NASA will retest Artemis 2 moon rocket after discovering fueling issues
NASA will fuel its moon rocket again this week, giving launch teams another dress rehearsal before the Artemis II test flight.
The U.S. space agency is targeting Thursday, Feb. 19, for the second "wet dress rehearsal," a practice countdown that uses real fuel but stops short of liftoff. Engineers replaced a filter in ground support equipment over the weekend and reconnected the line.
This redo test comes more than two weeks after a wet dress rehearsal hampered by hydrogen fuel leaks — the same issues that plagued Artemis I's launch in 2022. Hydrogen is notoriously susceptible to leaks because its small, lightweight molecules can seep out of minuscule cracks and crevices.
The rehearsal is critical to launch Artemis II, the first crewed mission to the moon in over 50 years. By running a realistic countdown and fueling sequence, engineers can confirm that the rocket, ground systems, and launch team all work together before committing to an actual launch attempt.
Mission leaders have identified March 6 as the earliest possible launch opportunity if the test goes well. Artemis II will send Commander Reid Wiseman, pilot Victor Glover, Christina Hammock Koch, and the Canadian Space Agency's Jeremy Hansen on a 10-day journey around the moon without landing, testing the Orion spaceship's life-support systems. It's a key step before NASA feels ready to put boots on the lunar surface in Artemis III.
"This is the first time this particular machine has borne witness to cryogens," said Amit Kshatriya, NASA associate administrator, referring to the ultra-cold liquid propellants. "How (the rocket) breathes and how it vents and how it wants to leak is something we have to characterize."
On Feb. 12, NASA performed an unannounced partial fueling test. That exercise provided some data for teams to pinpoint a trouble spot in the equipment suspected of restricting the flow of hydrogen into the Space Launch System rocket.
During the test on Thursday, NASA will load 700,000 gallons of propellant into the rocket and walk through the same steps they would follow on launch day. They will conduct a full countdown, practice holding and restarting the clock, and then drain the tanks to rehearse a scrub, or a canceled launch scenario.
Although the Artemis II astronauts will not participate, a separate team will head to the launchpad to practice Orion closeout work, including shutting the hatches. These are the same tasks performed shortly before a real launch and help ensure crews can move efficiently under tight timelines.
Controllers will also rehearse the final stretch of the countdown, known as the terminal count, which covers the last 10 minutes before liftoff. They plan to run that segment twice, pausing at 1 minute and 30 seconds, then again near the half-minute mark, before recycling the clock back to 10 minutes and repeating the sequence. This approach lets teams practice how they would respond to delays caused by weather or technical issues.
How to watch the wet dress rehearsal
Launch controllers reported to their consoles at Kennedy Space Center in Cape Canaveral, Florida, at 6:40 p.m. ET Tuesday to begin a nearly 50-hour lead-up to a mock launch. The simulated launch time is scheduled for 8:30 p.m. on Thursday, Feb. 19, with a four-hour window to complete the test.
NASA will provide a livestream video feed with additional camera views during the test, as well as share real-time updates on the Artemis blog, for the public to follow along.
"We try to test like we fly," said John Honeycutt, head of the Artemis II mission management team. "But this interface is a very complex interface."
Mission leaders won't set a formal launch date until engineers have reviewed the rehearsal data.