Friday, August 28, 2009
Tanking operations officially began at 2:45 pm EDT. Fueling of over 527,000 galls of both liquid oxygen and liquid hydrogen are beginning to flow into the huge rust colored tank.
Tanking was delayed only 11 minutes due to weather in the area.
Mission managers meet for over two hours as the subject of the liquid hydrogen fill and drain valve was discussed. Tuesday night, the 8 inch valve gave indications that it was still open when the launch team commanded it closed. Still unsure as to why it happened, manager worked a plan for late today when the command will be given for the valve to close.
According to NASA, "The plan includes being able to open and close the valve two times during the tanking process if the valve position indicator sensor doesn't work. Teams would use alternate means, including monitoring pressure in the system, to provide confidence the valve is closed for launch".
Lift-off remains set for 11:59:37 pm EDT tonight, as Discovery soars into earth orbit to begin a 13 day mission to the international space station.