RU2199474C2 - Inflatable device of passive deceleration system of last stage of launch vehicle - Google Patents

Abstract

FIELD: space engineering. SUBSTANCE: device includes container, developing mechanism and inflatable structure. Proposed device is made in form of autonomous monoblock rigidly secured on peripheral part adapter compartment of last stage of launch vehicle. Container is provided with spring-loaded doors engageable with swivel latches which are connected with locks-pushers of developing mechanism provided with pyro- hydraulic time relay engageable with locks-pushers. Units of developing mechanism are secured on outer side of container whose inner surface and surfaces of its doors are coated with elastic film secured to said surfaces over perimeter. Inflatable structure is made in form of set of spherical envelopes made from elastic polymer metallized film and enclosed in screen envelope which is secured to locking units found on container by means of lines. Lower rows of spherical envelopes are made from thicker film as compared with lower ones. EFFECT: simplified construction; enhanced reliability. 2 dwg

Description

 The device relates to space technology, and more specifically to inflatable devices of the passive braking system (PST) of the last stages of launch vehicles (LV).

 Inflatable braking devices are known from the literature, designed to slow the flight speed and reduce the orbit of the spacecraft, deployed to the working position on commands from the spacecraft control system or on command from the Earth, and used to compensate for gas leaks from the shell (manufacturing manufacturing defects, hit micrometeorites or technogenic particles) special onboard gas reserves (BINTI-1, Space Research, SPACE 09.90 - 10.90, VG 5, p. 33; BINTI-1, Space Research, RUB-89.15, 5.2.71 gyu, 9).

 The disadvantages of these devices include the complexity due to the need to have on board the device (stage LV) a working control system, working power sources, as well as special on-board gas reserves. In addition, as a rule, such structures have one inflatable element with large geometric dimensions (a ball with a diameter of 10 m or more), and, consequently, a greater degree of probability of damage by micrometeorites and technogenic particles. Along with this, it is technologically difficult to manufacture and test such large inflatable structures, and the presence of air residues in them (after evacuation and sealing inside the shell remains an air volume equal to the volume of the shell material - determined empirically) does not allow the shell to be deployed to the operating position simultaneously. And, as a rule, in order to avoid rupture of the shell, its deployment is carried out in two, three stages.

 Therefore, to go to each subsequent stage of disclosure, it is necessary either to submit additional commands to the opening devices, or to use protective shells made of special material that collapses over time from exposure to ionizing and ultraviolet radiation in outer space.

 There is also a method of creating inflatable space structures (patent RU 2026247 C1, 6 V 64 G 1/10), which describes the device of an inflatable space structure. The device consists of an elastic sealed shell, in the folded position placed in a container consisting of two halves, one of which is rigidly docked to the upper bottom of the tank of the last stage of the pH. The internal cavity of the shell by highways through a non-return valve and a pressure regulator is connected to the cavity of the fuel tank and the boost line associated with high-pressure cylinders mounted on the body of the launch vehicle. At the exit of the mains and fuel tank, controlled pyro valves are installed. In addition, the boost system contains another controlled pyrovalve and boost pressure regulator.

 The device allows to increase the useful volume of the inflatable structure without the use of special on-board gas reserves. After putting into orbit and the end of the propulsion system of the last stage of the launch vehicle, the internal cavity of the elastic shell is communicated with the pressurization system of the fuel tank and the remaining gas in this system is used to pressurize the shell.

 However, the device for implementing this method is also not without drawbacks. It is assumed that the device’s container can be installed directly on the fuel tank inside the structure of the last stage of the launch vehicle (shortening the length of the lines, reducing their resistance), but in the existing structures of the launch vehicle with a tight arrangement of nodes and assemblies in them, an arbitrary choice of zone for installing the device is unrealistic. In addition, the device is also difficult in design because it incorporates three pyro valves used to actuate commands from the control system of the last stage of the launch vehicle, two pressure regulators, and a check valve. The presence of such a number of controlled elements and automation nodes reduces the reliability of the device.

 The aim of the present invention is to remedy these disadvantages and to ensure the possibility of implementing the device on existing structures of the last stages of the pH by simplifying the design of the PST and increasing its reliability.

