INTERNATIONAL NEWS - The rocket and car entrepreneur told an audience in Adelaide, Australia, that he would begin building the necessary ships to support the mission next year.
He says he is refocusing his SpaceX company to work on just one type of vehicle that could do all of the firm's current work and interplanetary travel.
Known as the BFR, this rocket system could also carry people rapidly around the Earth from city to city.
Elon Musk: "That's not a typo"
"Most of what people consider to be long-distance trips could be completed in less than half-an-hour," he told the International Astronautical Congress.
Mr Musk first laid out his Mars ambitions at the IAC in 2016. Twelve months on, he returned with more detail.
His BFR, although still massive, is now a little smaller at 106m in height and 9m in width.
The major difference compared with the original version, however, was cost, the South African-born American said.
"I think we've figured out how to pay for it. This is very important."
The route to affordability, he explained, was in refocusing all of the company's efforts into the one system - and then using that to meet all its customers' needs.
