Elon Musk's SpaceX has successfully completed a world first test, landing part of their Starship back onto its launch pad.
This means the company's plan to develop a fully reusable and quickly deployable rocket is a lot closer.
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.
Since last month the agency and Elon Musk have been in a public spat after the FAA said it was seeking to fine his company, SpaceX, $633,000 for allegedly failing to follow its license conditions and not getting permits for previous flights.
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, hitting back against "false reporting" that part of the rocket was polluting the environment.
Filmed and edited by Beatrice Guzzardi.
Produced by Ian Casey.