The victory over the plasma - a new method for communicating with the spacecraft
Fürchte nicht schwere Arbeit, fürchte leere Reden.
Das ist unmöglich! But they did it. The Germans managed to conquer plasma deafness, dumbness and, probably, blindness to the heap.
Much has been written and debated on TopWar about plasma, hypersound and radio opacity for falling warheads. On the "Plasmostels of the USSR", however, there were also hot battles:
Plasma "stealth" - our response to the American "invisible".
US seeks to accelerate the development of hypersonic weapons.
Warhead: what's inside and how it works after separation from the rocket.
Plasma in military science. Projects and prospects.
Sometimes both articles and battles reached the point of absurdity.
Preface, which will take almost 2 / 3 articles. But it is necessary. No other way.
In the conditions of spacecraft entry into the atmosphere at hypersonic speeds, a huge amount of heat is released, which not only places high demands on thermal loads on the materials of the descent vehicle, but also leads to the formation of plasma around the SKA. This blocks (or rather, distorts) radio signals - as a result, the spacecraft is unable to communicate with its ground stations for several minutes.
The task of ensuring stable radio communications with descending spacecraft is very acute.
The task is also no less urgent in the military aspect: the CWSU of hypersonic missiles and ICBM warheads. For example, for:
3М-22 (“Zircon”) / in the photo demo BrahMos-II, but it is unlikely that 3М-22 will be different.
Object 4202 (Yu-71) (This is how Comrade Korotchenko represents it).
Or as it is presented by the Washington Times:
Radiolocation and radio communication through “such” plasma do not work: the total power of electromagnetic energy losses and radio noise radiation almost completely determine the reduction of the energy potential of the communication radio channel as a whole, increase significantly and predetermine the loss of radio communication on the descent trajectory.
The phenomenon of communication breakdown at the entrance to the atmosphere was discovered during the project “Mercury”, and then the programs “Gemini” and “Apollo”. It manifests itself at a height of decline of about 90 kilometers and to the mark of 40 kilometers - as a result of the rapid heating of the surface of a capsule falling in the atmosphere, a cloud-plasma film forms on its surface, acting as a kind of electromagnetic screen.
The effect is called (not officially) Radio Silence During Fiery Re-Entry.
At the end of film "Apollo-13"In which the failed lunar mission with three astronauts aboard it is presented, the spectators experience tensions related to the entrance of the spacecraft into the earth’s atmosphere. It was at that moment that the connection with the ship was interrupted, and flight operators in Houston America began to nervously smoke in those endlessly long and painful seconds. At this point, the spacecraft enters the atmosphere at the second cosmic velocity, which leads to its environment surrounded by hot ionized air, as a result of which communication with the Earth is interrupted.
To make it clearer, I will present the video of the entry into the atmosphere of SKA Soyuz TMA-13M:
As the most relevant example, the loss of communication and telemetry during test launches of the USAF X-51A Scramjet.
Hu from this "plasma" and where does it come from? I offer homemade preparations:
1. The option proposed by my counterpart, dear zholdosh (Kyrgyz language used - I did not swear, do not need a ban) OPERATOR (spelling and style are preserved):
Do not confuse the gift of God - TOKAMAK with fried eggs, flying at speeds above 5 M (1,5 km / s). Plasma formed around it due to shock dissociation of air molecules...
in the discussion of the article: On the beginning of sea trials of Zircon hypersonic rockets
This is not entirely true, but acceptable. In fact, everything is more complicated.
2. My option (not the fact that this is absolute knowledge):
- "natural" ionization of atmospheric air.
