NASA has postponed the pivotal fueling test for Artemis II because of a near-freezing chill in Florida, making a February space launch far less likely.

The so-called "wet dress rehearsal" will load the Space Launch System with 700,000 gallons of ultra‑cold propellants at the rocket's Kennedy Space Center launchpad in Cape Canaveral, Florida. The trial run, now targeted for Monday, Feb. 2, takes the countdown all the way to 29 seconds before liftoff, then stops.

How the test goes will determine when NASA actually lights those engines.

"We need to get through wet dress, we need to see what lessons we learn as a result of that, and that will ultimately lay out our path toward launch," Artemis launch director Charlie Blackwell‑Thompson said. "With a wet dress that is without significant issues, if everything goes to plan, then certainly there are opportunities within February that could be achievable."

Artemis II will be the agency's first flight to the moon with a crew in over 50 years. Three U.S. astronauts, Commander Reid Wiseman, pilot Victor Glover, and Christina Koch, and one Canadian astronaut, Jeremy Hansen, will ride in the Orion spacecraft, which they named Integrity. The 10-day journey, which could launch as early as Feb. 8, is a necessary flight test before NASA attempts to land astronauts on the lunar surface.

Here's how to watch NASA fill up the 322-foot mega moon rocket in this crucial test.

Artemis II launch director Charlie Blackwell-Thompson watches the mega moon rocket roll by the windows of the firing room.
Credit: NASA / Aubrey Gemignani

When is the wet dress rehearsal?

NASA has announced the wet dress rehearsal is now scheduled for Monday, Feb. 2 at 9 p.m. ET, two days later than officials had said earlier in the week, though the date and time could continue to change as the agency monitors weather and temperature conditions.

During the test, teams will fill the rocket with liquid oxygen and liquid hydrogen and rehearse every major step of launch‑day fueling. Controllers will run through all countdown procedures, including the final "terminal count," stopping at T‑29 seconds.

Will NASA broadcast the test?

Yes, although the agency has not released the link to the specific feed, NASA plans to stream the wet dress rehearsal live on its YouTube channel.

The individual stream links will be available on that page, "closer to activities," according to NASA. It's unclear how much forewarning the agency will provide. It's also likely NASA will broadcast the event on NASA+, its own free on-demand streaming service, though a placeholder link for it was not available as of midday Friday on the service's "scheduled events" page. Check NASA's Facebook page and X channel for coverage as well.

Since SLS rolled out to the pad on Jan. 17, NASA has maintained a steady 24-7 view of the rocket. But that feed won't be the one capturing the fueling test with commentary, according to officials.

From left, the Artemis II crew: Christina Hammock Koch, Jeremy Hansen, Victor Glover, and Reid Wiseman.
Credit: NASA / James Blair

What's the likelihood of success?

It's hard to predict the outcome of NASA's wet dress rehearsal, but how smoothly it goes will drive the launch timeline.

During Artemis I, NASA needed four fueling rehearsals because teams had trouble keeping the liquid oxygen cold enough, found hydrogen leaks where the ground pipes connect to the rocket, and ran into a problem with a valve that lets hydrogen flow back into the tank. From SLS's rollout in March 2022, it was an eight-month campaign before the rocket left Earth.

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But mission leaders say this time will be different. For Artemis II, they have changed how they pump the fuel, upgraded the connections between the rocket and the ground equipment, and redesigned and tested that troublesome valve with real super‑cold fuel.

"Why do we think that we'll be successful in Artemis II?" Blackwell-Thompson said. "It's the lessons that we learned."

When will Artemis 2 launch?

A launch window is the span of time when a rocket can lift off and still reach its planned destination in space. NASA has released the launch windows for February, March, and April. Mashable has provided an extensive explainer on launch opportunities for the upcoming crewed mission.

Because of the latest delays, that leaves only Feb. 8, 10, and 11 for this month before NASA starts looking into March. Despite having only publicized the launch dates through April, mission leaders said they actually have a handful of days available "in just about every month," Blackwell-Thompson said.