Space shuttle Discovery is poised for launch on Saturday on a mission to add Japan to the growing number of countries operating full-time space research laboratories in orbit. With clear skies and no technical problems, NASA managers gave the order for technicians to begin pumping more than 500,000 gallons of supercold liquid hydrogen and liquid oxygen into the shuttle's fuel tank for the 8 1/2-minute ride into orbit. Liftoff is scheduled for 5:02 p.m. EDT (2102 GMT). Meteorologists predicted an 80 percent chance of acceptable weather for launch,Reuters reported.
