A self-sufficient, easy-to-maintain offshore launch and recovery base and method of use thereof

Abstract

The present application relates to the technical field of floating buildings, and discloses an easy-to-maintain self-sufficient energy type offshore launch and recovery base and a use method thereof, in which rockets are launched in a following type pool in the middle of an offshore comprehensive platform, the pool is lowered below the sea surface during launching, the inner wall of the pool is covered by a steady flow in a gravity drainage mode, the steady flow is finally gathered at the bottom of the pool, a negative pressure is formed by using a shape-adjusted flow guide groove exhaust port, water is sucked into a water storage flow guide groove, water blown out of the water storage flow guide groove by the exhaust gas is returned again, and the liquid level is controlled so that the pool bottom is not exposed after the exhaust gas blows away the seawater, so that the position of the water storage flow guide groove bottom that is seriously ablated is always submerged by water and the liquid level is continuously rising, and a large amount of time and manpower does not need to be consumed for maintenance due to serious ablation, meanwhile, the steady flow and the rising liquid level cool and flush the position that has contacted the exhaust gas, and the launch does not need to be maintained almost before being launched again.

Description

Technical Field

[0001] This invention relates to the field of floating structure technology, and in particular to an easy-to-maintain, self-sufficient marine launch and recovery base and its usage method. Background Technology

[0002] Sea-based launch platforms are important facilities for launching rockets at sea. Compared with land-based launches, sea-based launches have the following advantages: 1. Sea-based launches are far from residential areas, are not subject to safety restrictions, and rockets can be recovered; 2. There is a wide range of launch sites to choose from, such as launching from the high seas near the equator, which saves fuel and ensures accurate orbital insertion.

[0003] Sea-based rocket launches can be conducted from barges or offshore platforms. A typical example of the former is the Dongfang Aerospace Port sea launch vessel, while a typical example of the latter is the Odyssey sea launch platform. The former is more flexible in use (it does not require tugboats), while the latter can easily keep costs very low. However, regardless of the launch method, the problem of rocket deflection is encountered. The rocket's base is usually not designed for aerodynamic heating, so parts other than the nozzle are not fire-resistant, requiring the rocket's exhaust flame to be deflected to prevent the rocket's base from being submerged in the exhaust flame. During sea launches, the refractory material in the deflector channel suffers far more severe erosion than on land. During launch, the exhaust flame outlet of the deflector channel spews out a sky full of refractory bricks, requiring a significant amount of time for grinding, cleaning, and replacing the refractory material.

[0004] The refractory material in the guide channel suffered severe erosion, mainly due to two factors: 1. During a sea-based launch, the direction of the ablation is the direction in which the ablation is most severe: When launching rockets at sea, the exhaust plume can be guided horizontally, downwards, or upwards. However, downward guidance can stir up a large area of ​​seawater, posing safety risks to the launch barge or platform. Therefore, current technologies use either horizontal or upward guidance. With horizontal guidance, to prevent the exhaust plume from burning the hull of the launch barge / launch platform's pontoons, launch is required from the edge, directing the exhaust plume to open sea surface. However, this can cause an imbalance in the barge / platform's center of gravity during launch, increasing the risk of accidents and limiting the size of the rockets that can be launched. For example, the Odyssey sea launch platform, being a non-powered, watertight platform (not requiring space or tonnage to be occupied by a propulsion system and watertight compartments), allows for rockets with a smaller tonnage than those launched from the lighter and smaller Eastern Spaceport barge, yet it experienced two accidents in just 32 launches. Therefore, upward guidance has become almost the only option for rocket launches at sea. However, when the rocket exhaust stream is directed upwards, it needs to make two 90-degree turns downwards to become upwards. This reversal process causes severe scouring and ablation at both bends.

