SpaceX just launched its seventh Falcon 9 rocket of the year. Riding atop the rocket was a Dragon capsule — but this isn't just any Dragon.

This was the first reused Dragon capsule that SpaceX has ever launched. The Dragon is designed to lift thousands of pounds of cargo to astronauts on board the International Space Station.

However, each time SpaceX has sent supplies to the ISS, its Dragon capsule has been condemned to burn up in the atmosphere. It's a waste and is exactly what SpaceX is fighting with its efforts to build fully reusable rockets.

Now, it has taken one step closer toward achieving that goal by launching a reused Dragon spacecraft, which it retrieved last year.

SpaceX has three main components it would like to have fully reusable: the first stage and second stage of its Falcon 9 rockets and its Dragon spacecraft.

It has now successfully reused two of those three major components, marking a new milestone for the space company.

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