NASA's dress rehearsal for $4.1 billion Artemis I rocket launch is delayed

Artemis I might not be heading to the moon quite as soon as planned.

The mission was scheduled for a "wet dress rehearsal" this weekend to allow NASA teams to simulate launch procedures without actually igniting the rocket and sending it into space.

Artemis I is the first in a series of increasingly complex missions aimed at making human exploration of the moon and Mars possible, according to NASA.

This afternoon, NASA announced that the 5.75 million-pound craft was struggling to pressurize its mobile launcher. That process is crucial to keeping hazardous gases from disturbing the rocket as it is pumped full of 700,000 gallons of cryogenic fuel.

In a tweet, NASA said it was assessing next steps for the rehearsal, including a media briefing this evening and a potential second try at a run-through Monday, April 4.

Despite the looming threat of lightning strikes, as of Sunday morning, things were looking good for the mission: Teams were approved to begin tanking the rocket and meteorologists confirmed that there were no weather violations.

An official launch date for Artemis has not been scheduled and is dependent on the success of this dress rehearsal. A lot is riding on this mission, as the rocket is reportedly the most expensive ever built.

There are no astronauts aboard Artemis I, but its launch will prepare NASA to send a human crew into space on the more complex follow-up mission Artemis II.