Elon Musk has halted the launch of the world's largest rocket, Starship, after a technical issue forced the billionaire to push back the mission by 48 hours.

SpaceX's super heavy rocket had been due to take off at 2.20pm UK time, however engineers called a halt to the countdown clock 40 seconds before the launch. 

The 390ft rocket, designed to one day carry humans to the Moon and Mars for Nasa, will remain on the launch pad at the billionaire's SpaceX spaceport in Boca Chica, Texas. 

As engineers discussed delaying the mission, Mr Musk said: "A pressurant valve appears to be frozen, so unless it starts operating soon, no launch today."

The company had started fuelling the rocket and preparing for its mission, which would have seen the two-stage Starship rocket take off and fly to a distance of 150 miles above the earth. 

Shortly after 2pm, John Insprucker, SpaceX's principal engineer, told the company's livestream: "The decision right now is that we are going to stop the launch for today." 

Mr Insprucker said the rocket's team had identified a pressurisation issue while fuelling the giant launch vehicle. The launch was pulled in favour of a dress rehearsal of the final mission.

Mr Musk later added: "Learned a lot today, now offloading propellant, retrying in a few days."

Starship's rocket is made up of two stages: a 230ft booster rocket, called Super Heavy, and the 164ft Starship module, that will one day carry cargo and crew. 

Both parts of the rocket are designed to be reusable. The rockets can descend back to earth so they can be recovered and fly again. For the first mission, Super Heavy is expected to splash down in the Gulf of Mexico, while Starship will land in the Pacific. 

Kate Tice, a SpaceX engineering manager, said: "We are expecting a minimum of 48 hours to recycle. We unfortunately had a hold on the countdown today."

SpaceX's Starship is bigger than the Saturn V rocket that carried astronauts to the Moon in the 1960s and 70s. The company is working with Nasa on a return to the lunar surface as early as December 2025.

Catch up with SpaceX's video below to see how the day unfolded.