The figure shows the resulting values of the equilibrium electron concentration (electron / cm ^ 3) depending on the altitude and velocity of the spacecraft entering the atmosphere;
-modulation of the entrance to the atmosphere, the angles of pitch and yaw (plasma "fonit" the bottom or fairing, or all of its parts (important for the item marked with *)), depending on the density (height) of the medium, the flow modes of the body gas change;
- shock wave, distance of waste and its form, heat exchange in the boundary layer, influence of whether thermal diffusion (individual components diffuse and enter into chemical reactions or not);
aerodynamic boundary layer serves as a source of energy transmitted to the surface of the apparatus during entry into the atmosphere (movement in it)
-type of thermal protection apparatus (*): heat accumulator or heat protection by ablation of mass (ablation);
during ablation a cocktail is generally obtained, since not only air molecules, but also molecules / atoms (ions, electrons) of heat protection are involved in plasma formation.
Liquid (**), which is obtained by heating and evaporation of the HRC, i.e. a melt of thermal protection flows (literally) over the surface of a hypersonic device (warhead).
photons knock electrons from molecules and atoms of the air and the apparatus itself (its thermal protection).
Yes, yes: at such energies and temperatures, quanta of light rip off electron clouds from the "building blocks" of matter), see [1]
- the magnetohydrodynamic effect on the plasma during hypersonic flow around the body and its effect on the plasma "skin" and heat and mass transfer in the shock and in the boundary layer [2];
- electrified bodies, induced electric fields *** on charges and even electrolysis (see **);
examples:
+ electrolyte and charge migration from the anode to the cathode;
+ a ball that sticks to the wall, if you rub it on the scalp (if bald, you can rub it on someone else's). And the wall is not electrified, it is neutral. However, "sticks"!
My son comes running home and says:
I want to show you the focus.
He takes a piece of paper, tears it into small pieces, pulls out his pen and rubs against his hair.
And then what happened, I think you guessed it ...
- discharges in supersonic flow;
and much more.
Perhaps I will finish and return to our "sheep". Which option to choose (operator or mine) - decide for yourself.
Remember only this picture *** (it is useful):
What is this harmful plasma interferes with radio waves and radar?
After all, plasma is seemingly "ionized quasineutral gas"! Gas, but not the gas.
- the antenna, simply speaking, is burning, and the antenna window (AO) can also burn through or change its dielectric constant.
We look at antennas SKA "East". All of these antennae will simply burn, starting at a height of 130 km.
- plasma electron density is constantly changing, the dielectric constant of the ionized gas is less than unity and depends on the frequency of oscillations.
- the larger the angle of incidence of the wave on the plasma, the greater the electron density is required for reflection and the greater the reflection occurs.
-phase and group propagation velocity of radio waves. If the operating frequency approaches the natural frequency of the ionized gas (ω → ω0), the group velocity decreases (υгр → 0), and the phase velocity increases sharply (υф → ∞). Wave energy loss.
- the total speed of the electron motion is the sum of the speed of the thermal motion uт and the speed acquired under the action of the electric field of the passing wave uЕ, and usually uт> uЕ.
If someone, after reading this poem, didn’t run to sign up for the “Teacher of Applied Physics” courses ... So, I wasted my time and your time in vain.
There have been several attempts to solve this problem:
1. Soviet approach (implemented).
- Low-directional microwave emitters of on-board antennas with heated heat shielding and material melt on thermal protection.
- On-board antennas with thermal protection, the original design of which has a reduced sensitivity of its radio transparency to the effects of high-temperature aerodynamic heating.
- Methods of radio lighting AO for the conditions of aerodynamic heating, providing a reduction of losses in the heated AO.
- The use of "long" heat-resistant antennas taken out of the plasma membrane film.
—Increased EFFICIENCY OF THE OPERATION RADIO ENGINEERING COMMUNICATION SYSTEMS OF RETURNED SPACE APPARATUS
- Due to the imposition of a constant electric field on the radiating surface of an AO, in this case there occurs a redistribution of charge in the melt on the surface of thermal protection, which leads to a decrease in losses in it, and hence to the enlightenment of the AO.
- Due to the supply of refrigerant through the porous heat shield to its surface, this results in a decrease in the temperature of the radiating surface of the AO to a temperature below the melting point.
