I am only playing at the warlord level (I like the building and exploring more then the conquest )
but, on 3 out of my last 4 games, I had the launch of the spaceship take place on the turn I won a cultural victory, on one of those, the vote was taken for diplomatic victory (with good odds I would win) but the results had not come in yet. I have had one occasion where the spaceship would have arrived before I won a domination victory, if I had not gotten stupid and accidently culture bombed my artist, instead of planting him (look extra spaces)

But it was the 3 launches out of 4 games on the same turn as the cultural victory I thought was interesting, especially since I wasn't trying for that win. Kind of fun to watch the spaceship launch, but for all of it I had to yes just one more turn it. The 4th game was a domination win.

For trivia question; Why didn't they spruce up the spaceship arrival video to match the launch? I am sure the answer is somewhere, but am lazy right now.