RU2821808C1 - Landing device of reusable first stage of carrier rocket and method of its landing - Google Patents

Abstract

FIELD: rocket and space engineering.

SUBSTANCE: invention relates to aircraft components landing. Method of landing reusable first stage of carrier rocket includes operations of unfolding landing supports and bringing the stage into a vertical position until the landing pad touches the landing supports at low speed. At the same time immediately after separation of the stage on the ascending section of the trajectory, the rotor blades are released and brought into the working position due to incident air flow, transfer of rotor to autorotation mode. Preset rotations of the rotor are maintained from the moment of operation start at the outlet to the return entry into the dense layers of the atmosphere and during their passage by controlling the common pitch of the blades. After the transition to the trajectory section with the steady-state low velocity head and the reduced rate of vertical descent, simultaneous control of common and cyclic pitch of blades is invoked. Before touching the ground, the landing supports are unfolded and the total pitch of the blades is quickly increased.

EFFECT: reliable drive of the stage to the specified area.

1 cl, 1 dwg

Description

Technical field

The invention relates to the field of rocket and space technology and can be used in the creation of reusable stages of launch vehicles.

State of the art

There is a known project for a landing device for the return stage of a launch vehicle (Magazine “PRETICH” 01/25/2022, article “A helicopter saves a space rocket - project”), containing a container with parachutes, a helicopter with a device for capturing the pilot chute cable, and a method for landing the stage, which consists of , that at a given height the parachutes are introduced into the air flow, after which the helicopter, using a special cable with a gripping device, hooks the rope of the stage's pilot chute and then ensures the transportation and landing of the stage on the landing pad. In December 2021, the American space company Rocket Lab successfully implemented this project, landing the first stage of the Electron light rocket. The disadvantage of the device and method of landing a stage is the insufficient reliability of preserving the stage and the impossibility of landing heavy stages in this way using a helicopter.

The landing device for the return stage of the launch vehicle is also known (Reporter Magazine, article “Revival of Baikal: What’s wrong with the Russian reusable rocket?”), taken as an analogue, containing, in a folded state along the stage body, a folding wing, as well as elements stabilizer, retracted landing gear for landing “airplane-style” on the airport runway, a control system with turbojet engines for controlled flight in the atmosphere and with a fuel supply for them, and a stage landing method, which consists in the fact that at a given altitude, after the stage is separated, the control system is switched on, sequentially folding the wing, turning on the turbojet engines and ensuring the extension of the landing gear for landing the stage on the runway and flight control. The disadvantage of the analogue and its landing method is a significant increase in the weight of the stage, which reduces the efficiency of the launch vehicle as a whole.

The closest to the proposed invention in technical essence and accepted as a prototype is the landing device of the returnable first stage of the launch vehicle and the method of its landing, used in the Amur-LNG launch vehicle project (Wikipedia). The landing device consists of four landing legs that are folded out until touching the landing pad at low speed, installed in the lower part of the stage and ensuring the preservation of the stage structure during landing, a landing control system, including throttled propulsion engines installed in the lower part of the stage used for landing, and an orientation system with jet engines that bring the stage into a vertical position before landing, and a landing method that consists in unfolding the landing legs and bringing the stage into a vertical position until the lower landing legs touch the landing pad at low speed. The disadvantage of the prototype is the need to have sustainer engines that can be fired multiple times, and also to leave 13 tons of fuel after separation to ensure operation of the sustainer engines during the descent phase, which leads to a reduction in the mass of the payload launched into low Earth orbit from 12.5 tons to 10.5 tons .

Thus, known technical solutions cannot ensure the landing of a reusable first stage of a launch vehicle without significantly reducing the reliability of bringing the stage into a given area or the mass of the payload being launched into orbit.

The reason preventing the solution of this technical problem is the lack of designs for methods for landing a reusable first stage of a launch vehicle that would ensure the necessary reliability of bringing the stage into a given area and a minimal reduction in the mass of the payload being launched into orbit.

Disclosure of the invention

A method for landing a reusable first stage of a launch vehicle is proposed, which ensures the necessary reliability of bringing the stage into a given landing area with the minimum possible reduction in the mass of the payload being launched into orbit.

A. A method is proposed for landing a reusable first stage of a launch vehicle, which contains the operations of unfolding the lower landing legs and bringing the stage into a vertical position until the landing legs touch the landing pad at low speed. Immediately after the stage is separated, in the ascending section of the trajectory, operations are carried out to release the rotor blades and bring them into working position due to the oncoming air flow. The transfer of the main rotor to the autorotation mode and the orientation of the longitudinal axis of the stage are carried out due to the oncoming air flow. From the moment the work begins at the exit until the return entry into the dense layers of the atmosphere and during their passage, maintaining constant specified rotor speeds is ensured by controlling the overall pitch of the blades. After the transition to a section of the trajectory with an established reduced velocity pressure and a reduced vertical descent rate, simultaneous control of the general and cyclic pitch of the blades is carried out to ensure the necessary reliability of bringing the stage to the specified landing area. Before touching the Earth, the landing legs are unfolded and the overall pitch of the blades is rapidly increased, their rotation speed decreases, but the lifting force of the propeller increases, due to which the residual speed of the stage descent is dampened.

