Elon Musk's SpaceX project is a quest to make space travel more economical. A key part of that quest is making reusable rockets: Rocket boosters usually burn or up crash into the ocean, but the Tesla and PayPal founder hopes to make them work more like airplanes -- flying, landing, and then flying again.

Newly released slow-motion video of an attempt to land a booster on a floating platform (dubbed "Just Read The Instructions") in the sea shows just how close SpaceX was to pulling the feat off earlier this week.

The booster, from a rocket delivering supplies to the International Space Station, can be seen extending landing gear as it makes the descent towards the platform -- an awfully small target in a big ocean. But it comes down too hard and tips over, resulting in a fiery flash.

This was SpaceX's second attempt to land its rocket on a such a platform. A January attempt also failed, while another recently planned try was scrapped due to sea conditions.

This graphic explains how the landing is supposed to work: