The Space Barons is the story of a group of billionaire entrepreneurs who are pouring their fortunes into the epic resurrection of the American space program. Nearly a half-century after Neil Armstrong walked on the moon, the Space Barons--most notably Elon Musk and Jeff Bezos, along with Richard Branson and Paul Allen--are using Silicon Valley-style innovation to dramatically lower the cost of space travel in a bold quest to build a transportation network to the stars. These entrepreneurs have upended industry after industry and are now pursuing the biggest disruption of all--space--in an effort to make it more accessible to the masses. It's a challenge unlike anything they previously attempted, a grand adventure filled with risk, failure, and ultimately, a series of triumphant breakthroughs. Based on years of reporting and exclusive interviews with all four billionaires, The Space Barons is the ultimate drama of risk and adventure. It is also a classic story of rivals--hard-charging startups warring with established contractors and the personal clashes of the leaders of this new space movement, particularly Musk and Bezos, as they aim for the moon and Mars and beyond.