It was published in 1950, before the age of space exploration. When we finally got out there it was discovered that a number of his suppositions were either dead on or very close. It is worth a read.
Yes, it was very good reading for me back in the 70’s. I didn’t swallow all his suppositions, but you are right that many were later proven true.
For me it is kind of like Atlas Shrugged, everybody should read it.