A method and system for vertical recovery of a rocket and a rocket

Abstract

The embodiment of the present application provides a rocket vertical recovery method, system and rocket, and the method comprises the following steps: after a sub-level rocket is separated, the thrust size of the central engine of the sub-level rocket is adjusted to a preset proportion of the rated thrust to provide positive overload for the propellant in the tank, and the propellant can be gathered at the outlet at the bottom of the tank through the positive overload; the flight direction of the sub-level rocket deviates from the current flight direction through bidirectional swinging of the central engine, and the posture of the sub-level rocket is kept in the posture of downward diving towards the earth direction; the posture of the sub-level rocket is adjusted from the posture of downward diving to the posture of upward flight through bidirectional swinging of the central engine, and the tangential force in two different directions tangent to the current flight direction of the sub-level rocket is generated at the same time, and the sub-level rocket is slowed down until landing on the earth. The small thrust of the sub-level rocket central engine thrust adjustment realizes the posture control and propellant management of the sub-level rocket recovery.

Description

Technical Field

[0001] This invention relates to the field of rocket recovery, specifically to a method, system, and rocket for vertical rocket recovery. Background Technology

[0002] Launch vehicles have become the primary tool for humankind's exploration of space. To date, almost all launch vehicles can only be used once, resulting in extremely high prices. Therefore, for humanity to conduct large-scale space exploration, it is necessary to minimize launch costs. The current mainstream idea is to reuse spacecraft to reduce launch costs.

[0003] The earliest reusable spacecraft, the Space Shuttle, while achieving the reuse of its orbiter and boosters, suffered from high maintenance costs and a high accident rate, ultimately leading to its retirement in 2011. In 2015, SpaceX successfully recovered the first stage of its Falcon 9 rocket, prompting a shift in rocket recovery research focus towards the recovery of individual stages. Currently, there are two methods for rocket recovery: one utilizes air resistance or lift for deceleration, i.e., aerodynamic deceleration; the other uses fuel combustion for deceleration, i.e., retro-thrust deceleration.

[0004] There are two main types of pneumatic deceleration and recovery launch vehicles: parachute recovery and reverse thrust deceleration recovery. Although parachute recovery technology is less technically difficult, has many types, and is widely used, it is limited by its own technical principle. The deceleration effect cannot meet the speed requirements of land or sea platform recovery, and the accuracy of uncontrolled landing is low. Therefore, it cannot be used as the main method of recovering chemical fuel rockets for large-scale space exploration in the future.

[0005] In the process of developing this invention, the applicant discovered at least the following problems in the prior art:

[0006] Thrust-reverse deceleration for reusable launch vehicles primarily involves the first stage using remaining fuel to adjust its attitude and trajectory after first and second stage separation, ultimately controlling the rocket's landing at a designated location. Launch vehicles typically employ vertical landing to minimize wear on the rocket's aerodynamic structure during descent. Thrust-reverse deceleration is now widely used and has been successfully implemented multiple times. Several companies, led by SpaceX, have completed testing of reusable rockets and some are already in service. Vertical means the rocket's orientation is 90 degrees to the ground, and it returns to Earth with a 90° (vertically downward) attitude.

[0007] Reverse-propulsion deceleration and recovery launch vehicles need to carry solid rockets during recovery. These solid rockets ignite in the first-stage recovery phase to reposition and sink the propellant. Simultaneously, an independent RCS (Reaction Control System) attitude control system is required for rocket attitude control. To achieve propellant repositioning and sinking, as well as rocket attitude control, the rocket system is quite complex. Furthermore, the rocket pressurization system is costly, with independent design of the oxygen and fuel tank pressurization systems, resulting in weak interdependence and a large number and variety of pipelines and valves. Propellant repositioning refers to the process where, during flight, negative overloads caused by tumbling and gliding disperse the propellant throughout the tanks. Repositioning involves providing positive overloads to the rocket, altering the propellant's distribution within the tanks, and re-gathering it at the bottom outlet of the tank. This prevents cavitation and ensures timely and smooth propellant intake for ignition during engine startup.

[0008] Solving the problems of cryogenic propellant repositioning and sinking during the recovery process of first-stage rockets, as well as rocket attitude control, while simultaneously reducing costs, has become a major challenge for first-stage rocket recovery. Therefore, there is an urgent need to develop low-cost first-stage rocket recovery procedures. Summary of the Invention

[0009] This invention provides a method, system, and rocket for vertical rocket recovery, which can solve the problems of cryogenic propellant repositioning and sinking to the bottom, rocket attitude control, and high cost in the recovery process of first-stage rockets in the prior art.

[0010] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a method for vertical recovery of a rocket, comprising:

[0011] Step 1: After the rocket launches and flies along the predetermined trajectory, and after the first-stage rocket and second-stage rocket separate, for the first-stage rocket, adjust the thrust of the central engine of the first-stage rocket to a preset proportion of the rated thrust to provide a positive overload to the propellant in the propellant tank that supplies the engine. The direction of the positive overload force is opposite to the flight direction of the first-stage rocket. Through the positive overload, the propellant can be concentrated at the outlet at the bottom of the tank. At the same time, shut down the other engines. The engines of the first-stage rocket are arranged as follows: on the cross-section of the first-stage rocket, the central engine is arranged in the middle, and the other engines are arranged on the periphery.

[0012] Step 2: By first bidirectionally swinging the central engine, two different tangential forces in different directions can be generated simultaneously, which are tangential to the current flight direction of the first-stage rocket. This causes the flight direction of the first-stage rocket to deviate from its current flight direction and adjust the flight direction of the first-stage rocket toward the Earth. After adjusting the flight direction of the first-stage rocket to be toward the Earth, the first-stage rocket is maintained in a downward diving attitude toward the Earth.

[0013] Step 3: By bidirectionally swinging the central engine again, two different tangential forces in different directions can be generated simultaneously, which are tangential to the current flight direction of the first-stage rocket. This causes the flight direction of the first-stage rocket to deviate from its current flight direction until it forms a 180° turn when separating from the second-stage rocket. This adjusts the attitude of the first-stage rocket from a downward diving attitude to an upward flight attitude, decelerating it until the first-stage rocket lands on Earth.

[0014] Secondly, a rocket vertical recovery system includes:

[0015] A positive overload supply unit is used, after the rocket launch and flight along a predetermined trajectory, and after the first and second stages of the rocket separate, to adjust the thrust of the central engine of the first stage rocket to a preset proportion of its rated thrust to provide a positive overload to the propellant in the propellant tank that supplies the engine. The direction of the positive overload force is opposite to the flight direction of the first stage rocket. This positive overload allows the propellant to accumulate at the outlet at the bottom of the tank. Simultaneously, other engines are shut down. The engines of the first stage rocket are arranged such that, on the cross-section of the first stage rocket, the central engine is located in the middle, and the other engines are located on the periphery.

[0016] The steering unit is used to initially generate two tangential forces in different directions tangential to the current flight direction of the first-stage rocket by bidirectionally swinging the central engine, causing the first-stage rocket's flight direction to deviate from its current flight direction and adjust its flight direction toward the Earth. After adjusting the first-stage rocket's flight direction toward the Earth, it maintains the first-stage rocket's downward diving attitude toward the Earth. Again, by bidirectionally swinging the central engine, it generates two tangential forces in different directions tangential to the current flight direction of the first-stage rocket, causing its flight direction to deviate from its current flight direction until the first-stage rocket's flight direction undergoes a 180° turn, adjusting its attitude from a downward diving attitude to an upward flying attitude, decelerating until it lands on Earth.

[0017] Thirdly, embodiments of the present invention provide a rocket, including the aforementioned rocket vertical recovery system.

[0018] The above technical solution has the following beneficial effects: After the first-stage rocket separates from the second-stage rocket, the thrust of the central engine of the first-stage rocket is adjusted to a preset ratio of the rated thrust to continuously provide positive overload to the propellant in the tank that supplies propellant to the engine. The direction of the positive overload force is opposite to the flight direction of the first-stage rocket. Through positive overload, the propellant can be concentrated at the outlet at the bottom of the tank. This can solve the problems of cryogenic propellant repositioning and sinking to the bottom during the recovery process of the first-stage rocket in the prior art, as well as the problems of rocket attitude control and high cost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a rocket vertical recovery method according to an embodiment of the present invention;

[0021] Figure 2 This is a vector diagram of a first-stage rocket according to an embodiment of the present invention;

[0022] Figure 3 This is a diagram showing the distribution and swaying direction of a first-stage engine according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the swing control principle of the central engine in an embodiment of the present invention;

[0024] Figure 5 This is a three-dimensional structural schematic diagram of the cross-shaped constant level seat according to an embodiment of the present invention;

[0025] Figure 6 This is a diagram illustrating the launch and recovery process of a first-stage rocket according to an embodiment of the present invention.

[0026] Figure 7 This is a diagram illustrating the launch process of a first-stage rocket according to an embodiment of the present invention;

[0027] Figure 8 This is a diagram illustrating the recovery process of a first-stage rocket according to an embodiment of the present invention;

[0028] Figure 9 This is a graph showing the number of engine working stations during the launch and recovery process of a first-stage rocket according to an embodiment of the present invention.

[0029] Figure 10 This is the landing leg support air supply system of a first-stage rocket according to an embodiment of the present invention;

[0030] Figure 11 This describes the implementation principle of the x-direction swing servo mechanism 5 and the y-direction swing servo mechanism 7 in this embodiment of the invention.

