This afternoon, in glorious detail, Elon Musk described his plan to send people to colonize Mars with his company SpaceX, the interplanetary transport startup he founded in 2002.
More than 100,000 people watched online as the entrepreneur spoke onstage at the International Astronautical Congress in Guadalajara, Mexico.
Musk described how Martian colonization would work. The ship he proposes to transport humans to the Red Planet is huge: 12 meters in diameter and 122 meters tall. It’s supposed to carry at least 100 people, have restaurants, a cinema, you name it. But there was one critical question he practically glossed over. How does SpaceX expect to pay for it all?
Although Musk joked about using Kickstarter to raise the tremendous amount of money he’ll need to pay for the ambitious project, “ultimately,” he said, “this will be a huge public-private partnership.”
:no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/7177789/Screen%20Shot%202016-09-27%20at%202.32.41%20PM.png)
NASA is already SpaceX’s biggest customer, and the government agency is signed up to shuttle astronauts to the International Space Station as early as next year.
While Musk noted that NASA missions will bring in some profit, he also made very clear that he will need more money to bring his vision of Martian habitation to fruition.
Throughout the hour-long presentation, Musk continually underscored themes in efficiency and recycling parts, and he even vowed to dedicate his personal profits to fund Mars colonization.
“I’m only personally accumulating assets in order to fund this,” said Musk.
It was an unusually technical presentation lecture for a public visionary project, probably in an effort to show the world, and the U.S. government, just how serious he is.
Sending 12 astronauts to Mars will cost an estimated $10 billion per person, Musk said. But if one million people sign up, the cost would drop to a mere $200,000 per traveler, which he compared to the price of a house.
So scale is going to be super important here.
Musk needs to find a way not just to make the rockets reusable, which has been a key talking point for SpaceX as it practiced landing rockets on a robotic boat throughout the year, but also make it safe and popular. Yet safety wasn’t a major theme today, although it did come up in audience questions.
Rather a more significant part of the presentation was dedicated to the reusability of the rockets, launching and refueling, all major factors in keeping the price down.
If Musk is going to make his dreams of a colony on Mars come true and convince the U.S. government it’s worth investing billions of taxpayer dollars to do so, he’ll have to be more persuasive on two counts:
- Musk needs to think of a more motivating reason to send people to Mars other than the fact that Earth is home to seven billion people, while Mars is home to zero.
- He’ll have to convince the American public that we’re not investing in giant rockets that will hurl brilliant scientists to their death in the cold throes of space.
Still, it’s all very exciting to think about.
This article originally appeared on Recode.net.