Trouble-Plagued Shuttle Prepares for Launch

After five frustrating delays, NASA aimed for an early morning launch today of the space shuttle Discovery on a mission featuring a pair of satellite releases and a spacewalk.

“We put our past disappointments behind us, and we’re ready to go,” shuttle test director Mike Leinbach said Saturday.

Weather forecasters expected a 70% chance of good weather for the 4:45 a.m. PDT launch. Thunderstorms were possible.

The mission has been on hold since mid-July because of equipment failures--including a risky engine shutdown three seconds before liftoff last month--a meteor shower and, most recently, an intensive paperwork review of Discovery’s primary payload.

That payload, the Advanced Communications Technology Satellite, was cleared for flight last week. Project managers confirmed none of the satellite transistors was from the same batch as those that had to be replaced on a weather satellite this summer.

The communication satellite, once deployed by Discovery’s five-member crew, is to be propelled into a 22,300-mile-high orbit. Seventy-three experiments are planned over the next two years by communication companies, broadcasting organizations, universities, hospitals, the military and the space agency.