Synchronised sequencing method and system for launching a space launcher, and launcher equipped with same

Abstract

The invention relates to a synchronised launch sequencing method for a space launcher comprising one or more on-board computers, a plurality of on-board fluidic devices including a propulsion system, and a plurality of on-board electrical devices, the method being implemented in the one or more on-board computers and comprising reversible steps of controlling / commanding the fluidic devices and reversible steps of controlling / commanding the electrical devices, the reversible electrical and fluidic steps being followed, respectively, by an irreversible step of starting a flight sequence and an irreversible step of starting the propulsion system of the launcher. The reversible control / command steps and the irreversible starting steps are controlled directly by the one or more on-board computers of the launcher.

Description

Method and system for synchronized sequencing for the takeoff of a space launcher, and launcher equipped with it FIELD OF THE INVENTION

[0001] The present invention relates to a synchronized sequencing method for the take-off of a space launcher. It also relates to a synchronized sequencing system implementing this method, as well as a space launcher adapted to this synchronized sequence system. STATE OF THE ART

[0002] During the final launch sequence of a launch vehicle, the final actions are performed automatically by software. This is called a synchronized sequence. On current launch vehicles, this synchronized sequence is performed by the control bench, which transfers control to the onboard computer at the last moment.

[0003] With reference to which schematically illustrates a typical synchronized sequence 1 of the state of the art, this sequence is divided between an electrical sequence 1E and a fluid sequence 1F conducted in parallel.

[0004] In a first reversible phase, the electrical sequence 1E includes a step 1E1 of arming the safety systems, a step 1E2 of preparing a control bench, while the fluid sequence 1F includes a step 1F1 of stopping the fuel top-ups, a step 1F2 of keeping the launcher propulsion systems cold, a step 1F3 of final loading of the propellants.

[0005] After passing a first rendezvous point called 1T1, the electrical sequence 1E continues with a step 1E3 of preparing the launcher's on-board computers while in the fluid sequence 1F, step 1F2 of keeping the propulsion systems cold is still being carried out, and two new steps 1F4 of pressurizing the tanks to flight pressure and 1F5 of leak testing are initiated.

[0006] After passing a second rendezvous point 1T2, the electrical sequence 1E includes a new step 1E4 of switching the fuel supplies, while in the fluid sequence 1F, the steps 1F4 of pressurization and 1F5 of leak testing are continued and the step 1F2 of keeping the system cold is completed and followed by a step 1F6 of keeping the on-board systems cold.

[0007] After passing a third rendezvous point 1T3, in the electrical sequence 1E, step 1E4 of switching the power supplies is completed and followed by new steps 1E5 of lifting the safety barriers and 1E7 of stopping the ground conditioning, carried out until reaching a fourth rendezvous point 1T4 from which a new step 1E8 of ignition of perishable systems (for example, batteries) is initiated. It is also at this fourth rendezvous point 1T4 that a new step 1E6 of management switching is initiated during which the control responsibilities of the ground computer will be transferred to one or more on-board computers of the launcher.

[0008] It is during this step 1E6 of management switching that an irreversible phase 1T5 begins at the end of 1T6 of which a step 1E9 of starting the flight sequence and a step 1F7 of starting the engines begin simultaneously.

[0009] The management switchover is done at the last moment, it requires freezing communications for the duration of the switchover, and developing a complex monitoring system for switching and verifying proper operation.

[0010] Two sequences run in parallel (one with electrical activities and one with fluid activities) requiring rendezvous points (i.e. an associated mechanism and margin control). The majority of activities are carried out on on-board equipment by the Ground.

[0011] In order to avoid management switching and better control the sequence, the present invention proposes that the synchronized sequence be carried out by the on-board computer. The control bench and ground resources are only there to ensure services and monitoring.

[0012] This objective is achieved with a method for synchronized sequencing of takeoff of a space launcher comprising one or more on-board computers, a plurality of on-board fluidic equipment including a propulsion system, and a plurality of on-board electrical equipment, this method being implemented in the on-board computer(s) and comprising reversible steps of control / command of the fluidic equipment and reversible steps of control / command of the electrical equipment, said reversible steps of a respectively electrical and fluidic nature being followed respectively by an irreversible step of starting a flight sequence and an irreversible step of starting the propulsion system of the launcher.

[0013] According to the invention, the reversible control / command steps and the irreversible start-up steps are directly controlled by the on-board computer(s) of the launcher.

[0014] The reversible steps of an electrical nature controlled by the on-board computer(s) may advantageously include all or part of the following steps: arming of the safety systems, preparation of the test bench, preparation of said on-board computer(s), switching of the power supply systems, lifting of safety barriers, switching on of perishable systems, stopping of ground conditioning.

[0015] The reversible stages of a fluidic nature controlled by the on-board computer may also include all or part of the following stages: stopping refuelling, final loading of fuels, pressurising the tanks to flight pressure, keeping the propulsion systems cold, keeping the on-board systems cold, leak testing.

[0016] According to another aspect of the invention, there is provided an on-board computer intended to equip a space launcher and implement the synchronized sequencing method according to any one of the preceding claims.

