Part 1 could be about Exogenisis I don't know about that but 2 seems to be about the astronauts but the third I see as the just looking over humanity's dark and destructive history and thinking that the world and the human race will never work if we continue to be so aggressive and violent and have wars and so on and its as if they are begging to start over again and promising that if they can they will get it right and make themselves as a race peaceful and try to create rather than destroy because truly that is what everyone wants. To live in a perfect society a utopia almost a place where no one is ever in danger or unsafe and everything is good with no pollution war or even violence and I believe that is what the third part is about because to me that makes sense.