Here's why landing a rocket on a ship just might save humanity

Remember this day: Friday, April 8, 2016.

It's when SpaceX, a company led by tech entrepreneur Elon Musk, may have pushed the course of human history more rapidly toward the stars.

Minutes after SpaceX successfully launched a 229-foot-tall Falcon 9 rocket from Cape Canaveral, Florida, the first and biggest part of it fell back to Earth.

But that multi-million-dollar rocket stage did not become junk at the bottom of the ocean, like nearly all rockets before it.

Instead, the rocket stage landed itself on an autonomous drone ship in the Atlantic Ocean.

Here's how SpaceX pulled off the incredible feat and what it might mean for the future of humanity.