NASAs planned mission to return humans to the moon will be delayed again after engineers discovered an interrupted flow of helium to the Artemis II Space Launch System rockets interim cryogenic propulsion stage.
This is the second time the astronauts two-week quarantine has been interrupted because of a mechanical issue. NASA announced last week that the launch could occur as soon as March 6.
The agency now targets an April launch.
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NASA plans to roll Artemis II and its Orion spacecraft off the launch pad Wednesday. The four-mile move to the Vehicle Assembly Building is expected to take about 12 hours.
Teams are reviewing potential causes of the issue, including the interface between ground and rocket lines used to route helium, a valve in the upper stage, and a filter between the ground and rocket, NASA said in a statement. They also are reviewing data from Artemis I, in which teams had to troubleshoot helium-related pressurization of the upper stage before launch.
The mission was previously postponed about four weeks after the agency found a problem with Orions liquid hydrogen tank during a rehearsal. The tank leaked excessive liquid hydrogen into the rockets core stage. Liquid hydrogen is used as a propellant.
Artemis I, launched in 2022, was the first mission in NASAs Artemis program, which aims to pave the way for deep space exploration beyond the moon. While Artemis I was uncrewed, Artemis II will send four astronauts on a lunar flyby. Artemis III is expected to include a crewed mission to the moons surface.
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The last time NASA sent astronauts to the moon was in 1972 during the Apollo 17 mission.