A Nuclear Rocket to the Stars

Today’s blog post in honor of NASA’s 60th anniversary comes from Oliver Manning, an intern in the Office of Public Media and Communications. Join us on Twitter on October 1 for #ArchivesInSpace with @NASAHistory for more NASA history from our holdings. 

The Saturn V rocket today is best known as the rocket that took Americans to the Moon, but when it was developed, it was intended to be much more. With the ability to put 118,000 pounds of cargo in low earth orbit, the Saturn V rocket had the largest payload of any American launch system, dwarfing even the later Space Shuttle with its 24,400-pound payload. Although the enormous capability of the Saturn V was not enough to save it from retirement at the end of the Apollo program, there were plans to continue its development and service life. One such plan involved supplementing the power of the Saturn V with a nuclear-powered engine.

Research began in the 1950s, when nuclear power was considered the way of the future. Nuclear rockets were the logical next step to extend current technologies and research into space flight. Nuclear rocket development began well before the Apollo program succeeded on putting an man on the Moon. NASA’s 1968 information video Nuclear Propulsion in Space describes current progress of the endeavor to build nuclear engines.

Saturn V Launch

The short film starts by making a case for nuclear rockets, with a distinctly 1960s animation style. Nuclear rockets, according to the video, provide more thrust with less weight and “will expand our ability to explore space.” Most interesting, the nuclear rocket on the Saturn 5, at least in the vision of this film, was never intended to replace all the stages. Conventional chemical rockets would remain in use for the first two stages, with the nuclear rocket replacing the third stage and, according to the narrator, “cutting some travel times in half.” Nuclear rockets were also seen as essential for a sustained human presence on the Moon—the animation shows lunar supply missions, complete with astronauts and vehicles roaming the lunar surface.


An overall hopeful tone pervades the film, with the narrator enthusiastically extolling all the overcome hurdles. Control systems, reactor designs, and a comprehensive test program stand as shining achievements of American technical prowess but are undercut by the sad reality that none of the research done would ever be applied. Even when a problem did develop, as it did with some of the Kiwi test reactors, nothing could stand in the face of progress, declares the narrator; the issues were quickly rectified, and “a correction was made.”


This dream of a nuclear rocket did not remain a prototype or hypothetical project. Instead, the early Kiwi test systems graduated into full-scale tests under the NERVA—the Nuclear Engine for Rocket Vehicle Application program. This full-fledged program saw the development of a functional nuclear rocket, one that was deemed ready for integration into NASA space vehicles. The NERVA program succeeded in creating a practical, functioning nuclear rocket, although this success would never translate into use.


The video ends with an extended hypothetical use of the NRX rocket, with modified Saturn 5s delivering several nuclear rockets into orbit to be linked together for a trip to Mars. Unfortunately, it was politics, not technology, that doomed the NERVA program, with the canceling of the Apollo program and budgetary cutbacks for NASA. The last Saturn 5 rocket would be launched in 1973, and the NERVA project would be terminated. The upbeat, can-do attitude of NASA’s promotional video was premature. The NERVA program and NRX rocket never made it to space, though not for a lack of trying.

Spaceship in Flight

If any bright spot remains, the concept of a nuclear-powered rocket still remains as a possibility for future missions to Mars, with NASA exploring the potential for nuclear powered spaceflight  as recently as 2018. The legacy and technology of the American journey to the Moon remains relevant to this day.


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