Why don't we just colonize come planets,before we start thinking about payments in space.
I think that the human civilization will be capable of colonizing other planets after the year 2100,if the Apocalypse didn't happen before the new century.
Nobody knows what will happen with the cryptocurrencies after 80 or 100 years.Cryptocurrencies might become obsolete by 2100.The human civilization might find other ways to reallocate resources,replacing the market economy and the use of currencies,both fiat and crypto.
I also don't think that the first human colonists would need currencies,when they arrive at a new planet.