When I red this thread premises it amused me - I thought "try the 1970's, post-Apollo slump for public opinion definitively NOT interested in space."
On the other hand:Science Fiction And Fantasy Book Sales Have Doubled Since 2010https://www.forbes.com/sites/adamrowe1/2018/06/19/science-fiction-and-fantasy-book-sales-have-doubled-since-2010/?sh=4d1a707c2edf