By Irene Klotz
CAPE CANAVERAL, Florida (Reuters) - Space shuttle Discoveryis poised for launch on Saturday on a mission to add Japan tothe growing number of countries operating full-time spaceresearch laboratories in orbit.
With clear skies and no technical problems, NASA managersgave the order for technicians to begin pumping more than500,000 gallons of supercold liquid hydrogen and liquid oxygeninto the shuttle's fuel tank for the 8 1/2-minute ride intoorbit. Liftoff is scheduled for 5:02 p.m. EDT (10:00 p.m.British time).
Meteorologists predicted an 80 percent chance of acceptableweather for launch.
In delivering Japan's bus-sized Kibo laboratory to theInternational Space Station, the United States will fulfil anagreement reached two decades ago to join with other countriesin building and operating an orbital base.
"This is a big step for the Japanese community," saidAkihiko Hoshide, a 39-year-old astronaut with the JapanAerospace Exploration Agency who is making his first flight.
Japan is the last of the 16-nation partnership to get itshardware in space and it will be next year before thethree-part lab is complete.
During its last shuttle mission in March, NASA installedKibo's storage room, which was launched with spare computersand experiment racks.
The 37-foot-(11-metre-) long, 16-ton main compartment ispacked aboard shuttle Discovery. The lab fits so snugly in theshuttle's 50-foot- (15-metre-) long cargo bay that NASA has noroom to fly an inspection boom that crews routinely use tocheck their ship for damage after launch.
Instead, the last shuttle crew to visit the space stationleft its boom behind for Discovery to use and return to Earth.
Technicians even had to pull out 35 pounds (16 kg) of spareparts from the shuttle's crew cabin when NASA agreed to fly apump to fix the space station's balky toilet.
THREE SPACEWALKS
Once in orbit, the Discovery crew plans to conduct threespacewalks to hook up the new lab, work on the station'scooling system and troubleshoot a problem that is hampering apair of solar wing panels from tracking the sun for power.
For now, there's plenty of electricity for all thestation's compartments, which include the U.S. Destinylaboratory, Europe's Columbus module, the Russian-made livingquarters and propulsion chambers, two connecting nodes and twoairlocks.
After Kibo is attached, the space station will be 71percent complete, with seven construction missions remaining.
One of those flights will be to deliver the final segmentof Kibo, a unique porch complete with robot arms for tending toexperiments in the open environment of space.
NASA wants to have the space station in perfect workingorder and fully stocked with spare parts before September 30,2010, when the shuttle fleet is due to be retired.
In addition to the construction missions and two resupplyflights, the U.S. space agency plans a final servicing call tothe Hubble Space Telescope, scheduled for October.
The seven-member Discovery crew includes a new flightengineer who will remain behind for a six-month mission aboardthe space station. Greg Chamitoff replaces Garrett Reisman whowill return home with the rest of the shuttle Discovery crew.
Discovery's flight, which is the 123rd in shuttle programhistory, is scheduled to last 14 days.
(Editing by Jim Loney and Bill Trott)
