 Elon Musk has made it clear he wants to colonize Mars. And now he's taking a big first step toward making that dream a reality. His company SpaceX announced that it plans to start sending spacecraft to the Red Planet as early as 2018. That means SpaceX could be the first private company to land hardware on another planet. The idea is to test out how to land large payloads on the Martian surface. To do that, SpaceX will be sending over its Red Dragon vehicle. It's a modified version of the Dragon cargo capsule that SpaceX uses to deliver supplies to the International Space Station. The Red Dragon has eight Super Draco engines embedded in its hull. During the descent to Mars, the engines will fire, allowing the spacecraft to land gently and in a controlled manner. It's a technique known as propulsive landing, and it's similar to how SpaceX lands its Falcon 9. But landing a spacecraft on Mars is a lot harder than landing one on Earth. The Martian atmosphere is one hundredth the density of Earth's atmosphere, so it provides less cushion for incoming spacecraft. That means really heavy objects run the risk of slamming into the Martian surface if they aren't slowed down enough. Right now, NASA only knows how to land 2,000 pounds on Mars, but with propulsive landings, even more weight could get to the surface safely. SpaceX's Red Dragon would be five to ten times larger than anything ever landed on Mars. There's still a lot to do before the Red Dragon missions can happen, though. SpaceX plans to transport the spacecraft to Mars using its Falcon Heavy, a souped-up version of the Falcon 9. The Falcon Heavy is still in development, though, so it has yet to fly. SpaceX says the rocket's first flight is supposed to happen in November of this year. Also, SpaceX has never landed the Dragon using the Super Dracos before. It's used the engines to make the vehicle ascend and even hover, but never land. SpaceX will try to propulsively land a Dragon cargo capsule on Earth first, after it returns from a station supply run. The Red Dragon missions are all privately funded, but SpaceX is still getting some help from NASA. The space agency said it will provide technical support to the company in exchange for data regarding the Dragon's landing attempts. Meanwhile, NASA is still hoping to send its own astronauts to Mars in the mid-2030s, but with SpaceX's announcement, the private company may be closer to doing it first. Want to learn more about how SpaceX lands its rockets? Check out our video on how they pulled it off. Or if you need an even more ambitious space exploration goal, check out our video on Starshot, which involves sending a spacecraft to Alpha Centauri with a laser.