Bad word choice on my part. I just meant government-sponsored space programs, in contrast to private attempts.

No, he means “governments.”

I can't think of any country that would try to run such (decades long) projects under the remit of a few years' government.

They would report to but be independent of government ministers, and likely span multiple governments.

'State' is what was meant. (Country, nation, fine; bit less accurate perhaps? But I wouldn't have batted an eyelid.)

No, "nation-state" is trying to make about about someone's smartitude. It's like "thread actor" in that regard, i. e. its a big word that important people use in their CNN interviews. The racing strip of sentences, basically.