[0031] The reference numerals in the attached figures are as follows:

[0032] 1. Engine fixed end; 2. Cross-shaft type constant level seat; 3. Combustion chamber; 4. Fixed end of x-direction oscillating servo mechanism; 5. x-direction oscillating servo mechanism; 6. Fixed end of y-direction oscillating servo mechanism; 7. y-direction oscillating servo mechanism; 8. Thrust chamber;

[0033] 51. Upper propellant tank; 52. Lower propellant tank; 300. Central engine; 54. Rocket flight direction; 55. Rocket positive overload direction; 56. Rocket negative overload direction;

[0034] 11. Connection end with rocket; 21. Connection end with engine; 31. X-axis; 41. Y-axis;

[0035] 100. Landing leg unlocking device #1; 101. Landing leg unlocking device #2; 103. Landing leg unlocking device #3; 102. Landing leg unlocking device #4;

[0036] 94. Room temperature helium cylinder; 95. First three-way valve; 96. First solenoid valve; 97. First orifice plate; 98. Four-way valve; 99. Second three-way valve;

[0037] 106. Landing leg opening sub-device I; 107. Landing leg opening sub-device II; 108. Landing leg opening sub-device III; 109. Landing leg opening sub-device IV; 104. Second solenoid valve; 105. Second orifice plate;

[0038] 20. Oil tank; 22. Hydraulic pump; 22. Motor; 23. Oil inlet pipe; 24. Signal source; 25. PID signal processing device; 26. Signal input device; 27. Solenoid valve; 28. Hydraulic line A; 29. ​​Hydraulic cylinder A interface; 30. Hydraulic cylinder; 33. Hydraulic cylinder A chamber; 32. Hydraulic cylinder B chamber; 33. Push rod; 34. Sealing device; 35. Sealing device; 36. Hydraulic cylinder B interface; 37. Hydraulic line B; 38. Oil outlet pipe. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, in conjunction with an embodiment of the present invention, a method for vertical recovery of a rocket is provided, comprising:

[0041] Step 1: After the rocket launches and flies along the predetermined trajectory, and after the first-stage rocket and second-stage rocket separate, for the first-stage rocket, the thrust of the central engine 300 of the first-stage rocket is adjusted to a preset proportion of the rated thrust to provide a positive overload to the propellant in the propellant tank that supplies the engine. The direction of the positive overload force is opposite to the flight direction of the first-stage rocket. Through the positive overload, the propellant can be concentrated at the outlet at the bottom of the tank. At the same time, the other engines are shut down. The engines of the first-stage rocket are arranged as follows: on the cross-section of the first-stage rocket, the central engine 300 is arranged in the middle, and the other engines are arranged on the periphery.

[0042] Step 2: By first bidirectionally swinging the central engine 300, two different tangential forces in different directions can be generated simultaneously, which are tangential to the current flight direction of the first-stage rocket. This causes the flight direction of the first-stage rocket to deviate from its current flight direction and adjust the flight direction of the first-stage rocket toward the Earth. After adjusting the flight direction of the first-stage rocket to the direction toward the Earth, the first-stage rocket is maintained in a downward diving attitude toward the Earth.

[0043] Step 3: By bidirectionally swinging the central engine 300 again, two different tangential forces in different directions can be generated simultaneously, which are tangential to the current flight direction of the first-stage rocket. This causes the flight direction of the first-stage rocket to deviate from its current flight direction until it forms a 180° turn when separating from the second-stage rocket. This adjusts the attitude of the first-stage rocket from a downward diving attitude to an upward flight attitude, decelerating it until the first-stage rocket lands safely on Earth.

[0044] After the first-stage rocket separates from the second-stage rocket, the thrust of the central engine 300 of the first-stage rocket is adjusted to a preset proportion of the rated thrust to continuously provide positive overload to the propellant in the propellant tank that supplies the engine. The direction of the positive overload force is opposite to the flight direction of the first-stage rocket. Through positive overload, the propellant can be concentrated at the outlet at the bottom of the tank. This can solve the problems of cryogenic propellant repositioning and sinking to the bottom during the recovery process of the first-stage rocket in the prior art, as well as the rocket attitude control problem and the high cost problem.

[0045] Initially, by bidirectionally oscillating the central engine 300, two tangential forces in different directions, tangential to the current flight direction of the first-stage rocket, can be generated simultaneously. This causes the central engine 300 to turn towards the Earth, maintaining the first-stage rocket's downward-sweeping attitude. Subsequently, by again bidirectionally oscillating the central engine 300, two tangential forces in different directions, tangential to the current flight direction of the first-stage rocket, can be generated simultaneously, adjusting the first-stage rocket's attitude from downward-sweeping to upward-sweeping, decelerating the first-stage rocket until it lands on Earth. This recovery and landing method is simple, low-cost, and easy to implement and popularize.

[0046] Preferably, step 2 further includes:

[0047] Step 21: After adjusting the direction of the first-stage rocket to face the Earth, stop the bidirectional swinging of the central engine 300 and maintain the first-stage rocket in a downward diving attitude towards the Earth. This will bring the first-stage rocket closer and closer to the Earth, and the downward diving will shorten the recovery time of the first-stage rocket and reduce the probability of the first-stage rocket colliding with space debris during long-term operation in space.

[0048] Preferably, step 3 specifically includes:

[0049] Step 31: By bidirectionally swinging the central engine 300 again, two different tangential forces in different directions can be generated simultaneously, which are tangential to the current flight direction of the first-stage rocket. This causes the flight direction of the first-stage rocket to deviate from the current flight direction until the flight direction of the first-stage rocket changes 180°. This adjusts the attitude of the first-stage rocket from a downward diving attitude to an upward flight attitude. The purpose is to enable the first-stage rocket to land in the attitude at launch, preparing for the subsequent attitude adjustment of the central engine 300 to 100% thrust to decelerate the first-stage rocket.

[0050] Step 32: Maintain the first-stage rocket in an upward flight attitude until it enters the atmosphere. When entering the atmosphere, the speed of the first-stage rocket is reduced to the designed entry speed. The purpose is to prevent the first-stage rocket from crashing due to excessive speed when re-entering the atmosphere. The central engine 300 is shut down so that the first-stage rocket can enter the gliding phase by free falling in the atmosphere. Shutting down the central engine 300 can save rocket fuel.

[0051] Preferably, step 3 specifically includes:

[0052] Step 33: After the set time for the coasting phase, the central engine 300 is activated. The thrust generated by the central engine 300 decelerates the first-stage rocket until it lands. The thrust generated by the central engine 300 decelerates the first-stage rocket, helping it land smoothly.

[0053] Preferably, the rocket vertical recovery method further includes:

[0054] Step 4: Supply air to the outrigger unlocking device through the unlocking air supply device, and release the fixed connection device through the outrigger unlocking device. The fixed connection device is used to connect the landing outrigger to the body of the first stage rocket. Supply air to the outrigger opening device through the outrigger opening air supply device, and open the landing outrigger through the outrigger opening device. The tail of the first stage rocket faces the ground, and the landing outrigger assists the first stage rocket in landing on the earth.

[0055] Step 4 and step 33 are executed simultaneously.

[0056] If the landing legs are not secured, they will sway up and down under strong vibrations during normal flight, potentially causing fatigue damage or even impacting and damaging the fuel tanks. Therefore, a securing device is required to hold the landing legs in place during flight. When deploying the landing legs, the securing device must be unlocked first to release each landing leg. Then, the landing legs can be deployed.

[0057] Preferably, in step 4, the outriggers include landing outrigger I, landing outrigger II, landing outrigger III, and landing outrigger IV;

[0058] The outrigger unlocking device includes a #1 landing outrigger unlocking sub-device 100, a #2 landing outrigger unlocking sub-device 101, a #3 landing outrigger unlocking sub-device 103, and a #4 landing outrigger unlocking sub-device 102; wherein, the #1 landing outrigger unlocking sub-device 100 is used to unlock the #1 landing outrigger, the #2 landing outrigger unlocking sub-device 101 is used to unlock the #2 landing outrigger, the #3 landing outrigger unlocking sub-device 103 is used to unlock the #3 landing outrigger, and the #4 landing outrigger unlocking sub-device 102 is used to unlock the #4 landing outrigger;

[0059] The unlocking gas supply device includes: a room temperature helium cylinder 94, a first three-way valve 95 arranged sequentially on the first gas supply pipeline after the room temperature helium cylinder 94, two first solenoid valves 96 arranged in parallel, a first orifice plate 97, a four-way valve 98, and a second three-way valve 99; wherein, the I# landing leg unlocking sub-device 100 and the II# landing leg unlocking sub-device 101 are connected to the four-way valve 98 and connected to the four-way valve 98 through the second three-way valve 99, and the III# landing leg unlocking sub-device 103 and the IV# landing leg unlocking sub-device 102 are connected to the second three-way valve 99;

[0060] Step 4 specifically includes:

[0061] Step 41: When supplying gas to the outrigger unlocking device, open one of the first solenoid valves 96, and let the helium in the room temperature helium cylinder 94 enter the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101 through the first three-way valve 95, the opened first solenoid valve 96, the first orifice plate 97 and the four-way valve 98 respectively, so as to supply gas to the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101 respectively, and open the fixed connection device on the I# landing outrigger and the II# landing outrigger respectively through the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101;

[0062] Step 42: The helium in the ambient temperature helium cylinder 94 is introduced into the III# landing leg unlocking device 103 and the IV# landing leg unlocking device 102 through the first three-way valve 95, the opened first solenoid valve 96, the first orifice plate 97, the four-way valve 98, and the second three-way valve 99, respectively, thereby supplying gas to the III# landing leg unlocking device 103 and the IV# landing leg unlocking device 102. The fixed connection devices on the III# landing leg and the IV# landing leg are opened through the III# landing leg unlocking device 103 and the IV# landing leg unlocking device 102, respectively.

[0063] Two first solenoid valves 96 are used for redundancy to prevent the landing outriggers from failing to open if one of the first solenoid valves 96 fails to open, thus causing the landing outriggers' unlocking and air supply device to fail.