[0005] II. During sea launches, the high temperatures of the rocket's propulsion channel are almost entirely withstood by the refractory materials: When launching from land, extra-large deflector channels can be dug to disperse the exhaust plume, and high-flow-rate spray systems can be installed to cool it down. However, when launching from sea, due to tonnage and power supply limitations, the size of the deflector channels and spray systems is restricted, and the high temperature of the rocket's deflector channels relies almost entirely on refractory materials to withstand it.

[0006] The above factors result in a significant time and manpower commitment for maintenance after a sea-based rocket launch. Furthermore, considering that barges / sea platforms are not as stable or convenient for material transfer within the site as land-based platforms, maintenance work is even more challenging. A major purpose of sea-based launches is to meet the urgent launch needs of a large number of low-Earth orbit (LEO) satellites, such as StarNet (a Chinese LEO network similar to Starlink, where orbital resources are scarce). Prolonged maintenance of the launch platform would be a serious disadvantage.

[0007] Sea launches also present some favorable conditions, with seawater being virtually inexhaustible and suitable for cooling and heat absorption. Similar to land-based launches, water is placed in the launch chute during sea-based launches. However, because the launch chute is pressurized during launch, it's difficult to replenish it with water. Furthermore, due to the smaller size of the launch chute, the initial water volume is smaller and quickly blew out, failing to provide effective cooling. Although the launch chute can be cooled by spraying water after the rocket leaves the launch platform, the refractory material within has already been eroded by then.

[0008] The inventors discovered in CFD simulations that the upper part of the guide channel was subjected to relatively less scouring and ablation, and the results of field investigations confirmed this conclusion. Summary of the Invention

[0009] This invention provides an easy-to-maintain, self-sufficient marine launch and recovery base and its usage method.

[0010] The technical problem to be solved is that the erosion of the refractory material in the rocket's guide channel is much more severe during sea launches than on land. At the same time, the maintenance work is more difficult due to the unstable site and the inconvenience of transferring materials within the site.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: an easy-to-maintain self-sufficient marine launch and recovery base, comprising a marine integrated platform that relies on floats to adjust the draft and relies on wave energy power generation devices to power the base, a following pool set in the middle of the marine integrated platform, a launch platform set in the center of the bottom of the following pool, a water storage and diversion channel set below the launch platform, and an inner dam and an outer dam at the outlet of the channel set on both sides of the exhaust port of the water storage and diversion channel. The following water tank is a frustum or truncated cone-shaped water tank with a cross-section that gradually increases from top to bottom. The side wall of the water tank is equipped with an inlet valve for adding water into the water tank, and the bottom of the water tank is equipped with a drain valve for draining the water accumulated in the following water tank after launch. The cross-section of the exhaust port gradually increases both upwards and downwards from the launch pad. The position where the cross-section of the exhaust port is the smallest is called the Venturi throat. The gap between the bottom of the outer dam of the channel outlet and the follow-up water pool is called the water intake. The water intake is adjacent to the Venturi throat and is used to allow seawater flowing down the side wall of the follow-up water pool to be sucked into the water storage guide channel by the negative pressure at the Venturi throat position. The following water tank, launch platform, and water storage diversion channel are all covered with refractory material at the locations where they come into contact with the rocket's exhaust flame. The inner dam and outer dam at the channel outlet are both made of refractory material. When the rocket has just been ignited on the launch pad, the sea-based launch and recovery base meets the following conditions: Condition 1: The offshore integrated platform is semi-submersible and the inlet valve is located below sea level; Condition 2: The inlet valve is open and the drain valve is closed; Condition 3: A stable flow has been established between the inlet valve and the water storage guide channel. The stable flow covers the wall of the follow-type water tank below the inlet valve, and the flow rate of the stable flow is not less than the maximum evaporation rate of the water storage guide channel. Condition 4: There is water in the water storage channel but it is not completely full. The liquid level is denoted as h, the seawater density is denoted as ρ, the gravitational acceleration is denoted as g, and ρgh is not less than the maximum pressure of the rocket exhaust flame at the water surface position.

