Soviet Origins of Stealth?

[Dilandu]

The inventor Stealth was called Viktor Tryschulkov. What Ufimtsev?! Solzhenitsyn writes - Tryschulkov.

Solzhenitsyn lies as his name suggest (rus. Solgat - to tell a lie, Lzhets - liar). The theory of stealth technology in USSR was indeed, developed by Ufimtsev in parallel with Lockheed works. Lockheed engineers actually used his book to check their own progress on ECHO-1 program. Soviet military did not took much interest in it, considering the efficient stealth to be outside of the available technology (and they actually were right - at that moment, of course).

The aforementioned "Viktor Tryshulyakov" seems to be a Solzhenitsyn own invention. He is not mentioned anywhere outside his books.

 

[Deleted member 12875]

Do you love Russia? Any priority of Russian discoveries is love for Russia. I understand Americans in comments. But if he writes Russian ... The invention of anti-radar technology in 1945-47 in the USSR is already interesting. Is it disgusting to you? Anti-Semites dislike Solzhenitsyn. This is a head-on question.

Good luck. It's all.

 

[Dilandu]

Any priority of Russian discoveries is love for Russia.

It's remind me of our old Russian anekdote:

"United Nations declared the year of elephant. All leading nations decided to publish a book about elephants.

Germans published the book titled "Elephants"

British published the book titled "Some facts about elephants"

French published the book titled "Elephants in the history of France"

And USSR published the book titled "Russia, as unquestioned motherland of all elephantkind...""

 

[Jemiba]

An interesting theme, and not started just as a personal opinion, but based on a book.
So far, so good, but there's no need to stray off into politics, or even personal attacks!
Please, stay on topic, answer the argument, not the poster, and everything will be fine here.

 

[Hobbes]

The excerpt merely says Tryshulyakov claimed to have found a way to absorb radar - and Tryshulyakov didn't give any details specific enough to allow Solzhenitsyn and colleagues to build a working sample, or even theorize how this would work.

I don't think you can call that an "invention of stealth technology". Tryshulyakov came up with an interesting theory, but didn't have a way to put it into practice. It would have required a series of experiments to find a material combination that worked, and evidently Tryshulyakov didn't get to that stage.

After the invention of radar, it'd be obvious to anyone working in this field that there should be a way to make aircraft invisible to radar, by either deflecting or absorbing the radar energy. A bunch of layers of partially-reflective materials is an obvious way to do this. So it's not surprising to me that an inventive Russian would think of this.

from Wikipedia:

The earliest forms of stealth coating were the materials called Sumpf and Schornsteinfeger, a coating used by the German navy during World War II for the snorkels (or periscopes) of submarines, to lower their reflectivity in the 20 cm radar band the Allies used. The material had a layered structure and was based on graphite particles and other semiconductive materials embedded in a rubber matrix. The material's efficiency was partially reduced by the action of sea water.

So by 1947 radar-absorbent materials had been used in combat. The difficulty with RAM was in finding a material that works well, and stands up to regular use.

Tryshulyakov's idea cannot be compared to the work Umfitsev did. Umfitsev developed a mathematical model that could be tested, and be applied to real-world objects. Lockheed built a tool on that model that made stealth practical, while at the same time Northrop was working on a more trial-and-error basis to find shapes that would deflect radar waves in desirable ways.

Tryshulyakov seems to have been one of the people who said "wouldn't it be nice if we were able to hide an aircraft from radar". Umfitsev's work made this practical.

 

[overscan (PaulMM)]

The inventor Stealth was called Viktor Tryschulkov. What Ufimtsev?! Solzhenitsyn writes - Tryschulkov.

Solzhenitsyn lies as his name suggest (rus. Solgat - to tell a lie, Lzhets - liar). The theory of stealth technology in USSR was indeed, developed by Ufimtsev in parallel with Lockheed works.

This is so far removed from reality...

In the 1960s Ufimtsev began developing a high-frequency asymptotic theory for predicting the scattering of electromagnetic waves from two-dimensional and three-dimensional objects.

He was solving a mathematical problem of describing how waves scatter. At no point was this anything to do with Stealth.Theoretical work.

His article was translated to English and attracted the attention of Denys Overholser at Lockheed, who realised he could use Ufimsev's work to help calculate the RCS of simple shapes with some accuracy. This was helpful in designing the first stealth aircraft.

Noone in the USSR seems to have taken any notice of Ufimtsev's work. Soviet stealth research came as a response to US work in this area, and was without any rigour or true understanding until the details of the F-117 were made public.

 

[Dilandu]

He was solving a mathematical problem of describing how waves scatter. At no point was this anything to do with Stealth.Theoretical work.

Agreed, and as I said -

The theory of stealth technology in USSR was indeed, developed by Ufimtsev

But I agree, I should said "the UNDERLYING theory beneath the stealth technology".

Noone in the USSR seems to have taken any notice of Ufimtsev's work. Soviet stealth research came as a response to US work in this area, and was without any rigour or true understanding until the details of the F-117 were made public.

