So far - Friday is a go!

Tanking Under Way For 11:59 p.m. Launch
Fri, 28 Aug 2009 02:23:08 PM CDT

Liquid hydrogen and liquid oxygen are flowing into the gigantic orange external tank of space shuttle Discovery this afternoon at NAA’s Kennedy Space Center in Florida. The tanking operations began at 2:45 p.m. EDT and it will take three hours to load the 500,000 gallons of propellants into the structure. The fuel will be consumed in 8 1/2 minutes as Discovery’s three main engines power the shuttle into orbit.



Launch is scheduled for 11:59 p.m. EDT tonight. Forecasters call for a 60 percent chance of acceptable conditions at launch time.



The mission management team reported that all the testing and analysis of Discovery's fill-and-drain valve during the last two days gives them a high degree of confidence the valve is working. Procedures have been approved in case there is a similar issue with the position sensor on the hydrogen fill-and-drain valve.



The plan includes being able to open and close the valve, or cycle it, 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.