NASA teams continue the countdown to the Artemis II wet dress rehearsal, a full-fuel test of the Space Launch System rocket, at Kennedy Space Center in Florida.
Overnight, engineers monitored the system as temperatures dropped and winds remained strong at the launch site.
This morning, at approximately L-39 hours and 30 minutes, the rocket’s core stage was fired.
In the coming hours, it is expected to be loaded with more than 700,000 gallons of liquid oxygen and liquid hydrogen during the tanking phase.
The process begins slowly, with the tanks filled, topped up, and then refilled as needed.
The interim cryogenic propulsion stage operated overnight, while the Orion spacecraft operated for several days due to colder than normal conditions in Florida.
Live coverage during NASA Artemis 2nd wet dress rehearsal
Engineers are preparing to charge Orion’s flight batteries and are ready to begin charging the core stage batteries as well.
Later in the day, teams will perform final work on the umbilical arms and conduct a walkdown on the launch pad.
Live video stream of the rocket on the pad running continuously on NASA’s YouTube channel; NASA is planning a separate feed during refuelling operations.
Real-time blog updates are also expected throughout the trial.
NASA’s official Artemis II status update has provided the information so far.
Includes countdown timeline simulated launch window
The countdown clock started at 8:13 pm Eastern Standard Time, which corresponds to 6:43 am Indian Standard Time.
This marked L-48 hours and 40 minutes ahead of the simulated launch window opening at 9 pm EST on Monday, February 2, or 7:30 am IST on Tuesday, February 3.
Rehearsals are expected to continue until around 1 am ESTÂ on February 3, which is 11:30 am IST. NASA’s countdown follows a structure built around both “L minus” and “T minus” times.
The L-minus tracks the time remaining until liftoff, while the T-minus tracks the sequence of events before launch.
Teams can pause the clock to manage tasks or align with a goal window.
During those holds, the T-minus clock stops, while the L-minus keeps running.
As part of rehearsals, teams will pause briefly at T-1 minutes and 30 seconds, restart the count, then pause again at T-33 seconds.
The clock will then be recycled back to T-10 minutes for a second terminal countdown, which will once again end at T-33 seconds.
The sequence is designed to reflect actual launch conditions, including situations where the launch may be delayed or scrubbed.
Once testing is finished, propellants will be removed from the rocket, and engineers will review the data before setting a formal launch target.
Artemis II crew milestone practice conducted without astronauts present
The Artemis II crew itself is not participating in the wet dress rehearsal, but crew-related milestones are still included in the timeline.
The Artemis closeout crew will practice launch-day procedures, including sealing the Orion crew module and closing the launch abort system hatch, as preparations continue for NASA’s first crewed Artemis mission around the Moon.
