Lander

Abstract

The application relates to the field of aerospace technology, in particular to a lander, which comprises a main body, a cold-gas jet assembly and multiple jet engines. The cold-gas jet assembly comprises a cooling high-pressure gas source and a ring jet. The ring jet is arranged at one end of the main body in a first direction. The multiple jet engines are arranged on one side of the main body where the ring jet is located, and the multiple jet engines are uniformly distributed around the ring jet. The jet port of the jet engine is arranged on the side of the ring jet. The ring jet is provided with at least one jet port arranged around the ring jet. The cooling high-pressure gas source is in communication with the ring jet, so that the cooling gas can be sprayed out to form a cooling gas film wrapping the main body under the jetting action of the ring jet. According to the lander provided by the application, the cooling gas film can heat-insulate and protect the main body. The outer heat-insulating material of the main body is reduced, the invalid mass ratio of the lander is reduced, and the wrapping difficulty of the main body is reduced.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and in particular to a lander. Background Technology

[0002] During landing, modern landers typically ignite their engines to propel the lander in the opposite direction (meaning the engines expel air towards the landing surface, propelling it away from the land) to decelerate. Once the lander reaches a certain altitude, the engines shut off, allowing for a smooth landing. As the distance to the landing surface decreases, especially with multi-engine landers, the plume field becomes more complex, resulting in a harsh thermal environment near the lander. As multi-engine landers approach the landing surface, a backflow zone forms at the engine center, impacting the lander's underside and causing a sharp increase in aerodynamic heat flux, making thermal protection difficult.

[0003] Current lander thermal protection typically involves covering the protected areas with insulating materials of low thermal conductivity. This method is simple in structure and widely used in spacecraft thermal protection. However, on the one hand, modern landers often carry various functional payloads on their exteriors, resulting in irregularly shaped protrusions or depressions on the lander's outer surface. When using thermal protection materials to cover complex surfaces (such as protrusions and depressions), separate covering is required for each surface, increasing both complexity and the mass of the covering material. On the other hand, as the requirements of space exploration missions become increasingly demanding, the landing process needs to be more stable, and the engine shutdown altitude requirement is lower. This makes the thermal environment on the bottom of the lander more severe. To ensure safety, thicker thermal protection materials are needed, increasing the lander's ineffective mass and reducing its effective mass, thus decreasing the spacecraft's sophistication and the mission's economic efficiency. Summary of the Invention

[0004] The purpose of this application is to provide a lander that addresses, to some extent, the technical problems of existing landers, which are mostly irregularly shaped and covered with thermal protective materials. Complex surfaces (such as surface protrusions and depressions) require separate covering, increasing complexity and the mass of the covering material. Furthermore, as the requirements of space exploration missions become increasingly demanding, the thermal environment at the bottom of the lander is becoming more severe. To ensure safety, thicker thermal protective materials are needed, increasing the ineffective mass of the lander, reducing its effective mass, and consequently lowering the spacecraft's sophistication and the economic efficiency of the space mission.

[0005] According to a first aspect of this application, a lander is provided, including a main body, a cold air injection assembly, and a plurality of injection engines. The cold air injection assembly includes a cooling high-pressure gas source and an alligator. The cooling high-pressure gas source is disposed within the main body, and the alligator is disposed at one end of the main body in a first direction. The plurality of injection engines are all disposed on the side of the main body where the alligator is located, and the plurality of injection engines are evenly distributed around the alligator circumferentially. Relative to the side of the main body opposite to the alligator, the injection nozzles of the injection engines are disposed facing the side of the alligator where the alligator is located.

[0006] The ring injector is provided with nozzles, which are arranged around the ring injector at least once. The cooling high-pressure gas source is connected to the ring injector so that the cooling gas in the cooling high-pressure gas source can be ejected from the nozzles at a predetermined speed under the jet action of the ring injector to form a cooling gas film covering the bottom of the main body.

[0007] Preferably, the ring injector includes a first disc portion and a second disc portion coaxially stacked on top of each other, the axes of the first disc portion and the second disc portion extending along the first direction, and the nozzle is an annular gap formed between the first disc portion and the second disc portion;

[0008] In the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer, the distance of the nozzle in the first direction first gradually decreases and then gradually increases.