-And also passive principle- it is the construction of heat protection from the combination of materials with different melting points, which leads to a redistribution of the temperature field over the surface of the heat protection and provides increased radio transparency on the SKA (warhead) part.
But the problem of passing an EMW (without loss and distortion) through such a "restless" plasma remains. And it is important not only for the SKA, but also at the launch of rockets and launch vehicles. RD torch - the same powerful plasma generator.
Telemetry is needed (the PMU always wants to know “What, Where, When?”), And radio control is used by many.
I will not upload photos and drawings here for obvious reasons, just to give one example: the 53Т6 interceptor (SH-08 / ABM-3A GAZELLE, Gazelle) PRO Am-135 "Amur".
The radio command control system, the defendant and the autopilot on board, the transfer of guidance commands and other commands occurs via the command transfer station (SEC) channel.
Antenna receiver commands and the respondent are located in pairs on 2 pcs. on the body of the rocket, the shielding of the antennas from the plasma arising from the flight of the rocket in the atmosphere occurs by the injection of freon or a liquid similar in its properties.
However, the OPERATOR again said better and clearer to me (style and spelling preserved):
Freon jet forms a gas non-plasma channel to maintain the radio command line between the point of guidance and the rocket. In the event of a missile leaving the radio horizon, it drops speed to 5M to ensure homing with on-board radar
.2. Chinese approach (draft)
- Amplification of the signal, which can be created by resonance, or coordinated electromagnetic oscillations, between the plasma shell and the surrounding, aircraft, a special layer. Scientists of the Celestial Empire propose to add a “matching layer” to create the necessary resonant conditions during a normal hypersonic flight.
It is assumed that the matching layer will work as a capacitor in a conventional electrical circuit. The plasma shell, on the other hand, acts as an inductor that prevents changes in the electrical current passing through it. When the capacitor and the inductor are connected together, they can form a resonant circuit.
As soon as resonance is reached, the energy will begin to circulate stably between the plasma and the matching layer, as in the case of conventional capacitance and inductance in an electrical circuit. As a result, the incoming radio signal from the Earth can spread through the matching layer and the plasma envelope, as if they do not exist.
The Chinese are tormented by similar problems as Houston:
Note: for effective operation of this approach, the thickness of the matching layer and the plasma shell must be less than the length of the electromagnetic waves used for communication with the aircraft. As a consequence: the proposed method will not workif the frequency range of the antennas is too high (as currently).
3. American approach
In the era of the Space Shuttle, the problem was partially solved using the reusable craft form. Its aerodynamic design gave rise to areas with a lower plasma flow density, which allows limited communication: the descent module - PCO in some parts of the trajectory.
Note: factors such as the angle of entry of the descent vehicle into the atmosphere, its speed (usually Mach 20-25), and its aerodynamic shape affect the density of the flow of ionized gas.
Again, I propose to watch the video: NASA Shuttle Endeavor Re-Entry Video (good recording):
Well, by "sly" we finally got to the most important thing for which this article was written:
4. Teutonic approach
The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) together with researchers from Stanford University (Stanford University in California) conducted at the beginning of 2016 fairly successful tests of the technology, which in the future will save astronauts from a communication breakdown when entering the atmosphere and may provide for the operation of on-board GOS locators for hypersonic missiles or warheads.
What did these heirs do Heinrich Hertz?
They combined the Soviet and Chinese approaches 2 to 1 (as shampoo and rinse), with their know-how.
In January, 2016, a joint startup conducted experiments with positive results.
A wind tunnel of supersonic and hyper-sound technologies was used for the tests. Department of DLR at the Institute of Aerodynamics and Technology Flow in Cologne and arc heater high power to create a plasma.
The actual test conditions were recreated based on the mathematical models of American scientists from Stanford University, led by Siddarth Krishnamoorthy. A test device (simulator of a descent vehicle) consisting of a heat shield and a transmitting heat-resistant radio device (transmitter) was exposed to a plasma stream heated to several thousand degrees.
An antenna for receiving radio signals was installed outside the hot gas stream.
