RU2759358C1 - Suborbital spacecraft and the method for its braking in the atmosphere - Google Patents

Abstract

FIELD: space technology.

SUBSTANCE: group of inventions relates to the management and design of multiple-use spacecraft with vertical take-off and landing, which can be used for space tourism, high-altitude parachute jumps, etc. The suborbital SC contains a frame, landing supports, propulsion system, control system, crew seats and two groups of flaps with actuators pivotally connected to the frame. When folded, one group of flaps forms the head fairing, and the other forms the side surface of the SC. The number of flaps in the groups is the same, and in the open state, the flaps of one group are located between the flaps of the other group in the projection on the direction of flight. The crew seats are ejection seats, and a group of flaps forming the head fairing is installed above them with a gap. When the SC is decelerated, before entering the atmosphere, the flaps are opened at maximum angles, then, with an increase in overload, the flaps are smoothly folded to the minimum opening angle, paused and then smoothly opened again at maximum angles. The control program is obtained as a result of pre-flight mathematical modeling of the descent process.

EFFECT: decrease in the peak overload value during the descent of the SC in the atmosphere.

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Description

The invention relates to rocket and space technology, more precisely to reusable suborbital space transport vehicles with vertical takeoff and landing, and can be used for space tourism, high-altitude parachute jumps and other purposes.

Known ships and rocket stages of repeated use, differing in the method of landing - using wings or parachutes (for example, RF patents No. 2442727, 20.02.2012, IPC: B64G 1/14 (2006.01); No. 2441815, 10.02.2012, IPC: B64G 1 / 14 (2006.01); # 2333868, 20.09.2008, IPC: B64G 1/16 (2006.01) These ships use one device for take-off - rocket engines, and for landing - other devices - wings or parachutes.

Also known are reusable ships and rocket stages that carry out vertical take-off and landing using only rocket engines (RF patents No. 2309088, 10/27/2007, IPC: B64G 1/14 (2006.01); 2318704 C2, 03/10/2008, IPC: B64G 1 / 14 (2006.01) They do not have special aerodynamic surfaces to stabilize the descent in the atmosphere, therefore, during a controlled descent, additional fuel must be consumed to operate the attitude control engines.

Known suborbital spacecraft with braking surfaces according to patent US 8408497 (B2), 04/02/2013, IPC: B64G 1/62 (2006.01). This ship produces a stabilized descent in the atmosphere using brake flaps located at the top of the ship's cylindrical hull. The disadvantage of this ship is the redundancy of structural elements, since the shields are not part of the hull.

The closest to the proposed technical solution is a single-stage reusable spacecraft and its control method during descent (US 5873549 (A), 02.23.1999, IPC: B64G 1/14 (2006.01); B64G 1/24 (2006.01); B64G 1/28 (2006.01); B64G 1/62 (2006.01).

The ship includes a frame, landing supports, a propulsion system, a control system, a payload, an external fixed skin and two groups of flaps, each of which is pivotally connected to the frame and equipped with a drive connected to the control system. The fixed skin, together with the shields, forms the aerodynamic surface of the ship. Each flap with its upper or lower edge is pivotally connected to the frame and has a drive for deflecting the flap at a certain angle. Shields are intended for attitude control, and partly for braking the ship during its descent into the atmosphere. When the ship moves upwards with its bow forward, the rear flaps are used, and when moving downward astern forward, the front flaps are used. The total area of the shields is significantly less than the total surface of the ship.

The prototype of the method for braking this ship in the atmosphere consists in opening the flaps during descent, which leads to an increase in the aerodynamic drag force, as well as in controlling the magnitude of the g-force and time.

The disadvantage of the design is that a small part of the outer aerodynamic surface of the ship is used as brake flaps, and also that the flaps of the two groups are opened alternately. As a result, the total area of the open flaps is sufficient to stabilize the spacecraft, but not enough to influence the magnitude of the overload during braking in the atmosphere.

The disadvantage of the method of braking the ship is that the position of the flaps does not change after their deployment. Therefore, when passing the maximum overload zone, the value of this overload cannot be reduced.

The objective of the invention is to eliminate these disadvantages.

The technical result of the invention is to reduce the peak value of the overload during the descent of the ship in the atmosphere due to the large relative area of the brake flaps and active control of this area.

