In April 2013, a Dutch company announced plans to send people to Mars to colonize the planet.

The catch? It’s a one way trip.

The company, called Mars One, began accepting applicants to send four humans in August. More than 200,000 people applied, and the mission is set to land on Mars in 2025. The company announced plans for an unmanned mission to launch in 2018, to begin transporting supplies and exploring the area the colonists would be living. They will live in pods, and a new crew will be sent every two years in hopes of creating a population on the red planet.

The biggest obstacle, the company says, is money. The mission requires $6 billion, and the company has already raised $200,000 by donation. They have yet to disclose how much they have fundraised through private investors.

For more information, check out the detailed plan released by Mars One.