Back in 1962, engineers argued over using nuclear, chemical, or electric...

https://dlf-ne.org/is-nuclear-propulsion-worth-it-just-to-shave-time-to-mars/

Back in 1962, engineers argued over using nuclear, chemical, or electric engines to reach the moon. It wasn't just physics; it was ego and budget battles. I read the original planning memos to see how they settled the debate