SpaceX launched one of its Falcon 9 rockets on Sunday, only to watch it erupt in a ball of fire.

But the explosion was intentional and went exactly as planned. It was the final step in a long process of testing the company's Crew Dragon capsule a spaceship designed to carry astronauts to and from the International Space Station.

Boeing has designed a similar spacecraft, and the two companies are racing to fly NASA astronauts on US-made spacecraft for the first time in nearly a decade.

Since NASA ended its space-shuttle program in 2011, the agency has relied exclusively on Russia to ferry its astronauts to and from orbit in Soyuz spacecraft. But those seats have gotten increasingly expensive: A single round-trip seat now costs NASA about $85 million. So the space agency launched its Commercial Crew program to spur the development of new American-made spacecraft.

The program put private companies in competition for billions of dollars' worth of government contracts. SpaceX and Boeing came out on top.

SpaceX's latest test has teed Elon Musk's rocket company up to launch its first-ever human passengers this spring.

"This critical test puts us on the cusp of once again launching American astronauts on American rockets from American soil," Jim Bridenstine, NASA's administrator, tweeted shortly after the mission.

Here's how SpaceX and Boeing became NASA's best shot at resurrecting American spaceflight.

Read the original here:

How SpaceX and Boeing became NASA's best shot to revive US spaceflight - Business Insider