Back in 1962, NASA engineers fought over whether to trust nuclear or chemical...

https://shed-wiki.win/index.php/Is_Nuclear_Propulsion_Worth_It_Just_to_Shave_Time_to_Mars%3F

Back in 1962, NASA engineers fought over whether to trust nuclear or chemical engines for the Moon. The public saw a seamless mission, but these memos reveal a mess of bruised egos and real technical fear