MOSCOW (Sputnik) — Russia's NPO Energomash company has supplied all four RD-181 engines scheduled for delivery in 2017 to the United States, according to the rocket engine manufacturer's statement released on Wednesday.
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"In line with the contractual obligations, NPO Energomash on October 31, 2017, shipped two RD-181 engines to the United States… This is the second delivery of engines to the US. The program for the delivery of RD-181s in 2017 has been completed."
According to NPO Energomash chief Igor Arbuzov's previous statement, Russia planned to supply to the United States in 2017 a total of 11 RD-180 engines and four RD-181 engines.
The issue of replacing the Russian rocket engines arose amid the deterioration of relations between Moscow and Washington in 2014 as a result of sanctions imposed on Russia over the Ukrainian crisis.
Legislators, with Senator John McCain being one of the strongest advocates of the Russian engine's replacement, passed a law requiring the United States to develop a domestically produced next-generation rocket propulsion system by 2019 so as not to rely on the RD-180s.
The Pentagon leadership has reportedly set to substitute the engines with the domestic technology by 2020. However, later it was announced that the Atlas V carrier rockets with RD-180 will be used through 2024 or 2025.
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However, in December 2015, the US Congress passed a budget that includes a provision allowing the country to continue buying the Russian RD-180 rocket engines.