With PayPal out of the picture, Musk was free to pursue a (literally) loftier goal: space. And he had the money to do that. Disappointed that NASA had no plans for a manned mission to Mars, he dreamed up a project called Mars Oasis, which would create a greenhouse on the Red Planet. As part of that otherworldly concept, he co-founded SpaceX in 2002, a company meant to make space travel more practical [source: Bierend].
SpaceX was born in part after Musk did the math and realized that space missions would be much more affordable if someone could develop a dependable and reusable rocket system. So, that's exactly what he set out to do. As of 2018, SpaceX has achieved more than 100 launches, thanks in part to its smartly designed Falcon rockets and Crew Dragon capsules, and has transported astronauts to the International Space Station. And it booked its first paying passenger to the moon in September 2018.
Musk intends to establish a self-sustaining colony on Mars one day. He plans to put the first human explorers on Mars by 2024, and NASA is definitely interested. As of 2018, SpaceX has received more than $3 billion in U.S. government awards to build spacecraft, like the aforementioned Falcon rockets [source: Mosher].