NASA will attempt to fully load its Space Launch System rocket more than 700000 gallons of liquid hydrogen and liquid oxygen this week at conclusion of full launch countdown rehearsal.

The operation called wet dress rehearsal or WDR will start will call to stations inside Firing Room 1 at Launch Control Center at 6:40 pm EST on Tuesday Feb 17.

It will culminate the actual fueling of rocket on Thursday Feb 19 aiming towards simulated T-0 at 8:30 pm EST,

Space

This second full length fueling demonstration comes week after NASA conducted what it called confidence Test on Thursday Feb 12.

During operation teams loaded unspecified amount of liquid hydrogen onto rocket core stage to assess new replaced seals in area used to fill rocket with propellant.

During the first WDR that concluded on Feb 3 NASA encountered hydrogen leaks as they moved from slow fill rate of LH2 to fast fill on core stage which required the loading to pause at time.

Hydrogen is combustible and so NASA has restrictions around concentrated it can be once its airborne.

Teams exceeded the 16 percent LH2 limit during process of pressurizing the tanks the terminal count on WDR-1 and clock stopped at T-5 minutes and 15 seconds.

This second full length fueling comes the week after NASA conducted what it called confidence test on Thursday Feb 12.

Teams loaded unspecified amount of liquid hydrogen LH2 onto rockets core stage to assess new replace seals in area used to fill rocket with propellant.

There was new ground instruments issued that cropped up which reduce the flow of liquid hydrogen into rocket according to blog post shared.

We desire to get inside terminal count we want to hold and desire to verify out three minute hold capability which is you have got all of your cryo prop system in launch ready state and can hold them there for up to three minutes.

We desire to demonstrate a recycle which is when you go down and you have planned cutoff in countdown come back and re target a new T-0 and be able that within the lauch window. she added.

Did not get chance to do that and then we would comes down do the handoff to ALS and then cutoff shortly thereafter.

Those objective are back on table for WDR-2 Launch controllers intend to take count down to T-1 minute and 30 seconds hold for up to three minutes proceed through the terminal count down T-33 second and then pause again.

ISS

Running into issues inside terminal count during WDR-1. Blackwell Thompson waived off the chance of conducing a second terminal  count attempt due to issues seen during fueling campaign.