ELON Musk has a timeline of when he hopes to send humans to Mars.
The ultimate goal is for his SpaceX company to put a person on the Red Planet by 2024 and build a self-sustaining city by 2050.
SpaceX recently completed its second 'hop' test for its Starship rocket prototype.
The goal is to use Starship to take astronauts to the Moon, Mars and beyond.
During a virtual appearance last month on the , Musk said: "We've got to build the city and get to the point where it's self-sustaining.
"I want to emphasize, this is a very hard and dangerous and difficult thing.
"Not for the faint of heart. Good chance you'll die. And it's going to be tough, tough going, but it'll be pretty glorious if it works out."
To get to this Mars city goal, Musk seems to have a rough timeline set in place.
SpaceX are working on a Super Heavy rocket booster, which could be ready to test by the next Starship event which is in October.
Advertisement that SpaceX might be giving a progress update report in the same month.
In 2021, Musk has said Starship's first orbital flight would "probably" happen.