Colonising Space/Leaving earth with the right attitude
From AdCiv
If mankind colonises space, enabled by a programme based upon free and open-source-style collaboration, it would set the tone for future generations living off-Earth, in terms of encouraging co-operation and resource sharing.
This iconic example should influence these subsequent generations and help reduce the chances of purely self-serving forms of commercialism taking root. It might also lessen the likelihood of conflicts arising from aggressive, exclusionist groups that might otherwise have been more common.
If we do successfully colonise space, eventually more of humanity will exist off the Earth than on it, so the fact that their whole way of life might be owed to this human-centric, inclusive movement would be fairly significant.