[0009] Preferably, the side of the first disc facing away from the second disc is a plane, and the thickness of the first disc in the first direction gradually increases and then gradually decreases in the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer.

[0010] Preferably, the side of the second disc facing away from the first disc is a plane, and the thickness of the first disc in the first direction gradually increases and then decreases in the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer.

[0011] Preferably, the first disc portion is disposed on the side of the second disc portion facing the main body portion;

[0012] The ring injector further includes a connecting pipe, a connecting column, and a connecting rib. The connecting pipe and the connecting column both extend along the first direction. One end of the connecting pipe is connected to the first disc and communicates with the nozzle. The other end of the connecting pipe is connected to the main body and communicates with the cooling high-pressure gas source.

[0013] One end of the connecting post is connected to the second disc, and at least a portion of the connecting post extends into the communicating pipe. The connecting rib is disposed between the communicating pipe and the connecting post and connects the communicating pipe and the connecting post.

[0014] Preferably, the minimum distance from the nozzle to the main body is 0.1m to 0.2m.

[0015] Preferably, the cold air injection assembly further includes:

[0016] A control valve is installed between the ring injector and the cooling high-pressure gas source to control the connection between the ring injector and the cooling high-pressure gas source;

[0017] A filter is disposed between the control valve and the high-pressure cooling gas source to filter the cooling gas flowing out from the high-pressure cooling gas source;

[0018] A pressure control unit is disposed between the filter and the control valve to control the pressure of the cooling gas flowing out from the high-pressure cooling gas source.

[0019] Preferably, the predetermined speed is supersonic.

[0020] Preferably, the cooling gas is an inert gas or nitrogen;

[0021] When the cooling gas is in the high-pressure cooling gas source, the cooling gas is either gaseous or liquid.

[0022] Preferably, the system further includes a plurality of landing legs, which are disposed on the side of the main body where the ring launcher is located. The plurality of landing legs are evenly distributed around the circumference of the ring launcher, and the number of landing legs disposed between each pair of adjacent jet engines is the same.

[0023] Compared with the prior art, the beneficial effects of this application are as follows:

[0024] The lander provided in this application has an annular ejector positioned on the side of the main body facing the jet engine's nozzles. Specifically, during landing / ascent, the annular ejector is positioned on the side of the main body facing the landing surface. The annular ejector is connected to a high-pressure cooling gas source, allowing high-pressure cooling gas to be ejected from nozzles arranged at least once around the annular ejector at a predetermined speed. This allows the high-pressure cooling gas to be sprayed outwards from the annular ejector as a center, forming a cooling gas film that covers the bottom of the main body. The backflow of the jet engine's exhaust gas is blocked by this cooling gas film. Figure 4 and Figure 5This diagram shows a simulated temperature distribution with and without the ring launcher in a predetermined environmental condition (where the lander's dimensions, jet engine output power, the lander's environment, and speed are all the same). (Comparison) Figure 4 and Figure 5 The ambient temperature around the main body dropped significantly after the ringer was activated, indicating that the cooling gas film generated by the ringer effectively insulated and protected the main body. This reduced or even eliminated the need to cover the outside of the main body with heat-insulating material, effectively reducing the proportion of ineffective mass of the lander and improving its economic efficiency. Furthermore, compared to using heat-insulating material, the cooling gas film can quickly and effectively adapt to and adhere to the surface of the main body, reducing the difficulty of covering the main body.

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is an isometric structural diagram of the lander provided in the embodiments of this application;

[0028] Figure 2 A schematic diagram of the cross-sectional structure obtained by cutting the ringer along the plane containing the axis of the ringer in the embodiment of this application;

[0029] Figure 3 This is a connection diagram of the cold air injection assembly provided in an embodiment of this application;

[0030] Figure 4 A temperature distribution simulation diagram provided for an embodiment of this application when the lander is in a predetermined state and the ringer is turned off;

[0031] Figure 5 This is a temperature distribution simulation diagram provided for an embodiment of this application when the lander is in a predetermined environmental state and the radiator is activated.

