This is an interesting concept. And while I feel that of course this one will be doomed, maybe it can open discussion on what we will do with the concept of nations once we enter space.

For example: a colony is settled on Mars, with astronauts from various countries. They stay, what would their, or their children's nationalities be?

And yes, I did sign up to become a citizen :)

They'd be a colony only until they were self-sufficient. Then they'd become a nation through declaration and maybe war.

Their founder are planning to use URBOCOP (as I understand) -https://room.eu.com/article/urbocop-saving-planet-earth