Thu, 11 Feb 2010 08:11:25 AM EST
The launch team is ready to begin filling the rocket's propellant tanks with cryogenic liquid oxygen and liquid hydrogen. The booster's RP-1 tank is already loaded. Tanking will begin with "chilldown," which cools and conditions the ground equipment and transfer lines that will come in contact with these extremely cold propellants.
The 10-foot-wide, 41.5-foot-tall Centaur upper stage will be filled with 4,150 gallons of liquid oxygen and 12,680 gallons of liquid hydrogen; the Atlas V booster's propellant tanks hold 48,860 gallons of liquid oxygen and 25,540 gallons of RP-1.
The countdown will pick up once again at 8:13 a.m. as we come out of the T-2 hour hold.