[0012] Furthermore, both the inlet valve and the outlet valve are automatic valves. The inlet valve is located outside the range swept by the rocket's exhaust plume and has a wire mesh at its inlet for intercepting marine life. The outlet valve is located within the exhaust plume dead zone at the bottom edge of the follow-up pool.

[0013] Furthermore, in condition 3, the minimum mass flow rate Q of the steady flow is determined in the following manner: Under the conditions of seawater temperature and sea level pressure, the enthalpy change of a unit mass of water evaporating into steam at the boiling point temperature is denoted as ΔHw. In a rocket awaiting launch, the thermal efficiency of the liquid rocket engine is denoted as fl, the heat of reaction per unit mass of liquid rocket propellant is denoted as ΔHl, and the mass flow rate of the propellant after rocket ignition is denoted as ql. In a rocket to be launched, the thermal efficiency of the solid rocket motor is denoted as fs, the heat of reaction per unit mass of solid rocket propellant is denoted as ΔHs, the operating time of the solid rocket motor is denoted as t, and the total mass of the solid rocket propellant is denoted as M. Q=[(1-fl)×ΔHl×ql+(1-fs)×ΔHs×M / t] / ΔHw.

[0014] Furthermore, the following water tank is a steel water tank, and the offshore integrated platform includes, from bottom to top, a pontoon, a grid platform, and a platform plate. The steel water tank is embedded in the grid platform and welded to the grid platform, and is connected to the sacrificial anode.

[0015] Furthermore, the locations where the follow-up water tank, launch pad, and water storage diversion channel come into contact with the rocket's exhaust flame are all covered with fire-resistant reinforced concrete. The inner dam and outer dam of the channel outlet are both made of fire-resistant reinforced concrete, and the reinforcing bars in the fire-resistant reinforced concrete are welded to the follow-up water tank. The refractory reinforced concrete surfaces of the following water tank and the launch pad are also covered with water-soaked asbestos pads, with the reinforcing bars in the refractory reinforced concrete extending outwards and catching the asbestos pads.

[0016] Furthermore, the outer dam and inner dam of the slot outlet are arranged around the launch pad and tilted outwards, with the height of the outer dam being at least three times that of the inner dam.

[0017] Furthermore, the edge of the following water tank is provided with a tower or gantry crane for hoisting the rocket onto the launch pad.

[0018] A method for using an easy-to-maintain, self-sufficient, marine launch and recovery base, comprising the following steps: Step 1: Move the sea-based launch and recovery base to the launch area; Step 2: Adjust the draft of the offshore integrated platform to make it semi-submerged with the inlet valve below sea level; Step 3: Level the launch platform, then hoist the rocket onto the launch platform and fuel it; Step 4: Open the inlet valve, close the drain valve, and release water into the water storage channel. Once the liquid level in the water storage channel meets condition 4, ignite the rocket. At the same time, the liquid level in the follow-up water tank will continue to rise. Step 5: After the rocket launch, the follow-up water tank continues to fill with water until all areas touched by the rocket's exhaust flame are submerged in seawater, then the water inlet valve is closed; Step Six: Adjust the draft of the offshore integrated platform so that the bottom of the follow-up pool is higher than the sea surface, open the drain valve to drain the water in the follow-up pool, and use the residual heat to evaporate the water stains.

