Nasa conducts second rocket fuel test ahead of Artemis moon mission

Nasa has taken another crack at fuelling its giant moon rocket after leaks halted a initial dress rehearsal and delayed the first lunar trip by astronauts in more than half a century.

For the second time this month, launch teams pumped more than 700,000 gallons (2.6 million litres) of supercold fuel into the rocket atop its launch pad at Kennedy Space Centre in Florida.

Engineers counted all the way down to the half-minute mark as planned, then turned back the clocks to run through the final 10 minutes again.

Nasa completed the test late at night and said there was minimal hydrogen leakage, well within safety limits.

It was the most critical and challenging part of the two-day practice countdown.

Engineers are analysing the data, with the outcome determining whether a March launch is possible for the Artemis II moon mission with four astronauts.

In a positive sign, the US-Canadian crew prepared to enter a two-week quarantine period on Friday to provide what Nasa called flexibility within the March launch window. Three of the astronauts joined the launch team on Thursday to monitor progress.

During the rehearsal two weeks ago, dangerous amounts of supercold liquid hydrogen escaped from the connections between the pad and the 322ft (98-metre) Space Launch System rocket.

Engineers replaced a pair of seals and a clogged filter in hopes of getting through the repeat test at Kennedy Space Centre. Nasa said Thursday’s results gave engineers confidence in the new seals.

The soonest the astronauts could soar is March 6. They will become the first people to fly to the moon – making a 10-day out-and-back trip with no stops – since Apollo 17 in 1972. They will not orbit or land.

Nasa has been battling hydrogen fuel leaks ever since the space shuttle era, which provided many of the SLS engines. The first Artemis test flight without anyone on board was grounded for months by leaking hydrogen before finally blasting off in November 2022.