The Space Launch System’s core stage liquid hydrogen tank is now full and is being replenished as some of the supercold propellant boils off. Since resuming liquid hydrogen fast fill operations, the rate of the hydrogen leak at the tail service mast umbilical quick disconnect has remained within allowable rates. The core stage liquid oxygen tank also is in the replenish phase.
Teams are pressing ahead with operations to load propellants into the interim cryogenic propulsion stage of the rocket. Once liquid hydrogen and liquid oxygen loading on the stage reach the replenish phase, the pre-press test, one of the objectives for today’s demonstration, will occur.
The pre-pressurization test will bring the core stage liquid hydrogen tank up to the pressure level it will experience just before launch while engineers calibrate the settings for conditioning the engines at a higher flow rate, as will be done during the terminal count on launch day.