This is a huge step forward in SpaceX's quest to build reusable rockets. This landing was a moment SpaceX has been working toward for years.
Here's what the historic landing looked like, which the company broadcast live:
The company has already landed a rocket on land, but this is the first time it has successfully landed a rocket at sea. A sea-based landing is a much more challenging feat, because the landing platform is a moving target getting tossed around in the water.
The company will now have to inspect the rocket to see if it's ready to fly again.