Candrea Thomas/Launch Commentator: This is shuttle launch control at T-minus three hours and holding.
The countdown for space shuttle Endeavour's STS-126 mission to the
International Space Station is under way and on schedule.
Launch is scheduled for 7:55 p.m. eastern time from Launch Pad 39A at NASA's Kennedy Space Center here in Florida.
The launch window is about five minutes. Managers and engineers in Firing Room 4
at Launch Control Center are monitoring the countdown.
There are currently no issues that are being worked that would delay launch.
Countdown began this morning with the tanking, which was on time at 10:30 a.m. and was completed at 1:30 p.m.
We're now in stable replenish. The external fuel tank was loaded with more than
500,000 gallons of super-cold liquid oxygen-hydrogen, which is used by the shuttle's three main engines at liftoff.
This morning the STS-126 crew awoke at 11:00 a.m. for their launch.
They had breakfast about 11:30 a.m. and they received final medical exams.
In just a while, the astronauts will receive a weather briefing from the ascent team flight.
At the shuttle launch pad, the Final Inspection Team is currently working its way up the launch structure.
The launch director, Mike Lienbach, followed cryogenic tanking operations.
Then, he dispatched his team of engineers and safety personnel to the pad.
The team's purpose is to make a final inspection of the launch pad and the shuttle
to make sure it's ready for launch this evening.
The STS mission will give the station the ability to support twice the number of crew,
going from three to six crew members next year.
The equipment is being carried up in a Multi-Purpose Logistics Module named Leonardo.
Along with the work inside the station, there's four spacewalks to repair the Solar Alpha Rotary Joints.
These joints generate the power needed for the extra crew members.
There are two, 10-foot wide wagon-wheel shaped joints on the station's truss,
which allows the electricity-generating solar arrays to rotate so they're always getting as much sun as possible.
STS-126 is the 124th space shuttle flight and the 27th flight to the station.
This is Endeavour's 22nd flight and this is the fourth flight in 2008.
The mission will be docked during the 10th Anniversary of the space station on Nov. 20.