[0064] Preferably, in step 4, the outriggers include landing outrigger I, landing outrigger II, landing outrigger III, and landing outrigger IV;

[0065] The outrigger deployment device includes a #1 landing outrigger deployment sub-device 106, a #2 landing outrigger deployment sub-device 107, a #3 landing outrigger deployment sub-device 108, and a #4 landing outrigger deployment sub-device 109; wherein, the #1 landing outrigger deployment sub-device 106 is used to deploy the #1 landing outrigger, the #2 landing outrigger deployment sub-device 107 is used to deploy the #2 landing outrigger, the #3 landing outrigger deployment sub-device 108 is used to deploy the #3 landing outrigger, and the #4 landing outrigger deployment sub-device 109 is used to deploy the #4 landing outrigger;

[0066] The outrigger opening gas supply device includes: a room temperature helium cylinder 94, a first tee 95 located sequentially after the room temperature helium cylinder 94 on the first gas supply pipeline, two second solenoid valves 104 arranged in parallel, and a second orifice plate 105; wherein, the I# landing outrigger opening sub-device 106, the II# landing outrigger opening sub-device 107, the III# landing outrigger opening sub-device 108, and the IV# landing outrigger opening sub-device 109 are connected in parallel after the second orifice plate 105;

[0067] Step 4 specifically includes:

[0068] Step 43: When supplying gas to the outrigger deployment device, open one of the second solenoid valves 104, allowing helium from the ambient temperature helium cylinder 94 to enter the I# landing outrigger deployment sub-device 106, the II# landing outrigger deployment sub-device 107, the III# landing outrigger deployment sub-device 108, and the IV# landing outrigger deployment sub-device 109 respectively via the first three-way valve 95, the second solenoid valve 104, and the second orifice plate 105; thus supplying gas to the I# landing outrigger deployment sub-device 106, the II# landing outrigger deployment sub-device 107, the III# landing outrigger deployment sub-device 108, and the IV# landing outrigger deployment sub-device 109. Air is supplied to landing leg opening sub-device 107, landing leg opening sub-device 108, and landing leg opening sub-device 109, respectively, so that landing leg I, landing leg II, landing leg III, and landing leg IV can be opened through landing leg opening sub-device 106, landing leg II, landing leg III, and landing leg IV, respectively.

[0069] Step 44: With the tail of the first-stage rocket facing the ground, the first-stage rocket is landed on Earth by the I# landing leg, the II# landing leg, the III# landing leg, and the IV# landing leg.

[0070] Two secondary solenoid valves 104 are used for redundancy to prevent the landing outriggers from failing to open and causing the air supply to the outriggers to fail.

[0071] Preferably, step 2 specifically includes:

[0072] By bidirectionally oscillating the central engine 300 via a cross-shaped oscillation, two tangential forces in different directions can be generated simultaneously, tangential to the current flight direction of the first-stage rocket, wherein:

[0073] The cross-shaped oscillating element includes a cross-shaped constant-level seat 2. One end of the cross-shaped constant-level seat 2 is connected to the engine fixed end 1, which is connected to the rocket body of the first-stage rocket. The other end of the cross-shaped constant-level seat 2 is connected to the combustion chamber 3 of the central engine 300. The combustion chamber 3 of the central engine 300 is connected to the thrust chamber 8 of the central engine 300. The thrust chamber 8 is farther away from the cross-shaped constant-level seat 2 than the combustion chamber 3.

[0074] The cross-shaped leveling seat 2 is provided with an x-axis 31 and a y-axis 41 in a cross shape. The x-axis 31 and the y-axis 41 are respectively located in the x-direction and y-direction of the cross section of the first stage rocket. The cross-shaped leveling seat 2 is also provided with a vertical axis that is perpendicular to the cross section of the first stage rocket and passes through the cross-shaped leveling seat 2. The cross-shaped leveling seat 2 can rotate around the vertical axis.

[0075] The cross-shaped constant level seat 2 also includes a rocket connection end 11 and an engine connection end 21; the rocket connection end 11 is fixed to the rocket body by welding, and the engine connection end 21 is fixed to the central engine 300 by welding.

[0076] The x-axis 31 passes through the rocket connection end 11 and can rotate within the rocket connection end 11; the y-axis 41 passes through the engine connection end 21 and can rotate within the engine connection end 21.

[0077] The cross-shaped swing also includes a servo mechanism, which includes a retractable x-direction swing servo mechanism 5 and a retractable y-direction swing servo mechanism 7. One end of the x-direction swing servo mechanism 5 is connected to the body of the first stage rocket through the x-direction swing servo mechanism fixed end 4, and the other end of the x-direction swing servo mechanism 5 is connected to the combustion chamber 3. The x-direction swing servo mechanism 5 and the x-direction axis 31 are on the same first plane.

[0078] like Figure 11 As shown, the implementation principles of the x-direction oscillating servo mechanism 5 and the y-direction oscillating servo mechanism 7 are as follows:

[0079] Signal source 24 receives the swing signal from the center engine 300 of the first-stage rocket; PID signal processing device 25 converts the swing signal from the first-stage rocket into opening and closing signals for solenoid valve 27; signal input device 26 inputs the opening and closing signals of solenoid valve 27 into solenoid valve 27. Oil tank 20 supplies hydraulic oil to hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32, and simultaneously recycles the hydraulic oil in hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32.

[0080] The x-direction oscillating servo mechanism 5 and the y-direction oscillating servo mechanism 7 include hydraulic push rods and are driven by hydraulic oil. When the solenoid valve 27 is de-energized, the oil inlet P is connected to A, the oil inlet pipe 23 is connected to the A hydraulic pipe 28, the oil outlet T is connected to B, and the oil outlet pipe 38 is connected to the B hydraulic pipe 37. The hydraulic oil in the oil tank 20 is pressurized by the hydraulic pump 221 and enters the A hydraulic cylinder interface 29 through the oil inlet pipe 23, the solenoid valve 27, and the A hydraulic pipe 28, supplying hydraulic oil to the A chamber 311 of the hydraulic cylinder, causing the push rod 33 to move to the right, thereby increasing the length of the hydraulic push rod; at the same time, the hydraulic oil in the B chamber 32 of the hydraulic cylinder returns to the oil tank 20 through the B hydraulic cylinder interface 36, the B hydraulic pipe 37, the solenoid valve 27, and the oil outlet pipe 38.

[0081] Hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32 are sealed by sealing device 34, and hydraulic cylinder B chamber 32 is sealed to the outside world by sealing device 35.

[0082] When solenoid valve 27 is energized, oil inlet P is connected to B, oil inlet pipe 23 is connected to hydraulic pipe 37 of B, oil outlet T is connected to A, and oil outlet pipe 38 is connected to hydraulic pipe 28 of A. The hydraulic oil in oil tank 20 is pressurized by hydraulic pump 221 (motor 22 provides power to hydraulic pump 221) and enters hydraulic cylinder interface 36 of B through oil inlet pipe 23, solenoid valve 27, and hydraulic pipe 37 of B, supplying hydraulic oil to chamber 32 of hydraulic cylinder B, causing push rod 33 to move to the left, thus reducing the length of hydraulic push rod; at the same time, the hydraulic oil in chamber 311 of hydraulic cylinder A returns to oil tank 20 through hydraulic cylinder interface 29 of A, hydraulic pipe 28 of A, solenoid valve 27, and oil outlet pipe 38. One end of the y-direction oscillating servo mechanism 7 is connected to the body of the first-stage rocket via the y-direction oscillating servo mechanism fixed end 6, and the other end of the y-direction oscillating servo mechanism 7 is connected to the combustion chamber 3. The y-direction oscillating servo mechanism 7 and the y-direction axis 41 are on the same second plane.

[0083] Engine fixed end 1 and cross-shaft type constant level seat 2 correspond to the crank fixed point of the crank-rocker mechanism; cross-shaft type constant level seat 2 and combustion chamber 3 correspond to the crank of the crank-rocker mechanism; x-direction rocking servo mechanism 5 corresponds to the combination of rocker block and rocker arm of the crank-rocker mechanism; x-direction rocking servo mechanism fixed end 4 corresponds to the rotation point of rocker block of the crank-rocker mechanism; similarly, engine fixed end 1 and cross-shaft type constant level seat 2 correspond to the crank fixed point of the crank-rocker mechanism; cross-shaft type constant level seat 2 and combustion chamber 3 correspond to the crank of the crank-rocker mechanism; y-direction rocking servo mechanism 7 corresponds to the combination of rocker block and rocker arm of the crank-rocker mechanism; y-direction rocking servo mechanism fixed end 6 corresponds to the rotation point of rocker block of the crank-rocker mechanism. The cross-axis type constant-mount seat has a simple and reliable structure. Without the cross-axis type constant-mount seat 2, the central engine 300 can only be fixedly connected to the rocket body and cannot rotate. However, with the cross-axis type constant-mount seat 2, the rocket body and the central engine 300 can be separated, allowing the central engine 300 to achieve its predetermined movement. Thrust direction control is achieved through double cross-shaped oscillation: When the spacecraft control system issues a control command, the x-direction oscillation servo mechanism and the y-direction oscillation servo mechanism 7 continuously extend and retract. According to the cooperation of the x-direction axis 31 and the y-direction axis 41 with the cross-axis type constant-mount seat 2, the thrust chamber 8 is pushed to oscillate around the vertical axis of the cross-axis type constant-mount seat 2. The angle of the thrust chamber 8 is changed according to the attitude change of the first-stage rocket (i.e., the current angle of the thrust chamber 8 is changed), thereby changing the thrust direction and providing thrust vector control (generating control torque) for the first-stage rocket, enabling the first-stage rocket to fly along a predetermined trajectory and perform pitch, yaw, or roll movements.

[0084] Preferably, step 2 specifically includes:

[0085] The extension and retraction of the x-direction swing servo mechanism 5 causes the thrust chamber 8 to swing around the cross-shaped constant level seat 2 as the center of mass in the first plane along the x-direction axis 31, generating a tangential force in the first direction that is tangential to the current flight direction of the first stage rocket. The tangential force in the first direction causes the thrust chamber 8 to swing around the vertical axis, thereby enabling the first stage rocket to rotate along the vertical axis.

[0086] The extension and retraction of the y-direction oscillating servo mechanism 7 causes the thrust chamber 8 to oscillate around the cross-shaped constant-level seat 2 in the second plane along the y-direction axis 41, generating a tangential force in the second direction that is tangential to the current flight direction of the first-stage rocket. This tangential force causes the thrust chamber 8 to oscillate around the vertical axis.