[0032] Figure label:

[0033] 1-Cold air injection assembly; 11-Cooling high-pressure air source; 12-Annular injector; 121-First disc section; 122-Second disc section; 123-Nozzle; 124-Connecting pipe; 125-Connecting column; 126-Connecting rib; 13-Control valve; 14-Filter; 15-Pressure control section; 2-Main body; 3-Injection engine; 4-Landing legs.

[0034] F1 - First direction. Detailed Implementation

[0035] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0036] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0037] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The following reference Figures 1 to 5 This application describes a lander according to some embodiments.

[0041] See Figures 1 to 5As shown, an embodiment of the first aspect of this application provides a lander including a main body 2, a cold air injection assembly 1, and a plurality of injection engines 3. The cold air injection assembly 1 includes a high-pressure cooling gas source 11 and an annular injector 12. The high-pressure cooling gas source 11 is disposed within the main body 2. The annular injector 12 is disposed at one end of the main body 2 in a first direction F1. The plurality of injection engines 3 are all disposed on the side of the main body 2 where the annular injector 12 is located, and the plurality of injection engines 3 are evenly distributed around the circumference of the annular injector 12. The injection nozzles of the injection engines 3 are disposed facing the side of the main body 2 opposite to the annular injector 12. The annular injector 12 is provided with nozzles 123, which are arranged at least circumferentially around the annular injector 12. The high-pressure cooling gas source 11 is connected to the annular injector 12, so that the cooling gas in the high-pressure cooling gas source 11 can reach a predetermined velocity and be ejected from the nozzles 123 under the injection action of the annular injector 12, thereby forming a cooling gas film covering the bottom of the main body 2.

[0042] According to the lander provided by the above-described technical features, by setting the ring injector 12 on the side facing the nozzle of the jet engine 3 of the main body 2, that is, during the landing / lifting process, the ring injector 12 can be set on the side of the main body 2 facing the landing surface. The ring injector 12 is connected to the high-pressure cooling gas source 11, allowing high-pressure cooling gas to be ejected from the nozzles 123 arranged at least once around the ring injector 12 at a predetermined speed. This allows the high-pressure cooling gas to be ejected outwards from the ring injector 12 as the center, forming a cooling gas film that can cover the bottom of the main body. The backflow of the airflow emitted by the jet engine 3 can be blocked by this cooling gas film. Figure 4 and Figure 5 The diagram shows a simulated temperature distribution with and without the ring launcher 12 in a predetermined environmental condition (where the lander's dimensions, jet engine 3's output power, the lander's environment, and the lander's speed are all the same). (Comparison) Figure 4 and Figure 5 After the ringer 12 is activated, the ambient temperature around the main body 2 drops significantly, indicating that the cooling gas film generated by the ringer 12 can effectively provide thermal insulation protection for the main body 2. This reduces or even eliminates the need to cover the outside of the main body 2 with thermal insulation material, effectively reducing the proportion of ineffective mass of the lander and improving its economy. Furthermore, compared to using thermal insulation material, the cooling gas film can quickly and effectively adapt to and adhere to the surface of the main body 2, reducing the difficulty of covering the main body 2.

[0043] See Figure 1 and Figure 2The figure shows an example of the first direction F1 mentioned above. Preferably, the first direction F1 can be the gravitational direction of the planet where the lander is located. In other words, when the lander is in the landing / lifting state, the ringer 12 can be located at the bottom of the main body 2 to block the airflow rebounding from the landing surface to the lander.

[0044] Preferably, such as Figure 1 As shown, the number of the above-mentioned ring emitters 12 can be one. The ring emitter 12 can be coaxially arranged with the main body 2, that is, the ring emitter 12 can be arranged at the bottom center of the main body 2 to ensure uniform coverage of the main body 2 in all directions and to ensure uniform coverage of the cooling gas film.

[0045] It should be noted that the number of ring emitters 12 is not limited to one. As long as it can be ensured that the cooling gas films emitted by each ring emitter 12 do not interfere with each other or that the impact interference between the cooling gas films emitted by each ring emitter 12 does not affect the protection of the main body 2, the number of ring emitters 12 can also be multiple, for example, two, three, four... or more.

[0046] Preferably, such as Figure 2 As shown, the ring injector 12 may include a first disc portion 121 and a second disc portion 122 that are coaxially stacked on top of each other, wherein the axes of both the first disc portion 121 and the second disc portion 122 extend along a first direction F1, such that the annular gap formed between the first disc portion 121 and the second disc portion 122 serves as the aforementioned nozzle 123.

