RU2698608C2 - Method for limitation of passive existence period of elements of spacecraft in circumterrestrial space and device for its implementation - Google Patents

Abstract

FIELD: astronautics.SUBSTANCE: group of inventions relates to the manufacture and operation of spacecraft (SC) structure and equipment, mainly AES. At the end of the spacecraft active existence period its elements are changed to a gaseous state under the influence of space factors. To this end, spacecraft elements are made from materials with sublimation property under the influence of said factors. At that conditions of accelerated sublimation are created by removing protective film from spacecraft elements and/or by heating them. Loss of weight of elements is provided in the specified order, preventing formation of spacecraft fragments and separated parts. Proposed device comprises self-destructing unit of spacecraft according to program for activation of accelerated sublimation of spacecraft elements. Provided is a radio channel for receiving command for self-destruction of spacecraft from ground control centre.EFFECT: technical result consists in improvement of efficiency of prevention of technogenic contamination of circumterrestrial space by elements of space garbage.4 cl, 13 dwg

Description

The invention is intended for use in rocket and space technology to prevent technological clogging of near-Earth space.

After the expiration of the active existence of the spacecraft begins its period of passive existence. From this moment, the spacecraft becomes space debris and poses a danger to space activities.

Known methods and devices for eliminating man-made clogging of near-Earth space.

A known method of destruction of fragments of space debris by exposure to them by laser radiation. For example, the NASA Ames Research Center, led by James Mason, is developing a medium-power laser (about 5 kW) that will affect objects for one to two hours a day. Up to 10 space debris objects can be irradiated in a low Earth orbit per day [http://www.dailytechinfo.org/space/2199-nasa-sobiraetsya-sbivat-kosmicheskij-musor-s-pomoshhyu-nazemnogo-lazera.html]. The disadvantage of this method is the high energy consumption and its low productivity in the destruction of spatially distributed fragments of space debris.

Analogs of the present invention are technical solutions for the removal of bulky fragments of space debris, including non-functioning spacecraft, using specialized spacecraft that capture space debris, or acting on it and removing from orbit. Analogs are patents No. RU 2040448, RU 2040449, RU 2046081, RU 2000259.

Analogues of the invention in another field are methods of self-destruction of objects after the end of their functional use in order to comply with environmental requirements: household films, containers, etc. Since 2012, the United States Defense Advanced Research Projects Agency (DARPA) has been implementing a soluble electronics project. This program involves the development of electronic circuits and components that, if necessary, could be dissolved in water. The program involves the American company IBM and the University of Iowa. In parallel, several companies and universities are creating self-destructing electronics. At the end of May 2015, engineers at the University of Illinois at Urbana-Champaign announced the creation of the first fully self-destructing microcircuit under the influence of heat. It also includes a radio controller that allows you to start the self-destruction process by an external command [https://nplus1.ru/news/2015/10/09/vanishing, Journal of Polymer Science, Volume 27, Issue 25 July 1, 2015, https: //nplus1.ru/news/2015/05/23/your-mission-complete].

A self-destructing device consists of an electronic circuit printed with magnesium on a thin and flexible film of a cyclic phthalaldehyde polymer. From above they are covered with a layer of wax, in which many microscopic droplets of weak acid are enclosed. If the device is heated to a certain temperature, the wax begins to melt, micro droplets of acid are released, and when heated in the polymer of phthalaldehyde, the depolymerization reaction begins. Therefore, the film consisting of it quickly decomposes. Then begins the acid degradation of metal parts. After a short time, the device disappears as an object.

The whole process can be started at any time by an external command. For this, a radio frequency sensor and a heat inducing coil are included in the device. The user can send a special signal that will turn on this coil. It will begin to heat up and give a start to the self-destruction of the microcircuit. The decomposition process is set by changing the thickness of the wax layer, acid concentration and heating temperature. The chip completely disintegrates in 20 seconds, after two minutes of heating.

As a development of the self-destructing facility, the Xerox PARC Research Center has created a collapsing Gorilla Glass tempered glass chip [http://onlinelibrary.wiley.com/doi/10.1002/adma.201501180/abstract].

Self-destructive electronics is intended for use in biomedical implants or self-destructive military equipment. The use of such technologies will reduce the amount of garbage that is difficult to decompose in natural conditions.

Advanced Defense Engineering Agency (DARPA) is designing the “endangered” unmanned aerial vehicles that will be used by special operations forces. Such vehicles will deliver important equipment to special forces units and then disappear without a trace. In October 2015, DARPA initiated a project to develop “endangered” drones. The project was called ICARUS. The development of the UAV is planned to be completed within 26 months after the conclusion of a contract with one of the American companies [Defense Systems, https://nplus1.ru/news/2015/10/09/vanishing].

