I generally someone who defends the idea that SW is fantasy and not proper sci-fi, but EC Henry’s latest video makes some interesting observations about how ANH was much more “scientific” than what SW later evolved into. He’s doesn’t mention the early drafts, but it’s interest in hindsight how the they seemed to flip between sci-fi and fantasy ideas, until Lucas finally settled for a somewhat more fantastical approach and then doubled down on the idea in the following films.

Star Wars is More Scientific than You Realize
https://www.youtube.com/watch?v=AEPM-Bqc8fQ - from the EC Henry YouTube channel (5 mins long).