Petr Levochkin, chief designer of NPO “Energomash, designer and manufacturer of the famous “RD-180” family of engines, commented on the PR statement of Elon Musk about the “superiority” of “Raptor” engine, created by SpaceX:

“The SpaceX company creates the “Raptor” engine on oxygen and methane components or, as is customary in the Russian classification, the gas-gas scheme.

In such schemes, such a pressure level in the combustion chamber is not something extraordinary – in our designs for these schemes we lay down the pressure level in the chamber over 300 atmospheres.

And the parameter pressure in the chamber is not the output characteristic of the engine, such as thrust and specific impulse.

However, Mr. Musk, not being a technical specialist, does not take into account that the “RD-180” engine for the Atlas launch vehicle uses a completely different fuel circuit – “oxygen-kerosene”, and these are another parameters of the engine operation.

It is like comparing a diesel and a gasoline internal combustion engine.

And if we take into account the fact, that “Energomash” certified the engine with a 10% reserve, then the pressure in the “RD-180” combustion chamber is above 280 atmospheres.

Despite the fact, that our companies are competitors, we as engineers welcome the first successes of colleagues from SpaceX in the field of rocket engine building.

Indeed, during the development of the Raptor engine, American engineers reached a record pressure level in the chamber.

This indicates a fairly high level of development and production processes at SpaceX. ”