 This goal is achieved by the fact that the device is made in the form of an autonomous monoblock rigidly fixed on the peripheral part of the transition compartment of the last stage of the launch vehicle, while the device’s container is equipped with spring-loaded flaps interacting with pivoting latches that are associated with pusher-locks of the opening mechanism equipped with pyrohydraulic a time relay interacting with pusher locks, wherein the nodes of the opening mechanism are fixed on the outside of the container, the inner surface which, as well as its flaps, are covered with an elastic film glued around the perimeter, and the inflatable structure is made in the form of a set of spherical shells (with a diameter of not more than 4 m) of an elastic polymer metallized film enclosed in a mesh sheath, which is secured to the fixation nodes via slings, located on the container, while the lower rows of spherical shells are made of a film of a greater thickness than the upper ones.

 In Fig.1, 2 shows the proposed device inflatable PST.

 The device consists of a container, a mechanism for its disclosure and an inflatable structure.

 The container 1 is a three-dimensional structure, rigidly fixed to the transition compartment of the last stage of the PH 2, with a curved bottom and a lid and flat side walls, made to ensure unhindered exit of the inflatable structure inclined with respect to the bottom. The cover is made of two leaflets 3 spring-loaded in the axes and held in the closed position by pivoting latches 4. On the bottom there are nodes 5 for fixing the slings holding the inflatable structure, and nodes of the container opening mechanism are fixed on the outside.

 The mechanism for opening the container includes two pusher locks 6 and a pyro-hydraulic time switch, consisting of a pyrocheck 7, a hydraulic cylinder 8 and a spring 9. The piston of the hydraulic cylinder 8 is equipped with a throttle 10, with which the time delay of the operation of the pusher locks 6 is adjusted, and therefore and the time of withdrawal of the inflatable structure, to exclude the possibility of collision of the separating last stage of PH 2 with the spacecraft. The rods of the pusher locks 6 are connected with the levers of the rotary latches 4. In turn, the levers of the pusher locks 6 are connected through the bracket 11 to the piston rod of the hydraulic cylinder 8.

 The inflatable structure that provides the required aerodynamic braking surface consists of a set of spherical shells 12 of small diameter (not more than 4 m) made of a polymer metallized film resistant to the effects of outer space and enclosed in a mesh shell 13, which is secured with straps 14 to nodes 5.

 The deployment of the inflatable structure in working condition is ensured by the residual air (P = 0.1 MPa) inside the shells. Due to the small diameter of the spherical shells, the steps of their deployment are not required, because in this case the dynamics of the opening is not accompanied by their destruction. In addition, simplifies the technology of their manufacture and testing. And from the point of view of susceptibility to micrometeorites and technogenic particles, a stacked inflatable structure is more reliable than a single large-sized one.

 To ensure the safety of the inflatable structure when it comes in contact with the structure of the last stage of PH 2, which has angular perturbations, and when leaving the container 1, the lower rows of spherical shells 12 are made of a film of a greater thickness than the upper ones, and the inner surfaces of the container 1 and the casing 3 along the contour of the film in such a way that after the opening of the wings 3 and when the inflatable structure exits, the film coatings form protective “pillows” 15 due to the residual air.

 The operation of the device is as follows.

 Simultaneously with the command to separate the last stage of the PH 2, the command to activate the pyrocheck 7 passes. Further, the system operates autonomously. The pyrocheck, when activated, releases the spring 9 of the pyrohydraulic time switch, which, unclenching, presses the fluid through the throttle 10 into the adjacent cavity of the hydraulic cylinder 8, while ensuring the movement of the piston with the rod at a given speed, providing a given full stroke time. The rod of the hydraulic cylinder 8, rigidly connected to the bracket 11, acts through it on the levers of the pusher locks 6. The pusher locks 6 act and turn the latches 5, releasing the spring-loaded flaps 3 of the container lid 1. The flaps open, freeing the exit area of the spherical shells of the inflatable structure, which leaving the container 1, inflate to a working state. The proposed technical solution will improve the reliability of the device and simplify its design.

Claims (1)

 A device for an inflatable passive braking system of the last stage of the launch vehicle, including a container, a mechanism for opening it and an inflatable structure, characterized in that the device is an autonomous monoblock rigidly mounted on the peripheral part of the transition compartment of the last stage of the launch vehicle, while the device’s container is equipped with spring-loaded flaps interacting with pivoting latches, which are connected with pusher locks of the opening mechanism equipped with a pyro-hydraulic time relay nor interacting with pusher locks, and the nodes of the opening mechanism are fixed on the outside of the container, the inner surface of which and its wings are covered with an elastic film glued along the perimeter to these surfaces, and the inflatable structure is made in the form of a set of spherical shells made of elastic polymer metallized films enclosed in a mesh shell, which by means of slings is fixed to fixation nodes located on the container, the lower rows of spherical shells being made from a film of greater thickness than the upper ones.

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