That's true.

 

[overscan (PaulMM)]

Ufimtsev's theory is one of the parts of RCS modelling but far from "the underlying theory". If anything that is the 19th century Maxwell's equations.

 

[tequilashooter]

What's the underlying theory excluding one of the skunkworks engineers calling it a Rosetta stone of stealth?

Feeling cute, probably going to have both skunkwork engineer quotes for each post I make.

 

[overscan (PaulMM)]

The 'Rosetta Stone' idiom describes a keystone piece of information that unlocks a greater body of knowledge. That is accurate.

Ufimtsev's theory was the keystone piece of information that "unlocked" the ability for Lockheed to accurately predict radar cross sections of flat planes, which lead to the development of the F-117 at Lockheed.

Northrop managed to do a fairly good job on their XST without it, coming from a different angle, and in some respects Lockheed became enslaved by their breakthrough into sticking with faceted designs too long because they understood how to measure them.

You are also falling into the "great man" historical fallacy. Denys Overholser recognized a practical application of a piece of relatively arcane mathematics. Teams of engineers turned that into a workable body of engineering knowledge called "Stealth." Ufimtsev's work was important but it wasn't "how to design a stealth aircraft".

The US were working on Stealth aircraft well before Overholser found that report. If he hadn't most likely Northrop would have won and built their XST. History would unfold differently.

 

[icyplanetnhc (Steve)]

Northrop managed to do a fairly good job on their XST without it, coming from a different angle, and in some respects Lockheed became enslaved by their breakthrough into sticking with faceted designs too long because they understood how to measure them.

That is true, Lockheed's faceted designs lost to Northrop's curved shapes for the ATB (B-2) and the ATA (A-12), during the ATF RFI, Lockheed had a poor showing and was initially last out of the seven companies due to their commitment to faceting (it was more or less a tailed F-117 with afterburning engines). That was when they shifted away from faceting, but even their initial Configuration 090P submission for the RFP bore some resemblances to the F-117 in the forward fuselage, although Lockheed's first place ranking after the down-select was more due to their systems engineering and technology development efforts.

 

[Scar]

1) Ufimtsev didn't invent Stealth. His monography was about math methods of calculation the optimal shape of radioantennas to make them more effective in terms of gain. That's why it was openly published and has become available to LM/Skunks and gave them the idea to use this math not for the signal gain, but for its weakening.

2) There is a fundamental difference between the method of RCS reduction via EM-wave deflection - Stealth form; and its attenuation - Radiation-absorbent material or RAM.

3) RAM were widely known long before 1973.

 

[tequilashooter]

1) Ufimtsev didn't invent Stealth. His monography was about math methods of calculation the optimal shape of radioantennas to make them more effective in terms of gain. That's why it was openly published and has become available to LM/Skunks and gave them the idea to use this math not for the signal gain, but for its weakening.

2) There is a fundamental difference between the method of RCS reduction via EM-wave deflection - Stealth form; and its attenuation - Radiation-absorbent material or RAM.

3) RAM were widely known long before 1973.

Dont think Mindstorm from Russia defense would last much of a week here, but I will just re-iterate what he posted over there not to bring back bad memories, but if that someone had a response for mindstorm before leaving that forum(dont blame him I would be screwed continuing that arguement with him as well) as last being seen or what anyone elses thoughts are on what he said. His words not mine.

"That is completely false.

For one PTD has been much more fundamental for B2 Spirit program than for F-117; in facts ,as anyone can easily understand, capability to compute re-radiating cones both for shadow boundaries and caustic diffracting regions (where OTD mostly fail) was literally critical, above all for designs incorporating asymptotic curved edges, including the subsequent US fighter type designs.

As said by the same Kenneth Mitzner (the Northrop theoretical seminal and development mind, togheter with F. Oshiro, behind B-2 and Tacit Blue) B-2 program would have been practically impossible without the PTD:

"I cannot imagine the B-2 having been designed without the influence of his work," Dr. Mitzner added. "Let me put it this way: without Ufimtsev, today's stealth aircraft would probably have looked the way the speculative artists portrayed them, before their real shapes were publicly disclosed"
Also today the most advanced solution system of equations for computing diffraction fields generated by, so called, VLO and ULO aerodynamics objects are kept in Federation's Institutes, not US ones , with a theoretical understanding edge that in those decades even widened.
What US brands can instead surely boast is the large scale production mastering, with all the related making and maintenance engineering know-how cumulated, of similar complex LO vehicles.

The ridiculous story, likely created, from thin air, by part of some westener with very small knowledges and instead a very big grudge about the fact that this true "allowing" technology for all western stealth designs was coming from directly Soviet Institutes (a thing that deeply worry them......and at reason i can add) circulating about how the, supposedly, "less evolved" F-117 faceted design was created using PTD because of the limits in processign capabilities of computers of the times while the "most advanced" B-2 ,F-22 and F-35 designs has been created using different, unspecified, "US-developed theoretical basis" is a true offense to human intelligence.

