Technical problems accompanying the development of a new Vulcan rocket by the United Launch Alliance (ULA) may make it impossible for the Pentagon to abandon the Russian RD-180 engine by 2022, as required by Congress. This is reported by SpaceNews, referring to the report of the U.S. Government Accountability Office.
According to this document, there are problems associated with the development of the company Blue Origin engine BE-4, which may make it impossible to certify Vulcan in 2021. As a consequence, there could be a situation where the Pentagon will have to rely on the Atlas 5 rocket in 2022 and beyond.
SpaceNews recalls that in 2016, Congress banned the Pentagon from using an Atlas 5 rocket with a Russian RD-180 engine after 2022.
In April, Roskosmos reported that the Energomash Research and Production Association handed over six RD-180 engines to the U.S. side on April 14, the last delivery under the current contract.
In July 2020, Blue Origin delivered the first BE-4 to ULA, which is not for production but for testing.
The Vulcan is being built to replace the Atlas 5. The two single-chamber BE-4s on the first stage of the Vulcan launcher (actually Atlas 6) will combine to produce more thrust than the single twin-chambered Atlas 5 first-stage RD-180. Unlike the kerosene-fueled RD-180, the BE-4 uses methane. The Vulcan rocket with the American BE-4 should replace the Atlas 5 carrier with the Russian RD-180.