[0019] Compared with existing technologies, the present invention provides an easy-to-maintain, self-sufficient marine launch and recovery base and its usage method, which have the following advantages: In this invention, a rocket is launched from a follow-up water tank in the middle of an offshore integrated platform. During launch, the water tank is lowered below the sea surface. Gravity drainage is used (the cooling flow rate is very large, and this method can meet the flow rate requirements even when large pumping equipment cannot be equipped, and the water flow is uniform). The inner wall of the water tank is covered by a stable flow, which eventually converges at the bottom of the water tank. A negative pressure is created by the flame exhaust port of the adjusted flow channel, which draws water into the water storage channel. Water blown out of the water storage channel by the tail flame will also return. The liquid level is controlled so that the bottom of the water tank will not be exposed after the flame tail flame blows the seawater. This ensures that the severely ablated areas at the bottom of the water storage channel are always submerged and the liquid level keeps rising. This prevents the need for a lot of time and manpower for maintenance due to severe ablation. At the same time, the stable flow and the rising liquid level cool and flush the areas that have been in contact with the tail flame. After launch, almost no maintenance is required for relaunch. In this invention, for the same tonnage, the underlying integrated marine platform has better resistance to wind and waves, can better withstand the instantaneous impacts during rocket launch and recovery, and is also less expensive. Furthermore, existing wave energy power generation platforms can be utilized to avoid idleness when there are no launch or recovery missions, thereby further improving economic efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an easy-to-maintain, self-sufficient marine launch and recovery base according to the present invention; Figure 2 The diagram shows the internal structure of an easy-to-maintain, self-sufficient marine launch and recovery base of the present invention during rocket ignition. To avoid obstruction, the supporting structures of the launch pad, the inner dam of the trough outlet, and the outer dam of the trough outlet have been removed from the diagram. In the diagram, 1-integrated offshore platform, 2-following pool, 3-launch pad, 4-water storage and diversion channel, 5-inner dam at channel outlet, 6-outer dam at channel outlet, 7-Venturi throat, 8-water intake, 9-sea level. Detailed Implementation

[0021] Note that a significant portion of the combustion products of rockets launched from the sea-based launch and recovery base described in this invention will be discharged into the sea. Therefore, rockets using toxic propellants are not suitable for launch using this method. Furthermore, rocket recovery has relatively low platform requirements; meeting launch requirements suffices for recovery. The main challenge lies in rocket control rather than the platform itself, and rocket control is not the focus of this invention. Therefore, this section primarily discusses rocket launch operations.

[0022] like Figure 1-2As shown, an easy-to-maintain, self-sufficient marine launch and recovery base includes an integrated marine platform 1 that adjusts its draft using floats and supplies power to the base using wave energy generators; a following pool 2 located in the middle of the integrated marine platform 1; a launch platform 3 located at the bottom center of the following pool 2; a water storage and diversion channel 4 located below the launch platform 3; and inner dam 5 and outer dam 6 at the outlet of the channel located on both sides of the exhaust port of the water storage and diversion channel 4. The reason the pool is named "follow" is because its liquid level rises continuously as the rocket launches.

[0023] The follow-up water tank 2 is a frustum or truncated cone-shaped water tank with a cross-section that gradually increases from top to bottom. The side wall of the water tank is equipped with an inlet valve for adding water into the water tank, and the bottom of the water tank is equipped with a drain valve for draining the water accumulated in the follow-up water tank 2 after launch. The purpose of designing the follow-type water tank 2 in this shape is threefold: first, to ensure a stable flow of seawater on its sidewalls (where the fluid's state, velocity, and flow rate remain constant across all cross-sections), preventing the rocket's exhaust plume from scorching the tank's sidewalls during launch; second, to allow water to accumulate at the bottom, enabling the water blown out by the rocket to return; and third, to create an exhaust plume dead zone at the bottom (a localized space in the flow system where the fluid essentially does not participate in the main flow and only moves locally in place).

[0024] The cross-section of the exhaust port gradually increases both upwards and downwards from the launch pad 3. The position with the smallest cross-section of the exhaust port is called the Venturi throat 7. The gap between the bottom of the outer dam 6 of the channel outlet and the follow-up water pool 2 is called the suction port 8. The suction port 8 is adjacent to the Venturi throat 7 and is used to allow seawater flowing down the side wall of the follow-up water pool 2 to be sucked into the water storage guide channel 4 by the negative pressure at the position of the Venturi throat 7. After the rocket ignites, the water storage channel 4 is under significant positive pressure, making it difficult for water to enter. However, high-speed airflow exits from the exhaust port. By controlling the shape of the exhaust port, a Venturi effect can be created, resulting in negative pressure at that location, thereby drawing in seawater.

