Nasa said in a blog post on Saturday it is taking steps to potentially roll back the Artemis II rocket launch after discovering an interrupted flow of helium.

The agency said it is taking steps to roll the Artemis II rocket and Orion spacecraft back to the vehicle assembly building at the Kennedy Space Center in Florida.

“This will almost assuredly impact the March launch window,” Nasa said.

The agency observed overnight an interrupted flow of helium in the space launch system rocket’s interim cryogenic propulsion stage. Helium flow is required for launch.

Nasa had said on Friday it was targeting 6 March for the launch of four astronauts around the moon and back as part of its Artemis II mission after successfully completing a fueling test that had caused it to stand down earlier this month.

The Artemis II mission’s four astronauts, three Americans – Reid Wiseman, Victor Glover and Christina Koch – and one Canadian, Jeremy Hansen, were entering a second period of quarantine on Friday in anticipation of the new target launch date, which Nasa announced “with caveats” because it said there was still much preparatory work to do after Thursday’s fueling test.

Nasa has several dates available in early March to launch Artemis, which will conduct a 10-day trip around the moon, but not land. The flight will take humans further into space then ever before and, according to Nasa, the mission will fly about 4,700 miles (7,600km) beyond the far side of the moon, surpassing the distance record set by Apollo 13 in 1970. The mission will test systems for future deep-space exploration.

The mission is in preparation for Artemis III, scheduled for 2028, which will be the first human landing on the moon since the final Apollo program flight in December 1972.

Richard Luscombe contributed reporting