In a nutshell: Elon Musk during a recent interview with podcaster Lex Fridman said that in the worst case scenario, it'll be roughly a decade before SpaceX is able to land a human being on Mars. A key limiting factor today, however, is money: it's simply too expensive to send anyone to the Red Planet right now.
About a half hour into the interview, Fridman asked Musk when he thinks SpaceX would land a human on the Red Planet. After a more than 20-second delay to think about it, Musk said the best case would be about five years and the worst case would be closer to 10 years.
A major determining factor in getting humans to Mars is engineering the vehicle that'll take astronauts there. "Starship is the most complex and advanced rocket that's ever been made," Musk said. The SpaceX CEO added that the fundamental optimization of Starship is minimizing the cost per ton to orbit and ultimately, the cost per ton to the surface of Mars.
Right now, Musk said, money is the limiting factor. "You couldn't fly to Mars for a trillion dollars. No amount of money could get you a ticket to Mars," he said.
The serial entrepreneur made it clear that he doesn't just want to have "flags and footprints" on Mars then not come back for a half century like we did with the Moon.
Musk said earlier this year on Twitter that SpaceX aims to land Starships on Mars well before 2030, adding that the really hard part will be building the first self-sustaining base. By 2050, Musk hopes to have a million people on Mars.