The launch of NASA’s new Artemis I Moon rocket is facing a potentially lengthy delay after a second postponement.
Controllers tried and failed again on Saturday to get the Space Launch System (SLS) vehicle to lift off. They were thwarted by a fuel leak.
Engineers now want to inspect the rocket, and any repairs may need to happen in the workshop rather than on the launch pad.
The whole process is certain to lead to a setback of several weeks.
It means we may not see a third launch attempt before mid-October at the earliest.
The SLS is the most powerful rocket ever developed by the US space agency, and is designed to send astronauts and their equipment back to the Moon after an absence of 50 years.
Much of the enormous thrust comes from burning almost three million litres of super-cold liquid hydrogen and oxygen in four big engines on the vehicle’s underside.
But when controllers sent the command early on Saturday morning to fill the rocket’s hydrogen tank, an alarm went off, indicating there was a leak.
The problem was traced to the connection where the hydrogen was being pumped into the vehicle.
Controllers tried a number of fixes, including allowing the hardware to warm up for short periods to reset the seal, but they were not successful. (BBC)