NASA conducts second rocket fueling test that will decide when Artemis astronauts head to the moon

CAPE CANAVERAL, Fla. (AP) — NASA took another crack at fueling its giant moon rocket Thursday after leaks halted the 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 began pumping more than 700,000 gallons (2.6 million liters) of supercold fuel into the rocket atop its launch pad.

It’s the most critical and challenging part of the two-day practice countdown. The outcome will determine whether a March launch is possible for the Artemis II moon mission with four astronauts.

During the rehearsal two weeks ago, dangerous amounts of supercold liquid hydrogen escaped from the connections between the pad and the 322-foot (98-meter) 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 Center.

NASA won’t set a launch date for the Artemis II mission until it passes the fueling demonstration. Like last time, the crew — three Americans and one Canadian — watched the test from afar.

The soonest 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 won’t 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.

Going years between flights exacerbates the problem, according to NASA’s new administrator Jared Isaacman, a tech entrepreneur who financed his own trips to orbit through SpaceX.

Just two months into the job, Isaacman already is promising to redesign the fuel connections between the rocket and pad before the next Artemis III launch. Still a few years away, that mission will attempt to land two astronauts near the moon’s south pole.

“We will not launch unless we are ready and the safety of our astronauts will remain the highest priority,” he said last week on X.

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