This morning, NASA officially announced a no earlier than March 6th target launch date for Artemis II. That date is contingent on completion of some work at the launch pad, and a positive result from the upcoming Launch Readiness Review, which is scheduled for late next week.
When NASA wrapped up the first Artemis II wet dress rehearsal on February 3 at Kennedy Space Center, they had successfully filled the SLS rocket’s tanks with cryogenic propellant. That was the good news, but the less welcome bad news was that the test revealed higher-than-allowable hydrogen gas leaks at the Tail Service Mast Unit on the launch pad. Obviously, those leaks must be repaired before a launch attempt.
Not long after propellant draining was complete after WDR-1, technicians began working to access the TSMU umbilical. They detached both the rocket-side and ground-side interface plates to inspect the area where elevated hydrogen levels were detected, and replaced seals around two fueling lines.
The two tail service masts — each about three stories tall — provide the cryogenic propellant lines and electrical cable connections to the SLS core stage. They tilt back before launch and include “quick disconnects” — mechanisms that instantaneously detach at liftoff to ensure safe retraction.
Reconnecting the interfaces is expected to be complete by Monday, Feb. 9. Engineers are still evaluating the root cause of the leak, and the removed seals are being analyzed. NASA also plans additional testing at Stennis Space Center in Bay St. Louis, Mississippi, to evaluate the dynamics of the interface plates. Engineers are reviewing options to verify the repair before committing to the next full wet dress rehearsal.
Here’s a breakdown of the repairs underway and the operational changes NASA is making for WDR-2:
| Type | Change | Details |
|---|---|---|
| Hardware Fix | Two seals replaced | Seals replaced around fueling lines at the tail service mast umbilical where hydrogen concentrations exceeded allowable levels. Removed seals are being analyzed and additional plate dynamics testing is planned at Stennis. |
| Operations | Orion hatch closed before test | The crew module hatch will be sealed prior to the rehearsal. The closeout crew — who on launch day help astronauts into their seats and close both Orion hatches — will not be deployed to the pad. |
| Operations | Crew access arm stays extended | The arm will not be retracted during the next rehearsal. Engineers successfully demonstrated during the Feb. 3 test that the ground launch sequencer can retract it during the final countdown phase, so that objective is already complete. |
| Timeline | One extra hour in countdown | NASA has added 30 minutes of extra hold time at each of two planned holds — one before and one after tanking operations — to allow more time for troubleshooting. The total countdown is now one hour longer. This does not affect the crew’s launch-day timeline. |
| Focus Shift | Rehearsal focused on fueling | With the crew access arm retraction and other pad objectives already demonstrated, the next WDR will concentrate on tanking operations and verifying the hydrogen leak repair. |
Source: NASA, “NASA Conducts Repairs, Analysis Ahead of Next Artemis II Fueling Test,” Feb. 8, 2026
NASA continues to eye March as the next potential launch opportunity but will not set a targeted launch date until after completing a successful wet dress rehearsal and reviewing the data. The critical second WDR is set to start as soon as this Friday, February 13th.
When NASA’s Artemis II moon rocket rolls out to Launch Complex 39B this weekend, sharp-eyed observers will notice something new on the core stage: four thin metal fins that weren’t there for Artemis I.
They’re called strakes, and they exist because the rocket’s first flight revealed a problem nobody fully anticipated.
After Artemis I launched in November 2022, Boeing and NASA engineers dug into the flight data and found that the Space Launch System experienced higher-than-expected vibrations near the points where the twin solid rocket boosters attach to the core stage. The culprit turned out to be turbulent airflow swirling through the gap between the boosters and the orange core stage during ascent—an aerodynamic nuisance that needed fixing before astronauts climbed aboard.
The fix itself is elegantly simple. Strakes are fin-like structures commonly used on aircraft to manage airflow, but they’d never been added to the SLS core stage. Boeing’s engineering team ran the numbers through wind tunnel tests and computational fluid dynamics simulations, then designed four strakes sized and positioned to calm the turbulence and dampen vibrations for Artemis II and all future flights.
Getting them installed on an already-aggressive schedule required some hustle on NASA and Boeing’s part. “We immediately pulled together a team—the best of the best,” said Brandon Burroughs, who led the strake implementation effort. “The team worked around the clock and even through the year-end break. By working closely with NASA and streamlining processes, we did in weeks what would normally be done in years.”
Before drilling a single hole at Kennedy Space Center, technicians practiced the procedure in Huntsville, Alabama. The strakes were ready to install before the core stage was fully stacked on the mobile launcher—a critical bit of timing that avoided the access headaches that would’ve come once the solid rocket boosters were in place.
It’s a small addition with big implications.
Artemis II will carry four astronauts on a roughly 10-day trip around the moon, the first crewed flight beyond Earth orbit in more than half a century. Every improvement to the rocket brings NASA one step closer to landing crews on the lunar surface—and eventually, Mars.
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