The technical result is achieved by the fact that in a suborbital spacecraft, which includes a frame, landing supports, a propulsion system, a control system, a crew seat and at least one of two groups of brake flaps, each of which is pivotally connected to the frame and equipped with a drive, in the folded state one a group of flaps forms the head fairing, and the other group forms the side surface of the ship, while all the flaps are connected to the frame by their lower edge, the number of flaps in both groups is the same, and in the open state the flaps of one group are located between the flaps of the other group in projection to the direction of flight.

In addition, the crew seats are made of ejection, and a group of flaps forming the head fairing is installed above them with a gap that provides the possibility of ejection in the entire range of opening angles of the said flaps.

The technical result is also achieved due to the fact that in the method of braking a suborbital spacecraft in the atmosphere, which consists in opening the brake flaps during descent and controlling the magnitude of the accelerometer overload and timer time, before entering the atmosphere, the flaps are opened to maximum angles, then, at increasing overload to value A, the flaps are smoothly folded over time T1 to the minimum opening angle, pause for time T2, and then smoothly open again during time T3 to the maximum opening angle, while the values of A, T1, T2 and T3 are obtained before the flight, according to the results of mathematical modeling of the descent process, and the angles of the maximum opening of the flaps are selected from the condition of simultaneously ensuring the maximum value of the area of their projection onto the direction of flight and stabilizing the descent of the ship.

The essence of the invention is illustrated by graphic materials (Fig. 1-3).

Figure 1 schematically shows the design of the proposed ship.

Figure 2 shows graphs of the dependence of the magnitude of the overload on the descent time from an altitude of 110 km with folded flaps (curve 11), with flaps fully open (curve 12), and with a variable projection area of the flaps (curve 13).

The table (Fig. 3) shows the values of the flight parameters, which correspond to the graph 13 in Fig. 2.

The ship includes a frame 1, landing supports 2, a propulsion system consisting of a propulsion engine 3 and orientation engines 4, a control system (not shown in the figures), crew seats 5, brake flaps of one (hereinafter - upper) group in a folded biv open 7 state, brake flaps of another (hereinafter - lower) group in folded 8 and in open 9 state, as well as drives 10 of flaps. The upper group of flaps in position 6 forms the head fairing. The lower group of flaps in position 8 forms the side surface of the ship. All the flaps are connected to the frame 1 by their lower edge, the number of flaps in both groups is the same, and in the open state the flaps 7 of one group are located between the flaps 9 of the other group in projection to the direction of flight.

The ship does not have a sealed capsule for the crew, the crew seats 5 are made ejection, and the group of flaps 6, forming the head fairing, is installed above them with a gap that provides the possibility of ejection in the entire range of opening angles of these flaps.

The proposed ship works as follows.

Before takeoff, the crew members are in ejection seats 5 in protective suits with individual parachutes. All shields are folded. During takeoff and ascent, the ship moves with acceleration under the action of the propulsion engine 3 along a trajectory close to vertical. The orientation of the spacecraft relative to the center of mass is carried out by orientation engines 4. The control system of the spacecraft during the entire flight monitors the movement parameters and controls the executive bodies according to a given program. The control system includes positioning sensors, for example, GPS-GLONASS, orientation, for example, a gyroscopic type, an inertial-type accelerometer, a radio altimeter and a controller with a flight program and a built-in timer. Shields in position 6 perform the function of a head fairing, providing a decrease in air resistance and protection of the crew from high-speed pressure. After gaining speed and turning off the main engine 3 (at an altitude of approximately 40-50 km at a speed of 1-1.5 km / s), the ship performs a ballistic flight to an altitude of about 100 km. In this section, the orientation of the ship is also performed by the orientation engines 4. The residual amount of fuel in the tanks of the ship must be sufficient to complete the landing.

At a height close to the maximum, with the help of actuators 10, all flaps are opened from position 6 to position 7, and from position 8 to position 9, which corresponds to the maximum braking surface area. The ship, under the influence of gravity, stops lifting and begins to descend to the ground with increasing speed. At an altitude of about 50-60 kilometers, when the high-speed air pressure becomes sufficient to influence the ship, the flaps in positions 7 and 9 begin to perform the function of stabilizing the flight, turn the ship into position with the engine 3 to the ground and further maintain this position. Stabilization is ensured by the fact that in the open position of the flaps, in the entire range of their opening angles, the center of aerodynamic air pressure is above the ship's center of mass.

