JP2020029806A - Astronomical landing machine and its using method - Google Patents

Abstract

To provide an astronomical landing machine capable of landing with landing legs shorter than a nozzle, and its using method.SOLUTION: An astronomical landing machine includes a landing machine main body 2 descending and landing toward a celestial body surface a, a thruster 4 fixed to a lower portion of the landing machine body 2 and jetting a gas jet to a lower part to control a descending speed, and landing legs 6 fixed to a lower portion of the landing machine main body 2, kept into contact with the celestial body surface a at a lower end, and supporting the landing machine main body 2. The thruster 4 has a nozzle 8 extended to a lower part with respect to lower ends of the landing legs 6, and divided into an upper side 8b and a lower side 8b at an upper part with respect to the lower ends of the landing legs 6, and a nozzle deformation mechanism 10 for deforming the nozzle 8 so that a lowermost end 8e of the nozzle 8 is positioned at an upper part with respect to the lower ends of the landing legs 6 from an upper side 8a of the nozzle 8 while passing off the lower side 8b.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a celestial body landing device that lands on a celestial body having no atmosphere and gravity.

In the universe, there are celestial bodies, such as the moon, that have no atmosphere even with gravity. Landing aircraft intended for landing on such celestial bodies have been conventionally manufactured.
For the landing aircraft to land without failure due to excessive collision acceleration, the landing aircraft must be decelerated against the gravity of the celestial body. Since it is a celestial body without the atmosphere, landing methods such as parachutes that use air resistance to decelerate cannot be used. Therefore, in such a landing aircraft, in order to reduce the impact at the time of landing, it descends slowly while injecting combustion gas from the nozzle toward the celestial body, and lands with the legs surrounding the nozzle. For example, Patent Document 1 is disclosed as such a landing aircraft.

  When the landing aircraft disclosed in Patent Literature 1 lands on the celestial body surface, the nozzle descends downward (celestial body side). The landing gear legs were configured to be longer than the nozzles so that the legs supporting the body of the landing gear contact the surface of the celestial body before the nozzles.

JP-A-11-105797

FIG. 1 is a front view of a conventional landing aircraft 31. FIG.
In order for the landing aircraft to obtain thrust in a vacuum, the longer the nozzle length, the better the exhaust efficiency and the higher the specific thrust and thrust. If the thrust increases, even if the engine is downsized, the same thrust as when a large engine having a short nozzle is mounted can be obtained. If the specific thrust increases, the amount of fuel to be mounted can be reduced even when the same deceleration is performed. Therefore, in order to reduce the size of the engine and the weight of the landing aircraft by reducing the amount of fuel on board, it is preferable that the length of the nozzle is long.
Therefore, the conventional landing aircraft 31 used a long nozzle 38 as shown in this figure.

  However, as described above, when the landing aircraft 31 lands on the celestial body, the nozzle 38 always descends downward (the celestial body side). The longer the nozzle 38, the longer the leg 36 of the landing gear 31 must be, and the mass of the landing gear 31 has increased accordingly.

In addition, there is a limit on the maximum diameter that can be mounted on a rocket. In order to mount the lander 31 having a long leg 36 on the rocket, the movable mechanism 40 for narrowing the leg 36 in the rocket and expanding the leg 36 during landing is required. For example, in the example of the movable mechanism 40 in this figure, each leg 36 requires one cylinder 40a.
As described above, in the conventional landing aircraft 31, the mass of the legs 36 has increased due to the provision of the movable mechanism 40. In addition, the provision of the movable mechanism 40 has increased the risk of failure. Therefore, there has been a demand for a landing machine 31 that can be mounted on a rocket without the movable mechanism 40 on the leg 36 and can be operated with a small amount of fuel and a small engine.

  On the other hand, the landing aircraft 31 carries a rover, a person, and the like on the fuel tank 35 in the landing aircraft main body 32. If the landing gear 31 has long legs 36, it is necessary to drop a rover, a person, and the like from a high position on the ground, and the slopes and ladders required for that purpose are long or steep. Therefore, there has been a demand to make the height of the landed aircraft 31 as low as possible.

  The present invention has been made to solve the above-mentioned problems. That is, an object of the present invention is to provide an astronomical landing machine capable of landing with a landing leg shorter than the nozzle and a method of using the same.