[0025] The locations where the follow-up water tank 2, launch platform 3, and water storage diversion channel 4 come into contact with the rocket's exhaust flame are all covered with refractory material. The inner dam 5 at the channel outlet and the outer dam 6 at the channel outlet are both made of refractory material. The inner dam 5 at the outlet of the channel and the outer dam 6 at the outlet of the channel need to be in contact with the tail flame for a long time, but they do not need to face the impact of the tail flame directly or bear any force. They only need to withstand high temperatures, so they can be made entirely of refractory materials.

[0026] With the rocket just ignited on launch pad 3, the sea-based launch and recovery base meets the following conditions: Condition 1: The offshore integrated platform 1 is semi-submersible and its inlet valve is located 9 meters below sea level; This is to create a height difference, allowing for the release of large quantities of water into the following water tank 2 via gravity drainage. During rocket launch, several tons or even more propellant are consumed in a short period, requiring an enormous amount of water for cooling. Offshore platforms are not suitable for integrating a large number of pumps for water supply; therefore, gravity drainage is chosen to release water directly. In this embodiment, the inlet valve is a remotely controlled gate.

[0027] Condition 2: The inlet valve is open and the drain valve is closed; Condition 3: A stable flow has been established between the inlet valve and the water storage guide trough 4. The stable flow covers the wall of the follow-type water tank 2 located below the inlet valve, and the flow rate of the stable flow is not less than the maximum evaporation rate of the water storage guide trough 4. To ensure a stable flow covering the sidewalls of the following water tank 2, numerous inlet valves can be evenly spaced along its sidewalls. If fewer inlet valves are installed, a liquid distributor needs to be placed around the circumference of the following water tank 2. The stable flow is equivalent to a water film several centimeters thick, blocking the exhaust plume of the rising rocket.

[0028] Condition 4: There is water in the water storage channel 4 but it is not completely full. The liquid level is denoted as h, the seawater density is denoted as ρ, the gravitational acceleration is denoted as g, and ρgh is not less than the maximum pressure of the rocket tail flame at the water surface position.

[0029] This condition is to ensure that when the rocket's exhaust plume purges the water in the water storage channel 4, it does not blow the water to the bottom of the channel. The water storage channel 4 cannot be completely filled during the period from rocket ignition to 31-2 meters away from the launch pad; otherwise, it would be unable to guide water flow. Considering this period is very short, the water storage channel 4 will not be full at rocket ignition, nor will it be full 31-2 meters away from the launch pad. Of course, if a very extreme stable flow rate is set, then verification is required to prevent the water storage channel 4 from being completely filled during the period from rocket ignition to 31-2 meters away from the launch pad.

[0030] The "maximum pressure of the rocket exhaust at the water surface" is different from the pressure in the rocket combustion chamber. It is the pressure that decreases significantly after the exhaust flows through an open space and diffuses. It can be obtained using CFD software.

[0031] Both the inlet valve and the outlet valve are automatic valves. The inlet valve is located outside the range swept by the rocket's exhaust plume and has a wire mesh at its inlet for intercepting marine life. The outlet valve is located within the exhaust plume dead zone at the bottom edge of the follow-up pool 2.

[0032] Here, the exhaust dead zone refers to the area where the exhaust flame basically does not participate in the main fluid flow and only moves locally in place. The range swept by the rocket exhaust flame and the exhaust dead zone can be obtained through CFD simulation.