The objective of this invention is to develop a method for landing a reusable first stage of a launch vehicle, ensuring the necessary reliability of bringing the stage into a given landing area with the minimum possible reduction in the mass of the payload being launched into orbit.

The problem is solved by the fact that the method of landing a reusable first stage of a launch vehicle, containing the operations of unfolding the lower landing legs and bringing the stage into a vertical position until the landing legs touch the landing pad at low speed, according to the invention, immediately after separation of the stage, operations are carried out on the ascending section of the trajectory releasing the main rotor blades and bringing them into working position due to the oncoming air flow, switching the main rotor to the autorotation mode, maintaining constant set rotor speeds from the moment the work begins at the exit until the return entry into the dense layers of the atmosphere and during their passage by controlling the collective pitch blades, and after the transition to a section of the trajectory with a steady reduced velocity pressure and a reduced vertical descent rate, the total and cyclic pitch of the blades is simultaneously controlled to ensure the necessary reliability of bringing the stage to a given landing area, while before touching the Earth, the landing legs are folded out and the total is rapidly increased pitch of the blades, the speed of their rotation decreases, but the lifting force of the propeller increases, due to which the residual rate of descent of the stage is extinguished.

The essence of the invention is illustrated by the drawing.

In fig. Figure 1 shows a diagram of the landing device of the reusable first stage of the launch vehicle.

In this diagram:

1 - base;

2 - fixed pipe;

3 - rotating pipe;

4 - main rotor hub;

5 - vertical hinge bushing;

6 - rotor of a reversible stepper motor;

7 - stator of a reversible stepper motor;

8 - fixed pipe;

9 - fixed platform;

10 - receiving antenna;

11 - radio-transparent fairing;

12 - support bearing of the axial hinge;

13 - angular contact bearing of the axial hinge;

14 - angular contact bearing between pipes;

15 - support bearing between pipes.

Carrying out the invention

An example of a possible implementation of the proposed technical solution.

The landing device of the reusable first stage of the launch vehicle consists of four landing supports (not shown in Fig. 1) installed symmetrically at the bottom of the stage. The landing device (Fig. 1) consists of a base 1 resting on the upper shell of the stage, a stationary power pipe 2 installed on it, a rotating pipe 3 with a main rotor bushing 4 fixed on top of it. In this case, the bushing of the vertical hinge 5 of the blade is connected to the rotor of the reversible stepper motor 6, which together with the stator of the reversible stepper motor 7 forms the axial hinge of the rotor. Inside the rotating pipe 3 there is a fixed pipe 8, passing through the rotating hub of the main rotor 4 and ending with a fixed platform 9, on which the receiving antenna 10 of the consumer equipment of the global navigation positioning system is installed under a radio-transparent fairing 11. The design of the device uses a support bearing of the axial hinge 12, radially - thrust bearing of the axial hinge 13, angular contact bearing between the pipes 14 and support bearing between the pipes 15.

The device has the following characteristics. The diameter of the cylindrical part of the stage body is 4.1 m, the mass of the stage at the moment of touching the Earth's surface is assumed to be greater by 1 ton of its dry mass due to the filling of the fuel lines and the guaranteed remaining fuel and equal to 26.4 tons. The number of main rotor blades is 6. Length the blades are 10 m, width 0.3 m. The main rotor blades, their power elements and casing are made of titanium. The total mass of the stage due to the use of the main rotor increases by 1.3 tons. In the reusable version, 13 tons are not used at the first stage launch site in order to ensure its subsequent dynamic descent, which leads to a decrease in the mass of the payload launched into low Earth orbit by 2 tons It follows from this that with an increase in the mass of the stage by 1.3 tons due to the use of a main rotor, the mass of the payload launched into low Earth orbit decreases by 0.2 tons and becomes equal to 12.3 tons.

As a result of the application of the present invention, a technical solution aimed at developing a method for landing a reusable first stage, ensuring the necessary reliability of bringing it to a given area and minimal reduction in the mass of the payload launched into orbit, is implemented through the use of a method of lowering the stage in the Earth’s atmosphere “helicopter-style” in autorotation mode without fuel consumption.

Claims (1)

A method of landing a reusable first stage of a launch vehicle, containing the operations of unfolding the landing legs and bringing the stage into a vertical position until the landing legs touch the landing pad at low speed, characterized in that immediately after the separation of the stage on the ascending section of the trajectory, the operations of releasing the rotor blades and bringing them into working position due to the oncoming air flow, switching the main rotor to the autorotation mode, maintaining constant set rotor speeds from the moment the work begins at the exit until the return entry into the dense layers of the atmosphere and during their passage by controlling the common pitch of the blades, and after the transition For a section of the trajectory with an established reduced velocity pressure and a reduced vertical descent speed, the overall and cyclic pitch of the blades is simultaneously controlled to ensure the necessary reliability of bringing the stage to a given landing area, while before touching the Earth, the landing legs are folded out and the overall pitch of the blades is rapidly increased, the speed decreases their rotation, but the lifting force of the propeller increases, due to which the residual rate of descent of the stage is dampened.

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