The essence of the idea: in the immediate vicinity of the transmitter antenna, a negative field (minus) is generated, which repels the ionized plasma flow (negative ions and electrons). The result is a window in the plasma cocoon for transmitting and receiving radio signals.
The field is generated like this (this is a scheme from another product, but the essence is the same):
You can also use a capacitor, when it is charged with direct current, a positive charge appears on one of the plates, a negative charge appears on the other:
This window cannot exist open for a long time, because:
- The plasma film is not stationary relative to the object due to the high flow rates and other thermo-gas-dynamic processes described above:
“There are positively charged ions in the plasma, which with great pleasure will be attracted to the negative field generator.
The behavior of ions and electrons (the picture is not from this process, but perfectly explains the phenomenon):
Therefore, the field is pulsed, the voltage is generated with a frequency of every few milliseconds.
This interval is sufficient to ensure the transmission and reception of data.
From the photos it can be seen that the thoughtful Germans do not create AO on the head fairing or in the tail of the aircraft, and pick in the "thinnest" place: perpendicular to the longitudinal axis of the device somewhere on 1 / 3 from the beginning of the body.
I haven’t received any answers from them yet (but I received an invitation to visit and “talk heart to heart over a glass of tea” on this topic), but I can assume the following:
1. At this point, the thinnest layer of the plasma "skin".
2. Trying to break through the plasma on the very fairing (end) - is meaningless. There is not enough strength or health. There is the most terrible place: shock waves, ions (protons) and electrons are born, ablation goes on, HRC turns into liquid, which partially evaporates, partially flows further (in its liquid matters).
In general: anomaly, and continuous.
Again I will quote the Operator that I really liked:
Do not confuse the gift of God - TOKAMAK with fried eggs, flying at speeds above 5 M (1,5 km / s)
3. In the tail of the SA (at the butt end) it is also meaningless: there is a very long trace-tail.
Bottom vacuum, mix of turbulent-laminar flow, tearing, collapsing. Plasma cavitation in one word: something like washing clothes in a washing machine during its maximum burbulization.
Here, only my assumptions based on (**), (***) and the postulates above, where I nudil about the properties of the plasma: plasma (ions and electrons) is generated on the fairing (terminations), then the ions as heavy and, probably, due to the electrification of the skin of the apparatus or the electrolyte from the ablative isolation, or due to the gas-dynamic pressure of the medium, they migrate to the tail of the SKA.
And electrons, as more nimble and light, and probably due to electrification of the skin, like those cunning migrants in the EEC, occupy "warm" places along the body of the apparatus.
At the same time, the plasma (cocoon around the apparatus) as a whole remains neutral and, of course, "quasi".
In this "weakest link", the Germans use their negative gun by punching the antenna window in the plasma layer (well, like our freon injection on 53Т6). As soon as the potential changes strongly, ions with a positive charge running from the "front end" tend to fill this window, to a negative field and do not want to exfiltrate naturally into the bottom area (into the burbulyator), the window collapses, the field turns off, everything returns to stability and rest . Next impulse.
Until now, the radio communication method through the plasma shell using a pulsed electric field was developed only in numerical simulation.
Americans and us, and:
Note I am very sorry that we did not muddied this topic with the Germans.
They murdered us (the Stuttgart Institute for the Study of Design and Design Technology and the German Aerospace Center) with the EXEPRET project. But traded on the Americans .....
Krishnamurti himself impressed with the simplicity and speed of cooperation:
After three months, we had the opportunity to test our methodology in practice and at the same time obtained the available data and developments from the DLR in this area.
Ali Gulhan, Head of Supersonic and Hypersonic Technology, has an equally positive view:
Collaboration between the DLR and Stanford University is an ideal basis for solving the problem of communication failure with the descent capsule.
Radio communication technology will be further improved and adapted for use not only in new, but also in existing spacecraft.
By my ugly character, I will not restrain myself and throwing a pebble (or rather a whole grid of cobblestones for a couple of pudikas) in their direction:
Why are the Americans climbed to the Germans? I will explain.
