Critical test for NASA's Artemis 1 moon megarocket kicks off today

The Artemis 1 moon mission is about to embark on a critical prelaunch test.

The dress rehearsal for Artemis 1 will begin at Launch Pad 39B at Kennedy Space Center in Florida. The three-day test will take the Artemis 1 stack and the SLS megarocket to ensure that its various systems are behaving as expected. The test will see the mission team walk through the steps of a real launch.

The wet dress will start at 5 p.m. There is a call to stations at 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846

NASA's Artemis 1 moon mission is explained in photos.

The call to stations is a big milestone, because it is the time in which we are calling our teams, notifying them that the wet dress rehearsal test is officially underway.

The call to stations starts the clock for the test. Within the next 24 hours, Artemis 1 team members will check off a number of boxes, from filling the water tanks of the launch pad to power up the SLS core stage.

Most of the action will take place on Sunday. The team will pump more than one million gallons of propellant into the SLS tanks.

The time was at around 2:25 p.m. According to a NASA wet dress rehearsal explainer, on Sunday, the launch director will ask the team if they are ready to enter terminal count.

When it will be stopped, that count will go down to 33 seconds. The team will run through the steps again less than 10 seconds before the liftoff.

NASA doesn't plan to provide live commentary or stream the Artemis 1 team's communications, so you won't be able to follow these steps closely in real time. You can follow the agency's updates online, on its Artemis blog and on the micro-blogging site, micro-blogging site. During the test, NASA will stream video of the Artemis 1 stack on the launch pad.

The results of the wet dress rehearsal will be used by NASA to further prepare for Artemis 1, which will send an uncrewed Orion on a roughly month-long mission around the moon. Artemis 1 is expected to lift off in June, but the team has not set a target date.

Mike Wall is the author of Out There, a book about the search for alien life. You can follow him on social media. Follow us on social media.