A second fueling test on NASA’s Space Launch System rocket ended Thursday night, giving senior managers enough confidence to move forward with plans to launch four astronauts around the Moon as soon as March 6.

Unlike the first attempt to load propellants into the SLS rocket on February 2, there were no major leaks during Thursday’s practice countdown at Kennedy Space Center in Florida. Technicians swapped seals at the launch pad after hydrogen gas leaked from the rocket’s main fueling line earlier this month. This time, the seals held.

“For the most part, those fixes all performed pretty well yesterday,” said Lori Glaze, acting associate administrator for NASA’s exploration programs. “We were able to fully fuel the SLS rocket within the planned timeline.”

The results keep the Artemis II mission on track for liftoff as soon as next month. NASA gave up on a series of February launch opportunities after encountering a persistent hydrogen leak during the first Wet Dress Rehearsal (WDR).

“We’re now targeting March 6 as our earliest launch attempt,” Glaze said. “I am going to caveat that. I want to be open, transparent with all of you that there is still pending work. There’s work, a lot of forward work, that remains.”

If teams complete all of that work, liftoff of the Artemis II mission could occur within a two-hour window opening at 8:29 pm EST on March 6 (01:29 UTC on March 7). NASA has other launch dates available on March 7, 8, 9, and 11, but the mission may have to wait until April. There are approximately five days per month that the mission can depart the Earth after accounting for the position of the Moon in its orbit, the flight’s trajectory, and thermal and lighting constraints.

The Artemis II mission will last between nine and 10 days, taking NASA’s Orion spacecraft with commander Reid Wiseman, pilot Victor Glover, and mission specialists Christina Koch and Jeremy Hansen around the far side of the Moon before returning to Earth for splashdown in the Pacific Ocean. Wiseman’s crew will set the record for the farthest humans have ever traveled from Earth, and will become the first people to fly to the vicinity of the Moon since 1972.