The delivery of Blue Origin’s BE-4 was delayed over an issue with the engine’s complex single-shaft turbopump, the part of a rocket engine that injects flammable propellants during ignition with forces of 80,000 horsepower.ULA picked Blue Origin’s BE-4 in 2018 to power Vulcan, a two-stage heavy-lift rocket that will succeed ULA’s Atlas 5 workhorse.
