Elon Musk renames 'BFR' rocket to 'Starship' ahead of planned SpaceX trips to the Moon and Mars

Elon Musk has renamed the BFR, the spaceship that he hopes will carry humans to Mars.

It will now be known as Starship, he said, though the bottom part will have a separate name.

The BFR name had always been slightly controversial and strange: while SpaceX officially insisted it was short for "Big Falcon Rocket", the F really seemed to stand for something a little more explicit.

Mr Musk announced its new name on Twitter, giving little context for the change and no explanation of why it had happened.

"Renaming BFR to Starship," he wrote in the first post, in a characteristically short but momentous post. "Technically, two parts: Starship is the spaceship/upper stage & Super Heavy is the rocket booster needed to escape Earth’s deep gravity well (not needed for other planets or moons)," a follow-up read.

The spaceship – whatever its name – is SpaceX's big hope for the future of space travel. The company hopes that it will eventually replace not only the existing modes of deep space transport but its existing rockets and spacecraft, too.

Eventually, SpaceX hopes to use the Starship to carry people to Mars, where they will live, and possibly even beyond. In the shorter term, the company is aiming for a 2023 mission that will see a Japanese billionaire pay for a host of space tourists to take a trip around the Moon – if the Starship, which will cost around $5 billion to build – is ready in time.

Starship is actually the spacecraft's fourth name. Before it was known as the BFR, the spaceship was known as the Interplanetary Transport System or ITS – and before that it was called the Mars Colonial Transporter, or MCT, marking it out as part of Mr Musk's plan to send people to take over Mars.