Plasma Stealth: Past & Present
Introduction:
It seems almost every post on ATS that deals with plasma stealth technology stems from questions someone has after browsing to Venik's "
Aeronautics.Ru" website. Venik has done a remarkable job of accumulating a plethera of good information and has
one of the best aviation/aerospace reference material websites on the web.
It is my hope that this will not turn into the usual bashing of Russian or American technology, but rather generate curiosity and investigation. It is obvious that both sides have good reasons to follow the paths that they have chosen.
Plasma: What is it?
Plasma is the most common state of matter in the universe, it can carry electric currents, neutral particles and magnetic fields that exhibit collective effects.
Various examples of plasma around us are flames, lightning, neon lights, the Aurora Borealis, the corona around the sun, etc.
Plasma has been described as a being more closely related to fluids by some physicists and related to gases by others. What it actually resembles depends mostly on the density/temperature and energy of the matter.
Plasma technology has been a part of aerospace research for decades. Ever since it was discovered that there were communications black outs when space capsules were re-entering the atmosphere it has been known that plasma negatively affected RF signals.
The Basics: Plasma Stealth theory
There are 3 ways that plasma stealth functions.
1. Plasma aids in the absorption of the radar signals. This occurs when electromagnetic waves (radar) encounter charged particles causing the wave's energy to be transferred to the charged particles, thus no reflection back to the radar source.
2. Electromagnetic waves have a tendency to bend around the plasma field thus passing around the aircraft. Most aerospace radar specialists will tell you that this effect is at best minimal in decreasing Radar Cross Section (RCS).
3. Plasma can disturb electromagnetic waves to the point of transforming them to differing frequencies scattered all across the RF spectrum, rendering the electromagnetic waves that encounter the plasma virtually useless.
Background: The 1999 ITAR-TASS Claim
In January of 1999 Nicolai Novichkov of ITAR-TASS conducted an interview with Anatoliy Korteev, the director of the Russian Scientific Academy. In this interview it was revealed that Russian scientists had made significant strides in stealth techniques involving plasma. The Russian scientist outlined his perspective on the differences between the American and Russian approach to stealth. These differences being that American stealth is based on Radar Absorbent Material (RAM) and Radar Absorbent Structure (RAS)... This process as scientist Anatoliy Korteev stated is expensive to develop as well as to deploy and takes away from the overall manueverability of the airframe.
The article went on to discuss the method in which the plasma would protect the airframe from being observed by radar;
"If an object is surrounded by a cloud of plasma, several phenomenas are observed when the cloud interacts with electromagnetic waves radiated by enemy radar..."
For clarification, this article stated that the entire airframe of the plane would have to be engulfed in the plasma cloud in order for this stealth technique to be effective.
And finally the article states that the technology was already in it's 3rd generation, the device supposedly weighed approximately 100 kilograms, required only a "few tens of kilowatts" of power, and the development of the 3rd generation system had allowed clearance of the 1st and 2nd generation versions for export.
(
Link to TASS article transcript)
Russian Plasma Stealth: How would it work?
Exactly how the Russian plasma stealth generator touted by TASS in 1999 would work
is still undisclosed.
There are a variety of possibilities of how it could have operated, including the following:
1. An electromagnetic field is generated - the downside however, is that such a field would be detectable by electronic sensors.
2. A corona source that continuous breaks down or a pulsing tesla coil - again however, this would produce an EM field and thus be detectable.
3. A plasma laser firing out in front of the aircraft.
A common problem with each of these possibilities is that they require a lot of space, are heavy and consume a large amount of power.
Ok, enough of the 1999 claim - Let's move forward to 2003...
Russian Plasma Stealth: Questions from experts...
Investigating the subject of Russian plasma stealth
as stated in the 1999 TASS article elicited many skeptical responses from the physicists, aerospace engineers and military specialists whom I interviewed.
As stated in the introduction of this article, it is not out of nationalistic American pride that these experts in the field question the validity of the Russian claim, nor is it closed mindedness of the technology itself (which is very viable)... it's the methodologies by which the Russian researchers claim to accomplish this.
* One specialist in the area of military arms sales for a US intelligence agency pointed out that it was 5 1/2 years ago in January 1999 that the Tass News Agency's article announced this technology was to be exported and as of yet there is no such product for sale on the world's arms markets.
* An aerospace engineer for a leading US fighter manufacturer questioned how this ionized gas envelope would interact with the airflow over the control surfaces at flight speed. Also he wondered if sharp, angled manuevering would shear off the ionization thus exposing the aircraft to enemy radar.
* A physicist from Lawrence Livermore National Laboratory had questions about how the aircraft's onboard systems would interact with a surrounding plasma field. For instance in order for the plasma field to be effective it would have to to be so powerful that the aircraft itself would have to be shielded from it's own stealth system. Would this mean that they would have to employ something similar to a Faraday cage? If so, then how much would this additional weight negatively affect the performance and manueverability of a fighter aircraft?
