Artemis Moon rocket leaves launch pad... and heads to the hangar for repairs

Nasa's towering Artemis 2 rocket has departed the launch pad in Florida…

Unfortunately, not blasting upwards towards the Moon, but crawling slowly sideways to be repaired.

The 322-foot Space Launch System (SLS) rocket - about the height of Big Ben's Elizabeth Tower - has been moved back to a giant hangar called the Vehicle Assembly Building, where rockets are built and repaired at Kennedy Space Center.

The Artemis 2 mission will send four astronauts on a journey around the Moon.

The rocket, rolled out on 17 January, had been standing ready for more than a month as preparations were made for the launch, which was scheduled for February at the earliest.

Artemis 2 will not land on the Moon. But the 10-day mission is expected to take astronauts farther away from Earth than humans have ever been before.

Orion - the capsule where the astronauts sit - will fly thousands of miles beyond the far side of the Moon before heading home again.

A moon landing would take place during Artemis 3, which US President Donald Trump says he wants to see happen before the end of his second term in January 2029.

Engineers discovered a problem with the rocket's upper stage - the top section that gives the spacecraft its final powerful push into space.

A gas called helium was not flowing properly.

Helium is not used as fuel, but it plays a vital role. It helps push fuel through the rocket and keeps the fuel tanks at the correct pressure. Without it working perfectly, the rocket cannot launch safely.

This is the second delay to the mission launch.

Earlier, officials at Nasa had been feeling confident that the rocket was ready to fly by early March. Engineers had carried out a major practice run called a "wet dress rehearsal".

This is a full countdown test where the rocket is filled with real fuel - but the engines are not ignited. It allows teams to check that everything works properly before launch day.

This was the second time they had tried it. During the first attempt in February, engineers discovered leaks of liquid hydrogen, a very cold fuel used by the rocket.

Hydrogen is highly flammable, so even small leaks can be dangerous. The problem had to be fixed before testing could continue, which caused the first delay.

To fix the fault, the rocket has been slowly wheeled off the launch pad and back inside the enormous assembly building.

Moving the rocket slowly took over ten hours at the Kennedy Space Center in Cape Canaveral in Florida.

Now at the Vehicle Assembly Building, teams can safely inspect and repair it.

Due to the helium problem, Nasa is now aiming for 1 April at the earliest for a possible launch date.

The four Nasa astronauts who will sit in the Orion spacecraft at the top of the rocket are Americans Reid Wiseman, Victor Glover, Christina Koch, along with Canadian astronaut Jeremy Hansen.

Before launch, the four astronauts go into quarantine. This means they stay in a controlled environment and limit contact with other people so they don't catch illnesses like colds or flu.

For Artemis 2, the crew entered quarantine at Johnson Space Center in Houston, Texas, about two weeks before their planned launch. They can still speak to their families and mission teams, but visits are carefully controlled and everyone they meet must pass health checks.

When the launch was delayed, the astronauts were allowed to leave quarantine and return to more normal training. Once a new launch date is set, they will go back into quarantine again.