We would want to launch the MarsCoin blockchain when we launch ships to head to the Red Planet. They would run the hardware locally.
Transactions between Earth and Mars would require a value exchange, like currency exchange today.
By the time we actually start launching, I think/hope/dream that BTC will be at $2M per coin, so it will be enough to get them started.
Star Trek ceased needing a unit of account and medium of exchange for capital when they invented the replicator. When all it takes is energy to create any object we can program the design for, costs fall to zero and are covered by entropy itself. But that's beyond our tech capabilities, basically Clarketech.