* A plasma physicist working on a DoD project pondered how the Russian researchers handled the issue of photon emissions - visual glowing from plasma sources can be tracked using CCD sensors. Additional she stated that an ion field is detectable and it would seem that plasma stealth would likewise be detectable... she was also quick to point out that anything that is detectable can be shot down.
The State of Russian Plasma Stealth today: There is no Russian Plasma Cloud Stealth
In 2003 the Institute for Theoretical and Applied Electromagnetics (ITAE) at the Russian Academy of Sciences in Moscow flight tested a "plasma-controlled screen" for the Su-35's remarkably large 0.889 meter radar dish... (which shows up like sore thumb on an air defense radar).
This "plasma screen" is mounted in front of the radar dish and behind the nose-cone of the fighter jet. It is supposedly similar to a plasma TV screen made up of cells or rastars filled with neon, xenon or some other inert gas which is excited by an electrical current, and when there is no current going to the unit it is completely transparent to the Su-35's radar.
In demonstration videos this Plasma Controlled Screen is seen as a luminous panel in front of the dish. It is said to absorb some of the opponent's radar signal, scattering much of the remainder in all different directions while at the same time transforming the scattered signals to frequencies all over the RF spectrum.
Word from the ITAE is that they have not developed a system for a whole airframe like the 1999 claim in Tass, which would use plasma-generating antennas to ionize the air flowing over the aircraft in fact, ITAE researchers expressed the view that application of the 1999 stealth method would be nearly impossible unless applied to a high-altitude, relatively slow aircraft, this is because the airstream would dissipate the plasma faster than it could be generated. (Janes Defense Weekly, 2003 - {Original not available online} -
Transcript of original article)
So there it is, the same group of scientists (ITAE) who in 1999 stated via ITAR-TASS news agency that they had a 100kg plasma stealth unit in it's 3rd generation, 4 years later tell Bill Sweetman of Janes Defense Weekly the system was problematic due to the dissipation of the plasma field was too rapid for a fast flying fighter aircraft.
The ITAE scientist now have a much more practical system which is greeted with absolutely no skepticism from military and academic R&D specialists in the US and Great Britain.
US Stealth: Is Plasma a Consideration?
I have seen posts here on ATS and around the internet where people have anxiously expressed a concern that the US is not embracing this technology.
Although there is certainly a difference in the schools of thought surrounding stealth between Russia and the US, it is apparent both countries have dabbled in the other's stealthy techniques.
The Russians for instance are incorporating radar absorbing composites (RAM) as well as limited radar deflecting structural design (RAS) into their newest fighter designs... and then there is the Russian Tu-180, a flying wing bomber similar to the B-2 which a spokesman for Tupolev claims was flying before the US's B-2.
But what of US interest in plasma stealth?
We know the research is there...
In a 1998 article entitled "Are Plasmas Already Out There?", Janes Defense Weekly makes the suggestion that the US has plasma stealth technology already and that it may go hand in hand with electrostatic technology that decreases drag on aircraft.
Janes Defense Weekly, on June 17, 1998 - page 8
Janes also referred to a 1968 "Aviation Week" article which said the US had been researching the phenomenon related to plasma and aeronautics - this was a non-specific reference to Northrop's 1968 tech paper titled "Electroaerodynamics in Supersonic Flow".
What is known about American military research on plasma stealth seems to revolve around cold-plasma projects. Rob Barker, Program Manager for plasma research at the USAF's Scientific Research Office in Virginia has been funding low-temperature plasma research by a specialist named
Dr. Mounir Laroussi since 1996.
These current US Military/USAF research projects concerning �cold plasma� (most of which are classified) involve concepts using the air temperature ionized gas as; 1. a decontaminant for biological warfare, 2. protective shielding around sensitive electronic devices, 3. shielding from direct energy weapons (specifically microwave weapons) and as 4. a radar absorbing stealth technique.
Concluding Thoughts:
While writing this post, I interviewed some pretty impressive individuals in their respective fields, some of whom I really did not think I would get an audience with at all. I also had a rare opportunity to speak with an aerospace engineer for the Russian Aircraft Corporation (MiG) who was here in the US with a group touring a few major American aerospace companies.
The engineer from Russia did not consider the technology of a plasma cloud surrounding an aircraft to be ready to exit R&D and go into deployment for many years to come - and suggested that there are more expedient methods, not nearly as radical nor as potentially stealthy but are closer to deployment.
He had some interesting things to say - some of which included his compelling and well thought-out belief that the US also has plasma stealth... but that is for another post.
I will end this post with a quote by this Russian engineer named Vladimir...
"In Russia we are realists... we develop air defense that we hope can see a B-2, F-117 or F-22 in time to get off a shot, but there are many unknowns concerning these aircraft, including the F-117 simply because it has been upgraded since one was shot down over the Balkans, so we don't rest - we keep on improving.
