Commander George Zamka, Pilot Terry Virts, Mission Specialists Kathryn Hire, Stephen Robinson, Nicholas Patrick and Robert Behnken are being secured in their seats aboard shuttle Endeavour.
Radio checks are continuing for the crew while the countdown ticks down for an on-time liftoff at 4:39 a.m. EST.
The launch pad Closeout Crew will close the hatch, pressurize the crew cabin, check for leaks then finishing remaining work inside the pad’s White Room before departing.
Astronaut Chris Ferguson is flying weather reconnaissance in his T-38 jet. He will help evaluate conditions throughout the remainder of the countdown.