According to the present invention, a landing aircraft body descending and landing toward the celestial body surface,
A thruster fixed to a lower portion of the landing aircraft body to control a descending speed by injecting a gas jet downward,
A landing leg fixed to a lower portion of the landing aircraft main body and having a lower end abutting on a celestial body surface to support the landing aircraft main body,
The thruster is a nozzle extending below the lower end of the landing leg and divided into upper and lower sides above the lower end of the landing leg,
And a nozzle deformation mechanism configured to remove the lower side from the upper side of the nozzle and deform the nozzle so that the lowermost end of the nozzle is located above the lower end of the landing leg. Is done.

Further, according to the present invention, there is provided a method of using the above-mentioned celestial body landing aircraft,
(A) injecting the gas jet from the nozzle in the traveling direction while orbiting the orbit around the celestial body and starting descending toward the celestial body surface;
(B) removing the lower side from the upper side of the nozzle and deforming the nozzle so that the lowermost end of the nozzle is located above the lower end of the landing leg;
(C) There is provided a method of using a celestial lander, which controls the descent speed by injecting the gas jet downward from the lowermost end of the nozzle.

  According to the present invention, the nozzle is deformed during landing so that the lower end of the nozzle is located above the lower end of the landing leg by removing the lower side of the nozzle from the upper side using the nozzle deformation mechanism. Therefore, even if the landing leg is shorter than the nozzle, the landing leg can land. As a result, the landing leg is shorter than that of the conventional landing aircraft, so that the mass can be reduced. In addition, since the height of the landing aircraft body when landing on the celestial body can be lowered, the length of the slope required for lowering the rover and the length of the ladder required for humans to get off the landing aircraft body are shortened And the mass of the landing aircraft can be reduced accordingly.

  Also, since the landing aircraft of the present invention can employ short landing legs, it can be mounted on a rocket without a movable mechanism, and the mass of the landing aircraft can be reduced by the absence of the movable mechanism. In addition, since there is no movable mechanism, the risk of failure can be reduced.

It is a front view of the conventional landing machine. FIG. 2 is a front view of the celestial landing gear according to the first embodiment. It is explanatory sectional drawing of the thruster of 1st Embodiment. FIG. 4 is an explanatory diagram of a method of using the celestial body landing machine of the first embodiment. It is a front view of a celestial body landing machine of a 2nd embodiment. It is explanatory sectional drawing of the thruster of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the common parts in the respective drawings, and the duplicate description will be omitted.

(1st Embodiment)
FIG. 2 is a front view of the astronomical landing device 1 of the first embodiment.
The celestial body landing machine 1 of the present embodiment is a lander that lands on the surface of a celestial body A (hereinafter, celestial body surface a) that has no atmosphere even if there is gravity. The astronomical landing machine 1 includes a landing machine main body 2, a thruster 4, and a landing leg 6. In the following description, the celestial landing aircraft 1 will be simply referred to as the landing aircraft 1.
The landing machine main body 2 is a body that descends and landes toward the celestial body surface a, and has a mounted object such as a rover or a person mounted thereon. For example, in the landing aircraft 1 in the example of this figure, the landing aircraft main body 2 is mounted on the fuel tank 5.

A landing leg 6 and a thruster 4 are fixed to one side surface of the landing aircraft main body 2. At the time of landing, the landing aircraft 1 descends with the side to which the landing leg 6 and the thruster 4 are fixed facing downward (the celestial body surface side). Hereinafter, the side surface of the landing gear main body 2 to which the landing leg 6 and the thruster 4 are fixed is referred to as a lower portion of the landing gear main body 2.
The landing leg 6 extends below a divided end face 8c of the nozzle 8 described later. The landing leg 6 is configured to be shorter than the leg 36 of the conventional landing aircraft 31 equipped with an engine and a nozzle 38 of the same size as that mounted on the landing aircraft 1. When the landing machine 1 lands, the lower end of the landing leg 6 abuts on the celestial body surface a to support the landing machine body 2.

  When the landing aircraft 1 orbiting around the celestial body A starts a landing operation, the thruster 4 is used to reduce the orbiting speed. The same thruster 4 is also used to control the descending speed of the landing aircraft 1 to the celestial body A by injecting a gas jet downward (at the celestial body side) during landing.

