Nasa’s Artemis 1 Moon rocket launch has been postponed due to an issue with one of the engines.
The rocket had been due to take off from the Kennedy Space Centre in Cape Canaveral, Florida, during a two-hour window after 1.33pm BST, but was called off by the launch director moments before.
The space agency said: “Launch director Charlie Blackwell-Thompson has called a scrub of the attempt of the launch of Artemis 1.
“The issue that came up was an engine bleed which couldn’t be remedied but the rocket is currently in a stable configuration.
“It was mostly tanked but not completely tanked.
“Engineers are now working on a plan to continue gathering data about this particular engine and the bleed that didn’t work out.”
Nasa added that the first opportunity for the next launch attempt will be September 2 depending on how the engine bleed develops.
The unmanned flight marks the next chapter in putting humans back on the Moon, and is the first in Nasa’s Artemis programme.
There will be astronauts on board for subsequent missions, with the first crewed flight into space scheduled for 2024.
Nasa expects the first Artemis astronauts to land on the Moon in 2025.