Good article.

I tend to think an offworld colony would prefer their own altcoin or native barter system. In the event of a solar flare from the sun or communications blackout all financial transactions and economic activity for a colony would grind to a halt. In designing an offworld economic system various redundancies could be built in to address the event of catastrophic communications failure, which could negate the possibility of an earth dependent system being utilized.

An offworld currency system may need to be flexible to adapt to unforeseen or shifting economic & financial conditions which could rule out bitcoin with its rigid algorithmically determined supply.

Anyways sorry if this seems negative or too serious. The main reason I throw things like this out there is in the hope of triggering better discussion. And also because I liked your article & wish I had something worthwhile to contribute. I know I'm not good at this but have to try.  :/