That something is nuclear propulsion. Essentially, a nuclear rocket engine is a reactor that has hydrogen running through it as a propellant, which is heated to an astonishing 3,000 K (2,727 °C, 4,940 ...
The two announcements highlight RTX’s parallel work on both air-breathing and solid rocket propulsion technologies through its businesses. RTX made two propulsion announcements on Sept. 24, 2025, ...