SpaceColonization

Quora Answer : How long will it take for us humans to start a society on another planet?

Aug 25, 2015

At least 300 years. And only then if we're lucky.

We may get a "permanent" moon colony (something like the ISS, with regular, rotating crews) in the next 50 years. But only if there's a compelling reason. (Remember we've made more or less no moon colonization progress in the last 40 years.)

A manned Mars shot is probably still 100 years away. Not that it couldn't be done earlier if we REALLY, REALLY wanted to. But, the sad truth is that we don't. Not really. Not as much as we want to spend our scarce resources on other things. Not even ElonMusk has enough money or will for that.

Basically, I don't see us having manned flight to other planets in the solar system unless and until we have a fairly well established system of robot mining vessels regularly fetching resources from asteroids and comets.

It's just not viable to send things like water from Earth to Mars. Once it's possible to grab comets made of ice and harness them to our Earth-to-Mars or Earth-to-Jupiter transport, then we might consider it. Not until then.