The crucial test, known as the wet dress rehearsal, simulates every stage of launch without the rocket leaving the launchpad at Kennedy Space Center in Florida.
This process includes loading supercold propellant, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.
The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.
Three previous attempts at the wet dress rehearsal in April were unsuccessful, concluding before the rocket could be fully loaded with propellant due to various leaks, which according to NASA have since been corrected.
Wet dress rehearsal: What to expect
The Artemis rocket will begin its next attempt at the wet dress rehearsal Saturday at 5 p.m. ET. with a “call to stations,” when all of the teams associated with the mission report that they’re ready for the test to begin.
Preparations over the weekend will set up the Artemis team to start loading propellant into the rocket’s core stage and upper stage on Monday, June 20.
A two-hour test window will begin in the afternoon, with the Artemis team targeting the first countdown at 2:40 p.m. ET.
First, they will go through a countdown to 33 seconds before launch, then stop the cycle. The clock will be reset, then the countdown will resume again and run until about 10 seconds before a launch would occur.
The previous wet dress rehearsal attempts have already completed many objectives on the list to prepare the rocket for launch, said Charlie Blackwell-Thompson, Artemis launch director for NASA’s Exploration Ground Systems Program, during a news conference on Wednesday.
“We hope to finish them off this time around and get through the cryogenic loading operations along with terminal count,” she said. “Our team is ready to go and we’re looking forward to getting back to this test.”
Once the Artemis rocket stack completes its wet dress rehearsal, it will roll back into the space center’s Vehicle Assembly Building to wait for launch day.
There is a long history behind the arduous process to test new systems before launching a rocket, and what the Artemis team is facing is similar to what the Apollo and shuttle era teams experienced, including multiple test attempts and delays before launch.
“There’s not a single person on the team that shies away from the responsibility that we have to manage ourselves and our contractors and to deliver, and deliver means meeting those flight test objectives for (Artemis I), and meeting the objectives of the Artemis I program,” said Jim Free, associate administrator for NASA’s Exploration Systems Development Mission Directorate, during the news conference.