Watch: Why is the latest SpaceX rocket test a big deal?

Elon Musk's SpaceX has successfully completed a world first test, landing part of their Starship back onto its launch pad.

The BBC's science correspondent, Pallab Ghosh, explores why this "incredibly difficult" operation is a big deal for future exploration and what environmental concerns people may have about it.

The Federal Aviation Administration (FAA) , the US government body that approves all flights, had previously said there would be no launch before November as it reviewed the company's permits.

Before issuing a license, the FAA reviews the impact of the flight, in particular the effect on the environment.

In response to the fine, Musk threatened to sue the agency and SpaceX put out a public blog post, external hitting back against "false reporting" that part of the rocket was polluting the environment.

Filmed and edited by Beatrice Guzzardi.

Produced by Ian Casey.