SpaceX's Falcon 9 Rocket failed to successfully land after being launched into space Sunday.

The rocket returned to a floating barge in the Pacific Ocean and tried to land, but one of its legs gave out sending the rocket toppling over and exploding when it hit the surface, Independent reports.

Elon Musk's space company SpaceX has been trying to successfully land a rocket back on Earth's surface, but again the rocket failed to complete a successful landing at sea. SpaceX last attempt to land a rocket on land succeeded. 

Video Shows the Rocket Toppling Over

Video of the landing shows the rocket coming down quickly and landing. At first, it appears the rocket landed successfully, but one of its legs breaks and the rocket starts to topple over on its side. When it hits the barge's surface, the rocket bursts into flames.

Musk said one of the Falcon 9 Rocket's legs failed to lock into place upon landing and that is the reason why it broke, causing the rocket to fall over.

Reusable Rockets

SpaceX's goal is to land the rockets safely every time. If the rockets are able to land successfully each time, it means they could be reused for future missions. SpaceX says reusing rockets will greatly decrease the cost of space travel. With three failed landings at sea, it might be a while before SpaceX succeeds in their goal.

SpaceX has tried twice prior to Sunday's attempt to land a rocket successfully at sea. The first attempt was a failure because the rocket landed too fast. The second attempt was also a failure because the barge the rocket tried to land on was moving horizontally and caused the rocket to fall over.

Future Rockets Could Explode Too

Musk admits that SpaceX could have further unplanned explosions when testing rockets in the future, but he is confident that the company is making progress with its test.

SpaceX's main mission with the Falcon 9 Rocket was to deliver a payload up into space and they were successful in that.

Watch the video below.