The BE-4 is a powerful rocket engine developed by Blue Origin. It uses a combination of liquid oxygen and liquefied natural gas as propellants, which allows for efficient performance and reduced costs. Designed for heavy-lift launch vehicles, the BE-4 is intended to support various missions, including satellite deployment and crewed spaceflight. This engine is notable for its staged combustion cycle, which enhances its efficiency and thrust. The BE-4 is set to power the United Launch Alliance's Vulcan Centaur rocket, marking a significant step in the collaboration between private aerospace companies and government space initiatives.