1. VAT in Germany 19%, in America it is not. JiсIt is cheaper in the states, and there are still all sorts of taxes. And the euro is still more expensive than $. Computational capabilities of USA are not comparable with German ones.
Everything: big mage, gasoline, accommodation and food - cheaper in the US, significantly.
And transportation costs? Shook across the Atlantic!
2. Wind tunnels in the United States just heaps, including manipulating hypersound.
Any color and size.
3.Germany, in general, is not a leader in spacecraft, space communications and hypersonic weapons.
"I am again tormented by vague doubts"
If what has been achieved to be realized, then the problem of communication with the descent vehicle, reusable shuttle (MKTS), the launching rocket is solved (no matter the RN or a radio-guided missile interceptor).
And what are the broad prospects for ARGS 3М-22 (“Zircon”) and / or 4202 Object (U-71)?
Yes, it will not be a typical RLGSN, but let's say a SIDE REVIEW RLS with APERTURE SYNTHESIS:
What a great opportunity to tie the flight path to the terrain (analogs of TERCOM / DSMAC)!
And the transfer of data on the new target (target designation / redirection for RCC)?
Or a signal to retake the target or self-destruct the combat unit?
Afterword:
- All data I have taken from open sources, i.e. no need to run anywhere and report to anyone.
- Regarding the discussion with NEXUS about the Soviet Stealth sucked from the book "The broken sword of the empire" M. Kalashnikov, I would like to separately obmusolit the question of the Tu-160 ...
But! But Sergey Ivanovich (SSI) is still silent, but I would not want to fall under the distribution.
- Voyaka uh, corporal and the rest, you excuse me, but to break this article, as you recommended to me in
Rocket Fuel SagaIt seemed to me politically incorrect. The meaning and "connection of generations" is lost, so to speak.
“Hopefully, at least someone has passed his time over a bottle of tea and probably got something useful.”
Some terms
Original sources, as well as used documents, photos and videos:
-Improve the efficiency of the operation of onboard radio-technical communication systems of descent cosmic vehicles (thesis and author's abstract on HAC 05.12.07, Candidate of Technical Sciences Cordero, Liborio)
[1] "Kinetic theory of plasma and gas. Interaction of high-power laser pulses with a plasma", 2006, Kosyrev I.N.
[2] EXPERIMENTAL INVESTIGATION OF LOCAL MAGNETIC AND HYDRODYNAMIC EXPOSURE
ON SHOCK-WAVE STRUCTURE OF THE AIR FLOW UNDER THE HYPERSOUND CIRCUIT OF THE BODY, Yadrenkin MA
Numerical simulation of plasma on supercomputer systems,
Author S. I. Bastrakov, A. A. Gonoskov, R. V. Donchenko, E. S. Efimenko, A. V. Korzhimanov, I. B. Meerov
Das Ende der Funkstille - Windkanaltests simulieren neue Methode zur Kommunikation von Raumfahrzeugen
Abteilung „Über- und Hyperschalltechnologien“ (AS-HYP)
Versenden Drucken Institut für Aerodynamik und Strömungstechnik (IAS)
"Supersonic plasma aerodynamics" Department of Physical Electronics. Phys.
Martin J. Entrance to the atmosphere. Introduction to theory and practice / J. Martin. - M.: World, 1969.
"Spacecraft descent and thermal protection of spacecraft" (www.forums.airbase.ru)
The propagation of radio waves. Training manual for radio. specialist. universities. Ed. 2, pererabot. and add. M., "Higher School", 1975. Grudinskaya G. P.
Materials Stanford University (Stanford University)
Materials of the German Aerospace Center (DLR)
www.universetoday.com
www.militaryrussia.ru
www.space.com
www.wikipedia.org
www.nlo-mir.ru
www.24space.ru
www.nasa.gov
www.youtube.com
www.militaryrussia.ru
sahallin.livejournal.com/44379.html
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