what kind of catastrophic event are we talking about here that could lead to annihilation of all nodes on earth worldwide that we need a space node?!! and what would we need that if the human race is extinct, or is it just extinction of computers on earth 
I'm talking about a meteor or asteroid hitting the Earth in the future, as many scientists have already predicted. If this happens indeed, then expect to see the Bitcoin network weaken in its entirety like never before. Even Stephen Hawking predicted the extinction of the human race within 100 years in the future. We should be prepared for any catastrophic event, by preserving breakthrough technologies (like Bitcoin + Blockchain tech) as much as we can. With nodes on several planets within the solar system, the Bitcoin blockchain will live forever.
but in case of an extinction, who is left to even want bitcoin and technologies like blockchain! even if a catastrophe happens that wipes 80% of the planet, the remaining 20% aren't going to even care about "money" (that is bitcoin). they will need food and shelter, basically the very basic needs for survival.