The thruster 4 has a nozzle 8 extending below the lower end of the landing leg 6, and a nozzle deformation mechanism 10 for removing the lower side 8b from the upper side 8a of the nozzle 8.
FIG. 3 is an explanatory sectional view of the thruster 4 of the first embodiment. FIG. 3A is a diagram before the nozzle 8 is separated, and FIG. 3B is a diagram after the nozzle 8 is separated.

  As shown in FIGS. 3A and 3B, the nozzle 8 is divided into an upper side 8 a and a lower side 8 b above the lower end of the landing leg 6. The nozzle 8 is preferably divided outside the throat. While the nozzle 8 is used for a long time, the upper end 8a and the lower side 8b of the nozzle 8 are connected coaxially by, for example, a clamp band 10a between the lower edge of the upper side 8a and the upper edge of the lower side 8b. It is integrated. An O-ring 8d for preventing the leakage of the combustion gas may be fitted to the divided end face 8c of the nozzle 8 (the face where the lower end of the upper side 8a and the upper end of the lower side 8b are in contact).

  The nozzle deformation mechanism 10 may include, for example, the clamp band 10a and a pyrotechnic 10b that separates the upper side 8a of the nozzle 8 from the lower side 8b thereof using an explosive. In this case, the control device of the landing aircraft 1 is programmed to operate the pyrotechnic 10b at an appropriate timing.

  With this configuration, the landing aircraft 1 of the present embodiment can discard the lower side 8b of the nozzle 8 by destroying the clamp band 10a with the pyrotechnic 10b, and shorten the length of the nozzle 8 during the flight. Accordingly, the nozzle deformation mechanism 10 deforms the nozzle 8 so that the lowermost end 8e of the nozzle 8 is located above the lower end of the landing leg 6. In the case of the landing aircraft 1 of the present embodiment, the lower end of the upper side 8a of the nozzle 8 is the lowermost end 8e of the nozzle 8. Accordingly, the gas jet is jetted from the lower end of the upper side 8a of the nozzle 8.

FIG. 4 is an explanatory diagram of a method of using the celestial lander 1 of the first embodiment.
First, a rocket equipped with the landing device 1 of the present embodiment is projected from the earth, and the landing device 1 is put on an orbit around the celestial body A (the dashed line in the figure).
FIG. 4A shows the landing aircraft 1 orbiting around the celestial body A (dashed line in the figure). While orbiting, the gravitational force and centrifugal force of the celestial body A applied to the landing aircraft 1 are balanced. In other words, the landing aircraft 1 orbits around the celestial body A at a speed at which the centrifugal force balances the gravity of the celestial body A. In order for the landing aircraft 1 to descend on the celestial body A, it is necessary to reduce the orbiting speed of the landing aircraft 1 so that the centrifugal force applied to the landing aircraft 1 falls below the gravity of the celestial body A.

  FIG. 4B is a diagram in which the landing aircraft 1 is braking. Breaking means that the landing aircraft 1 lowers the orbiting speed of the landing aircraft 1 by injecting a gas jet in the traveling direction on the orbit. The landing aircraft 1 requires the most thrust when braking. Since the landing aircraft 1 decelerates by braking, the centrifugal force is weakened, and the landing aircraft 1 starts to descend toward the celestial body surface a as shown by a two-dot chain line in this figure.

FIG. 4C is a diagram when the landing aircraft 1 separates the lower side 8b of the nozzle 8, and FIG. 4D is a diagram when the gas jet is jetted toward the celestial body surface a before landing. FIG.
The landing machine 1 activates the nozzle deformation mechanism 10 after the braking and before the landing, removes the lower side 8b from the upper side 8a of the nozzle 8, and the lowermost end 8e of the nozzle 8 becomes the landing leg 6 The nozzle 8 is deformed so as to be located above the lower end of the nozzle 8.

Immediately before the landing, the gas jet is jetted downward (toward the celestial body) as shown in FIG. At this time, no thrust is required as much as the braking time shown in FIG. The thrust required before landing is less than about half the thrust required for braking. When the nozzle 8 is shortened to half the length of the whole, the thrust of the nozzle 8 after separation (that is, the thrust of the upper side 8a of the nozzle 8) is 80% to 90% of the thrust of the nozzle 8 of the original length. Becomes Therefore, even if the length of the nozzle 8 is shortened, a sufficient thrust required for landing can be obtained.
The separation of the lower side 8b of the nozzle 8 shown in FIG. 4C may be performed while performing the jetting for landing shown in FIG. 4D.

