According to the statement, obtained by RIA Novosti, Orbital is in the process of obtaining all necessary permits for the support of the use of RD-181 and approval of the recent contract with Russian design bureau NPO Energomash by appropriate US government agencies.
Additionally, a source from the Russia’s Federal Space Agency Roscosmos told the newspapers that the companies had a firm contract of 20 engines, out of the total 60, that were moving forward in the delivery process, with two more options that include 20 engines each.
Orbital says that they looked at several other propulsion providers, but decided to use the RD-181 engines, because the Russian designed engine offered «the best combination of schedule availability, technical performance and cost parameters as compared to other possible options," according to statement, released by the company on Tuesday.
In October, the Antares rocket, which was supposed to deliver over two tons of cargo to the ISS, exploded six seconds after the launch at the Wallops Flight Facility in Virginia.
