NASA has targeted Thursday, February 19, 2026, at 8:30 p.m. EST for the Artemis II wet dress rehearsal — the final major systems verification before the agency's first crewed lunar flyby in more than half a century.
Launch controllers began the nearly 50-hour countdown sequence on February 17 at 6:40 p.m. EST at Kennedy Space Center, Florida. If the rehearsal proceeds on schedule, it would clear the path to an earliest launch opportunity of March 6, 2026 for the actual crewed mission.
A wet dress rehearsal — the "wet" referring to the loading of cryogenic propellants into the rocket's tanks — is the most comprehensive test short of an actual launch attempt. For Artemis II, the exercise will walk the launch team through loading liquid hydrogen and liquid oxygen into the Space Launch System core stage and upper stage, running a full terminal countdown sequence, and demonstrating the ability to recycle the clock and drain the tanks safely. The team will conduct two terminal count sequences, pausing at T-minus 1 minute 30 seconds and T-minus 33 seconds before recycling to T-minus 10 minutes. The total test window is four hours.
Notably, the four Artemis II astronauts — Reid Wiseman, Victor Glover, Christina Koch, and Canadian Space Agency astronaut Jeremy Hansen — will not participate in the rehearsal itself. Ground teams will conduct spacecraft closeout procedures and hatch closure in their place.
The test follows resolution of a technical setback from a February 12 test, when teams identified a suspected filter issue in ground support equipment affecting liquid hydrogen flow. Technicians replaced the component before proceeding to the rehearsal attempt. That engineers diagnosed and corrected the problem within days is a sign of the program's operational maturity — a sharp contrast to the multiple scrub cycles and extended delays that pushed the Artemis I uncrewed test flight through repeated wet dress rehearsal attempts in 2022 before finally launching in November of that year.
The Artemis II mission will send its four-person crew on a free-return trajectory around the Moon — a figure-eight path that loops behind the lunar far side and returns to Earth without entering orbit. The mission is not a landing; it is a high-stakes systems validation of the Orion spacecraft's life support, communications, and crew interfaces under actual deep-space conditions. It will be the first time humans have traveled beyond low-Earth orbit since Gene Cernan departed the lunar surface in December 1972.
In space exploration, as across technological frontiers, engineering constraints meet human ambition — and occasionally, we achieve the impossible. The Artemis architecture represents a fundamentally different model from Apollo. Where Apollo was built and operated exclusively by government, Artemis integrates commercial partners at every layer: SpaceX's Starship serves as the Human Landing System for eventual surface missions, while commercial logistics providers will support the planned Gateway lunar orbital station intended as a staging post for sustainable lunar presence and eventual Mars missions.
A successful wet dress rehearsal tomorrow would mark a genuine inflection point. The program has faced persistent cost overruns, schedule pressure, and political scrutiny over NASA's reliance on the government-built SLS versus a purely commercial launch architecture. But the engineering is now at the threshold — the countdown clock is running, the pad is configured, and the rocket is stacked. For the Artemis II crew, and for the lunar program more broadly, the next 48 hours matter.