The shields also decelerate the ship in the atmosphere, and the braking force can vary from the minimum when the shields are folded and are in positions 6 and 8, to the maximum when they are fully open and in positions 7 and 9. This property makes it possible to reduce the maximum overload value. acting on the ship and crew, as follows. Before entering the atmosphere, the flaps are opened to the maximum permissible angle, to positions 7 and 9, i.e. the angle corresponding to the maximum braking surface area at which the stable stabilization of the ship is still maintained. During descent, the control system measures the current overload value using an accelerometer. With an increase in the overload and its achievement of a given value A, the flaps are smoothly folded, deflecting upward to positions 6 and 8 until the minimum area of the ship's midship is reached. The addition time is equal to the predetermined value T1. Then they pause for time T2, and then smoothly open the flaps again to the maximum area, in positions 7 and 9 during time T3. The values A, T1, T2, T3 are selected in advance, before the flight, by simulating the descent process on a mathematical model. By changing these parameters on the model, the minimum possible overload value is achieved. The effect of reducing the overload is achieved due to the fact that during the action of the maximum velocity air pressure, the area of the axial projection of the ship, i.e. the projection perpendicular to the direction of flight of the ship is the smallest, and the drag force, and with it the peak value of the overload, is reduced, although the duration of the action of this reduced overload increases, as shown in FIG. 2, graph 13. Values A, T1, T2 and T3 are entered into the controller program and used by it in flight to issue commands to the dashboard drives. The current values of the overload are measured by an accelerometer, and the time by a timer.

To assess the magnitude of overloads at different angles of flaps opening, mathematical modeling of the descent process was carried out with the following initial data:

- descent trajectory - vertical;

- the height of the beginning of the descent - 110 km;

- the area of the ship midship with folded flaps - 5 m ² ;

- the area of the axial projection of the fully open flaps - 20 m ² ;

- the area of the ship midship with fully open flaps - 25 m ² ;

- ship weight during descent - 2500 kg;

- the dependence of the air density on the altitude corresponds to the standard atmosphere;

- resistance coefficient Cx = 0.8.

To estimate the area of the flaps, it is assumed that the ship has a diameter of 2.5 m, the height of the lateral surface is 2.5 m, the length of the generatrix of the cone of the head fairing is 3 m. The total area of the flaps is 30 m ² , and taking into account their inclination and partial mutual shading - 20 m ² .

To reduce the mutual shading of the flaps in the open state, the number of flaps in both groups is the same, and the flaps of one group are located between the flaps of the other group in projection to the direction of flight.

The calculation results are shown in figure 2, which shows the graphs of the magnitude of the overload acting on the ship depending on the descent time at three positions of the flaps. Curve 11 (option 1) corresponds to fully closed flaps (ship midship area 5 m ² ), curve 12 (option 2) - to fully open and fixed flaps (ship midship area 25 m ² ), curve 13 (option 3) - variable flap area (the area of the midsection decreases from 25 to 5 m ² , and then increases again to 25 m ² ).

From the graphs (Fig. 2) it can be seen that the maximum overload in the first version is 3.9 g, in the second version 3.3 g, in the third - 2.3 g. Thus, the proposed method allows to reduce the maximum overload value by more than two times (if we count from the "ground" level 1 g) in comparison with the option of uncontrollable flaps of a small area when descending, i.e. with a prototype.

Based on the simulation results, it turned out that in the case of the above initial data, the flaps should begin to fold at overload A = 1.7 g, the addition time is T1 = 28 seconds. The flaps should be folded out again after a pause during the time T2 = 13 seconds, the opening time of the flaps is T3 = 25 seconds. The maximum overload is 2.3 g. In the table in FIG. 3 shows the values of altitude, speed, midship area and overload depending on the time from the start of the descent.

If only the upper group flaps are used for braking, they should be folded at overload A = 2 g, the addition time is T1 = 20 seconds, the pause is T2 = 10 seconds, the opening time is T3 = 20 seconds. The maximum overload is 2.7 g.

The above parameters for flap control depend on the altitude of the initial descent point, the mass of the ship, and the air density in altitude. These parameters, selected at the stage of mathematical modeling, must be entered into the program of the spacecraft controller before the flight.

Shields in positions 7 and 9 also perform aerodynamic control of the ship when it moves along a downward trajectory in order to bring it to the starting point, or another predetermined landing point. To do this, by the commands of the control system, one or more flaps are deflected upward by a given angle using the drive. In this case, the flow around the ship becomes asymmetric, the total aerodynamic force deviates from the vertical in the desired direction, which leads to a change in the descent trajectory in the same direction. Since the ascent and descent trajectory is initially chosen close to vertical, the ship needs a relatively low aerodynamic quality (0.1-0.3) to return to the launch point to compensate for wind displacement and control inaccuracies.