[0017] This on-board computer can be programmed to carry out all or part of the following steps: arming of the safety systems, preparation of the test bench, preparation of said on-board computer(s), switching of the power supply systems, lifting of safety barriers, switching on of perishable systems, stopping of ground conditioning.

[0018] It can also be programmed for all or part of the following steps: stopping refueling, final fuel loading, pressurizing tanks to flight pressure, keeping propulsion systems cold, keeping on-board systems cold, leak testing.

[0019] In the synchronized sequence performed by the launcher according to the invention, there is no management switching; only the on-board computer controls all the components. There is a single sequence without a rendezvous point and without the need to control margins.

[0020] Most activities are performed on on-board equipment by the On-Board. For Ground equipment, the on-board computer sends commands to the Ground to start / stop services. DESCRIPTION OF FIGURES

[0021] Lrepresents a block diagram of an example of a synchronized sequence of a launcher, representative of the state of the art;Lrepresents a block diagram of an example of a synchronized sequence of a launcher, according to the invention; andLillustrates schematically a launch installation implementing the synchronized sequence method according to the invention. DETAILED DESCRIPTION

[0022] We will now describe, with reference to figures 2 and 3, an example of implementation of the method for synchronized sequencing of the takeoff of a space launcher according to the invention, at the same time as the synchronized sequencing system for the implementation of this method.

[0023] A space launcher 10, shown schematically on a launch pad 4, 5, which is intended to place one or more satellites arranged under a fairing 14 into orbit, comprises an on-board computer 11 communicating with a ground control system 21 in a ground station 20.

[0024] The on-board computer 11 is designed to control all of the equipment on board the launcher 10, in particular a propulsion system 13, fuel tanks 12, an on-board cryogenic system 15 and numerous on-board actuators and sensors. Before the launcher 10 takes off, it is mechanically coupled to the launch pad and its critical components connected to ground equipment. Thus, the fuel tanks 12 are connected to a ground fuel supply unit 3, and the on-board cryogenic system 15 is connected to a ground cryogenic unit 6, while the on-board computer is connected – in wired and / or radio form – with the ground control system 21.

[0025] With the sequencing method according to the invention, it is the on-board computer 11 which has complete control of the entire launcher sequence, as illustrated in. Thus, the on-board computer 11 controls the upstream steps of the electrical sequence: 2E1 arming of the safety systems, 2E2 preparation of the control bench, 2E3 preparation of the on-board computer(s), 2E4 switching of the launcher's electrical power supplies, 2E5 raising of the safety barriers, 2E7 stopping of the ground conditioning, 2E8 ignition of the perishable systems.

[0026] The on-board computer 11 controls the steps of the fluid sequence in parallel: 2F1 stopping the refueling top-ups, 2F2 keeping the launcher systems cold by the Ground, 2F3 final loading of the propellants, 2F4 pressurizing the tanks to Flight pressure, 2F5 leak tests, 2F6 cooling down the on-board systems

[0027] During the irreversible phase 1T5 of the sequencing, the ignition steps 2E8 and cooling steps 2F6 are being executed under the control of the on-board computer 11. At the start of the takeoff phase 1T6, the on-board computer commands the start 2E9 of the flight sequence and the start 2F7 of the engines.

[0028] Of course, the invention is not limited to the exemplary embodiment which has just been described, and many other embodiments can be envisaged, without departing from the scope of the invention.

Claims

Method for synchronized sequencing of takeoff of a space launcher (10) comprising one or more on-board computers (11), a plurality of on-board fluidic equipment including a propulsion system (13), and a plurality of on-board electrical equipment, this method being implemented in the on-board computer(s) (10) and comprising reversible steps of control / command of the fluidic equipment and reversible steps of control / command of the electrical equipment, said reversible steps of a respectively electrical and fluidic nature being followed respectively by an irreversible step of starting a flight sequence and an irreversible step of starting the propulsion system of the launcher, characterized in that the reversible steps of control / command and the irreversible steps of start are directly controlled by the on-board computer(s) (11) of the launcher (10). Sequencing method according to the preceding claim, characterized in that the reversible steps of an electrical nature controlled by the on-board computer(s) comprise all or part of the following steps: arming the safety systems, preparing the control bench, preparing said on-board computer(s), switching the power supply systems, raising safety barriers, switching on perishable systems, stopping ground conditioning. Sequencing method according to one of the preceding claims, characterized in that the reversible steps of a fluidic nature controlled by the on-board computer comprise all or part of the following steps: stopping refueling, final loading of fuels, pressurizing the tanks to flight pressure, keeping the propulsion systems cold, keeping the on-board systems cold, leak testing. On-board computer intended to equip a space launcher and implement the synchronized sequencing method according to any one of the preceding claims. On-board computer according to the preceding claim, characterized in that it is programmed to carry out all or part of the following steps: arming the safety systems, preparing the control bench, preparing said on-board computer(s), switching the power supply systems, raising safety barriers, switching on perishable systems, stopping ground conditioning. On-board computer according to one of the two preceding claims, characterized in that it is programmed for all or part of the following steps: stopping refueling, final loading of fuels, pressurizing the tanks to flight pressure, keeping the propulsion systems cold, keeping the on-board systems cold, leak testing.

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