Musk suggested in a post on X that human landings could begin as early as 2029, though 2031 was more likely if the initial landings go well. Musk told investors on a conference call in April last year that he expected Optimus would be able to perform tasks in the factory by the end of 2024.

Elon Musk says SpaceX will go to Mars at the end of 2026 with Tesla's Optimus, a humanoid robot. If all goes well, humans could be headed to the red planet in 2029, Musk says.

Musk—who has a history of setting unrealized goals for his companies—says he wants to send humans to Mars by 2029, though he says 2031 may be more likely.