SpaceX’s Starship is scheduled to go to Mars late next year with Tesla’s humanoid robot Optimus. Elon Musk suggested that human missions could commence by 2029 or 2031 if initial landings are successful.

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.

A group of scientists from China and America have discovered that Mars once had an ocean after the Chinese Zhurong rover landed on the red planet.