In an interview with Inc., Musk explained why this project was one of the most important things to happen on Earth since its birth 4.5 billion years ago:
"There was the advent of single-celled life, multicelled life, the development of plants, then animals," he said in the article. "On this time scale, I'd put the extension of life to another planet slightly above the transition from life in the oceans to life on land."
To that end in 2002, Musk founded SpaceX, an aerospace manufacturer in Hawthorne, California, with the goal of making rockets more affordable.
SpaceX's Dragon spacecraft became the first commercial spacecraft to shuttle cargo between the International Space Station and Earth in 2012. Musk eventually wants to send humans to space in the Dragon capsule and has plans to send humans to colonize Mars.
He teased his Martian ambitions on Instagram in September 2015, but has said he will describe them in detail in late 2015.