[0047] It should be noted that although only the example of the two disc-shaped components, the first disc portion 121 and the second disc portion 122, forming an annular gap is shown above, it is not limited to this. As not shown in the figure, the annular emitter 12 may also include three, four or more disc-shaped components that are coaxially arranged and stacked along the first direction F1, and the above-mentioned annular gap can be formed between two adjacent disc-shaped components.

[0048] Preferably, such as Figure 2 As shown, in the radial direction of the ring injector 12 and from the center of the ring injector 12 to its edge, the distance of the nozzle 123 in the first direction F1 gradually decreases and then gradually increases. Thus, the nozzle 123 forms a gradually narrowing and then widening nozzle from the center to the edge, allowing the flow velocity of the cooling gas ejected through the ring injector 12 to reach supersonic speeds. In other words, the predetermined velocity can be supersonic. This effectively improves the coverage and stability of the cooling gas film, ensuring the protective effect of the cooling gas film on the main body 2.

[0049] Preferably, such as Figure 2As shown, the side of the first disc portion 121 facing away from the second disc portion 122 is a plane. In the radial direction of the ring injector 12 and in the direction from the center of the ring injector 12 to the edge of the ring injector 12, the thickness of the first disc portion 121 in the first direction F1 gradually increases and then gradually decreases, so that the nozzle 123 forms the above-mentioned pull-apart nozzle (i.e., the first disc portion 121 is a disc of unequal thickness).

[0050] Alternatively, as an example not shown in the figure, both sides of the second disk portion 122 in the first direction F1 can be planes, that is, the second disk portion 122 is a disk of equal thickness.

[0051] Preferably, such as Figure 2 As shown, the side of the second disc portion 122 facing away from the first disc portion 121 is a plane. In the radial direction of the ring injector 12 and in the direction from the center of the ring injector 12 to the edge of the ring injector 12, the thickness of the first disc portion 121 in the first direction F1 gradually increases and then gradually decreases, so that the nozzle 123 forms the above-mentioned pull-apart nozzle (i.e., the second disc portion 122 is a disc of unequal thickness).

[0052] Alternatively, as an example not shown in the figure, both sides of the first disk portion 121 in the first direction F1 can be planes, that is, the first disk portion 121 is a disk of equal thickness.

[0053] Preferably, such as Figure 2 As shown, both the first disc portion 121 and the second disc portion 122 are discs of unequal thickness. The thickest part of the first disc portion 121 in the first direction F1 and the thickest part of the second disc portion 122 in the first direction F1 are arranged opposite each other in the first direction F1. On the one hand, this ensures that the changing trend of the first disc and the second disc in the direction from the center of the ring injector 12 to the edge of the ring injector 12 is consistent, thus ensuring the effectiveness of the pull-valve nozzle. On the other hand, it effectively improves the stability of the narrow opening of the pull-valve nozzle (i.e., the thickest part of the first disc portion 121 in the first direction F1 or the thickest part of the second disc portion 122 in the first direction F1).

[0054] Preferably, such as Figure 2As shown, the first disc portion 121 is disposed on the side of the second disc portion 122 facing the main body portion 2. The ring injector 12 may also include a connecting pipe 124, a connecting post 125, and a connecting rib 126. The connecting pipe 124 and the connecting post 125 both extend along the first direction F1. One end of the connecting pipe 124 is connected to the first disc portion 121 and communicates with the nozzle 123. The other end of the connecting pipe 124 is connected to the main body portion 2 and communicates with the cooling high-pressure gas source 11. One end of the connecting post 125 is connected to the second disc portion 122, and at least a portion of the connecting post 125 extends into the connecting pipe 124. The connecting rib 126 is disposed between the connecting pipe 124 and the connecting post 125 and connects the connecting pipe 124 and the connecting post 125. In this way, on the one hand, the ring injector 12 can be connected to the cooling high-pressure gas source 11 through the connecting pipe 124, and the ring injector 12 can be fixed to the main body portion 2. On the other hand, by extending part of the connecting post 125 into the connecting pipe 124 and connecting it to the connecting pipe 124 via the connecting rib 126, the influence of the connecting rib 126 on the nozzle 123 is effectively reduced, thereby improving the integrity of the cooling gas film.

