I have full confidence that, given enough time, Musk can create the technology necessary to ferry people to Mars and establish a colony. That's an engineering problem, and as we've seen he's very adept at building companies to tackle those.

But the key problem then becomes: why would people want to spend $0.5m to deal with all the inconveniences of being a first settler on Mars? It takes months to go there, and once you're there you'll be stuck in cramped quarters with only basic amenities. Plus the health risks of radiation and equipment failure.

So people need to be compensated for these inconveniences and risks with a salary greater than they could make on Earth. This means that you need a functioning Martian economy. People won't go en masse without it making economic sense for them to do so. But in order for that to develop, the colony needs to produce something of value.

To draw an analogy to the European settlement of North America, the first permanent European settlements were port towns for exporting resources like furs and minerals back to Europe. In this way, the North American economy was bootstrapped off of the European economy.

The same thing needs to happen here where we need to bootstrap a Martian economy off of the Earth economy by exporting resources back to Earth.