Artemis moon mission ‘go’ for launch on Saturday, Nasa says

Nasa has given the green light for the 3 September launch of the Artemis I moon mission rocket and Orion spacecraft after its attempt on Monday was called off.

The American space agency said it has set a two-hour launch window for its 3 September attempt starting from 2.17pm EDT.

“We reviewed our risk acceptance rationale and our overall posture and we are setting up a launch attempt on 3 September, Saturday,” Artemis I mission manager Mike Sarafin said at a press briefing on Thursday.

Following the scrubbed attempt on 29 August due to a problem with one of the rocket’s engines, teams have updated procedures, practised operations and refined timelines, Nasa said in a blog post.

The problem on Monday began in the lead-up to the two-hour launch window at 8.33am EDT as controllers started what is called the engine bleed test.

The procedure allows some of the rocket’s cryogenic propellant to flow into the main engines to chill them down to handle the flows of liquid oxygen and liquid hydrogen necessary for launch.

But Nasa teams found Engine 3 was not properly being conditioned through the bleed process.

The space agency then officially scrubbed the launch at 8.36am EDT.

On Thursday, Nasa said in a statement that its teams have fixed the likely source of the leak, replacing a “flex-hose and a loose pressure sensor line”.

“Teams also retorqued, or tightened, the bolts surrounding that enclosure to ensure a tight seal when introducing the super-cooled propellants through those lines,” the space agency said.

It said teams would continue to monitor during fuelling operations, adding that no leaks were detected at ambient temperatures.

Nasa noted it is also tweaking the procedures that were followed during the Monday launch attempt.

It said teams would adjust protocols to chill down the engines about 30-45 minutes earlier in the countdown during the liquid hydrogen fast fill phase for the core stage.

The new process, it said, would provide additional time to cool the engines to appropriate temperatures for launch.

Meteorologists predict weather conditions would be 60 per cent favourable and are expected to improve throughout the window for Saturday.