The launch control team has begun chill down operations and resumed the countdown clock ahead of flowing super cold liquid oxygen (LOX) into the core stage tank. The new T-0 time for today’s test is 3:57 p.m. EDT for the first of the two terminal count runs for the wet dress rehearsal.
The process for the chill down, or cooling, uses the propellant lines to load the Space Launch System rocket’s core stage liquid oxygen in preparation for tanking. The liquid oxygen tank holds 196,000 gallons of liquid oxygen, cooled to minus 297 degrees Fahrenheit. Venting from the super-cold propellant may be visible during this time.
Liquid oxygen will soon flow into the rocket. Teams will fill the tank slowly at first and then will begin filling it more quickly. As the super cold liquid oxygen fills the core stage tank, some venting may be visible.
The next blog update will be provided when core stage liquid hydrogen loading begins.