[0087] The combined tangential force in the first direction and the tangential force in the second direction cause the flight direction of the first-stage rocket to deviate from its current flight direction.

[0088] Thrust direction control is achieved through a double-cross swing mechanism: When the spacecraft control system issues a control command, the x-direction swing servo mechanism and the y-direction swing servo mechanism 7 continuously extend and retract. According to the cooperation of the x-direction axis 31 and the y-direction axis 41 with the cross-shaped constant-level seat 2, the thrust chamber 8 will swing around the vertical axis of the cross-shaped constant-level seat 2. The angle of the thrust chamber 8 is changed according to the attitude change of the first-stage rocket (i.e., the current angle of the thrust chamber 8 is changed), thereby changing the thrust direction and providing thrust vector control (generating control torque) for the first-stage rocket, so that the first-stage rocket can fly along the predetermined trajectory.

[0089] In conjunction with embodiments of the present invention, a rocket vertical recovery system is provided, comprising:

[0090] A positive overload supply unit is used to, after the rocket launch and flight along a predetermined trajectory, and after the first and second stages of the rocket separate, adjust the thrust of the central engine 300 of the first stage rocket to a preset proportion of its rated thrust to provide a positive overload to the propellant in the propellant tank that supplies propellant to the engine. The direction of the positive overload force is opposite to the flight direction of the first stage rocket. This positive overload allows the propellant to accumulate at the outlet at the bottom of the tank. Simultaneously, other engines are shut down. The engines of the first stage rocket are arranged such that, on the cross-section of the first stage rocket, the central engine 300 is located in the middle, and the other engines are located on the periphery.

[0091] The steering unit is used to initially generate two tangential forces in different directions tangential to the current flight direction of the first-stage rocket by bidirectionally oscillating the central engine 300, causing the first-stage rocket's flight direction to deviate from its current flight direction and adjust its flight direction toward the Earth. After adjusting the first-stage rocket's flight direction toward the Earth, it maintains the first-stage rocket's downward diving attitude toward the Earth. Again, by bidirectionally oscillating the central engine 300, it generates two tangential forces in different directions tangential to the current flight direction of the first-stage rocket, causing its flight direction to deviate from its current flight direction until the first-stage rocket's flight direction undergoes a 180° turn, adjusting its attitude from a downward diving attitude to an upward flying attitude, decelerating until it lands on Earth.

[0092] After the first-stage rocket separates from the second-stage rocket, the thrust of the central engine 300 of the first-stage rocket is adjusted to a preset proportion of the rated thrust to continuously provide positive overload to the propellant in the propellant tank that supplies the engine. The direction of the positive overload force is opposite to the flight direction of the first-stage rocket. Through positive overload, the propellant can be concentrated at the outlet at the bottom of the tank. This can solve the problems of cryogenic propellant repositioning and sinking to the bottom during the recovery process of the first-stage rocket in the prior art, as well as the rocket attitude control problem and the high cost problem.

[0093] Initially, by bidirectionally oscillating the central engine 300, two tangential forces in different directions, tangential to the current flight direction of the first-stage rocket, can be generated simultaneously. This causes the central engine 300 to turn towards the Earth, maintaining the first-stage rocket's downward-sweeping attitude. Subsequently, by again bidirectionally oscillating the central engine 300, two tangential forces in different directions, tangential to the current flight direction of the first-stage rocket, can be generated simultaneously, adjusting the first-stage rocket's attitude from downward-sweeping to upward-sweeping, decelerating the first-stage rocket until it lands on Earth. This recovery and landing method is simple, low-cost, and easy to implement and popularize.

[0094] Preferably, the steering unit includes:

[0095] The swing subunit is used to stop the bidirectional swinging of the central engine 300 after adjusting the direction of the first-stage rocket to face the Earth, and to maintain the first-stage rocket in a downward diving attitude towards the Earth. This allows the first-stage rocket to get closer and closer to the Earth, and the downward diving can shorten the recovery time of the first-stage rocket and reduce the probability of the first-stage rocket colliding with space debris during long-term operation in space.

[0096] Preferably, the steering unit further includes a first deceleration subunit, wherein:

[0097] The swing subunit is also used to generate two different tangential forces in different directions that are tangential to the current flight direction of the first-stage rocket by swinging the central engine 300 in both directions. This causes the flight direction of the first-stage rocket to deviate from the current flight direction until the flight direction of the first-stage rocket changes by 180°, adjusting the attitude of the first-stage rocket from a downward diving attitude to an upward flight attitude. The purpose is to enable the first-stage rocket to land in the attitude at launch, preparing for the subsequent attitude adjustment of the central engine 300 to 100% thrust to decelerate the first-stage rocket.

[0098] The first deceleration subunit is used to maintain the first-stage rocket in an upward flight attitude until it enters the atmosphere. When entering the atmosphere, the speed of the first-stage rocket is reduced to the designed entry speed. The purpose is to prevent the first-stage rocket from crashing due to excessive speed when re-entering the atmosphere. The central engine 300 is shut down so that the first-stage rocket can enter the gliding phase by free falling in the atmosphere. Shutting down the central engine 300 can save rocket fuel.

[0099] Preferably, the steering unit further includes a second deceleration subunit, wherein:

[0100] The second deceleration subunit is used to activate the central engine 300 after a set time during the coasting phase. The thrust generated by the central engine 300 decelerates the first-stage rocket until it lands. The thrust generated by the central engine 300 decelerates the first-stage rocket, helping it land smoothly.

[0101] Preferably, the rocket vertical recovery system further includes:

[0102] The air supply device is used to supply air to the outrigger unlocking device, which releases the fixed connection device. The fixed connection device is used to connect the landing outrigger to the body of the first-stage rocket.

[0103] The outriggers are equipped with an air supply device to supply air to the outriggers opening device. The landing outriggers are then opened through the outriggers opening device, with the tail of the first-stage rocket facing the ground. The landing outriggers assist the first-stage rocket in landing on Earth.

[0104] Among them, the unlocking air supply device and the outrigger opening air supply device work synchronously with the second deceleration subunit.

[0105] If the landing legs are not secured, they will sway up and down under strong vibrations during normal flight, potentially causing fatigue damage or even impacting and damaging the fuel tanks. Therefore, a securing device is required to hold the landing legs in place during flight. When deploying the landing legs, the securing device must be unlocked first to release each landing leg. Then, the landing legs can be deployed.

[0106] Preferably, the outriggers include landing outrigger I, landing outrigger II, landing outrigger III, and landing outrigger IV;

[0107] The outrigger unlocking device includes a #1 landing outrigger unlocking sub-device 100, a #2 landing outrigger unlocking sub-device 101, a #3 landing outrigger unlocking sub-device 103, and a #4 landing outrigger unlocking sub-device 102; wherein, the #1 landing outrigger unlocking sub-device 100 is used to unlock the #1 landing outrigger, the #2 landing outrigger unlocking sub-device 101 is used to unlock the #2 landing outrigger, the #3 landing outrigger unlocking sub-device 103 is used to unlock the #3 landing outrigger, and the #4 landing outrigger unlocking sub-device 102 is used to unlock the #4 landing outrigger;

[0108] The unlocking gas supply device includes: a room temperature helium cylinder 94, a first three-way valve 95 arranged sequentially on the first gas supply pipeline after the room temperature helium cylinder 94, two first solenoid valves 96 arranged in parallel, a first orifice plate 97, a four-way valve 98, and a second three-way valve 99; wherein, the I# landing leg unlocking sub-device 100 and the II# landing leg unlocking sub-device 101 are connected to the four-way valve 98 and connected to the four-way valve 98 through the second three-way valve 99, and the III# landing leg unlocking sub-device 103 and the IV# landing leg unlocking sub-device 102 are connected to the second three-way valve 99;

[0109] When supplying gas to the outrigger unlocking device, one of the first solenoid valves 96 is opened, and helium from the room temperature helium cylinder 94 enters the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101 through the first three-way valve 95, the opened first solenoid valve 96, the first orifice plate 97 and the four-way valve 98, respectively, so as to supply gas to the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101, and open the fixed connection device on the I# landing outrigger and the II# landing outrigger, respectively, through the I# landing outrigger unlocking sub-device 100 and the II# landing outrigger unlocking sub-device 101;

[0110] Helium from the ambient temperature helium cylinder 94 is introduced into the III# landing leg unlocking device 103 and the IV# landing leg unlocking device 102 via the first three-way valve 95, the opened first solenoid valve 96, the first orifice plate 97, the four-way valve 98, and the second three-way valve 99, respectively. This supply of helium to the III# landing leg unlocking device 103 and the IV# landing leg unlocking device 102 allows the fixed connection devices on the III# landing leg and the IV# landing leg to be opened, respectively.

[0111] Two first solenoid valves 96 are used for redundancy to prevent the landing outriggers from failing to open if one of the first solenoid valves 96 fails to open, thus causing the landing outriggers' unlocking and air supply device to fail.