Researchers at Carnegie Mellon University are developing polymers that can break down to monomers under the influence of an electric pulse. The polymers are planned to be used in the development of “disappearing” parachutes, which will decompose very quickly and practically without a trace after cargo or fighter is transported from the plane to the ground. The development of electricity-degradable polymer is a side project of the ICARUS program. Researchers at Carnegie Mellon University have announced that they have already created the right polymer, but have not yet been able to develop a technology for the production of threads and fabrics from it. The polymer itself is stable so that the parachute made from it can withstand the load and can safely deliver the cargo to the ground. If researchers succeed in creating strings from a polymer that can pass an electric current through themselves and “disappear” under its influence, then the process of “disappearance” of the entire parachute will take from 20 minutes to two hours. Details about the polymer are not disclosed [http://aviationweek.com].

Proven methods of destroying rocket blocks by undermining spacecraft in outer space are not applicable, as they create a cloud of debris that becomes space debris.

The closest technical solution in the IPC ⁷ B64G class, adopted as a prototype, is a method for cleaning near-Earth space from space objects and small particles by their destruction (patent No. RU 2204508 "Method for the destruction of fragments of space debris"). According to this method, to destroy fragments of space debris in near-Earth space create obstacles on the trajectory of its orbit. An obstacle is formed by the dispersion of fine particles, moreover, an explosive material is used as a particle material with a detonation velocity exceeding the velocity of collision with fragments of space debris. Hexogen with a density of 1.7 ... 1.8 g / cm ^{3 is} used as an explosive, and the characteristic particle size is at least 1.5 mm. The technical result in the implementation of the invention by this method is to increase the productivity of the method by exposing the fragment of space debris to the energy of an explosion of particles, in addition to the impact-kinetic effect. Obstacle - spatially distributed particles

(cloud) of explosives after their detonation with fragments of space debris are converted into gas, without increasing the total mass of the fragments.

The method according to patent No. RU 2204508 is selected as a prototype of the invention.

The disadvantages of the prototype method are the need to output a specialized spacecraft to remove space debris, as well as the consequences of the further spread of fragments resulting from microexplosions on the destructible object of space debris.

The essence of the invention lies in the fact that the elements of the spacecraft are made from materials selected in such a way that after performing their functions, they are transferred to the gaseous state using the sublimation of matter in space vacuum.

The launch of such processes leads to a reduction in the period of passive existence of the spacecraft with the possibility of its complete self-destruction.

Incomplete self-destruction of a spacecraft also gives a positive effect due to a significant reduction in its mass as space debris, which reduces the risk of collision with existing spacecraft.

A method for limiting the passive existence of a spacecraft in near-Earth space due to the transfer of its elements to a gaseous state after the end of the active life of a spacecraft is that the elements of the spacecraft are made of materials that have the property of sublimation under the influence of space factors, and after the end of the active life of the spacecraft activate the phase transition of comic elements pparata from solid to gaseous state, for chegosozdayut accelerated conditions sublimation of these elements, providing a loss of weight in the order given, not permitting the formation of debris and separating parts.

The implementation of the method consists in the fact that after the end of the active life of the spacecraft on the elements of the spacecraft, a film is removed that protects these elements from the influence of space factors, for example by electrochemical or thermal effects, and provide accelerated mass loss of these elements.

The implementation of the method consists in the fact that after the end of the active life of the spacecraft, the elements of the spacecraft are heated to the temperature of accelerated sublimation of these elements and supported to lose the mass of the elements due to the transition to the gaseous state.

A device for limiting the passive existence of a spacecraft includes a spacecraft control unit connected to a spacecraft self-destruction unit, in the memory of which a spacecraft destruction model is introduced with a program of the sequence and time of launch of activation mechanisms for transferring elements of the spacecraft into a gaseous state, electrically connected with launching mechanisms activation of accelerated sublimation of elements by mechanisms of triggering the heating of space elements spacecraft and associated with the active time counter of the spacecraft issuing a command for the self-destruction of the spacecraft after the end of a given resource, moreover, the space self-destruction unit

the device through the radio channel and the spacecraft control unit is connected to the ground control center to receive a command for self-destruction in case of emergency loss of the spacecraft’s performance.

The essence of the proposed method is illustrated by the following figures.

FIG. 1 - spacecraft element prepared for self-destruction.

FIG. 2 - removal of the protective film from an element of the spacecraft to activate its sublimation in space vacuum.

FIG. 3 - sublimation of the spacecraft element in space vacuum.

FIG. 4 - evaporation rates in vacuum of the most commonly used materials.

FIG. 5 - design temperatures corresponding to 10% loss of organic matter per year at p = 1.333 * 10 ^-4 Pa.

FIG. 6 is a graph of testing a sample of material in space vacuum.

FIG. 7 - a solar battery as an element of a spacecraft equipped for self-destruction.

FIG. 8 - spacecraft in working condition.

FIG. 9 - the inclusion of activation of the sublimation of the elements of the spacecraft of the first stage after the end of its active existence.

FIG. 10 - the remains of the spacecraft after the sublimation inclusion stage.

FIG. 11 - the inclusion of heating the remnants of the spacecraft to translate them into a gaseous state.

FIG. 12 - the final results of the self-destruction of the spacecraft.

FIG. 13 is a simplified diagram of a device for self-destruction of elements of a spacecraft in a space vacuum.

In FIG. 1 shows a section through an element of a spacecraft 1, which is made of material 2, which, along with the necessary structural properties, has the property of active sublimation under conditions of space vacuum. From the influence of space vacuum, the material is protected by a protective film 3. Under the protective film, a coating 4 is applied to the element of the spacecraft to destroy the protective film. When an electrochemical effect is applied when an electric current is connected from the source 5 using the control circuit 6, after the end of the active life of the spacecraft, a reaction starts that removes the protective film. During thermal destruction of the protective film, in another embodiment, the coating 4 is made of an energy-concentrated material, for example, a pyrotechnic composition - a mixture of fuel, oxidizer, cement and special impurities, which is triggered by electric current, and generates heat 7 sufficient to remove the protective film from the material 2 (Fig. 2).

As a result, the element of the spacecraft 2 after the end of its active existence self-destructs under the influence of cosmic vacuum and solar radiation, losing mass in the process of sublimation 8 (Fig. 3).

The rate of evaporation of a substance in vacuum G (in g / cm ² × s) is described by the Langmuir formula

,

,

where p _n is the saturated vapor pressure of a given substance, Pa;

μ is the molar mass of the substance, g / mol;

T is the temperature of the evaporating surface, K.

The formula is derived for absolute vacuum, so the actual rate of evaporation of matter in real outer space will be slightly lower than the calculated one.

For metals used as structural materials and coatings, graphs of calculated dependences of the evaporation rate log G, g \ cm ^2. s on temperature T K are shown in Fig. 4.

The graphs show that in the real temperature range (123-423 K), the metals used as structural materials of the spacecraft are quite resistant to evaporation in vacuum; cadmium and zinc have the least resistance.

Inorganic materials (ceramics), consisting of oxides and other compounds with low vapor pressure, suitable for prolonged use in outer space, are most difficult to self-destruct and require significant heat exposure based on explosives, such as, for example, tricyclic urea.

Organic materials, unlike metals, lose matter not only due to evaporation or sublimation from the surface, but also when exposed to ultraviolet radiation, mainly due to decomposition that occurs throughout the volume of the part or element.

The properties of some organic materials are shown in the table (Fig. 5). The calculated temperatures correspond to 10% loss of substance per year at p = 1.333 * 10 ^-4 Pa. A significant temperature range is explained by the difference in monomers, polymers, the presence of impurities and additives in polymers, especially the catalysts used in the polymerization.

Sublimation is reduced by applying protective films to the surface, for example, phosphating and oxidizing are used as coatings on both organic and inorganic substances, plastic coatings are metallized - they are coated with a layer of aluminum, sometimes gold. Of the protective films in the implementation of the proposed method, choose those that are technologically convenient to remove from the elements of the spacecraft.

In FIG. Figure 6 shows a graph of the mass loss of the material of the structural element M% when exposed to space vacuum over time t using the example of testing a laboratory sample in a vacuum chamber.

The curves in the graph show:

1 - loss of atmospheric gases sorbed by the material;

2 - loss of contaminants and (or) additives;

3 - losses due to evaporation (sublimation) of the material of the laboratory sample;

4 - the total mass loss of the laboratory sample of the material of the structural element under the influence of space vacuum.

F - the end of the exposure of the laboratory sample in space vacuum.

R - partial restoration of the mass of the laboratory sample after interaction with atmospheric air.

α, β - characteristics of the rate of the process of mass loss.

[M.D. Nusinov. The effect of space vacuum on materials and devices of scientific equipment. Scientific and Technical Society of Instrument-Making Industry Academician S.I. Vavilova. 1987.]

In FIG. 7 shows a section of a solar battery, where: a protective glass 9, a transparent adhesive 10, an antireflection coating 11, a pn region of a junction 12, a silicon wafer 13, metal contacts 14.

For self-destruction of the solar battery, a protective glass is selected from a material with the property of accelerated sublimation (for example, organic matter) and provide its protection during the period of working functioning and deprotection after the end of the active life.

For the constituent parts of the solar battery, heat-generating coatings are added, which ensure that when they are launched after the end of the active life period, these parts are transferred to the gaseous state not only during sublimation, but also when they are melted in a heated state.

