Despite repeated calls by many on Capitol Hill to stop buying rocket engines from Russia, the United States currently has no domestically-made analogues to the RD-181s.
The RD-181 engines are used in the first stages of the Antares carrier rockets produced by Orbital Sciences Corporation.
Despite repeated calls by many on Capitol Hill to stop buying rocket engines from Russia, the United States currently has no domestically-made analogues to the RD-181s.
The hard fact is, however, that finding a replacement for the Russian engines is easier said than done.
Defense Undersecretary Frank Kendall, the Pentagon's chief arms buyer, earlier said that the development of a certified US replacement for the RD-181 would take at least five more years.
It was questionable whether the United Launch Alliance (ULA) could survive if the US military immediately stopped using the Russian engines.
US worries over the use of Russian rocket engines heightened after an Antares rocket, powered by a US-modified Soviet engine, blew up seconds after liftoff in October 2014.
Russian manufacturers then blamed the mishap on the US modifications of the NK-33 engine.
This dependency has sparked waves of concern in US government and aerospace circles amid heightened tensions between the United States and Russia.
John McCain, chairman of the Senate Armed Services Committee, and a fervent opponent of rocket engine purchases from Russia, announced during a hearing in January that he would introduce a bill aimed at ending the use of Russian rocket RD-181 engines.
The RD-181 deal is the second large-scale deal Energomash has made with a US company.
In the late 1990s, the company won a contract with United Launch Alliance to supply RD-180 engines for Atlas rockets. This contract, also valued at about $1 billion, is still in place.