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.

"It kind of reads like Shackleton's ad for arctic explorers: difficult, dangerous, good chance you'll die, excitement for those who survive."

But for those who go, opportunity awaits. "There is going to be an explosion of entrepreneurial activity, because Mars will need everything from iron foundries to pizza joints," Musk said.

For the billionaire himself, that vision of forging a new frontier as an explorer is part of a mindset that's fueled his success: focusing on optimism and rejecting limitations.

"You want to wake up in the morning and think the future is going to be great, and that's what being a spacefaring civilization is all about," Musk said at the International Astronautical Congress in 2017. "It's about believing in the future and thinking that the future will be better than the past. And I can't think of anything more exciting than going out there and being among the stars."

Life on Mars is a goal of Musk's SpaceX, which aims to use reusable rockets to eventually create "a self-sustaining civilization" there, according to the company's website. At South by Southwest in 2013, Musk said he would personally go to Mars when the company could continue running in his absence.

"I will go if I can be assured that SpaceX would go on without me," he said. "I've said I want to die on Mars, just not on impact."

Although Musk has a lot to say about the end of the world on Earth — predicting artificial intelligence and an impending World War 3 may destroy civilization — remaining focused on improvement is a key driver for him.

"There are a lot of negative things in the world. There are a lot of terrible things that are happening all over the world, all the time," said Musk during an appearance on a panel for HBO's show "Westworld" at South by Southwest. "There are lots of problems that need to get solved, there are lots of things that are miserable and kind of get you down."

But Musk advises finding purposeful work and focusing on the positive change you can affect.

"Life can not just be about solving one miserable problem after another, that can't be the only thing," he says. "There need to be things that inspire you, that make you glad to wake up in the morning and be part of humanity."

For him, that's what makes tackling space flight, electric vehicles, tunnels, artificial intelligence, and perhaps a new media venture, worthwhile pursuits.

"The thing that drives me is that I want to be able to think about the future and feel good about that," Musk said in 2017 to the National Governors Association. "That we're doing what we can to have the future be as good as possible, to be inspired by what is likely to happen and to look forward to the next day.

"That's what really drives me, is trying to figure out how to make sure things are great."

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