[0055] Preferably, the average diameter of the main body 2 can be 10 to 20 times the diameter of the ring injector 12 to ensure the coverage effect of the cooling gas film. Taking the diameter of the ring injector 12 as an example, the average diameter of the main body 2 can be 1 to 2 meters.

[0056] Preferably, the minimum distance from the nozzle 123 to the main body 2 can be 0.1m to 0.2m, so as to ensure that the cooling gas film sprayed by the ring injector 12 can cover all the protrusions provided on the main body 2.

[0057] In an embodiment, preferably, such as Figure 3 As shown, the cooling gas injection assembly 1 may further include a control valve 13, which is disposed between the ring injector 12 and the cooling high-pressure gas source 11 to control the connection between the ring injector 12 and the cooling high-pressure gas source 11. Optionally, the control valve 13 may be a solenoid valve, which may be communicatively connected to the lander's control system.

[0058] Preferably, such as Figure 3 As shown, the cold air injection assembly 1 may also include a filter 14, which may be disposed between the control valve 13 and the cooling high-pressure air source 11 to filter the cooling gas flowing out of the cooling high-pressure air source 11 and prevent impurities in the cooling air source from clogging the above-mentioned nozzle 123.

[0059] Preferably, such as Figure 3As shown, the cold gas injection assembly 1 may further include a pressure control unit 15, which is disposed between the filter 14 and the control valve 13 to control the pressure of the cooling gas flowing out from the high-pressure cooling gas source 11, so as to ensure the consistency of the cooling gas pressure input to the ring injector 12, thereby ensuring the continuous stability of the cooling gas film. Optionally, the air pressure unit may be a pressure reducing valve. Taking a lunar lander (i.e., a lander used for lunar landing) as an example, the pressure reducing valve can control the pressure of the cooling gas to be greater than or equal to 1 MPa, so as to ensure that the cooling gas ejected through the ring injector 12 can form a stable cooling gas film in the low-pressure environment of the moon, ensuring the protective effect of the cooling gas film.

[0060] Alternatively, the cooling gas can be an inert gas, such as helium, neon, argon, krypton, or xenon.

[0061] Preferably, the cooling gas can also be nitrogen to improve the lander's economy.

[0062] Preferably, the aforementioned high-pressure cooling gas source 11 can be a gas container (e.g., a gas cylinder) or a cooling gas generator.

[0063] Preferably, when the cooling gas is in the high-pressure cooling gas source 11, the cooling gas can be in a gaseous state to ensure the output stability of the cooling gas.

[0064] Optionally, when the cooling gas is in the high-pressure cooling gas source 11, the cooling gas can be in liquid state to increase the storage capacity of the high-pressure cooling gas source 11.

[0065] In an embodiment, such as Figure 1 As shown, the lander may also include multiple landing legs 4, which are located on the side of the ring launcher 12 of the main body 2. The multiple landing legs 4 are evenly distributed around the circumference of the ring launcher 12, and the number of landing legs 4 between each two adjacent jet engines 3 is the same.

[0066] like Figure 1 The example shown is that there are four jet engines 3 and four landing legs 4, with one landing leg 4 between every two adjacent jet engines 3. However, it is not limited to this and the number of jet engines 3 and landing legs 4 can be adjusted according to actual needs.

[0067] Based on the features described above, Figures 1 to 5 The following description uses the lander shown as an example, and will describe the lander's workflow in detail.

[0068] 1. Set environmental parameters according to the operating environment of the lander (for example, for lunar landing, set environmental parameters according to the lunar operating environment, i.e., according to the lunar gravitational acceleration and lunar atmospheric pressure, etc.) to simulate the landing process and the rise process from the landing surface of the lander to determine the safe altitude, i.e. the highest altitude at which the lander needs to be protected. In other words, the safe altitude is the position where the jet engine 3 is turned on. Set the control valve 13 to be turned on when the lander is below the safe altitude so that the cold gas jet assembly 1 sprays cooling gas to protect the main body 2.