"I tell you this not as one who is marketing a product, but as one who considers that his country's survival rests on it's ability to counter the US's capabilities... particularly in a technical sense. Again I stress not to counter the US... just it's capabilities. We Russians do not consider the US an enemy, but it would be irresponsible on our part to not be vigilant with the convolluted geopolitics in today's world."
Plasma Stealth: Past & Present, page 1
Active/Plasma Stealth Technology
Explanation of what is Plasma Stealth Technology and how it works
Couple of things to keep in mind: plasma is ionized gas particles. Therefore, plasma flow is a flow of ionized gas particles. Ion is an electrically charged particle or group of atoms. Plasma cloud is a quasineutral (total electrical charge is zero) collection of free charged particles. The vast majority of matter in the universe exists in plasma state. Near the Earth plasma can be found in the form of solar wind, magnetosphere and ionosphere. The main property of plasma (for our purposes) is its frequency, which is equal to a square root of a ratio of 4 * Pi * square of ion charge * concentration of ions to the mass of ion:
SQRT ( (4 * Pi * n * e^2) / m ),
where e is electron or ion charge, n is concentration of ions per volume of plasma and m is mass of ion.
There are several types of oscillations in plasma: low frequency (ion-sound waves), high frequency (oscillations of electrons relative to ions), spiral waves (in the presence of a magnetic field - "magnetosound"), and cross waves propagating along a magnetic field. A device for generating plasma is called
plasmatron. This device generates the so-called low-temperature plasma.
Russian Academy of Sciences recently revealed information about a novel "stealth" technology, that incorporates plasma fields. Russian ITAR/TASS news agency recently interviewed the director of the Keldysh Research Center (FKA Scientific Research Institute for Thermal Processes), Academician Anatoliy Koroteyev, who briefly summarized capabilities of plasma stealth system developed by his research center and the current status of the project. You can read the entire ITAR/TASS article in
Russian or in
English (
external link.) An interesting fact: Keldysh Research Center operates a unique plasma wind tunnel for analyzing propagation of electromagnetic waves in the vicinity of a spacecraft as well as for testing of antenna inserts and ion thrusters. Detailed info about Keldysh Research Center
here.
First, I would like to assure people with high school physics background that, at least in theory, the system, described by Academician Koroteyev, is perfectly valid. Interactions between various types of electromagnetic radiation and plasma fields were studied for many years in Russia, the United States and around the world. Among recent achievement in this area is a "plasma stealth" antenna developed by the US Navy for use on LO aircraft. The system employs a U-shaped glass tube filled with low-pressure gas (something like a fluorescent tube). This antenna is energized and acts as a highly-directional, electronically steered transmitter/receiver. When de-energized, the antenna is virtually transparent to hostile electromagnetic signals. One of the problems with such a system is its vulnerability to resonant signals. For more information click
here.
The system developed by the Russians is also based on electromagnetic wave-plasma interactions, but in a very different way. Russian stealth plasma device creates a plasma field around an aircraft. This field partially consumes electromagnetic energy of a hostile radar or causes it to bend around the aircraft, reducing the aircraft RCS by up to 100 times. Sounds fantastic? Not really: effects of dissipation and bending of electromagnetic signals in presence of plasma field have been observed for decades. If there is anything new about the system developed by the Russians it certainly is not the theoretical part but technical aspects of the plasma generator. Keldysh Research Center claims to have developed, built and tested a plasma shield generator that weighs only 100 kg.
Microwave-induced plasma "air spike"
The idea of creating a plasma field around an aircraft is not a new one either. Such a possibility was thoroughly studied by both Russians and Americans. This was done for very different reasons, however. Aircraft designers want to use a plasma shield generator on hypersonic aircraft. In this application, plasma may be generated by a powerful plasma laser and will act as a heat shield for an aircraft. There are plans to use such a system in conjunction with a magnetohydrodynamic (MHD) propulsion to achieve velocities up to Mach 50. For more information click
here or
here. This is truly unbelievable, but even this theoretically and technologically is perfectly possible. It is not known whether the plasma stealth system developed by the Russians employs a plasma laser or some other method for creating a plasma field. My personal opinion is that it has nothing to do with a plasma laser (which is a very large and very power-hungry device.)
Deep Space 1 satellite
Plasma physics was given priority in Russia many years ago, which resulted in a number of breakthroughs in theory as well as practical applications of plasma. Perhaps one of the most interesting and promising applications of plasma is the so-called
ion thruster, used to propel spacecraft. This technology was first developed in Russia (mainly by Keldysh Research Center) and recently successfully used on an American satellite
Deep Space 1. The system uses xenon gas as fuel and can achieve exhaust velocities of up to 30 km/sec (ten times that of an average rocket engine.) Wouldn't you like to understand how this ion drive really works? You go back to college or follow
this link to MSNBC excellent interactive "Ion Drive" guide. Interesting to note that first such "ion thrusters" were developed in USSR and used on Soviet spacecraft almost 30 years ago.
Active - Plasma Stealth Technology
