Recently, off the coast of Florida, a 22-story rocket hurtled out of the upper atmosphere, fired its engines, and briefly hovered upright over a stormy Atlantic ocean. The Falcon 9 launch vehicle was built by California space firm, SpaceX, and its progeny may revolutionize space travel—at least, that’s the hope.

Most space launches still run into the hundreds of millions of dollars. The Falcon 9 has already slashed costs to roughly $60 million. But that’s not enough for SpaceX CEO, Elon Musk. Early in the company’s history, Musk made it plain that to radically reduce costs, his firm would have to nail the holy grail—reusable rockets.

“If we become the biggest launch company in the world, making money hand over fist, but we’re still not reusable, I will consider us to have failed.”

He says the firm’s progress to date has been evolutionary, not revolutionary.

"Revolutionary" is too strong of a word. Musk will have to change the propulsion paradigm for that word to apply. To read more, click here.