The aerodynamic control of the ship along the pitch and yaw axes is carried out in the manner described above. Since the ship is an axisymmetric object, this control is sufficient to bring the ship to the landing point.

At the final stage of landing, the main engine 3 is switched on and the ship is braked. When the speed in front of the ground is reduced to practically zero, the landing is made on the landing supports 2. The orientation of the ship is carried out by the orientation engines 4.

Since the flaps in the proposed ship occupy the entire area of the nose fairing and side surface, their total area is much larger than in the prototype, which makes it possible to effectively use them for congestion control.

The proposed method of braking a suborbital vehicle allows significantly, more than 2 times in comparison with the prototype, to reduce the maximum overload during descent.

The main purpose of the proposed spacecraft is suborbital space tourism. During the flight, the crew members must physically feel the features of outer space, so the crew is outside the sealed capsule, directly in open space, in spacesuits. This makes it possible to supplement the perception of flight with the sensation of a space vacuum, which manifests itself in an increase in the rigidity and elasticity of the spacesuit, bright sunlight and temperature changes on the illuminated and shaded sides of the spacesuit. The state of weightlessness lasts about 3 minutes, during which time the crew members can unfasten from the seat and swim not only above the seat, but also at a certain distance from the ship, provided that they are prepared for this and connected to the ship with a halyard.

Another purpose of the ship is to conduct high-altitude parachute jumps. Currently, the achieved skydiving height is 41.4 km (Alan Eustace, 10/25/2014). The jump was made from a balloon. A further significant increase in jump height is possible only with the help of rocket systems. The proposed ship allows you to expand the range of heights up to almost 100 km. An athlete in a spacesuit with a parachute can leave the ship at any point on the trajectory after the end of the propulsion engine. He can use the ejection seat or simply push off the ship with his feet, and during zero gravity move away from the ship to a safe distance.

Crew members may choose to land by parachute or in a ship.

In the event of a ship accident at the start, during landing or at any other point of the trajectory, the crew can leave the ship using ejection seats and land on individual parachutes.

To ensure the listed capabilities in the proposed ship, the crew seats are made ejection, and the flaps forming the head fairing are installed above them with a gap that provides the possibility of ejection in the entire range of opening angles of these flaps.

The practical implementation of the proposed spacecraft can be based on the use of proven and reliable main units used in aviation and astronautics: a reusable liquid rocket engine with a thrust of 7-10 tons, orientation engines, a control system, K36 ejection seats or their lightweight counterparts, Sokol spacesuits. Shields can be made of duralumin or carbon fiber. The maximum speed of the ship during descent does not exceed 1 km / s, so the heat loads will be insignificant. The drives for each group of shields can be electric, for example, of the "screw-nut" type with a vertical screw on the motor axis, and a nut pivotally connected by rods to each shield. This design provides synchronous and symmetrical deflection of the flaps. For aerodynamic control of the ship, the propeller must deviate from the vertical in two mutually perpendicular directions.

Claims (3)

1. Suborbital spacecraft, including a frame, landing supports, propulsion system, control system, crew seats and two groups of shields, each of which is pivotally connected to the frame and equipped with a drive connected to the control system, characterized in that in the folded state one group the flaps form the head fairing, and the other group forms the side surface of the ship, while all the flaps are connected to the frame by their lower edge, the number of flaps in both groups is the same, and in the open state the flaps of one group are located between the flaps of the other group in projection to the direction of flight. 2. The suborbital spacecraft according to claim 1, characterized in that the crew seats are ejection-like, and a group of shields forming the head fairing is installed above them with a gap allowing ejection in the entire range of opening angles of said shields. 3. A method of braking a suborbital spacecraft in the atmosphere, consisting in opening the flaps during descent and controlling the magnitude of the overload and time, characterized in that before entering the atmosphere, the flaps are opened to maximum angles, then, when the overload increases to value A, the flaps are smoothly folded during the time T1 to the minimum opening angle, pause for the time T2, and then smoothly open again during the time T3 to the maximum opening angle, while the values of A, T1, T2 and T3 are obtained before the flight according to the results of mathematical modeling of the descent process, and the angles of the maximum opening of the flaps are selected from the condition of simultaneously ensuring the maximum value of the area of their projection onto the direction of flight and stabilizing the descent of the ship.

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