We're building thermonuclear spaceships again–this time for real

The military and NASA are collaborating on the development of nuclear thermal rockets (NTRs) for potential use in space exploration. The concept of NTRs involves using liquid hydrogen passed through a nuclear reactor core to generate thrust, offering increased fuel efficiency compared to traditional chemical rockets. The idea of nuclear-powered rockets dates back to the 1950s with the US Air Force's Rover program, initially aimed at intercontinental ballistic missiles. Challenges in adapting stationary nuclear reactors for flight include manufacturing fuel rods capable of withstanding high temperatures and addressing the corrosive nature of hydrogen at extreme heat levels. Los Alamos Scientific Laboratory proposed NTR designs in the 1950s, and the program gained momentum when it was transferred to NASA and the Atomic Energy Commission in 1958, becoming known as NERVA (Nuclear Engine for Rocket Vehicle Applications). The collaboration between NASA and AEC led to the development of space reactors to power these nuclear spaceships.