Ever since the Crimean crisis in 2014—precipitated by Russia’s annexation of the Ukrainian-held peninsula—Congress has increased pressure on the US aerospace industry to end its use of Russian-made rocket engines. In particular, legislators want United Launch Alliance to stop using the RD-180 engine in its Atlas V launch vehicle. This booster, with a 100 percent mission success rate, launches many of America’s national security payloads.

As United Launch Alliance plans to transition to US-made engines early next decade, and with other US rockets already flying or soon coming online, the Russian RD-180 manufacturers are looking to other markets. In doing so, they’ve found willing buyers in China, although this has come with some concerns.

Even though the rocket engine technology behind the RD-180 is 40 years old, it remains one of the highest performing engines in the world, with a near-perfect service record. With 860,000 pounds of thrust (about 3.8MN), the RD-180 also happens to be three times more powerful than any Chinese rocket engine.