Mon, 16 May 2011 01:43:20 -0500 Space shuttle Endeavour’s external tank is fully loaded with more than 500,000 gallons of liquid hydrogen and liquid oxygen in preparation for today’s 8:56 a.m. EDT launch. Tanking operations began Sunday, May 15 at 11:36 p.m. and concluded this morning at 2:36 a.m. The countdown has entered a planned 2.5-hour hold at T-3 hours, during which the tank will remain in “stable replenish” mode, the Close Out Crew will prepare the White Room for astronaut arrival, and the Final Inspection Team will conduct its inspections. Shuttle Weather Officer Kathy Winters continues to predict a 70 percent chance of favorable weather for today’s launch. The only concerns are for low cloud ceilings and high crosswinds at the Shuttle Landing Facility.