That's just plain wrong. Energiya/Buran was a fundamentally different system from STS, and only had a superficially similar look, as the silhouette was the only

That's just plain wrong. Energiya/Buran was a fundamentally different system from STS, and only had a superficially similar look, as the silhouette was the only copied part to conform with party requirements. For one, the orbiter was a separate autonomous spacecraft with its own fuel tanks and the main engines, not an integral part of the launcher. It used LOX/RP1 - in orbit! - for both RCS and main engines, with larger dV budget as a result. The control system was absolutely different. Etc etc etc. The Buran design process is pretty well documented in general, and a lot was written about it. The original starting OS-120 concept was pretty much a verbatim copy of the layout and high-level decisions of the Shuttle (they didn't have the "NASA plans", they only had a layout and open data), but they a) realized they couldn't make the SRBs as they used liquid fuels for ICBMs and didn't have the production capability for such large diameter solid rockets, and b) their own additional requirements crept in. So the design evolved over time into an entirely different one. >NASA caught on (with help from CIA) and implanted falsified heat tile formulas, which the Soviets copied. Their first Buran only flew once and mostly burned up on reentry due to the bad heat tiles. The heat tiles used a different material, and it didn't burn up, so this makes little sense.