FIG. 4E is a diagram in which the landing aircraft 1 has landed on the celestial body surface a.
The landing aircraft 1 controls the descent speed by jetting a gas jet from the lower end of the upper side 8a of the nozzle 8 toward the celestial body surface a, and lands on the celestial body surface a. At this time, the upper side 8a of the nozzle 8 is left at the lower part of the landing aircraft main body 2, but since the landing leg 6 extends below the lower end of the upper side 8a of the nozzle 8, the celestial body surface a The landing leg 6 touches down.

  Since the lower side 8b of the nozzle 8 is cut off during the landing to shorten the length of the nozzle 8, the landing leg 6 shorter than the conventional landing aircraft 31 can be used. As a result, the height of the landing aircraft main body 2 when landing on the celestial body A can be made lower than that of the conventional landing aircraft 31, so that a slope necessary for lowering the rover or a person descending from the landing aircraft main body 2 can be obtained. The length of the ladder necessary for the landing can be shortened, and the mass of the landing aircraft 1 can be reduced correspondingly.

  Further, since the landing gear 1 of the present embodiment can employ the short landing legs 6, it can be mounted on a rocket without the movable mechanism 40, and the mass of the landing aircraft 1 can be reduced by the absence of the movable mechanism 40. In addition, since there is no movable mechanism 40, the risk of failure can be reduced.

(2nd Embodiment)
FIG. 5 is a front view of the astronomical landing machine 1 according to the second embodiment. FIG. 6 is an explanatory sectional view of the thruster 4 of the second embodiment. FIG. 6A is a diagram before the nozzle 8 is shortened, and FIG. 6B is a diagram after the nozzle 8 is shortened.
The nozzle 8 of the present embodiment is divided into an upper side 8a and a lower side 8b above the lower end of the landing leg 6, as in the first embodiment. The divided end surface 8c (the end surface where the upper side 8a and the lower side 8b are in contact with each other) of the nozzle 8 in this figure is formed as a cylindrical surface centered on the central axis Z of the nozzle 8. Thus, the lower side 8b of the nozzle 8 can be removed from the upper side 8a of the nozzle 8 by moving the lower side 8b of the nozzle 8 upward in parallel with the central axis Z.

In the landing aircraft 1 of the second embodiment, the nozzle deformation mechanism 10 includes an actuator 12 that moves the lower side 8b of the divided nozzle 8 up and down. The actuator 12 is fixed to the landing aircraft main body 2, and moves the lower side 8 b of the nozzle 8 parallel to the central axis Z of the nozzle 8.
The actuator 12 may be, for example, a linear motion cylinder whose tip is connected to the lower side 8 b of the nozzle 8. However, the actuator 12 is not limited to this as long as it can move the lower side 8b of the nozzle 8 in the central axis direction. The actuator 12 may have, for example, a rack-and-pinion or a link mechanism.

When the lower side 8b of the nozzle 8 retreats upward by driving the actuator 12, the lower side 8b concentrically covers the upper side 8a as shown in FIG. 6B. In the case of the embodiment shown in this figure, the portion functioning as the nozzle 8 at this time is only the upper side 8a. Thus, the landing aircraft 1 controls the descent speed by jetting a gas jet from the lower end of the upper side 8a of the nozzle 8 toward the celestial body surface a, and lands on the celestial body surface a. In addition, as shown in this figure, the lower end of the upper side 8a may form the lowermost end 8e of the nozzle 8, but is not limited thereto. If the lower ends of the upper side 8a and the lower side 8b of the nozzle 8 are located above the lower end of the landing leg 6 as the lowermost end 8e of the nozzle 8, those forming the lowermost end 8e of the nozzle 8 are lower than the upper side 8a. Any of the sides 8b may be used. For example, the lower end of the lower side 8b of the nozzle 8 retracted upward may be lower than the lower end of the upper side 8a, and the lowermost end 8e of the nozzle 8 may be formed.
It is preferable that an O-ring 8d for preventing the leakage of the combustion gas is fitted to the divided end face 8c of the nozzle 8.

