When would a million-person Mars city be reached?

“From the point at which the first ship goes to Mars, it's probably somewhere between 20 to 50 total Mars rendezvous. So it's probably somewhere between maybe 40 to 100 years to achieve a fully self-sustaining civilization on Mars.”

— Elon Musk, 27 September 2016 · Watch: IAC 2016 — Making Humans a Multiplanetary Species · 26:25 ↗