Elon Musk/Twitter

Elon Musk’s private space endeavor SpaceX on Sunday conducted its first test of the Raptor rocket engine designed to take humans to Mars as early as 2024.

Musk tweeted about the test, which took place at the company’s McGregor, Texas, facility, ahead of his keynote address at the 67th annual International Astronautical Congress on Tuesday. In the speech, titled “Making Humans a Multiplanetary Species,” he is expected to unveil the design for the Mars Colonial Transporter, as well as his plan for colonizing the Red Planet.