As a result of alleged Russian interference in the internal affairs of Ukraine, the 2015 US National Defense Authorization Act (NDAA) prohibits the use of the Russian-made rocket engine, and directs the US Defense Department to develop a domestic alternative by 2019.

"The objective of 2019 is very aggressive, and it does not result in what is ultimately required, a launch vehicle and the supporting infrastructure," LaPlante said.

LaPlante explained that engines of the RD-180 caliber, which have not been fully developed in the United States, can explode during test and operations and destroy critical test infrastructure.

Even the five-to-seven year estimate is a stretch when compared to historical rocket engine development timelines that have ranged up to eight years, the US Air Force official noted.

The RD-180 has been the rocket engine for the Evolved Expendable Launch Vehicle (EELV), which has an unprecedented record of 80 successful launches over the past 30 years, LaPlante added.

On Tuesday, US-based companies United Launch Alliance (ULA) and Space X presented proposals for developing alternatives to the Russian-made RD-180 engines during the US House Armed Services Committee hearing.

Source: Sputnik News