Elon Musk explains his motivation to succeed: "There need to be things that inspire you"

When famed explorer Ernest Shackleton was recruiting men to come along on his 1914 Imperial Trans-Antarctic Expedition, the story goes that he published this ad for the job: "Men Wanted for Hazardous Journey. Small Wages, bitter cold, long months of complete darkness, constant danger, safe return doubtful. Honour and recognition in case of success."

SpaceX founder Elon Musk says the pitch for early travelers to explore Mars will be much the same.

"The Moon and Mars are often thought of as some escape hatch for rich people, but it won't be that at all," he said at music and tech conference South by Southwest Sunday. "For the early people that go to Mars, it will be far more dangerous.