Daniel wants to know why SpaceX exists if NASA already goes to space.

The answer starts with a man who flew to Moscow to buy a rocket -- and came home empty-handed.

NASA is a government agency. Funded by taxpayers, answerable to Congress, its job is to push the frontier -- deep space, scientific missions, things nobody has done before. That has always been its purpose. But for decades, getting to space at all was extraordinarily expensive. The main stages of most rockets were used once and then lost. They fell into the ocean or burned up in the atmosphere. Launching to space cost hundreds of millions of dollars in many cases. And everyone accepted it, because that was simply how rockets worked.

In 2001, Elon Musk had recently sold PayPal and had a different idea. He wanted to inspire people to care about space again. His plan wa ...