Launch of shuttle Endeavour and meteorologists expect good weather

NASA picked up the countdown Wednesday to Saturday's planned launch of shuttle Endeavour and meteorologists expect good weather for liftoff.

Endeavour and seven astronauts are scheduled to blast off from launch pad 39A at Kennedy Space Center at 7:17 a.m. Saturday on an assembly mission to the International Space Station.

The weather forecast calls for a 90-percent chance that conditions will be acceptable for launch, and NASA faced no technical showstoppers as countdown clocks began ticking.

"We worked hard to get here, and we're all eager to get Endeavour and her crew on their way to the International Space Station," said NASA Test Director Steve Payne.

"We should be good to go," added Air Force Lt. Col. Patrick Barrett, a
forecaster with the 45th Space Wing Weather Squadron.

The big job today: Prepping the shuttle's electrical power supply system.

NASA and contractor engineers will load supercold liquid hydrogen and liquid oxygen into the shuttle's fuel cell system.

The chemical reactants will be combined to produce the electricity required to run spaceship systems during a 16-day mission -- the longest station assembly flight to date.

Technicians also will be making final preparations for an external tank fuel-loading operation that is scheduled to begin at 9:52 p.m. Friday.

Led by veteran mission commander Mark Polansky, the Endeavour crew includes pilot Douglas Hurley and five mission specialists: Christopher Cassidy, Thomas Marshburn, Timothy Kopra, David Wolf and the Canadian Space Agency's Julie Payette.

The astronauts plan to deliver the third and final segment of the station's Japanese Kibo science research facility.

Now packed in the shuttle's payload bay, the segment is a pallet-like platform for microgravity science experiments that will be attached to the outside of the Kibo laboratory module.

The delivery will mark the end of a 20-year effort to design, develop, build, test and launch the largest of the station's four science research facilities.

So it soon will be sayonara for a group of 40 to 50 Japanese engineers, technicians and managers who have been working at KSC to prep parts of the Kibo lab since 2003.

"This has been a long journey for us and our Japanese colleagues. We have been working together for many, many years. and our sense of pride and accomplishment in getting to this point -- we can finally put the last pieces of Kibo into orbit and get that magnificent laboratory up and running at full strength -- is tempered just a little bit by the sadness that our Japanese colleagues here on the ground processing side of things will soon be going home to Japan," said NASA payload manager Scott Higginbotham.

"We all hope that our paths will cross again some day on some other magnificent joint international space effort."

An on-time launch would lead to a landing at KSC at 12:18 a.m. June 29.