In FIG. 8 shows a spacecraft 15 operating in an operational state during an active life.

In FIG. Figure 9 shows the process of transferring a spacecraft after the end of its active existence into a gaseous state when activating the activation of sublimation of elements of a spacecraft of the first stage. Areas of the beginning sublimation of materials of spacecraft elements are shown. In FIG. 10 shows the result of the self-destruction of elements of the spacecraft 15 after the first stage and the remaining parts of the structure and equipment of the spacecraft.

In FIG. 11 shows the ignition of fuel-generating coatings and the translation of the remaining elements of the spacecraft 15 into a gaseous state by heating these elements in accordance with a preset self-destruction program.

In FIG. 12 shows the final results of the self-destruction of the spacecraft, while not achieving its complete transfer to a gaseous state. To completely remove the danger of space debris, these residues are removed by other known methods. The resulting dust particles a few micrometers in size leave near-Earth space in accordance with the Poynting-Robertson effect. This is the process by which in the solar system dust particles slowly fall in a spiral towards the sun.

In FIG. 13 shows a simplified diagram of a device for implementing the proposed method. The control unit 19 of the spacecraft contains a program 20 of self-destruction of the spacecraft at a given time.

Program 20 provides, by means of electrical communication 21, after the end of the spacecraft’s active life through the control unit 19, a signal to activate the sublimation of spacecraft elements by triggering the removal of protective coatings from sublimation (solar panels - telecommunication a; spacecraft housing - telecommunication b) in the order not allowing the receipt of debris and separating parts, and then issuing a signal to turn on the heat-generating coatings (elements of the spacecraft - telecommunication in; app perature spacecraft - telecommunications g) and melting the remaining elements of the apparatus 16 and so that the weight loss was possible to complete the transition to the gaseous state in the vacuum space.

The self-destruction command can be received both from the memory of the control unit 19 in accordance with the laid down program 20, and from the ground control point 22 through the radio channel of the transceiver equipment 23 of the spacecraft with the antenna-feeder device 24. The backup device is an independent unit 25 of the resource counter, which issues a command for the self-destruction of the spacecraft according to the embedded value of the maximum period of functioning of the spacecraft.

The spacecraft’s self-destruction program includes a self-destruction model. It determines the sequence of self-destruction of elements of the spacecraft, in which the requirements of the Guidelines of the UN Committee on the Peaceful Uses of Outer Space for the Prevention of Space Debris are met. In accordance with them, the creation, formation of debris, parts, fragments separated from the spacecraft is not allowed.

The technical effect of using the method is to increase the efficiency of preventing technogenic clogging of near-Earth space due to the removal of spacecraft by the method of self-destruction in a given period of time by transferring them to a gaseous state.

Economic efficiency when using the method of self-destruction of a spacecraft after its use is ensured by reducing costs in comparison with analogue and prototype methods, since it does not require the launching of expensive spacecraft of space debris cleaners or directors of objects affecting space debris, as well as the use of laser systems for impact on space debris by ground means.

Claims (4)

1. A method of limiting the passive existence of a spacecraft in near-Earth space due to the transfer of its elements to a gaseous state after the end of the active life of a spacecraft, characterized in that the elements of the spacecraft are made of materials having the property of sublimation under the influence of outer space factors, moreover after the expiration of the active existence of the spacecraft, the phase transition of the space elements is activated pparata from solid to gaseous state, which creates conditions for rapid sublimation of these elements, ensuring their weight loss in a predetermined order that does not allow the formation of debris and separating parts. 2. The method according to p. 1, characterized in that after the expiration of the active existence of the spacecraft on the elements of the spacecraft remove the film that protects these elements from the influence of space factors, for example, by electrochemical exposure and provide accelerated mass loss of these elements. 3. The method according to p. 1, characterized in that after the end of the active life of the spacecraft, the elements of the spacecraft are heated to a temperature of accelerated sublimation of these elements and maintain it to lose the mass of the elements due to the transition to a gaseous state. 4. A device for limiting the passive existence of a spacecraft, characterized in that the spacecraft control unit is connected to a spacecraft self-destruction unit, in the memory of which a spacecraft destruction model is introduced with a program of the sequence and time of launch of activation mechanisms for transferring elements of the spacecraft into the gaseous state, electrically connected with mechanisms for triggering activation of accelerated sublimation of elements, mechanisms for triggering heating elements of the spacecraft and associated with the spacecraft active existence time counter, issuing a command to self-destroy the spacecraft after the end of the specified resource, and the self-destruction unit of the spacecraft through the radio channel and the spacecraft control unit is connected to the ground control center to receive a self-destruction command in case of emergency operation spacecraft.

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