П. Уфимцев works was deeply examined in two instances by two different Soviet military Scientific Commissions and rightly considered publicly releasable .
Hard radar data (in the latests years coming also from Syrian airspace control) most than 50 years later, give today perfect reason to the correctness of the scientific assessment of the time."

About instead its importance for, at the time, the over-ocean scientifical community of the field it WAS much more than merely what you define 'the book on stealth' (at least for western approach to aircraft designs with reduced area of dispersion in high frequency radar regimes) it was the true "Rosetta Stone breakthrough for stealth technology" as said directly by Ben Rich -the Director of the team at SkunkWorks charged to carry on the XST program-.

Whats OTD and PTD?

 

[Justo Miranda]

Based on a theoretical study published in 1962 by the Russian mathematician Pyotr Ufimtsev, Lockheed scientist William Schroeder concluded that a surface cut into facets such as diamonds could be used to reflect radar waves in all directions... except for the receiver. If the use of right-angle junctions was avoided, it would be possible to disperse 99 per cent of the incident electromagnetic energy.

In theory this physical principle could be useful to camouflage land vehicles and even warships, but its use in airplanes seemed impossible, it would have been necessary to re-write everything that was known about aerodynamics.

In 1975 a team of computer scientists from Lockheed, under the direction of Denys Overholser, created the "Echo-1" program capable of automatically determining the radar signature of any aircraft model.

Thanks to "Echo-1" Lockheed designers were able to create an aircraft, with sharply swept wings, capable of flying at high subsonic speed despite being fully covered with polygonal facets that avoided 90-degree corners.

The first prototype code named "Have Blue" made its first flight in the Area 51 test site on December 1, 1977.

Both the development and flight tests of the "Have Blue" were carried out under Special Access Programs (SAF) restrictions that override normal chains of command.

 

[Scar]

Again, Ufimtsev didn't invent Stealth. Stealth is a complex of methods to hide the object from the enemy sensors, while Ufimtsev developed his math apparatus to increase antennas effectiveness. But of course Ufimtsev's monography provided great help and influence to US works on Stealth technology.

It's like you can use one and the same math to make airliner or fighter or missile. Or you can use polyamide for car tires production(which polyamide fiber, better known as Kevlar was invented for, originally), or to make the armor for military use.

Nearly every technology is a double-edged blade, you can use to cut the bread...or throats.

 

[icyplanetnhc (Steve)]

PTD is the Physical Theory of Diffraction.

Northrop’s XST was developed without Ufimtsev’s work. Indeed, the first American engineer to take note of the translated work was Overholser of Lockheed, who created the Overholser calculator that was instrumental in developing the F-117. Although Northrop’s XST didn’t match the F-117 in X-band stealth, it had a wider low-RCS bandwidth, especially at lower frequencies. Subsequent stealth design efforts by Northrop, including Tacit Blue and ATB (B-2), did use Ufimtsev’s work.

Ufimtsev’s PTD publication no doubt has profound influence on the development of stealth aircraft, but it’s one of many breakthroughs that made it possible.

https://www.northropgrumman.com/wp-content/uploads/B-2-Spirit-of-Innovation.pdf

 

[overscan (PaulMM)]

Yes that's my point. No one is denying it is a very useful mathematical tool. Stealth was invented by American engineers, and one of the key tools they used was the Physical Theory of Diffraction (PTD) created by the Russian Ufimtsev. He deserves credit for his work, for enabling the work of others, but not for all the subsequent work other people did using it. The Stealth pioneers have always given him ample credit.

I also never said that the B-2 didn't use PTD. It absolutely did, its a great tool.

The Northrop XST didn't, but was still a basically viable Stealth design, my point being Stealth aircraft design is possible without PTD. Painful, but possible. But once you have the tool in your arsenal, you use it!

I'm also unsure why not believing that

The theory of stealth technology in USSR was indeed, developed by Ufimtsev in parallel with Lockheed works.

Makes me biased against Russia. Ufimtsev's PTD was published way earlier than the XST program. Parallel it is not. The Physical Theory of Diffraction was invented in the USSR years prior to "Lockheed works" on Stealth.

 

[quellish]

Ufimtsev's theory is one of the parts of RCS modelling but far from "the underlying theory". If anything that is the 19th century Maxwell's equations.

Ufimtsev's method only models the contribution of edges to scattering, not surfaces themselves. While important it is only part of the solution for predicting RCS.

 

[Archibald]

Ryan Model 154 / AQM-91 / COMPASS ARROW was semi-stealth... before stealth, and in ways different from SR-71 / D-21.
So there are probably different paths toward "stealth"...

 

[Scar]

Ryan Model 154 / AQM-91 / COMPASS ARROW was semi-stealth... before stealth, and in ways different from SR-71 / D-21.
So there are probably different paths toward "stealth"...

Every flying wing or blended body aircraft can be described as "semi-stealth". But this doesn't mean there is some other way, other than deflection and/or attenuation.