With this configuration, the landing aircraft 1 of the present embodiment can reuse the lower side 8b of the nozzle 8.
Further, even if the actuator 12 is provided, the lower side 8b of the nozzle 8 can be moved up and down by one actuator 12, so that the conventional landing aircraft 31 which requires the movable mechanism 40 for each of the plurality of legs 36 is required. Thus, the risk of failure can be reduced. Note that a plurality of actuators 12 may be provided.

In the method of using the landing machine 1 of the present embodiment, the same timing as when the lower side 8b of the nozzle 8 is separated in the landing machine 1 of the first embodiment (after braking and before landing (FIG. 4 (C))), the actuator 12 is driven to move the lower side 8b of the nozzle 8 upward. Note that the actuator 12 may be driven to move the lower side 8b of the nozzle 8 upward while ejecting the gas jet for the landing shown in FIG. 4D.
Other configurations, effects, and methods of use of the landing aircraft 1 of the present embodiment are the same as those of the first embodiment.

  According to the present invention described above, the lower end 8e of the nozzle 8 is positioned higher than the lower end of the landing leg 6 by removing the lower side 8b of the nozzle 8 from the upper side 8a during landing using the nozzle deformation mechanism 10. As described above, since the nozzle 8 is deformed during the landing, the landing leg 6 can land even if the landing leg 6 is shorter than the nozzle 8. Thus, the mass of the landing gear 6 can be reduced as much as the landing gear 6 is shorter than the conventional landing gear 31. In addition, since the height of the landing gear body 2 at the time of landing on the celestial body A can be reduced, the length of the slope required for lowering the rover and the length of the ladder required for a person to get off the landing gear body 2 Can be shortened, and the mass of the landing aircraft 1 can be reduced accordingly.

  Further, since the landing gear 1 of the present embodiment can employ the short landing legs 6, it can be mounted on a rocket without the movable mechanism 40, and the mass of the landing aircraft 1 can be reduced by the absence of the movable mechanism 40. In addition, since there is no movable mechanism 40, the risk of failure can be reduced.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

A celestial body, Z central axis, a celestial body surface,
1 celestial landing aircraft (landing aircraft), 2 landing aircraft main body,
4 thrusters, 5 fuel tanks, 6 landing gear,
8 nozzle, 8a upper side, 8b lower side,
8c split end face, 8d O-ring, 8e bottom end,
10 Nozzle deformation mechanism, 10a clamp band, 10b pyrotechnic,
12 actuator, 31 conventional landing gear, 32 landing gear body,
35 fuel tank, 36 legs, 38 nozzles,
40 movable mechanism, 40a cylinder

Claims (4)

Landing aircraft body descending and landing toward the celestial body surface,
A thruster fixed to a lower portion of the landing aircraft body and controlling a descending speed by injecting a gas jet downward,
A landing leg fixed to a lower portion of the landing machine main body and having a lower end in contact with a celestial body surface to support the landing machine main body,
The thruster is a nozzle that extends below the lower end of the landing leg and is divided into an upper side and a lower side above the lower end of the landing leg,
And a nozzle deformation mechanism configured to remove the lower side from the upper side of the nozzle and deform the nozzle so that the lowermost end of the nozzle is located above the lower end of the landing leg. The nozzle deformation mechanism has an actuator for vertically moving the lower side of the nozzle disengaged from the upper side of the nozzle,
The actuator moves the lower side of the nozzle upward, whereby the lower end of the upper side of the nozzle or the lower end of the lower side of the nozzle becomes the lowermost end of the nozzle, and the landing leg The astronomical landing machine according to claim 1, wherein the nozzle is deformed so as to be located above the lower end of the astronomical object.   The nozzle deformation mechanism separates the lower side of the nozzle from the upper side of the nozzle, so that the lower end of the upper side of the nozzle becomes the lowermost end of the nozzle and the lower end of the landing leg. The astronomical landing gear according to claim 1, wherein the nozzle is deformed so as to be located above. A method of using the astronomical landing machine according to claim 1,
(A) injecting the gas jet from the nozzle in the traveling direction while orbiting the orbit around the celestial body and starting descending toward the celestial body surface;
(B) removing the lower side from the upper side of the nozzle and deforming the nozzle so that the lowermost end of the nozzle is located above the lower end of the landing leg;
(C) A method of using a celestial landing aircraft, which controls the descent speed by injecting the gas jet downward from the lowermost end of the nozzle.

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