Elon Musk, SpaceX founder and CEO of Tesla, is preparing to send his Starships to Mars in a couple of years.

Musk made the announcement in an X post on Saturday, writing, “The first Starships to Mars will launch in 2 years when the next Earth-Mars transfer window opens.”

He added:

These will be uncrewed to test the reliability of landing intact on Mars. If those landings go well, then the first crewed flights to Mars will be in 4 years. Flight rate will grow exponentially from there, with the goal of building a self-sustaining city in about 20 years.

Being multiplanetary will vastly increase the probable lifespan of consciousness, as we will no longer have all our eggs, literally and metabolically, on one planet.

Social media users reacted to his post with thoughts and questions. One person wrote, “I’m curious why humans would initially be sent to Mars. Why wouldn’t a bunch of robots be sent to build the necessary infrastructure required for habitability?”

“What a time to be alive!” another user commented.

 In May, Musk predicted there would be a human city on Mars within 30 years, Breitbart News reported:

According to Musk, an uncrewed mission to Mars could be achieved in less than five years, while landing humans on the planet might take less than a decade. He further projected that a city could potentially be established on Mars within 20 years, and with certainty, within 30 years, securing the future of human civilization beyond Earth.

Many seem excited about the potential of a Mars city, but it should be noted that Musk has a history of presenting wildly unrealistic timelines.

SpaceX, the company Musk founded in 2002, has  became the first private company to develop a liquid-propellant rocket that successfully reached orbit and the first to send a spacecraft and astronauts to the International Space Station. It should be noted, however, that SpaceX has yet to take humans out of low-Earth orbit.

During an interview in July, Musk said he believes we should allocate a small percent of our economy “to extending life beyond Earth and ultimately to other star systems.”