IT·Science Talk

Artemis II slips to March: what a wet dress rehearsal actually is

Saw a few people confused about why a "rehearsal" could delay a Moon flight, so here's a short summary from the GONOM post. A wet dress rehearsal is a full simulated countdown with the rocket actually fueled. On 2 February they loaded more than 700,000 gallons of cryogenic propellant into the SLS, and the countdown stopped automatically at T-minus 5:15 when a liquid hydrogen leak spiked.

The Weather Network traced the leak to one of the umbilicals connecting the rocket to the mobile launcher. There were smaller issues too: audio dropouts and a hatch valve that needed retightening. NASA now says March is the earliest opportunity. Honestly this is the system working as intended. Better to find a leak on the pad with nobody aboard than anywhere else.