Elon Musk has a plan, and it’s about as audacious as they come. Not content with living on our pale blue dot, Musk and his company SpaceX want to colonize Mars, fast. They say they’ll send a duo of supply ships to the red planet within five years. By 2024, they’re aiming to send the first humans. From there they have visions of building a space port, a city and, ultimately, a planet they’d like to “geoengineer” to be as welcoming as a second Earth.