This is part of IEEE Spectrum's Special Report: Why Mars? Why Now?
In the history of life itself, there are only a handful of really big milestones: single-celled life, multicellular life, differentiation of plants and animals, life extending from the oceans to land, mammals, consciousness. On that scale, the next important step is obvious: making life multiplanetary. By that I mean the permanent extension of life beyond Earth. A goal like that, something that is important on the scale of life itself, deserves at least a small amount of our resources—less than we spend on health care but probably more than we spend on cosmetics.
To me, making life multiplanetary means going to Mars. We can skip Venus, whose atmosphere is highly acidic and roasting hot; Mercury, which is too close to the sun; and the moons of the gas giants, which are too far away from the sun. Mars alone is doable.
When I was studying physics in college, it seemed to me that space exploration was one of the three areas that would most affect the future of humanity, along with the Internet and sustainable energy. At the time, I didn’t expect to be personally involved in space, an arena I thought was so expensive that it could only be the province of government. As for the Internet, I wasn’t sure how I could earn a living in an industry that barely existed apart from university and government networks. Therefore, I started on the sustainable energy problem by trying to develop ultrahigh-energy capacitors for electric vehicles.
But in the summer of 1995, just before embarking on a Ph.D. program in materials science and applied physics at Stanford University, I realized that the Internet was entering a phase of exponential growth. I had the choice of either watching the Internet get built or helping to build it, and I felt pretty sure I could do something useful there while earning at least enough money to pay the rent (although at the time no one had made any significant money on the Internet). The capacitor research, on the other hand, seemed much less likely to succeed.
I applied to Netscape, the only major Internet software company at the time, but got no response, so I deferred grad studies to start my own company, Zip2. About four years later, Compaq bought Zip2 for US $300 million, allowing me to cofound PayPal, which eBay bought in 2002 for $1.5 billion. I then had enough capital to think seriously about space exploration (and sustainable energy, too—but that’s another story).
At first, I thought I’d use some of my PayPal money to popularize the idea of life on Mars. I settled on a mission called Mars Oasis, which would land a small robotic greenhouse that would establish life on another planet and show great images of green plants on a red background. It would get the public excited, and we’d learn a lot about what it takes to sustain plant life on the surface of Mars.
I quickly found that the biggest obstacle was the cost of the launch. A U.S. Delta II rocket would cost $60 million, while a refurbished Russian intercontinental ballistic missile would cost $10 million—without the necessary third stage.