[0112] Preferably, the outriggers include landing outrigger I, landing outrigger II, landing outrigger III, and landing outrigger IV;

[0113] The outrigger deployment device includes a #1 landing outrigger deployment sub-device 106, a #2 landing outrigger deployment sub-device 107, a #3 landing outrigger deployment sub-device 108, and a #4 landing outrigger deployment sub-device 109; wherein, the #1 landing outrigger deployment sub-device 106 is used to deploy the #1 landing outrigger, the #2 landing outrigger deployment sub-device 107 is used to deploy the #2 landing outrigger, the #3 landing outrigger deployment sub-device 108 is used to deploy the #3 landing outrigger, and the #4 landing outrigger deployment sub-device 109 is used to deploy the #4 landing outrigger;

[0114] The outrigger opening gas supply device includes: a room temperature helium cylinder 94, a first tee 95 located sequentially after the room temperature helium cylinder 94 on the first gas supply pipeline, two second solenoid valves 104 arranged in parallel, and a second orifice plate 105; wherein, the I# landing outrigger opening sub-device 106, the II# landing outrigger opening sub-device 107, the III# landing outrigger opening sub-device 108, and the IV# landing outrigger opening sub-device 109 are connected in parallel after the second orifice plate 105;

[0115] When supplying gas to the outrigger deployment device, one of the second solenoid valves 104 is opened, allowing helium from the ambient temperature helium cylinder 94 to enter the I# landing outrigger deployment sub-device 106, the II# landing outrigger deployment sub-device 107, the III# landing outrigger deployment sub-device 108, and the IV# landing outrigger deployment sub-device 109 respectively via the first three-way valve 95, the second solenoid valve 104, and the second orifice plate 105; thus supplying gas to the I# landing outrigger deployment sub-device 106, the II# landing outrigger deployment sub-device 107, the III# landing outrigger deployment sub-device 108, and the IV# landing outrigger deployment sub-device 109. Air is supplied to the landing leg opening sub-device 107, the landing leg opening sub-device 108, and the landing leg opening sub-device 109, respectively, so that the landing leg I, the landing leg II, the landing leg III, and the landing leg IV can be opened through the landing leg opening sub-device 106, the landing leg opening sub-device 107, the landing leg III, and the landing leg IV, respectively.

[0116] The tail of the first-stage rocket faces the ground, and the first-stage rocket is landed on Earth by the I# landing leg, the II# landing leg, the III# landing leg, and the IV# landing leg.

[0117] Two secondary solenoid valves 104 are used for redundancy to prevent the landing outriggers from failing to open and causing the air supply to the outriggers to fail.

[0118] Preferably, the steering unit is specifically used for:

[0119] By bidirectionally oscillating the central engine 300 via a cross-shaped oscillation, two tangential forces in different directions can be generated simultaneously, tangential to the current flight direction of the first-stage rocket, wherein:

[0120] The cross-shaped oscillating element includes a cross-shaped constant-level seat 2. One end of the cross-shaped constant-level seat 2 is connected to the engine fixed end 1, which is connected to the rocket body of the first-stage rocket. The other end of the cross-shaped constant-level seat 2 is connected to the combustion chamber 3 of the central engine 300. The combustion chamber 3 of the central engine 300 is connected to the thrust chamber 8 of the central engine 300. The thrust chamber 8 is farther away from the cross-shaped constant-level seat 2 than the combustion chamber 3.

[0121] The cross-shaped leveling seat 2 is provided with an x-axis 31 and a y-axis 41 in a cross shape. The x-axis 31 and the y-axis 41 are respectively located in the x-direction and y-direction of the cross section of the first stage rocket. The cross-shaped leveling seat 2 is also provided with a vertical axis that is perpendicular to the cross section of the first stage rocket and passes through the cross-shaped leveling seat 2. The cross-shaped leveling seat 2 can rotate around the vertical axis.

[0122] The cross-shaped constant level seat 2 also includes a rocket connection end 11 and an engine connection end 21; the rocket connection end 11 is fixed to the rocket body by welding, and the engine connection end 21 is fixed to the central engine 300 by welding.

[0123] The x-axis 31 passes through the rocket connection end 11 and can rotate within the rocket connection end 11; the y-axis 41 passes through the engine connection end 21 and can rotate within the engine connection end 21.

[0124] The cross-shaped swing also includes a servo mechanism, which includes a retractable x-direction swing servo mechanism 5 and a retractable y-direction swing servo mechanism 7. One end of the x-direction swing servo mechanism 5 is connected to the body of the first stage rocket through the x-direction swing servo mechanism fixed end 4, and the other end of the x-direction swing servo mechanism 5 is connected to the combustion chamber 3. The x-direction swing servo mechanism 5 and the x-direction axis 31 are on the same first plane.

[0125] like Figure 11 As shown, the implementation principles of the x-direction oscillating servo mechanism 5 and the y-direction oscillating servo mechanism 7 are as follows:

[0126] Signal source 24 receives the swing signal from the center engine 300 of the first-stage rocket; PID signal processing device 25 converts the swing signal from the first-stage rocket into opening and closing signals for solenoid valve 27; signal input device 26 inputs the opening and closing signals of solenoid valve 27 into solenoid valve 27. Oil tank 20 supplies hydraulic oil to hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32, and simultaneously recycles the hydraulic oil in hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32.

[0127] The x-direction oscillating servo mechanism 5 and the y-direction oscillating servo mechanism 7 include hydraulic push rods and are driven by hydraulic oil. When the solenoid valve 27 is de-energized, the oil inlet P is connected to A, the oil inlet pipe 23 is connected to the A hydraulic pipe 28, the oil outlet T is connected to B, and the oil outlet pipe 38 is connected to the B hydraulic pipe 37. The hydraulic oil in the oil tank 20 is pressurized by the hydraulic pump 221 and enters the A hydraulic cylinder interface 29 through the oil inlet pipe 23, the solenoid valve 27, and the A hydraulic pipe 28, supplying hydraulic oil to the A chamber 311 of the hydraulic cylinder, causing the push rod 33 to move to the right, thereby increasing the length of the hydraulic push rod; at the same time, the hydraulic oil in the B chamber 32 of the hydraulic cylinder returns to the oil tank 20 through the B hydraulic cylinder interface 36, the B hydraulic pipe 37, the solenoid valve 27, and the oil outlet pipe 38.

[0128] Hydraulic cylinder A chamber 311 and hydraulic cylinder B chamber 32 are sealed by sealing device 34, and hydraulic cylinder B chamber 32 is sealed to the outside world by sealing device 35.

[0129] When solenoid valve 27 is energized, oil inlet P is connected to B, oil inlet pipe 23 is connected to hydraulic pipe 37 of B, oil outlet T is connected to A, and oil outlet pipe 38 is connected to hydraulic pipe 28 of A. The hydraulic oil in oil tank 20 is pressurized by hydraulic pump 221 (motor 22 provides power to hydraulic pump 221) and enters hydraulic cylinder interface 36 of B through oil inlet pipe 23, solenoid valve 27, and hydraulic pipe 37 of B, supplying hydraulic oil to chamber 32 of hydraulic cylinder B, causing push rod 33 to move to the left, thus reducing the length of hydraulic push rod; at the same time, the hydraulic oil in chamber 311 of hydraulic cylinder A returns to oil tank 20 through hydraulic cylinder interface 29 of A, hydraulic pipe 28 of A, solenoid valve 27, and oil outlet pipe 38. One end of the y-direction oscillating servo mechanism 7 is connected to the body of the first-stage rocket via the y-direction oscillating servo mechanism fixed end 6, and the other end of the y-direction oscillating servo mechanism 7 is connected to the combustion chamber 3. The y-direction oscillating servo mechanism 7 and the y-direction axis 41 are on the same second plane.

[0130] Engine fixed end 1 and cross-shaft type constant level seat 2 correspond to the crank fixed point of the crank-rocker mechanism; cross-shaft type constant level seat 2 and combustion chamber 3 correspond to the crank of the crank-rocker mechanism; x-direction rocking servo mechanism 5 corresponds to the combination of rocker block and rocker arm of the crank-rocker mechanism; x-direction rocking servo mechanism fixed end 4 corresponds to the rotation point of rocker block of the crank-rocker mechanism; similarly, engine fixed end 1 and cross-shaft type constant level seat 2 correspond to the crank fixed point of the crank-rocker mechanism; cross-shaft type constant level seat 2 and combustion chamber 3 correspond to the crank of the crank-rocker mechanism; y-direction rocking servo mechanism 7 corresponds to the combination of rocker block and rocker arm of the crank-rocker mechanism; y-direction rocking servo mechanism fixed end 6 corresponds to the rotation point of rocker block of the crank-rocker mechanism. The cross-axis type constant-mount seat has a simple and reliable structure. Without the cross-axis type constant-mount seat 2, the central engine 300 can only be fixedly connected to the rocket body and cannot rotate. However, with the cross-axis type constant-mount seat 2, the rocket body and the central engine 300 can be separated, allowing the central engine 300 to achieve its predetermined movement. Thrust direction control is achieved through double cross-shaped oscillation: When the spacecraft control system issues a control command, the x-direction oscillation servo mechanism and the y-direction oscillation servo mechanism 7 continuously extend and retract. According to the cooperation of the x-direction axis 31 and the y-direction axis 41 with the cross-axis type constant-mount seat 2, the thrust chamber 8 is pushed to oscillate around the vertical axis of the cross-axis type constant-mount seat 2. The angle of the thrust chamber 8 is changed according to the attitude change of the first-stage rocket (i.e., the current angle of the thrust chamber 8 is changed), thereby changing the thrust direction and providing thrust vector control (generating control torque) for the first-stage rocket, enabling the first-stage rocket to fly along a predetermined trajectory and perform pitch, yaw, or roll movements.

[0131] Preferably, the steering unit is specifically used for:

[0132] The extension and retraction of the x-direction swing servo mechanism 5 causes the thrust chamber 8 to swing around the cross-shaped constant level seat 2 as the center of mass in the first plane along the x-direction axis 31, generating a tangential force in the first direction that is tangential to the current flight direction of the first stage rocket. The tangential force in the first direction causes the thrust chamber 8 to swing around the vertical axis, thereby enabling the first stage rocket to rotate along the vertical axis.

[0133] The extension and retraction of the y-direction oscillating servo mechanism 7 causes the thrust chamber 8 to oscillate around the cross-shaped constant-level seat 2 in the second plane along the y-direction axis 41, generating a tangential force in the second direction that is tangential to the current flight direction of the first-stage rocket. This tangential force causes the thrust chamber 8 to oscillate around the vertical axis.

[0134] The combined tangential force in the first direction and the tangential force in the second direction cause the flight direction of the first-stage rocket to deviate from its current flight direction.

