Musk warned there was no guarantee he would be able to meet the Starship timeframe he set out and much depended on overcoming a number of technical challenges, during flight-test development, especially a post-launch refuelling operation while orbiting Earth.
He previously said he aimed to send an unmanned vehicle to the red planet as early as 2018 and had targeted 2024 to launch a first crewed mission there.
Humans would land on Mars as part of the second or third flights, he said on Thursday, but the first trip would be in the hands of one or more humanoid Optimus design robots built by Tesla, the electric vehicle and battery maker he leads.
The current target to land a human on
Mars using Starship is 2028, but it has yet to make an orbit of Earth.
Musk said he wants to make it so that "anyone who wants to move to Mars and help build a new civilisation can do so. Anyone out there. How cool would that be?".
At the end of 2026, Mars and Earth align around the sun, reducing the distance between the two planets to its shortest, but still seven to nine months' travelling time by spacecraft.
Musk said they had a 50-50 chance of meeting that deadline and if Starship isn't ready by then, SpaceX would wait another two years before trying again.
100 Years ago Robert Goddard launch first liquid fuel rocket...