) according to one of the two preceding claims, characterized in that the auxiliary propulsion system (S) includes a propellant tank arranged to supply both the reaction control thrusters (RCS) (8OA,8OB) and the auxiliary propulsion units APU (13,16).
8. Space launcher (1) according to the preceding claim, characterized in that the propellant tanks (14,17) intended to supply the auxiliary propulsion units (13,16) are arranged face to face in a section between the first and second stages (E1,E2) to balance the position of the center of mass of the auxiliary propulsion system (S) on the pitch and yaw axes of said launcher (1).
9. Space launcher (1) according to any one of claims 5 to 8, characterized in that the two reaction control thruster subassemblies (8OA,8OB) and the two auxiliary propulsion units APU (13,16) are connected to the propellant tanks (14,17) by a single shared propellant line.
10. Space launcher (1) according to the preceding claim, characterized in that an auxiliary propulsion subassembly (8A,8B) each comprising a reaction control propulsion (RCS) subassembly (8OA,8OB), an auxiliary propulsion unit (APU) (13,16), a mechanical support piece, and electrical connection and propellant supply interfaces, is designed as a self-contained assembly prior to being integrated into said launcher (1).
11. Space launcher (1) according to the preceding claim, characterized in that the nozzle outlets of the reaction control thrusters (RCS) and the auxiliary propulsion unit (APU) are located outside the frame of the second stage (E2).
12. Space launcher (1) according to the preceding claim, wherein the auxiliary propulsion system (S) comprises auxiliary propulsion system actuators and auxiliary propulsion system sensors, characterized in that it further interfaces and communicates, during the flight of said launcher, with the power supply system (PDS) of said launcher to supply said actuators and with the data acquisition system (DAS) of said launcher to which said sensors are connected.
13. Auxiliary propulsion system (APS) (S) equipping a space launcher (1) according to any one of the preceding claims, this space launcher comprising including a first stage (El)
14. equipped with a first propulsion system dedicated to the intra-atmospheric flight phase of said launcher and a second stage (E2) intended to receive a payload and comprising a Navier main engine (10), characterized in that it comprises two auxiliary propulsion units (APU) (13,16) and a set of reaction control thrusters (RCS) (81-83;84-86) responsible for attitude control of said second stage (E2) during the extra-atmospheric flight phase of said launcher (1). Auxiliary propulsion system (S) according to the preceding claim, characterized in that it is organized into two auxiliary propulsion sub-assemblies (8A,8B) each comprising an auxiliary propulsion unit (APU) (13,16) and a reaction control thruster (RCS) sub-assembly (8OA,8OB), these two auxiliary propulsion sub-assemblies (8A,8B) being arranged on either side of the Navier main engine (10).