SpaceX plans its first trip to the red planet in 2022, carrying only cargo, to be followed by a manned mission in 2024, Musk, who runs the company and electric luxury car company Tesla Inc, said at a conference in Adelaide.
NASA's first human mission to Mars is expected about a decade later.
Musk, the chief executive and lead designer of Space Exploration Technologies, said SpaceX has shrunk the size of the rocket ship it is developing to go to Mars, aiming to start construction on the first spaceship in the first half of next year.
As for the intercontinental passenger rocket - a concept familiar to science fiction fans - Musk said, "If you build a ship that's capable of going to Mars, what if you take that same ship and go from one place to another on Earth? We looked at that and the results are quite interesting."
Musk had previously planned to use a suite of space vehicles to support the colonization of Mars, beginning with an unmanned capsule called Red Dragon in 2018, but he said SpaceX is now focused on a single, slimmer and shorter rocket instead.
The rocket would be partially reusable and capable of flight directly from Earth to Mars, could still carry 100 passengers, and could also be used for fast transport on Earth, Musk said.
Musk's SpaceX is one of several ventures that have said they want to open up space routes to Mars.
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