For the second time in a week, Nasa has had to postpone the launch of its new Artemis I Moon rocket.
A liquid hydrogen leak forced the cancellation of the unmanned test flight.
The US Space Agency attempted to launch the Space Launch System (SLS) rocket on Monday but postponed the launch just 40 minutes before lift-off due to engine difficulties.
Engineers now want to check the rocket, and any repairs may have to be done in the workshop rather than on the launch pad, which means we may not see a third launch attempt until next month.
What Happened?

The Space Launch System, Nasa’s Moon rocket, is the largest and most powerful rocket ever created by Nasa.
It will be used to transfer humans and equipment to the Moon.
The SLS’s immense power is derived in part by the combustion of about three MILLION liters of super-cold liquid hydrogen and oxygen in four large engines.
However, when engineers began to fill the rocket’s hydrogen tank, an alarm went out, indicating that there was a leak.
Controllers attempted many methods to resolve the issue but were unsuccessful.
Mike Sarafin, Nasa’s Artemis mission manager, stated that the rocket’s critical future role in human spaceflight necessitated utmost caution.
He remarked: “We’ll fly when we’re ready.”
“And as part of this maiden test flight, we’re learning about the vehicle and how to operate it,” he continued.

A third lift-off attempt before the middle of October is improbable if the spacecraft is rolled back to the engineering building a few miles distant.
Nasa went on to say that the choice to attempt a third launch “will basically depend on the possibilities that the team comes back with, which is likely on Monday or early Tuesday morning.”