[0033] In condition 3, the minimum mass flow rate Q of the steady flow is determined in the following way: The enthalpy change of a unit mass of water evaporating into steam at its boiling point temperature under seawater temperature and sea level pressure is denoted as ΔHw. In a rocket awaiting launch, the thermal efficiency of the liquid rocket engine is denoted as fl, the heat of reaction per unit mass of liquid rocket propellant is denoted as ΔHl, and the mass flow rate of the propellant after rocket ignition is denoted as ql. In a rocket to be launched, the thermal efficiency of the solid rocket motor is denoted as fs, the heat of reaction per unit mass of solid rocket propellant is denoted as ΔHs, the operating time of the solid rocket motor is denoted as t, and the total mass of the solid rocket propellant is denoted as M. Q=[(1-fl)×ΔHl×ql+(1-fs)×ΔHs×M / t] / ΔHw.

[0034] Existing technologies include solid-propellant rockets, liquid-propellant rockets, and rockets with liquid core stages and solid boosters; this formula encompasses all three types. The propellant here includes both fuel and a corresponding proportion of oxidizer. For liquid rocket engines, the amount of propellant consumed per unit time is a relatively fixed design value that can be precisely calculated. For solid rocket engines, the amount of propellant consumed per unit time is a continuously increasing value (the propellant grain diffuses and burns outwards from the central axis, thus burning faster and faster). Here, an average value is used instead. This average value is greater than the amount of propellant consumed per unit time in the initial stage of launch (resulting in a slightly larger calculated Q), but not by much. This simplifies the calculation and ensures the result meets the requirements.

[0035] The following water tank 2 is a steel water tank. The offshore integrated platform 1 includes, from bottom to top, a pontoon, a grid platform, and a platform plate. The steel water tank is embedded in the grid platform and welded to the grid platform, and is connected to the sacrificial anode.

[0036] In this way, while meeting structural strength requirements, all the easily corroded structures are electrically connected as a single unit. Only one electrical connection with the sacrificial anode is needed to meet corrosion resistance requirements. Additional transverse ribs and back ridges can be welded to the outside of the steel tank to further enhance its strength.

[0037] The locations where the follow-up water tank 2, launch pad 3, and water storage diversion channel 4 come into contact with the rocket exhaust flame are all covered with fire-resistant reinforced concrete. The inner dam 5 and outer dam 6 at the channel outlet are both made of fire-resistant reinforced concrete, and the steel bars in the fire-resistant reinforced concrete are welded to the follow-up water tank 2. This structure is less prone to detachment than refractory layers constructed with refractory bricks, but its disadvantage lies in the greater difficulty of removal. Considering that the design of this invention results in minimal refractory layer erosion, it requires frequent removal and replacement; cracking (which may occur due to significant temperature variations in the operating environment) can be repaired by grouting. The reinforcing steel protective layer should be thicker than conventional reinforced concrete, at least three centimeters thick, to prevent the reinforcing steel from melting.

[0038] The refractory reinforced concrete surfaces of the following water tank 2 and the launch pad 3 are also covered with water-soaked asbestos pads, with the reinforcing bars in the refractory reinforced concrete extending outwards and catching the asbestos pads.

[0039] Although launch platform 3 does not need to directly face most of the exhaust plume (the exhaust plume enters the guide channel through the hole on launch platform 3), it will still be subject to some exhaust plume scouring. Since this area is not submerged before the liquid level rises, an additional water-soaked asbestos pad is installed to protect the refractory reinforced concrete here for a short period (this protection is no longer needed after the liquid level rises), and it is easy to replace if it is breached. The asbestos pad on the surface of the refractory reinforced concrete of the following water tank 2 is used to prevent water splashing.

[0040] The outer dam 6 and the inner dam 5 of the slot outlet are arranged around the launch pad 3 and tilted outwards. The height of the outer dam 6 is at least three times that of the inner dam 5 of the slot outlet.

[0041] The outer dam 6 at the outlet of the channel is a water storage structure to prevent the tail flame from gushing out along the intake 8 and interrupting the steady flow, so it must have sufficient height.

