We picture the space race as a smooth march, but the archives tell a messier...

https://papa-wiki.win/index.php/What_Does_a_Mission_Architecture_Decision_Actually_Include%3F

We picture the space race as a smooth march, but the archives tell a messier story. Engineers spent years in a gridlock between nuclear, chemical, and electric propulsion. Physics was the easy part; getting everyone to agree was the mission.