It was not the lack of funds but a lack of understanding of the ability of turning the Ufimtsev’s work into a practical air vehicle. For example the USSR had the funds to develop the MiG-29 and the Su-27 both of which first flew in (1977) the same year as the Have Blue project and went operational one year before the F-117. In addition Ufmtsev’s work was specifically associated with antenna development and not radar signature reduction. So there is no indication that the Soviets were close to understanding low signature technology at the time of the F-117’s development. If there was any understanding that Ufmtsev's work had practical military applications his paper would have been highly classified.
"In Rich's own words, the unsung hero of Lockheed's effort was an anonymous staff mathematician and electrical engineer named Denys Overholser. Overholser and his mentor, another mathematician named Bill Schroeder, had discussed the possibilities of utilizing some of the equations associated with optical scattering (how electromagnetic waves bounce off variously shaped objects) on this project. Both had the rather odd hobby of reading obscure Russian mathematics papers and had made the ultimate "nerd's nerd" discovery. They had stumbled across a paper published in Moscow a decade earlier titled "Method of Edge Waves in the Physical Theory of Diffraction." It had been written by Pyotr Ufimtsev, the Soviet's chief scientist at the Moscow Institute of Radio Engineering and the last in a long line of scientists developing a long series of wave equations originally derived centuries ago by the Scottish physicist James Clerk Maxwell.
The U.S. intelligence community had helped translate this research and brought it to the West. The paper was in no way classified or related to weapons development at all. It was purely theoretical math.
Years later, Ufimtsev immigrated to the United States to teach at the University of California, Los Angeles, and only then discovered his inadvertent contribution to the development of stealth aircraft.
The equations that Ufimtsev had developed made the reflections of radio waves off hard surfaces predictable. Not invisible, transparent, or tactical in any way-just predictable. The problem for Lockheed was that the calculations were so ferociously difficult that the most advanced supercomputers in the world at the time could only compute results for flat surfaces. Any attempt to perform the calculations for the curved surfaces you would find on a conventional aircraft-well, those machines would still be grinding away toward a solution today.
Schroeder recognized how these equations could be applied to Lockheed's current project. The solution was not even to attempt to design an aircraft with any curved surfaces, but to build one with dozens, or perhaps hundreds, of individual flat triangular and rectangular plates. Then the challenge was to compute the reflection from each and every flat surface before adding them all together to build a picture of the aircraft's total radar signature. Once you knew where every bit of radar reflection was coming from, you could then reorient those individual plates so that the reflection would go off in a direction away from the radar looking at it."
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