In 1962, engineers spent more time arguing over propulsion than actually...

https://lima-wiki.win/index.php/Stop_Calling_It_%22Game-Changing%22:_A_Practical_Guide_to_Comparing_Mars_Propulsion

In 1962, engineers spent more time arguing over propulsion than actually building rockets. The debate between nuclear, chemical, and electric engines wasn't just technical; it was a battle over the future of spaceflight