[0069] 2. Based on the planned landing trajectory, determine the landing time required for the lander to ascend from a safe altitude to the landing process (if a return trip is required, also increase the takeoff time required for the lander to ascend to a safe altitude). On this basis, add a certain margin to determine the pressure and volume of the high-pressure gas source. Select the optimal pressure relief valve's downstream pressure based on the protection effect. For example, for a lunar lander (i.e., a lander used for lunar landing), the protection effect is best when the pressure relief valve controls the cooling gas pressure to be greater than or equal to 1 MPa.

[0070] 3. During the lander's landing process, when the lander descends to a safe altitude, both the jet engine 3 and control valve 13 are activated. When the lander decelerates to a safe landing speed, the jet engine 3 is deactivated and control valve 13 is closed.

[0071] 4. During the lander's ascent, after opening control valve 13, start jet engine 3 to propel the lander upward until a safe altitude is reached, then close control valve 13.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A lander, characterized in that, The device includes a main body, a cold air injection assembly, and multiple injection engines. The cold air injection assembly includes a cooling high-pressure air source and an alligator. The cooling high-pressure air source is disposed within the main body. The alligator is disposed at one end of the main body in a first direction. The multiple injection engines are disposed on the side of the main body where the alligator is located, and the multiple injection engines are evenly distributed around the alligator circumferentially. Relative to the side of the main body opposite to the alligator, the injection nozzles of the injection engines are disposed facing the side where the alligator is located. The ring injector is provided with nozzles, which are arranged around the ring injector at least once. The cooling high-pressure gas source is connected to the ring injector so that the cooling gas in the cooling high-pressure gas source can reach a predetermined speed and be ejected from the nozzles under the jet action of the ring injector to form a cooling gas film that wraps around the bottom of the main body. The ring injector includes a first disc and a second disc that are coaxially stacked on top of each other, with the axes of the first disc and the second disc extending along the first direction, and the nozzle being an annular gap formed between the first disc and the second disc. In the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer, the distance of the nozzle in the first direction first gradually decreases and then gradually increases.

2. The lander according to claim 1, characterized in that, The side of the first disc facing away from the second disc is a plane. In the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer, the thickness of the first disc gradually increases and then gradually decreases in a first direction.

3. The lander according to claim 1 or 2, characterized in that, The side of the second disc facing away from the first disc is a plane. In the radial direction of the ringer and in the direction from the center of the ringer to the edge of the ringer, the thickness of the first disc in the first direction first gradually increases and then gradually decreases.

4. The lander according to claim 1, characterized in that, The first disc portion is disposed on the side of the second disc portion facing the main body portion; The ring injector further includes a connecting pipe, a connecting column, and a connecting rib. The connecting pipe and the connecting column both extend along the first direction. One end of the connecting pipe is connected to the first disc and communicates with the nozzle. The other end of the connecting pipe is connected to the main body and communicates with the cooling high-pressure gas source. One end of the connecting post is connected to the second disc, and at least a portion of the connecting post extends into the communicating pipe. The connecting rib is disposed between the communicating pipe and the connecting post and connects the communicating pipe and the connecting post.

5. The lander according to claim 1, characterized in that, The minimum distance from the nozzle to the main body is 0.1m to 0.2m.

6. The lander according to claim 4, characterized in that, The cold air injection assembly also includes: A control valve is installed between the ring injector and the cooling high-pressure gas source to control the connection between the ring injector and the cooling high-pressure gas source; A filter is disposed between the control valve and the high-pressure cooling gas source to filter the cooling gas flowing out from the high-pressure cooling gas source; A pressure control unit is disposed between the filter and the control valve to control the pressure of the cooling gas flowing out from the high-pressure cooling gas source.

7. The lander according to claim 1, characterized in that, The predetermined speed is supersonic.

8. The lander according to claim 1, characterized in that, The cooling gas is an inert gas or nitrogen; When the cooling gas is in the high-pressure cooling gas source, the cooling gas is either gaseous or liquid.

9. The lander according to claim 1, characterized in that, It also includes multiple landing legs, which are located on the side of the main body where the ring launcher is located. The multiple landing legs are evenly distributed around the circumference of the ring launcher, and the number of landing legs between each pair of adjacent jet engines is the same.

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