Space shuttle Endeavour’s external tank has been loaded with about 500,000 gallons of liquid hydrogen and liquid oxygen; the propellants that will power the shuttle’s three main engines during launch.
Pumps at the launch pad will continue to trickle in a small amount of supercold chemicals to replace the amount that boils off during the countdown.
The Final Inspection Team and Closeout Crew will head out to the pad for their specialized tasks. The inspection team will look for signs of debris or ice buildup on the shuttle and external tank, while the Closeout Crew will prepare Endeavour for its crew of six.
Liftoff remains on schedule for 4:39 a.m. EST.