Blue Engine 4
The Blue Engine 4 (BE-4) is a state-of-the-art liquid rocket engine developed by Blue Origin, an aerospace manufacturer and sub-orbital spaceflight services company founded by Jeff Bezos. The BE-4 uses liquefied methane as its fuel and operates on an oxygen-rich staged combustion cycle, which is a highly efficient and advanced method of propulsion.
Development of the BE-4 began in 2011, although it was only publicly announced in September 2014. The engine's development was funded through a combination of private investments and public contracts. Originally intended for use on Blue Origin's own launch vehicle, the New Glenn, the BE-4 was also selected by United Launch Alliance (ULA) in 2014 for its Vulcan Centaur rocket. This rocket is designed to replace the Atlas V and Delta IV rockets.
The BE-4's first flight aboard the Vulcan Centaur took place on January 8, 2024, and it was launched on New Glenn for the first time on January 16, 2025. The production of this engine is located in Huntsville, Alabama, as announced by Blue Origin's president, Rob Meyerson, in June 2017.
The BE-4 is designed to provide a high thrust-to-weight ratio and is an evolution in rocket engine technology, particularly due to its use of methane fuel. This choice of propellant is part of a growing trend to use methane in rocket engines because it burns cleaner than traditional rocket fuels such as kerosene, resulting in less soot and longer engine life. The choice of an oxygen-rich combustion cycle also contributes to higher efficiency and reduced thermal stress on engine components.
Blue Origin's entry into the liquid rocket engine market was further solidified through its partnership with ULA and other companies, filling a crucial gap in the defense industrial base following the acquisition of Pratt & Whitney Rocketdyne by Aerojet in 2012.
The BE-4 is one of several engines developed by Blue Origin: