Reusable rocket

Rockets used to be thrown away after one launch, falling into the sea. A reusable rocket sends its cargo up, then restarts its engines to slow down and lands upright on the ground or on a ship at sea.

SpaceX's Falcon 9 made recovering and reusing its lower stage an everyday event. Now there are attempts to reuse the whole rocket, and companies in several countries are working to catch up.

Imagine how expensive a ticket would be if a plane were thrown away after one flight. Rocket prices have dropped a lot because rockets are now used again.

It is the biggest change that lowered launch costs. It is also why businesses that put thousands of satellites in orbit became possible.