NASA Begins Mock Artemis 2 Launch Countdown Ahead of Fueling Test

The upcoming mission to send three Americans and one Canadian on a 10-day trip around the moon is the first U.S. human lunar venture in more than half-a-century.

Published on Feb. 24, 2026

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NASA has begun a countdown and fueling test for its SLS rocket at the Kennedy Space Center that will determine an Artemis 2 launch date. The test, known as a wet dress rehearsal, includes a mock countdown and the fueling and draining of the Space Launch System (SLS) rocket. The launch rehearsal is the second such preflight test NASA is conducting in February after the first one ended with the discovery of an issue with the SLS that caused the Artemis 2 mission to slip at least a month.

Why it matters

The upcoming Artemis 2 mission is the first U.S. human lunar venture in more than half-a-century, and the outcome of this wet dress rehearsal will be critical as NASA looks to commit to another launch date. While Artemis 2 could still get off the ground as early as the first week of March, that launch could fall even further into 2026 if NASA's repairs to the SLS are found to be insufficient.

The details

The test comes after teams replaced a filter in ground support equipment. Ground teams will evaluate whether replaced seals on the rocket will prevent further liquid hydrogen leaks. The simulated launch window is scheduled to open at 8:30 p.m. ET Feb. 19, with the test lasting for up to four hours.

  • The countdown kicked off around 7 p.m. ET Tuesday, Feb. 17.
  • As of 7 a.m. ET, Feb. 19, teams had begun configuring the rocket with gas nitrogen.

The players

NASA

The National Aeronautics and Space Administration, an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and space research.

Space Launch System (SLS)

NASA's massive moon rocket that will launch the Artemis 2 mission.

Orion capsule

The spacecraft that will carry the Artemis 2 crew, built by Lockheed Martin.

Reid Wiseman

NASA astronaut who is part of the Artemis 2 crew.

Victor Glover

NASA astronaut who is part of the Artemis 2 crew.

Christina Koch

NASA astronaut who is part of the Artemis 2 crew.

Jeremy Hansen

Canadian Space Agency astronaut who is part of the Artemis 2 crew.

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What’s next

NASA will conduct an analysis known as a flight readiness review in which they assess a variety of factors, including the status of the spacecraft, before committing to a new launch date for Artemis 2.

The takeaway

The outcome of this wet dress rehearsal will be critical in determining when NASA can launch the Artemis 2 mission, the first U.S. human lunar venture in more than half-a-century, as the agency works to resolve issues with the SLS rocket and commit to a new launch date.