[0135] Thrust direction control is achieved through a double-cross swing mechanism: When the spacecraft control system issues a control command, the x-direction swing servo mechanism and the y-direction swing servo mechanism 7 continuously extend and retract. According to the cooperation of the x-direction axis 31 and the y-direction axis 41 with the cross-shaped constant-level seat 2, the thrust chamber 8 will swing around the vertical axis of the cross-shaped constant-level seat 2. The angle of the thrust chamber 8 is changed according to the attitude change of the first-stage rocket (i.e., the current angle of the thrust chamber 8 is changed), thereby changing the thrust direction and providing thrust vector control (generating control torque) for the first-stage rocket, so that the first-stage rocket can fly along the predetermined trajectory.

[0136] In conjunction with embodiments of the present invention, a rocket is provided, including any type of rocket vertical recovery system.

[0137] The technical solutions of the present invention will be described in detail below with reference to specific application examples. For technical details not described in the implementation process, please refer to the relevant descriptions above.

[0138] like Figure 6 The diagram shown illustrates the launch and recovery process of the first-stage rocket. Figure 9 As shown, this is a curve showing the number of engine working stations during the recovery process of the first-stage rocket.

[0139] 1. Time t0 is the moment when the engine of the first stage rocket is ignited for the first time.

[0140] 2. Time t1 is the moment when the first-stage rocket passes through the atmosphere, also known as the moment of maximum dynamic pressure. For example... Figure 7 The image shown is a diagram of the launch process of the first-stage rocket.

[0141] 3. Time t2 is the shutdown time of the eight engines surrounding the first-stage engine. The thrust of one central engine (300) is adjusted to 5% of its rated thrust. This adjustment is maintained from time t2 to time t6. Time t0 to t2 represents the first ignition and flight phase of the first-stage rocket, also known as the rocket launch phase. Figure 8 The diagram shown illustrates the recovery process of the first-stage rocket.

[0142] In this embodiment of the invention, the main means of repositioning is to provide the rocket with a positive overload (to provide the rocket with a thrust in the opposite direction so that the liquid can sink). Utilizing the small thrust state of the central engine is to provide the rocket with a small thrust state, thus providing the rocket with a positive overload.

[0143] like Figure 2The diagram shows a vector image of a first-stage rocket. The rocket flight direction 54 is defined as the axial direction of the first-stage rocket, pointing from the central engine 300 towards the upper propellant tank 51. The positive overload direction 55 is defined as the axial direction of the first-stage rocket, pointing from the upper propellant tank 51 towards the central engine 300, opposite to the flight direction. The negative overload direction 56 is defined as the axial direction of the rocket, consistent with the flight direction, pointing from the central engine towards the upper propellant tank 51. The central engine 300 includes a combustion chamber 3 and a thrust chamber 8, supplying propellant to the combustion chamber 3 through tanks (including the upper propellant tank 51 and the lower propellant tank 52).

[0144] like Figure 3 The diagram shows the engine distribution and oscillation direction of the first-stage rocket. The first-stage rocket consists of nine engines: one central engine 300 and eight surrounding engines. The central engine 300 has a bidirectional pendulum function, ensuring the first-stage rocket can oscillate in different directions during recovery. The oscillation of the central engine 300 provides tangential force to the rocket, allowing the slender rocket to rotate around its center (center of mass), controlling the angle of attack between the rocket and the ground (adjusting the rocket's attitude).

[0145] The bidirectional oscillation is composed of a cross-shaped constant level seat and servo mechanisms (x-direction oscillation servo mechanism 5 and y-direction oscillation servo mechanism 7). The servo mechanisms are responsible for extension and retraction, and the cross-shaped constant level seat is responsible for rotation, forming a crank-rocker mechanism. Through the extension and retraction of the x-direction oscillation servo mechanism 5, the central engine 300 oscillates in the x-direction with the constant level seat as the center of mass.

[0146] The specific three-dimensional structural diagram of the cross-shaped constant level seat 2 is as follows: Figure 5 As shown, the cross-shaped constant level seat 2 is located on top of the central engine 300 and connects the central engine 300 and the rocket body respectively.

[0147] Figure 4 In the crank-rocker mechanism, the engine fixed end 1 and the cross-shaft type constant level seat 2 are equivalent to the crank fixed point; the cross-shaft type constant level seat 2 and the combustion chamber 3 are equivalent to the crank of the crank-rocker mechanism; the x-direction rocking servo mechanism 5 is equivalent to the combination of the rocker block and rocker arm of the crank-rocker mechanism; the x-direction rocking servo mechanism fixed end 4 is equivalent to the rotation point of the rocker block of the crank-rocker mechanism.

[0148] Similarly, the engine fixed end 1 and the cross-shaft type constant level seat 2 are equivalent to the crank fixed point of the crank rocker mechanism; the cross-shaft type constant level seat 2 and the combustion chamber 3 are equivalent to the crank of the crank rocker mechanism; the y-direction rocking servo mechanism 7 is equivalent to the combination of the rocker block and rocker arm of the crank rocker mechanism; the y-direction rocking servo mechanism fixed end 6 is equivalent to the rotation point of the rocker block of the crank rocker mechanism.

[0149] The cross-axis type constant-mount seat has a simple and reliable structure. Without the cross-axis type constant-mount seat 2, the central engine 300 can only be fixedly connected to the rocket body and cannot rotate. However, with the cross-axis type constant-mount seat 2, the rocket body and the central engine 300 can be separated, allowing the central engine 300 to achieve its predetermined movement. Thrust direction control is achieved through double cross-shaped oscillation: When the spacecraft control system issues a control command, the x-direction oscillation servo mechanism and the y-direction oscillation servo mechanism 7 continuously extend and retract. According to the cooperation of the x-direction axis 31 and the y-direction axis 41 with the cross-axis type constant-mount seat 2, the thrust chamber 8 is pushed to oscillate around the vertical axis of the cross-axis type constant-mount seat 2. The angle of the thrust chamber 8 is changed according to the attitude change of the first-stage rocket (i.e., the current angle of the thrust chamber 8 is changed), thereby changing the thrust direction and providing thrust vector control (generating control torque) for the first-stage rocket, enabling the first-stage rocket to fly along a predetermined trajectory and perform pitch, yaw, or roll movements.

[0150] 4. At time t3, the first-stage rocket is in its turning phase. Tangential force is provided by the oscillation of the center engine 300 to achieve attitude control of the first-stage rocket. For example... Figure 4 The diagram shown is a schematic of the swing control principle of the central engine 300.

[0151] The center engine 300 swings to a certain angle, for example, the angle is 6° between the thrust direction of the center engine 300 and the current flight direction of the first stage rocket. The tangential thrust of F×sin6° can provide a certain torque to the first stage rocket, so that the first stage rocket rotates.

[0152] 5. At time t4, the first-stage rocket completes its turning phase. Utilizing 5% of the rated thrust of the central engine 300, the first-stage rocket is oriented towards the lower right, maintaining its downward-to-right dive. Consider the first-stage rocket as a point mass, positioned to the lower right of the point mass.

[0153] 6. The period from t4 to t5 is the downward dive phase of the first-stage rocket recovery process. Utilizing the downward dive of the first stage during the t4-t5 period can shorten the recovery time of the first-stage rocket and reduce the probability of the first-stage rocket colliding with space debris during its long-term operation in space.

[0154] 7. The period from t4 to t5 is the time when the first-stage rocket dives downwards, which shortens the recovery time of the first-stage rocket and reduces the launch cycle of the first-stage rocket. This also reduces the temperature rise of the cryogenic propellant in the oxygen tank due to prolonged solar radiation, and shortens the operating time of electrical components, thereby increasing the lifespan and number of uses of the rocket's electrical products.

[0155] 8. At time t5, the first-stage rocket makes a 180° turn, swinging 5% of the rated thrust of the center engine 300 to adjust the attitude of the first-stage rocket from a downward diving attitude to an upward attitude, thus preparing the first-stage rocket for deceleration.

[0156] 9. At time t6, the first-stage rocket completes its 180° turn and the center engine 300 is adjusted to 100% thrust. After completing the attitude adjustment, the center engine 300 is adjusted to high thrust to decelerate the first-stage rocket, reducing its re-entry velocity into the atmosphere. The first re-entry into the atmosphere refers to the first-stage rocket's journey from the ground into space. This process prevents the first-stage rocket from re-entering the atmosphere at excessively high speeds, which could lead to a crash.

[0157] The period from t5 to t6 is the attitude adjustment phase for the first-stage rocket's 180° turn, changing its downward dive attitude to an upward attitude, in preparation for adjusting the center engine 300 to 100% thrust to decelerate the first-stage rocket later.

[0158] 10. Time t7 is the moment when the first-stage rocket re-enters the atmosphere. At this time, the first-stage rocket has decelerated to the design speed. Decelerating the first-stage rocket to the predetermined speed during re-entry into the atmosphere can reduce the dynamic pressure of the first-stage rocket during re-entry into the atmosphere.

[0159] Measures can be taken to reduce the dynamic pressure experienced by the first-stage rocket during reentry into the atmosphere. Atmospheric dynamic pressure refers to the pressure exerted by air flowing at a certain speed on the surface of an object perpendicular to the airflow direction. Its value is proportional to the air density and the square of the airflow velocity, and the calculation formula is usually q = 1 / 2 × ρ × v 2 (q is dynamic pressure, ρ is air density, v is air velocity).

[0160] Excessive dynamic pressure can exert tremendous forces on the structure of the first-stage rocket, even causing structural damage. Therefore, it is necessary to control the rocket's attitude and adopt appropriate deceleration methods to keep the dynamic pressure it experiences during reentry within a safe range, thus ensuring the rocket's safe return.

[0161] 11. At time t8, the first-stage rocket shuts down. At this point, the first-stage rocket has decelerated to its design speed and completed its reentry into the atmosphere. Therefore, the central engine 300 of the first-stage rocket shuts down to conserve rocket fuel. The central engine 300 enters its first shutdown state, initiating the first-stage rocket's gliding phase in the atmosphere, where it undergoes free fall.