[0042] The edge of the follow-up water tank 2 is equipped with a tower or gantry crane for hoisting the rocket onto the launch pad 3.

[0043] The gantry crane here can be set across the following water tank 2 for easy hoisting, and the subsequent recycling operation can also be carried out using the gantry crane.

[0044] A method for using an easy-to-maintain, self-sufficient, marine launch and recovery base, comprising the following steps: Step 1: Tow the sea launch and recovery base to the launch area using a tugboat; Step 2: Adjust the draft of the offshore integrated platform 1 to make it semi-submerged with the inlet valve located 9 meters below sea level; Step 3: Level the launch platform, then hoist the rocket onto the launch platform and add fuel; of course, if it is a pure solid rocket, fueling is not required. Step 4: Open the inlet valve, close the drain valve, and release water into the water storage and diversion tank 4. Once the liquid level in the water storage and diversion tank 4 meets condition 4, the rocket will ignite, and the liquid level in the follow-up water tank 2 will continue to rise. The rise in liquid level serves two purposes: firstly, to cool the burned areas promptly, and secondly, to facilitate cleaning and prevent the formation of scale from combustion products. Step 5: After the rocket launch, the follow-up water tank 2 continues to fill with water until all areas touched by the rocket's exhaust flame are submerged by seawater, then the water inlet valve is closed; Step Six: Adjust the draft of the offshore integrated platform 1 so that the bottom of the following water tank 2 is higher than the sea surface, open the drain valve to drain the water in the following water tank 2, and use the residual heat to evaporate the water stains.

[0045] At this point, inspect the platform for damage. If cracks are found in the refractory reinforced concrete, repair them by grouting. If the asbestos pad is damaged, replace it at the damaged location. Finally, wipe away the salt deposits with a cloth (wiping away the salt deposits will also remove dirt), and you can proceed with the next launch.

[0046] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A self-sufficient, easy-to-maintain marine launch and recovery base, characterized in that: It includes an offshore integrated platform (1) that relies on buoys to adjust the draft and relies on wave energy power generation devices to power the base, a follow-up pool (2) set in the middle of the offshore integrated platform (1), a launch platform (3) set in the center of the bottom of the follow-up pool (2), a water storage and diversion channel (4) set below the launch platform (3), and an inner dam (5) and an outer dam (6) at the outlet of the channel on both sides of the flame outlet of the water storage and diversion channel (4). The following water tank (2) is a frustum or truncated cone-shaped water tank with a cross-section that gradually decreases from top to bottom. The side wall of the water tank is provided with an inlet valve for releasing water into the water tank, and the bottom of the water tank is provided with a drain valve for draining the water accumulated in the following water tank (2) after launch. The exhaust port expands downward from the launch platform (3) and the cross-section gradually increases upward. The position with the smallest cross-section of the exhaust port is called the Venturi throat (7). The gap between the bottom of the outer dam (6) of the channel outlet and the follow-up water pool (2) is called the water intake (8). The water intake (8) is adjacent to the Venturi throat (7) and is used to allow seawater flowing down the side wall of the follow-up water pool (2) to be sucked into the water storage guide channel (4) by the negative pressure at the position of the Venturi throat (7). The following water tank (2), launch platform (3), and water storage diversion channel (4) are all covered with refractory material at the positions where they contact the rocket tail flame. The inner dam (5) and outer dam (6) at the channel outlet are both made of refractory material. When the rocket on the launch pad (3) has just been ignited, the sea-based launch and recovery base meets the following conditions: Condition 1: The offshore integrated platform (1) is semi-submersible and the inlet valve is located below sea level (9); Condition 2: The inlet valve is open and the drain valve is closed; Condition 3: A stable flow has been established between the inlet valve and the water storage guide channel (4), the stable flow covers the wall of the follow-type water tank (2) below the inlet valve, and the flow rate of the stable flow is not less than the maximum evaporation of the water storage guide channel (4); Condition 4: There is water in the water storage channel (4) but it is not completely full. The liquid level is recorded as h, the seawater density is recorded as ρ, the gravitational acceleration is recorded as g, and ρgh is not less than the maximum pressure of the rocket tail flame at the water surface position.

2. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: Both the inlet valve and the outlet valve are automatic valves. The inlet valve is located outside the range swept by the rocket's exhaust flame and has a wire mesh at the inlet for intercepting marine life. The outlet valve is located in the exhaust flame dead zone at the bottom edge of the follow-type pool (2).

3. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: In condition 3, the minimum mass flow rate Q of the steady flow is determined in the following way: Under sea temperature and sea level (9) pressure, the enthalpy change of a unit mass of water evaporating into steam at the boiling point temperature is denoted as ΔHw; In a rocket awaiting launch, the thermal efficiency of the liquid rocket engine is denoted as fl, the heat of reaction per unit mass of liquid rocket propellant is denoted as ΔHl, and the mass flow rate of the propellant after rocket ignition is denoted as ql. In a rocket to be launched, the thermal efficiency of the solid rocket motor is denoted as fs, the heat of reaction per unit mass of solid rocket propellant is denoted as ΔHs, the operating time of the solid rocket motor is denoted as t, and the total mass of the solid rocket propellant is denoted as M. Q=[(1-fl)×ΔHl×ql+(1-fs)×ΔHs×M / t] / ΔHw.

4. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: The following water tank (2) is a steel water tank. The offshore integrated platform (1) includes, from bottom to top, a pontoon, a grid platform, and a platform plate. The steel water tank is embedded in the grid platform and welded to the grid platform, and is electrically connected to the sacrificial anode.

5. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: The positions of the following water tank (2), launch platform (3), and water storage diversion channel (4) that come into contact with the rocket tail flame are all covered with fire-resistant reinforced concrete. The inner dam (5) and outer dam (6) of the channel outlet are both made of fire-resistant reinforced concrete, and the steel bars in the fire-resistant reinforced concrete are welded to the following water tank (2). The refractory reinforced concrete surface of the following water tank (2) and the refractory reinforced concrete surface of the launch platform (3) are also covered with water-soaked asbestos pads, and the steel bars in the refractory reinforced concrete are thrown outward and hooked onto the asbestos pads.

6. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: The outer dam (6) and inner dam (5) of the slot outlet are arranged around the launch pad (3) and tilted outwards. The height of the outer dam (6) of the slot outlet is at least three times that of the inner dam (5) of the slot outlet.

7. The easily maintained, self-sufficient, marine launch and recovery base according to claim 1, characterized in that: The edge of the following water tank (2) is provided with a tower or gantry crane for hoisting the rocket onto the launch pad (3).

8. A method for using an easy-to-maintain, self-sufficient, marine launch and recovery base, characterized in that: Launching rockets at sea using an easily maintainable, self-sufficient, marine launch and recovery base as described in claim 1, and including the following steps: Step 1: Move the sea-based launch and recovery base to the launch area; Step 2: Adjust the draft of the offshore integrated platform (1) to make it semi-submerged and the water inlet valve located below the sea level (9); Step 3: Level the launch platform, then hoist the rocket onto the launch platform and fuel it; Step 4: Open the inlet valve, close the drain valve, and release water into the water storage guide tank (4). When the liquid level in the water storage guide tank (4) meets condition 4, the rocket is ignited, and at the same time the liquid level in the follow-up water tank (2) continues to rise. Step 5: After the rocket launch, the follow-up water tank (2) continues to fill with water until all the areas touched by the rocket's exhaust flame are submerged by seawater, and then the water inlet valve is closed; Step 6: Adjust the draft of the offshore integrated platform (1) so that the bottom of the following pool (2) is higher than the sea surface, open the drain valve to drain the water in the following pool (2), and use the residual heat to evaporate the water stains.

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