The reliable and relatively cheap RD-180 engine is designed by a Russian research and development company especially for the US Atlas carrier rockets, but there are reportedly plans to put them to use in the production of Russian super-heavy rockets.
The head of SpaceX Elon Musk has praised the RD-180’s engine, designed and manufactured by Russia’s NPO Energomash and used on the American booster Atlas V, noting though that the need to exploit it is “embarrassing:”
The Russian-designed liquid-fuel rocket engine RD-180 powers the first stage of the American rocket carrier Atlas V. As many as 85 flights of rockets powered by the engine have been conducted to date.
After US-Russia relations deteriorated over the Crimean issue in 2014, US lawmakers slapped limits on would-be RD-180 purchases, passing a law that required the US to phase out the Russian-made engines in favour of domestically produced next-generation rocket propulsion systems.
However, the following year, the US Congress passed a budget that included a provision allowing the country to go on buying the Russian RD-180 rocket engines. Shortly after, the ULA ordered an additional batch of 20 RD-180 engines at the Pentagon’s request.
Separately, there were earlier reports on the intention to use the engine RD-180 in a Russian rocket of the super-heavy class.