[0162] From time t6 to t8, the central engine 300 is adjusted to 100% of its rated thrust to decelerate the first-stage rocket. During this process, the high thrust is used to decelerate the first-stage rocket, which reduces its reentry velocity into the atmosphere and its dynamic pressure. At the same time, reducing the speed of the first-stage rocket can effectively reduce the friction between the first-stage rocket and the atmosphere, preventing the first-stage rocket from overheating drastically during recovery.

[0163] 12. At time t9, the central engine of the first-stage rocket is activated for the second time. The thrust generated by the central engine 300 decelerates the first-stage rocket and helps it land smoothly.

[0164] The period from t8 to t9 is the gliding phase of the first-stage rocket in the atmosphere, during which the first-stage rocket undergoes free fall.

[0165] 13. t 10 This moment marks the second engine shutdown of the first-stage rocket, and also the moment the first-stage rocket lands safely and smoothly. At this moment, the first-stage rocket has completed the launch and recovery process.

[0166] t9 time ~ t 10 At this moment, the first-stage rocket ignites a second time to reduce its descent speed, which helps it land safely and smoothly.

[0167] During the recovery process, landing legs were used for a safe landing, from time t9 to t0. 10 Air is supplied to the outrigger unlocking device at regular intervals to unlock and supply air to landing outriggers I, II, III, and IV. A schematic diagram of the first-stage rocket landing leg support air supply system is shown below. Figure 10 As shown.

[0168] If the landing legs are not secured, they will sway up and down under strong vibrations during normal flight, potentially causing fatigue damage or even impacting and damaging the fuel tanks. Therefore, a securing device is required to hold the landing legs in place during flight. When deploying the landing legs, the securing device must be unlocked first to release each landing leg. Then, the landing legs can be deployed.

[0169] 14. t 11 The moment marks the independent flight of the second-stage rocket.

[0170] 15. t 12 The time is when the fairing is jettisoned by the second-stage rocket.

[0171] The main purposes of jettisoning the fairing on the second-stage rocket are as follows: to reduce weight. In order to ensure that the satellite (and other payloads) can pass smoothly through the atmosphere and to prevent the atmospheric airflow from affecting the satellite during supersonic flight, a fairing is set on the outer surface of the satellite. Since the atmosphere is extremely thin in space, the airflow will have little impact on the satellite, so it can be jettisoned. This reduces the unnecessary weight of the rocket itself, making subsequent flights more efficient and saving fuel consumption.

[0172] To facilitate subsequent operations, jettisoning the fairing allows the satellite and other payloads to be better exposed, which is convenient for a series of related actions after entering orbit, such as deploying the satellite antenna and solar panels. It also facilitates the separation of the satellite from the rocket (satellite-rocket separation) and the rocket's ability to send multiple payloads into the predetermined orbit in a sequential and accurate manner.

[0173] The beneficial technical effects achieved by the embodiments of the present invention are as follows:

[0174] The launch and recovery of the first-stage rocket were achieved through two ignitions. Launch refers to the period from liftoff (t0) to the separation of the first and second stages (t2), while recovery refers to the period from the separation of the first and second stages (t2) to the re-landing of the first stage. Generally, launch and recovery are discussed together, representing two distinct operational phases. A rocket design must simultaneously meet both requirements; therefore, the term "recovery rocket" typically refers to the entire launch and recovery process. The first-stage rocket's first ignition flight phase, from t0 to t2, achieved the rocket's launch.

[0175] At the separation time of the first and second stage rockets (t2), the thrust of the first-stage rocket's central engine is adjusted to 5% to achieve attitude control and propellant management during the first-stage rocket's recovery phase. After separation, from t3 to t4, the 5% thrust engine's oscillation provides tangential force to the first-stage rocket, achieving attitude control and adjusting its attitude to a downward dive. During the downward dive phase from t4 to t5, the first-stage rocket's recovery time is shortened, preventing prolonged thermal radiation from causing the cryogenic propellant in the oxygen and fuel tanks to overheat or evaporate. Simultaneously, reducing the recovery time by diving also reduces the operating time of electrical components, increasing their lifespan and number of uses. From t5 to t6, the rocket utilizes the oscillation of the central engine to provide tangential force for attitude control of the first-stage rocket, and its attitude then rotates 180° downwards to upwards. From time t6 to t8, the thrust of the central engine is adjusted to 100% of its rated value. This high thrust enables rapid deceleration of the first-stage rocket, reducing its reentry velocity and preventing it from experiencing excessive dynamic pressure and rapid temperature rise due to friction with the atmosphere. By restarting the central engine, the descent speed and attitude of the first-stage rocket are adjusted, ensuring a highly precise and stable descent. This guarantees that the impact force at landing is within a reasonable range, preventing landing failure or damage due to excessive speed or attitude deviation. From t8 to t9, the first-stage rocket glides in the atmosphere. From t9 to t10, the central engine ignites a second time, ensuring a safe and stable landing of the first-stage rocket.

[0176] With the surrounding engines shut down, the central engine adjusts its thrust by regulating the power of the propellant turbine, shifting it from a high-thrust state to a low-thrust state. This is because propellant management only requires a small thrust to meet the requirements, and a large thrust is unnecessary.

[0177] By adjusting the thrust of the central engine 300 to 5% of its rated thrust, the rocket achieved low overload, enabling the management of liquid oxygen propellant. Continuous ignition of the central engine facilitated propellant repositioning and management, reducing the development difficulty of the first-stage rocket propellant management system.

[0178] Traditional methods for attitude adjustment during the recovery of a first-stage rocket rely on an independent RCS system to adjust the rocket's attitude using exhaust gases. This independent RCS system not only increases the rocket's complexity but also raises the development difficulty of the first-stage rocket. Alternatively, the attitude control during recovery is achieved by using the oscillation of the central engine to generate tangential force. In contrast to traditional RCS attitude control, this invention utilizes the oscillation of the central engine to adjust the attitude of the first-stage rocket, thus reducing the development difficulty of the first-stage rocket.

[0179] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0180] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0181] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0182] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0183] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of vertical recovery of a rocket, characterized in that, Comprising: Step 1, after the rocket is launched and flies along the predetermined orbit, and the first stage rocket and the second stage rocket included in the rocket are separated, for the first stage rocket, the thrust size of the central engine (300) of the first stage rocket is adjusted to a preset proportion of the rated thrust to provide a positive overload for the propellant in the tank providing propellant for the engine, the direction of the positive overload force is opposite to the flight direction of the first stage rocket, and the positive overload enables the propellant to gather at the outlet at the bottom of the tank; meanwhile, the other engines are closed; wherein, all the engines of the first stage rocket are arranged as follows: in the cross section of the first stage rocket, the central engine (300) is arranged in the middle, and the other engines are arranged on the periphery; Step 2, the first time, the bidirectional swinging of the central engine (300) can simultaneously generate two different directions of tangential force tangent to the current flight direction of the first stage rocket, so that the flight direction of the first stage rocket deviates from the current flight direction, and the flight direction of the first stage rocket is adjusted towards the direction of the earth; after adjusting the running direction of the first stage rocket to the direction of the earth, the downward diving posture of the first stage rocket towards the direction of the earth is maintained; Step 3, the second time, the bidirectional swinging of the central engine (300) can simultaneously generate two different directions of tangential force tangent to the current flight direction of the first stage rocket, so that the flight direction of the first stage rocket deviates from the current flight direction, until the flight direction of the first stage rocket is turned by 180°, the posture of the first stage rocket is adjusted from the downward diving posture to the upward flight posture, and the speed is reduced until landing on the earth.

2. The method of claim 1, wherein, Step 2 further comprises: Step 21, after adjusting the running direction of the first stage rocket to the direction of the earth, stop bidirectional swinging of the central engine (300), and maintain the downward diving posture of the first stage rocket towards the direction of the earth.

3. The method of claim 1, wherein, Step 3 specifically comprises: Step 31, the second time, the bidirectional swinging of the central engine (300) can simultaneously generate two different directions of tangential force tangent to the current flight direction of the first stage rocket, so that the flight direction of the first stage rocket deviates from the current flight direction, until the flight direction of the first stage rocket when separated from the second stage rocket forms a 180° turn, and the posture of the first stage rocket is adjusted from the downward diving posture to the upward flight posture; Step 32, maintain the upward flight posture of the first stage rocket until entering the atmosphere, and the running speed of the first stage rocket is reduced to the designed entering speed when entering the atmosphere, turn off the central engine (300) so that the first stage rocket does free fall in the atmosphere to enter the glide phase.

4. The method of claim 3, wherein, Step 3 specifically comprises: Step 33, after setting the time of the glide phase, turn on the central engine (300), and the thrust generated by the central engine (300) reduces the speed of the first stage rocket, until the first stage rocket lands.

5. The method of claim 4, wherein, Further comprising: Step 4, supply air to the leg unlocking device through the unlocking air supply device, unlock the fixed connecting device through the leg unlocking device, the fixed connecting device is used to connect the landing leg to the body of the first stage rocket; supply air to the leg opening device through the leg opening air supply device, open the landing leg through the leg opening device, the tail of the first stage rocket faces the ground, and the landing leg assists the first stage rocket to land on the earth; Wherein, step 4 is executed synchronously with step 33.

6. The method of claim 5, wherein, In step 4, the landing leg includes I# landing leg, II# landing leg, III# landing leg and IV# landing leg. The leg unlocking device includes I# landing leg unlocking sub device (100), II# landing leg unlocking sub device (101), III# landing leg unlocking sub device (103) and IV# landing leg unlocking sub device (102); wherein, the I# landing leg unlocking sub device (100) is used to unlock the I# landing leg, the II# landing leg unlocking sub device (101) is used to unlock the II# landing leg, the III# landing leg unlocking sub device (103) is used to unlock the III# landing leg, and the IV# landing leg unlocking sub device (102) is used to unlock the IV# landing leg; The unlocking air supply device includes: a normal temperature helium tank (94), a first three-way valve (95) arranged after the normal temperature helium tank (94) and in the first air supply pipeline in sequence, two first electromagnetic valves (96) arranged side by side, and a first orifice plate (97), a four-way valve (98) and a second three-way valve (99); wherein, the I# landing leg unlocking sub device (100) and the II# landing leg unlocking sub device (101) are connected to the four-way valve (98), connected to the four-way valve (98) through the second three-way valve (99), the III# landing leg unlocking sub device (103) and the IV# landing leg unlocking sub device (102) are connected to the second three-way valve (99).

7. The method of claim 6, wherein, Step 4 specifically includes: Step 41, when supplying air to the leg unlocking device, open one of the first electromagnetic valves (96), and helium in the normal temperature helium tank (94) enters the I# landing leg unlocking sub device (100) and the II# landing leg unlocking sub device (101) through the first three-way valve (95), the opened first electromagnetic valve (96), the first orifice plate (97) and the four-way valve (98) respectively, realizing air supply to the I# landing leg unlocking sub device (100) and the II# landing leg unlocking sub device (101) respectively, and opening the fixed connecting device on the I# landing leg and the II# landing leg through the I# landing leg unlocking sub device (100) and the II# landing leg unlocking sub device (101) respectively; Step 42, when supplying air to the leg opening device, open the other first electromagnetic valve (96), and helium in the normal temperature helium tank (94) enters the III# landing leg unlocking sub device (103) and the IV# landing leg unlocking sub device (102) through the first three-way valve (95), the opened first electromagnetic valve (96), the first orifice plate (97) and the four-way valve (98) respectively, realizing air supply to the III# landing leg unlocking sub device (103) and the IV# landing leg unlocking sub device (102) respectively, and opening the fixed connecting device on the III# landing leg and the IV# landing leg through the III# landing leg unlocking sub device (103) and the IV# landing leg unlocking sub device (102) respectively. Step 42, the helium in the normal temperature helium cylinder (94) enters the III# landing leg unlocking sub-device (103) and the IV# landing leg unlocking sub-device (102) through the first three-way (95), the first electromagnetic valve (96), the first orifice plate (97), the four-way (98) and the second three-way (99) respectively, so as to supply gas to the III# landing leg unlocking sub-device (103) and the IV# landing leg unlocking sub-device (102), and open the fixed connection device on the III# landing leg and the IV# landing leg through the III# landing leg unlocking sub-device (103) and the IV# landing leg unlocking sub-device (102) respectively.

8. The method of claim 5, wherein, In step 4, the landing legs include I# landing leg, II# landing leg, III# landing leg and IV# landing leg; The landing leg opening device includes I# landing leg opening sub-device (106), II# landing leg opening sub-device (107), III# landing leg opening sub-device (108) and IV# landing leg opening sub-device (109); wherein the I# landing leg opening sub-device (106) is used to open the I# landing leg, the II# landing leg opening sub-device (107) is used to open the II# landing leg, the III# landing leg opening sub-device (108) is used to open the III# landing leg, and the IV# landing leg opening sub-device (109) is used to open the IV# landing leg; The landing leg opening gas supply device includes: a normal temperature helium cylinder (94), a first three-way (95) arranged after the normal temperature helium cylinder (94) and in turn on the first gas supply pipeline, two second electromagnetic valves (104) arranged side by side, and a second orifice plate (105); wherein the I# landing leg opening sub-device (106), the II# landing leg opening sub-device (107), the III# landing leg opening sub-device (108) and the IV# landing leg opening sub-device (109) are connected side by side after the second orifice plate (105).

9. The method of claim 8, wherein, Step 4 specifically includes: Step 43, open one of the second electromagnetic valve (104) to supply gas for the leg opening device, helium in the normal temperature helium cylinder (94) enters into the I# landing leg opening sub-device (106), the II# landing leg opening sub-device (107), the III# landing leg opening sub-device (108) and the IV# landing leg opening sub-device (109) through the first three-way (95), the second electromagnetic valve (104), the second orifice plate (105) respectively; realize the gas supply for the I# landing leg opening sub-device (106), the II# landing leg opening sub-device (107), the III# landing leg opening sub-device (108) and the IV# landing leg opening sub-device (109), through the I# landing leg opening sub-device (106), the II# landing leg opening sub-device (107), the III# landing leg opening sub-device (108) and the IV# landing leg opening sub-device (109) to open the I# landing leg, the II# landing leg, the III# landing leg and the IV# landing leg respectively; Step 44, the tail of the first stage rocket is towards the ground, and the first stage rocket is landed on the earth through the I# landing leg, the II# landing leg, the III# landing leg and the IV# landing leg.

10. The method of claim 5, wherein, Step 2, specifically comprising: The bidirectional swing of the center engine (300) through the cross swing can simultaneously generate two different directions of tangential force tangent to the current flight direction of the first stage rocket, wherein: The cross swing includes a cross shaft type gimbals (2), one end of the cross shaft type gimbals (2) is connected to an engine fixed end (1), the engine fixed end (1) is connected to the rocket body of the first stage rocket, the other end of the cross shaft type gimbals (2) is connected to the combustion chamber (3) of the center engine (300), the combustion chamber (3) of the center engine (300) is connected to the thrust chamber (8) of the center engine (300), the thrust chamber (8) is farther away from the cross shaft type gimbals (2) than the combustion chamber (3); The cross swing further comprises a servo mechanism, which comprises: x a direction swing servo mechanism (5) and a telescopic y direction swing servo mechanism (7), the x one end of the direction swing servo mechanism (5) is connected to the rocket body of the first stage rocket through x a direction swing servo mechanism fixed end (4), and the x the other end of the direction swing servo mechanism (5) is connected to the combustion chamber (3); The y One end of the direction swing servo mechanism (7) is connected to the rocket body of the first stage rocket through y The fixed end (6) of the direction swing servo mechanism is connected to the rocket body of the first stage rocket, and the y The other end of the direction swing servo mechanism (7) is connected to the combustion chamber (3).

11. The method of claim 10, wherein, In step 2, The cross axle type gimbals (2) are provided in a cross manner x The direction shaft (31) and y The direction shaft (41), the x The direction shaft (31) and the y The direction shaft (41) are respectively located in the mutually perpendicular x Direction and y Direction on the first stage rocket cross section, the cross axle type gimbals (2) are also provided with a vertical shaft perpendicular to the first stage rocket cross section and penetrating the cross axle type gimbals (2), and the cross axle type gimbals (2) can rotate around the vertical shaft; The cross shaft type gimbals (2) further includes a rocket connecting end (11) and an engine connecting end (21); The x A direction shaft (31) penetrates the rocket connecting end (11) and is rotatable in the rocket connecting end (11), and the y A direction shaft (41) penetrates the engine connecting end (21) and is rotatable in the engine connecting end (21). The x The direction swing servo mechanism (5) is common with the x The direction shaft (31) is common in the first plane. The y The direction swing servo mechanism (7) is common with the y The direction shaft (41) is common in the second plane.

12. The method of claim 11, wherein, Step 2, specifically comprising: By the described x The extension and retraction of the direction swing servo mechanism (5) itself makes the thrust chamber (8) swing in the first plane with the cross axle type gimbals (2) as the center of mass along the x The direction shaft (31) swings, generating the first direction tangential force tangent to the current flight direction of the first stage rocket, which makes the thrust chamber (8) swing around the vertical shaft, and further makes the first stage rocket able to rotate along the vertical shaft; By the y The extension and retraction of the yaw servo mechanism (7) itself makes the thrust chamber (8) swing in the second plane along the cross-axis type gimbals (2) as the center of mass y The direction shaft (41) swings, generating a tangential force in the second direction tangent to the current flight direction of the first-stage rocket, and the tangential force in the second direction makes the thrust chamber (8) swing around the vertical shaft, The first direction of tangential force and the second direction of tangential force together make the flight direction of the first stage rocket deviate from the current flight direction.

13. A rocket vertical recovery system characterized by, Comprising: The positive overload providing unit is used for adjusting the thrust size of the central engine (300) of the first-stage rocket to a preset proportional size of the rated thrust to provide a positive overload for the propellant in the tank for providing propellant for the engine after the first-stage rocket flies according to a predetermined orbit and the first-stage rocket and the second-stage rocket included in the rocket are separated, the force direction of the positive overload is opposite to the flight direction of the first-stage rocket, and the positive overload enables the propellant to gather at the outlet at the bottom of the tank; meanwhile, other engines are closed; wherein all the engines of the first-stage rocket are arranged as follows: in the cross section of the first-stage rocket, the central engine (300) is arranged in the middle, and other engines are arranged in the periphery; The turning unit includes a cross swing, and the bidirectional swing of the central engine (300) through the cross swing can simultaneously generate two different tangential forces tangent to the current flight direction of the first-stage rocket, so that the flight direction of the first-stage rocket deviates from the current flight direction and adjusts the flight direction of the first-stage rocket toward the direction of the earth; after the running direction of the first-stage rocket is adjusted to the direction toward the earth, the downward diving posture of the first-stage rocket toward the direction of the earth is maintained; the bidirectional swing of the central engine (300) again can simultaneously generate two different tangential forces tangent to the current flight direction of the first-stage rocket, so that the flight direction of the first-stage rocket deviates from the current flight direction until the flight direction of the first-stage rocket is turned by 180°, the posture of the first-stage rocket is adjusted from the downward diving posture to the upward flying posture, and the speed is reduced until landing on the earth; The bidirectional swing of the central engine (300) through the cross swing can simultaneously generate two different tangential forces tangent to the current flight direction of the first-stage rocket, wherein: The cross swing includes a cross shaft type gimbals (2), one end of the cross shaft type gimbals (2) is connected to an engine fixed end (1), the engine fixed end (1) is connected to the rocket body of the first-stage rocket, the other end of the cross shaft type gimbals (2) is connected to the combustion chamber (3) of the central engine (300), the combustion chamber (3) of the central engine (300) is connected to the thrust chamber (8) of the central engine (300), and the thrust chamber (8) is farther away from the cross shaft type gimbals (2) than the combustion chamber (3).

14. A rocket, characterized in that The rocket vertical recovery system includes the rocket vertical recovery system of claim 13.

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